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  • 1975-1979  (1,385)
  • 1975  (1,385)
  • Inorganic Chemistry  (723)
  • Life and Medical Sciences  (533)
  • Engineering  (84)
  • Nuclear reactions
  • Rat
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Material
Years
  • 1975-1979  (1,385)
Year
Keywords
  • 1
    Electronic Resource
    Electronic Resource
    Ultrastructural studies on the myocardial capillaries of the experimentally lathyritic rat, protective effect of certain flavonoids (1975)
    Springer
    Virchows Archiv 365 (1975), S. 201-212 
    Details
    ISSN: 1432-2307
    Keywords: Lathyrism ; Capillaries ; Rat ; Ultrastructure ; Flavonoids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ultrastructure of rat myocardial capillaries was studied in the course of experimental lathyrism. Endothelial cells were hypertrophic, with a sinuous profile of the plasma membrane facing the lumen and with a consistent increase of pinocytotic vesicles; the nuclei were irregular in shape; ATPase activity was no more demonstrable. Therefore, various and well distinct structural endothelial mechanisms seem to be primarily involved, causing an alteration of the dynamics of transcellular exchanges and of the permeability of the vascular wall. Simultaneous treatment with certain flavonoids, (O-(β-hydroxyethyl)-rutosides and Na(+)-epicatechin-2-sulfonate), resulted in a less pronounced alteration and a more rapid recovery. The possibility of the existence of a common site of action of lathyrogens and flavonoids is raised in the discussion.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00434039
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  • 2
    Electronic Resource
    Electronic Resource
    Technique of lymphography in the rat (1975)
    Springer
    Research in experimental medicine 165 (1975), S. 213-217 
    Details
    ISSN: 1433-8580
    Keywords: Rat ; Lymph nodes ; lymphography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Most the lymphatic system in the rat was directly observed in our experiment by radiological means. The lymphatics of the limbs were firstly revealed by subcutaneous injection of Patent Blue V. Lipiodol was used as radio-opaque compound injected by a micro-technique fully described by the authors.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01971380
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  • 3
    Electronic Resource
    Electronic Resource
    Action de la rubratoxine B sur la respiration des mitochondries hépatiques de rat (1975)
    Springer
    Mycopathologia 55 (1975), S. 53-55 
    Details
    ISSN: 1573-0832
    Keywords: Rubratoxine B ; Mitochondria ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The in vitro effect of rubratoxin B on the electron transport system of rat liver mitochondria was investigated. This mycotoxin depressed oxygen consumption in ADP-lacking mitochondria and in ADP-coupled mitochondria, using succinate or β-hydroxybutyrate as substrats. Rubratoxin B is neither an oxidative-phosphorylation inhibitor nor uncoupling agent. Its effect is compared with aflatoxin B1.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00467092
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  • 4
    Electronic Resource
    Electronic Resource
    The onset of synaptogenesis in rat temporal cortex (1975)
    Springer
    Anatomy and embryology 148 (1975), S. 73-87 
    Details
    ISSN: 1432-0568
    Keywords: Rat ; Temporal cortex ; Synaptogenesis ; Retzius-Cajal cells ; Poly morphous cells
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The onset of synaptogenesis was studied in the temporal cortex of rat fetuses whose age ranged between 15 and 19 days of gestation. First synapses were found at a surprisingly early stage of cortical development: on day 16. These contacts showed relatively few vesicles and very inconspicuous membrane-thickenings. They were located in the marginal layer, above as well as below the narrow band formed by the newly arrived first neuroblasts of the prospective cortical plate. The postsynaptic structures were probably dendrites of the horizontally or obliquely orientated neurons scattered throughout the marginal layer (such neurons were seen even within the cell-dense band). On day 17, the cortical plate separated the differentiated cells definitely into a superficial and a deep population. As on the following days, synapses were found above and below the cortical plate but not within it. In addition to contacts showing the same features as those described on day 16, there were already synapses with numerous vesicles and clearly asymmetric membrane thickenings. On days 18 and 19 the borders of the cortical plate became more clear-cut. The well-differentiated neurons situated above and below this plate could now be identified as Retzius-Cajal cells of the prospective molecular layer and as polymorphous cells of the layer VI b respectively. The presence of axo-somatic contacts on these neurons provided direct evidence that both cell types are targets for synapses. Desmosome-like junctions were found even in the youngest fetuses studied. Their roughly symmetric membrane thickenings were clearly more conspicuous than those of earliest synapses. Desmosome-like junctions occurred very frequently between structures which subsequently were never seen to become synaptically linked. During the entire period studied, numerous coated vesicles fused with cell membranes were noted. Such “open” vesicles were seen on neurons (sometimes in the immediate vicinity of synapses) but also on non-nervous, extracortical as well as intracortical structures. Thus there does not seem to be a specific relationship between desmosome-like junctions and coated vesicles on the one hand and synapse formation on the other.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00315564
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  • 5
    Electronic Resource
    Electronic Resource
    Quantitative studies of the effect of progesterone on endometrial morphology of the spayed rat (1975)
    Springer
    Anatomy and embryology 148 (1975), S. 47-58 
    Details
    ISSN: 1432-0568
    Keywords: Rat ; Endometrium ; Ultrastructure ; Progesterone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effects of various dosages and of various time periods of treatment with progesterone have been studied in the spayed, mature rat. Test objects were the cells of the luminal epithelium and of the endometrial stroma which were examined by qualitative and quantitative electron microscopy. No significant response was observed in epithelial or stromal cells until after 12 hrs of progesterone treatment. The nuclei of both cell types were then more circular than earlier with reduced long diameters. The functional significance of this change in configuration is unclear since only in the stromal cells was it followed by nuclear growth. Further, after 12 hrs of treatment the relative amounts of mitochondria and granular endoplasmic reticulum of stromal cells were reduced while the volume of the stromal cell cytoplasm appeared enlarged. This is taken as evidence that progesterone causes an intracellular oedema probably by decreasing cell membrane permeability. This response is probably not specific for the stroma but also includes the luminal epithelium, although the volume of the epithelial cell cytoplasm could not be determined here. Nucleolar enlargement did occur in stromal cells and was observed after 12 hrs of treatment but was not significant until after 24 hrs. At this point of time the net amount of granular endoplasmic reticulum in stromal and epithelial cells was increased indicating an increased protein synthesis in both cell types. However, only in the stromal cells was this associated with nucleolar enlargement, which supports the idea that progesterone stimulates protein synthesis through different mechanisms in the two cell types. Testing various dosages of progesterone showed that 0.5 mg had an effect similar to 5 mg of progesterone. When 0.05 mg progesterone was injected the only effect observed was an increase in the amount of apical vesicles of the luminal epithelium, showing that the epithelium is more sensitive to progesterone than the stroma.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00315562
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  • 6
    Electronic Resource
    Electronic Resource
    Effects of guanethidine on paraganglionic cells in the superior cervical ganglion of the rat (1975)
    Springer
    Anatomy and embryology 148 (1975), S. 89-97 
    Details
    ISSN: 1432-0568
    Keywords: Superior cervical ganglion ; Paraganglionic cells ; Rat ; Guanethidine ; Catecholamines
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Paraganglionic cells in the rat superior cervical ganglion were investigated by fluorescence and electron microscopy following treatment with guanethidine for 5–30 days. Control animals received saline and guanidine. Fluorescence cytophotometric measurements revealed a general decrease in the catecholamine content of paraganglionic cells in guanethidine-treated animals. However a few cell clusters showed focal increases. Similarly by electron microscopy there was a general decrease in the number of dense core vesicles in the majority of paraganglionic cells with a minority of cell clusters showing increases.—guanethidine—as well as guanidine—treated animals showed non-specific cytological alterations such as mitochondrial swelling and increase of cytoplasmic glycogen. However no changes of catecholamine contents and of dense core vesicles were noted in control animals. These results confirm the conception that in rat paraganglionic cells the dense core vesicles are the main storage site of catecholamines. The marked difference in the response of some cell clusters to the experimental treatment can be considered as evidence of functional heterogeneity of this cell population in the rat superior cervical ganglion.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00315565
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  • 7
    Electronic Resource
    Electronic Resource
    Influence of adrenalectomy, total body X-irradiation and dexamethasone on the amount of CRF-Granules and “classical” neurosecretory material in the rat neurohypophysis (1975)
    Springer
    Anatomy and embryology 148 (1975), S. 267-278 
    Details
    ISSN: 1432-0568
    Keywords: Corticotropin releasing factor ; Neurosecretion ; Hypophysis ; X-irradiation ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In 195 female Wistar rats the influence of adrenalectomy, total body X-irradiation and dexamethasone treatment on the amount of CRF-granules in the external zone of the median eminence and “classical” neurosecretory material (NSM) in the internal zone of the median and in the posterior lobe of the hypophysis has been studied. In the normal rat only very few CRF-granules occur. 15 days after adrenalectomy increased amounts of CRF-granules but normal amounts of “classical” NSM are found. X-irradiation leads to a slight diminishment of “classical” NSM in normal rats. In adrenalectomized animals X-irradiation causes no changes in the amount of “classical” NSM but a marked decrease in the amount of CRF-granules. Application of dexamethasone from the 15th to 18th day after adrenalectomy enhances the augmentation of CRF-granules in irradiated and non-irradiated rats but does not influence the amount of “classical” NSM. The findings show that no correlation exists between the quantitative changes of CRF-granules and “classical” NSM under the experimental conditions used. Therefore it is to be assumed that the release of the two substances is regulated by different control mechanisms and that the substances have a different functional significance. The observations do not exclude the possibility that CRF-granules and “classical” NSM are biochemically identical.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00319847
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  • 8
    Electronic Resource
    Electronic Resource
    Effect of antiphlogistics on blood-brain barrier in lymphostatic encephalopathic and in normal rats (1975)
    Springer
    Inflammation research 5 (1975), S. 57-61 
    Details
    ISSN: 1420-908X
    Keywords: Rat ; Lymphostatic encephalopathy ; Harmine ; Tremor ; Antiphlogistics ; Blood-brain barrier ; Permeability
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Injection of the tremorigenic alkaloid harmine into lymphostatic encephalopathic rats leads to a longer duration of tremor and higher brain concentrations than in shamoperated controls. In lymphostatic encephalopathic as well as in normal rats different antiphlogistics shorten the tremor duration and decrease harmine concentraion in brain. The antiphlogistics do not influence the plasma concentration of harmine, its protein binding and its tremorend concentration in brain. The effect of antiphlogistics in lymphostatic encephalopathic rats is considered as a consequence of the reduced blood-brain barrier permeability. Obviously in sick animals the blood-brain barrier permeability for harmine is not increased; the prolonged harmine tremor and the increased alkaloid concentration in the brain are consequences of the impaired cerebral lymphatic drainage only.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02027160
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  • 9
    Electronic Resource
    Electronic Resource
    Differential morphological reaction of experimental CNS tumour clonesin vitro to dibutyryl cyclic AMP or serum-free medium, resp. (1975)
    Springer
    Acta neuropathologica 33 (1975), S. 325-332 
    Details
    ISSN: 1432-0533
    Keywords: Experimental CNS tumours ; Methylnitrosourea ; Ethylnitrosourea ; Clonal growth ; Serum-free culture ; db cAMP treatment ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Six clones from methylnitrosourea (MNU) or ethylnitrosourea (ENU) induced tumours obtained in the nervous system of the rat were cultured in serum-free medium or treated with dibutyryl cyclic AMP (db cAMP) in vitro. All clones originated from longterm cultures. Three clones forming sarcomas after syngeneic transplantation showed only very slight changes following treatment, whereas the three glioma clones showed striking alterations. They formed long processes or showed rounding of their perikarya. In serum-free medium the cellular shape is intermediate between that seen in normal conditions and that seen in db cAMP treated cultures. The altered cultures resemble the primary cultures of the respective tumours. The relationship of these alterations to tumour types are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00686164
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  • 10
    Electronic Resource
    Electronic Resource
    Thyroxine treatment and insulin secretion in the rat (1975)
    Springer
    Diabetologia 11 (1975), S. 49-55 
    Details
    ISSN: 1432-0428
    Keywords: Rat ; blood glucose ; plasma insulin ; pancreas perfusion ; insulin secretion ; thyroxine ; glucose ; tolbutamide ; pyruvate ; isoprenaline
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Thyroxine treatment increases blood glucose and plasma insulin levels in the rat. The hypoglycemic effect of tolbutamide is more pronounced in treated animals. The immediate insulin secretory response of the isolated perfused pancreas to maximal, but not to submaximal, glucose stimuli was increased after thyroxine treatment, especially in the lower dose range. However, as thyroxine treatment reduces insulin release during the prolonged late phase, the total amount of insulin released from the pancreas is reduced. Both the early response to tolbutamide and the subsequent basal secretion were increased after thyroxine treatment. When the pancreas of treated rats was exposed to glucose plus pyruvate the inhibition of the late phase was reversed. Isoprenaline did not overcome the inhibitory effect of thyroxine treatment on the late phase of glucose-induced insulin release. Thyroxine induces a selective inhibition of glucose induced insulin release which is reversed by pyruvate; this indicates that thyroxine interferes with the glycolysis in the beta cell.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00422818
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  • 11
    Electronic Resource
    Electronic Resource
    Diabetogenic effect and inhibition of insulin secretion induced in normal rats by ammonium infusions (1975)
    Springer
    Diabetologia 11 (1975), S. 439-443 
    Details
    ISSN: 1432-0428
    Keywords: Rat ; ammonium infusion ; blood ammonia ; glucose metabolism ; plasma immunoreactive insulin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In order to explain the abnormalities of glucose metabolism previously observed in patients with blood ammonia elevation, the effect of a transitory hyperammonemia on I. V. glucose tolerance was investigated in rats. An I. V. glucose tolerance test was performed in 3 groups of 15 rats 60 min after the beginning of a 95 min infusion of either a 2 ml isotonic NaCl solution (control group) or ammonium acetate solutions at low (0.50 μmol/kg/min. NH4+) or high doses (1.70 μmol/kg/min NH4+). The “high” NH4+infusion produced an increase of blood ammonia to levels near 1000 μg/100 ml, a significant decrease in the K coefficient for glucose disappearance (2.53 × 10−2±0.20 compared to 4.92 × 10−2±0.13 in control group) and a suppression of the radioimmunological plasma insulin (I.R.I.) response to glucose. With the “low” NH4 + infusion the hyperammonemia was less pronounced (200–300 μg/100 ml), but the decrease in K(3.02 × 10−2±0.15) and in the first phase of I.R.I, release remained significant. The decrease in glucose disappearance rate could be accounted for by the proportional decrease in insulin secretion. Thus glucose intolerance induced by ammonium acetate infusions may be due to a direct effect of NH4 + on the pancreas. These abnormalities in glucose metabolism depend on the quantity of infused ammonium.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00429913
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  • 12
    Electronic Resource
    Electronic Resource
    Types of neuronal responses in the rat thalamus to peripheral temperature changes (1975)
    Springer
    Experimental brain research 23 (1975), S. 157-166 
    Details
    ISSN: 1432-1106
    Keywords: Ventrobasal thalamus complex ; Thermosensitivity ; Burstactivity ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Recordings were made of spike-trains from 163 neurons of the rostral part of the ventrobasal thalamus complex of the rat while the temperature of the scrotal skin was altered. The following results were obtained: 55 neurons were nonthermosensitive, 7 neurons cold-sensitive and 101 neurons warm-sensitive. In the case of the warm-sensitive cells a definite discrimination was possible: 61.4% of the neurons altered their firing behavior during peripheral cooling, changing from relatively even spike frequency to burst firing. This change could be induced repeatedly by altering the temperature. 38.6% of the neurons, on the other hand, reacted to cooling by slowing down their frequency. By way of statistical methods the firing patterns of the two response-types were analyzed more precisely and the differences in response to temperature stimuli more exactly defined. Likewise, the spatial distribution of the two response-types of warm-sensitive cells exhibited differences; whereas the cells devoid of burst activity occured rather uniformly in the region of the thalamus studied, the cells with bursting activity were confined more to the mediocaudal region. These findings are discussed with regard to the phenomenon of peripheral bursts and to the projection of thermoafferent pathways onto the ventrobasal thalamus complex. The functional interpretation of the various cell reactions and their role in the central processing of thermoafferent signals still remains unexplained and requires comparative studies of peripheral and central parts of the thermoafferent system.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00235458
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  • 13
    Electronic Resource
    Electronic Resource
    A quantitative study of subsurface cisterns and their relationships in normal and axotomized hypoglossal neurones (1975)
    Springer
    Experimental brain research 22 (1975), S. 175-183 
    Details
    ISSN: 1432-1106
    Keywords: Rat ; Hypoglossal nucleus ; Axotomy ; Subsurface cisterns
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A quantitative ultrastructural survey was made of subsurface cisterns and their association with overlying structures in the left hypoglossal nucleus of normal rats, and rats which had received left hypoglossal axotomies 7–84 days previously. Subsurface cisterns in normal rats occurred in some hypoglossal neurones, and, sporadically, in proximal dendrites. They were mostly subsynaptic, and often associated with Nissl substance. From 7–14 days postoperatively, when many somatic boutons temporarily lost contact with the perikaryal surface, and were replaced by a microglial sheath, the percentage of perikaryon with underlying cistern was significantly reduced. The Nissl substance was also dispersed at this stage, and not restored until 28 days postoperatively. At 21 days normal percentages of subsurface cistern were restored, but the cisterns were now mostly subastrocytic, an astrocytic sheath having replaced the microglial sheath. From 63 days onwards the cisterns were mostly subsynaptic again as boutons returned to the regenerating perikarya and the temporary astrocytic sheath disappeared. It is suggested that subsurface cisterns might alter the overlying perikaryal surface in some way during neuronal regeneration, causing certain boutons to adhere there.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237687
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  • 14
    Electronic Resource
    Electronic Resource
    Quantitative studies on the supraoptic nucleus in the rat. II. Afferent fiber connections (1975)
    Springer
    Experimental brain research 22 (1975), S. 525-540 
    Details
    ISSN: 1432-1106
    Keywords: Supraoptic nucleus ; Quantitative electron microscopy ; Afferent fiber connections ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A quantitative electron microscopic study of synaptic terminal degeneration was performed in the supraoptic nucleus (NSO) after a variety of major transections or ablations, destroying or interrupting in different combinations the afferent pathways known from earlier and own light microscopic degeneration studies. Solutions of a set of equations, expressing the percentage degenerations in synaptic profiles after different combinations in which the several pathways are interrupted by the various interferences, enabled the authors to give the following percentage numbers for afferent synapses from different sources. 32.7% of supraoptic afferents originate from the brain stem probably representing the monoaminergic innervation of this nucleus. The medial basal hypothalamus (21.0%), amygdala (13.5%), septum (13.5%), hippocampus (8.5%) and olfactory tubercle and further rostral cortical region (17.0%) are the other main sites of origin of supraoptic nucleus afferents. There are no supraoptic afferents from the optic nerve, superior cervical ganglion or fimbria hippocampi.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237352
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  • 15
    Electronic Resource
    Electronic Resource
    Studies with N,N-dimethylformamide for embryotoxic and teratogenic effects on rats after dynamic inhalation (1975)
    Springer
    International archives of occupational and environmental health 34 (1975), S. 167-175 
    Details
    ISSN: 1432-1246
    Keywords: N,N-Dimethylformamide ; Embryotoxicity ; Rat ; Inhalation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The purpose of this study, which was conducted for industrial toxicological reasons, was to investigate the possible embryotoxic and teratogenic effects after inhalation of dimethylformamide in rats. In a dynamic inhalation apparatus groups of 22–23 rats were subjected to approx. 18 ppm (maximum allowable concentration in the working area, MAC=20 ppm) and 172 ppm in the air for 6 hrs/day on 10 consecutive days, i.e. from the 6th to 15th day of gestation. The dimethylformamide inhalation did not cause any visible impairment to female rats as regards general behaviour, appearance or weight development during the treatment or the entire gestation period. The gestation rate was unchanged. The development of the fetuses was not influenced in any way by the exposure of the pregnant animals to approx. 18 ppm. In contrast the fetuses taken by caesarean section from the dams exposed to 172 ppm weighed significantly less than the fetuses of the control animals. Skeletal development of these fetuses, however, was normal. All other reproduction parameters were within the normal range for this strain. The study showed that the inhalation of dimethylformamide in concentration up to approx. 10 times the MAC had no teratogenic effect on rats.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01371738
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  • 16
    Electronic Resource
    Electronic Resource
    Effects of delta-9-tetrahydrocannabinol on social behaviour in the laboratory mouse and rat (1975)
    Springer
    Psychopharmacology 44 (1975), S. 287-289 
    Details
    ISSN: 1432-2072
    Keywords: Delta-9-tetrahydrocannabinol ; Social behaviour ; Mouse ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The behavioural effects of delta-9-tetrahydrocannabinol in mice and rats have been studied by an ethological analysis of encounters between animals injected with the drug and partners injected with the solvent (Tween-saline). In both species, Immobility was increased and Non-Social Activity reduced after injections of 5 mg/kg of delta-9-tetrahydrocannabinol. Flight was increased in treated mice but not in treated rats. Aggression was not significantly altered in either species. Thus, in the mouse, the qualitative behavioural effects of delta-9-tetrahydrocannabinol were similar to those previously reported for crude cannabis resin. Comparison of the dose-response data indicated that some other constituents of cannabis may reduce the Flight reaction from delta-9-tetrahydrocannabinol although not interfering with Immobility.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00428908
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  • 17
    Electronic Resource
    Electronic Resource
    Coronary blood flow in rats native to simulated high altitude and in rats exposed to it later in life (1975)
    Springer
    Pflügers Archiv 355 (1975), S. 49-62 
    Details
    ISSN: 1432-2013
    Keywords: High Altitude ; Coronary Blood Flow ; Cardiac Output ; Cardiac Hypertrophy ; Rat ; TissueP O 2
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In rats exposed to a simulated high altitude of 3500 m for their whole prenatal and postnatal life a severe cardiac hypertrophy develops. In rats born and first staying 5 weeks at sea level and then being exposed to simulated high altitude, only a unilateral right cardiac hypertrophy occurs. In both groups nutritional coronary blood flow was estimated in left ventricle, right ventricle, and septum and was compared with control animals of similar age. Coronary blood flow was measured at hypoxia in all groups. At first cardiac output was determined by the Fick principle, then86Rb was applied and the animals were killed after 55 sec. Activity of86Rb was measured in both cardiac ventricles and septum and the fractional uptake was calculated. According to Sapirstein (1956, 1958) the distribution of86Rb follows the distribution of cardiac output and from both these data the nutritional blood flow to the parts of the heart may be estimated. Cardiac output was similar in rats exposed to simulated high altitude later in life (“newcomers”) and in control animals, but it was significantly lower in rats born in the low pressure chamber (“natives”). Fractions of cardiac output supplying cardiac ventricles and septum in rats from both hypoxic groups were significantly higher than in control animals. In the “natives” they were significantly higher than in the “newcomers”. The fractions of cardiac output in both “newcomers” and “natives” remained significantly higher than those of the control animals, also when calculated per gram of heart tissue. Nutritional coronary blood flow (in ml/min) was higher in both ventricles and septum of the “newcomers” and in the right ventricle of the “natives”, and lower in the septum of the “natives”, when compared with control animals. Coronary blood flow per gram of heart tissue (in ml/min·g) was significantly higher in all cardiac parts of the “newcomers”, but it was about the same in all cardiac parts of the “natives” when compared with controls. The importance of observed changes concerning myocardial tissue oxygenation is analyzed by using Krogh's cylindrical tissue model.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00584799
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  • 18
    Electronic Resource
    Electronic Resource
    Handling of allantoin by the rat kidney (1975)
    Springer
    Pflügers Archiv 357 (1975), S. 201-207 
    Details
    ISSN: 1432-2013
    Keywords: Allantoin ; Uricase ; Kidney ; Clearance ; Micropuncture ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Renal excretion of allantoin was measured by tracer techniques. After injection of 2-C14 urate and H3 inulin, clearances of allantoin and inulin were measured and both proximal and distal tubules were micropunctured. In confirmation of earlier results 2-C14 urate injected into an intact animal is very rapidly converted to C14 allantoin: after 15 min more than 90% of urinary tracer is present as allantoin. It was further observed that 1) allantoin clearance is essentially identical with inulin clearance over a wide range of urine flows; 2) no net transport of allantoin occurs in either proximal or distal tubules. Clearly allantoin is handled by the rat kidney like inulin. The total excretion of filtered allantoin unlike that of filtered urate provides an easy and effective mechanism for animals possessing the enzyme uricase to dispose of their purine loads.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00585975
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  • 19
    Electronic Resource
    Electronic Resource
    Pancreatic enzyme secretion in the conscious rat (1975)
    Springer
    Pflügers Archiv 353 (1975), S. 171-189 
    Details
    ISSN: 1432-2013
    Keywords: Enzyme Secretion ; Hormonal Stimulation ; Narcosis ; Pancreas ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. A method for collecting duodenal juice and gastric content separately, in conscious rats, is described. Metal cannulas were implanted into the stomach fundus. For the main experiment a double lumen tube was inserted through the cannula via the pylorus into the duodenum. 2. The following secretion patterns were observed: a) In the resting state there was a constant flow rate of duodenal volume, bicarbonate, trypsin and amylase. b) Cholinergic stimuli were capable of increasing enzyme secretion as much as fourfold for a period of 30 to 40 min when administered as a single subcutaneous injection. This effect was annulled by atropine. c) Secretin and cholecystokinin-pancreozymin given together in a single injection s. c. or i. v., elicited a similarly strong response. d) Identical ranges of the secretion maxima were found with a tendency to decrease after the first hour, when the hormones were infused either s. c. or i. v. e) Doses from 0.5 to 25 U/100 g b. w./hr showed identical responses. Doses below 0.2 U/100 g/hr were without effect. 3. Narcosis (pentobarbital) inhibited markedly the resting and stimulated enzyme secretion. 4. The method is suitable for examination of physiological and pharmacological effects on resting and stimulated enzyme secretion of the rat pancreas.
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    URL: http://dx.doi.org/10.1007/BF00599877
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  • 20
    Electronic Resource
    Electronic Resource
    Regeneration in grafts of normal and denervated rat muscles (1975)
    Springer
    Pflügers Archiv 353 (1975), S. 215-225 
    Details
    ISSN: 1432-2013
    Keywords: Muscle Regeneration ; Muscle Transplantation ; Contractile Properties of Muscle Transplants ; Denervation of Muscle ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The soleus or extensor digitorum longus muscles of young rats were freely grafted into the bed of the corresponding contralateral muscle. The grafts were of normal muscle or muscles which had been denervated for 14 days. Grafts of normal muscle were characterized by little or no contractile activity for the first 2–4 days after transplantation. In contrast, denervated grafts contracted weakly, but consistently, throughout this early period. The patterns of contraction were complex. In early transplants, the contractions were due entirely to surviving muscle fibers in the graft, and the contractile characteristics were those of denervated muscle fibers. After the first week, contractions of newly regenerating muscle fibers within the grafts were superimposed upon and later took over those from the fibers that survived the original transplantation. The contraction time approached those of the normal soleus or extensor muscles during the second month after grafting, and the grafts contracted like fast or slow muscles.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00584285
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  • 21
    Electronic Resource
    Electronic Resource
    An ultrastructural study of normal and injured hypoglossal nuclei after injection of horseradish peroxidase (1975)
    Springer
    Experimental brain research 23 (1975), S. 463-470 
    Details
    ISSN: 1432-1106
    Keywords: Rat ; Hypoglossal nucleus ; Axotomy ; Horseradish peroxidase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The left hypoglossal nuclei of normal rats, and rats which had received left hypoglossal nerve axotomies 7–21 days previously, were studied by electron microscopy after injection of horseradish peroxidase as a marker of extracellular space and pinocytosis. Quantitative analysis showed that the number of pinocytotically-derived structures in presynaptic boutons was significantly increased in rats at 7, 14, and 21 days after axotomy when compared with normal rats. It was suggested that presynaptic boutons which became detached from injured neurones retracted by a membrane cycling mechanism involving pinocytotic uptake of bouton plasmalemma, without compensatory membrane production elsewhere. It was confirmed that the channels in the microglial cells communicated with the extracellular space.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00234915
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  • 22
    Electronic Resource
    Electronic Resource
    Comparison of the biological effects in rat of high doses of two 4-amino-7-chloroquinoline derivatives (1975)
    Springer
    Archives of toxicology 34 (1975), S. 309-314 
    Details
    ISSN: 1432-0738
    Keywords: Glafenine ; Chloroquine ; 4-Amino-7-chloroquinoline ; Rat ; Glafenin ; Chloroquin ; 4-Amino-7-chlorchinolin ; Ratte
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Bei oraler Zufuhr in einer Dosierung von 150 bis 450 mg/kg 2 Tage hintereinander an etwa 100 g schweren Ratten bewirkt Glafenin eine vorübergehende Nephritis mit Steigerung von Blutharnstoff, Hypertrophie der Nebennieren und Veränderungen des Serumproteinogramms. An die 4-Amino-7-chlorochinolin-Struktur scheinen diese toxischen Wirkungen nicht gebunden zu sein, denn die ähnlichen Derivate, Chloroquin und Amodiaquin, rufen sie in äquimolekulären Dosen nicht hervor. Glycerol, ein im Organismus entstehendes Hydrolysisprodukt des Glafenins, zeigte sich auch wirkungslos. Die Toxicität ist wahrscheinlich auf das Glafenin selbst oder sein saures Abbauprodukt 4-(0-carboxyphenylammo-7-chlorochinolin, zurückzuführen.
    Notes: Abstract When given orally in elevated but nonlethal doses (150 to 450 mg/kg, on 2 consecutive days), glafenine induces in rats (body weight 100 g) a transient nephritis with an increase in blood urea, hypertrophy of adrenals, and some changes in the serum proteinogram. These effects do not appear to be due to the 4-amino-7-chloroquinoline structure from which glafenine is derived, as they are not observed with the structural analogue chloroquine given at equimolar doses under the same conditions. Further, they do not appear to be due to glycerol, the by-product of metabolic glafenine hydrolysis. The responsible molecule appears to be either glafenine itself or its acid metabolite 4-(0-carboxyphenylamino) 7-chloroquinoline.
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    URL: http://dx.doi.org/10.1007/BF00353850
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  • 23
    Electronic Resource
    Electronic Resource
    Influence of chelation therapy on acute lead intoxication in rats (1975)
    Springer
    Archives of toxicology 34 (1975), S. 213-225 
    Details
    ISSN: 1432-0738
    Keywords: Lead ; Chelating agents ; Toxicity ; Rat ; Blei ; Chelatbildner ; Toxicität ; Ratte
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die intraperitoneale Verabfolgung von Pb-Acetat führt zu einer mäßigen und vorübergehenden hypochromen Anämie, zu einer lang dauernden erhöhten Ausscheidung der δ-Aminolävulinsäure mit dem Urin, während die Ausscheidung der alkalischen Phosphatase überhaupt nicht und die von Lactatdehydrogenase nur geringfügig beeinflußtwird. Es wird gefolgert, daß weder die hamatologische Reaktion noch die angedeutete Nephrotoxicität für die letale Wirkung von Pb verantwortlich sind. Die Chelattherapie begann 3 Tage nach der letzten Pb-Dosis und erstreckte sich auf 7 Wochen, wobei die intraperitoneale Tages-dosis 25, 50 bzw. 100 μmol/kg betrug. Die Wirksamkeit in bezug auf die Erhöhung der Pb-Ausscheidung mit dem Urin nahm in der Reihenfolge ab: Ca-Diäthylentriaminpentaacetat 〉 2,3-Dimercaptopropan-1-sulfonat 〉 Zn-Diäthylentriaminpentaacetat 〉 D-Penicillamin. Das vermehrt ausgeschiedene Pb stammt im wesentlichen aus dem Skelett. Die Chelatbildner erniedrigten ebenfalls die Ausscheidung der δ-Aminolävulinsäure, erwiesen sich aber als unwirksam, die hämatologische Reaktion und die letale Wirkung von Pb günstig zu beeinflussen. Durch diese negativen Ergebnisse wird der Wert der Chelatbehandlung von Fällen akuter Pb-Vergiftung in Frage gestellt.
    Notes: Abstract The intraperitoneal administration of Pb acetate (5 × 20 mg Pb/kg per day) evokes a moderate and transient hypochromic anemia, a long-lasting enhanced urinary excretion of δ-aminolevulinic acid whereas the urinary excretion of alkaline phosphatase is not affected and that of lactic debyhrogenase only marginally. It is concluded that neither the hematologic response nor the slight nephrotoxicity are responsible for the lethal action of Pb. Chelate treatment started 3 days after the last Pb dose and was continued over 7 weeks. The daily intraperitoneal dose was 25, 50, and 100 μmol/kg, respectively. The efficacy in promoting the urinary excretion of Pb decreased in the following order: Ca diethylenetriaminepentaacetate 〉 2,3-dimercaptopropane-1-sulfonate 〉 Zn diethylenetriaminepentaacetate 〉 D-penicillamine. This effect was mainly due to the mobilization of skeletal Pb. The chelating agents also lowered the excretion of δ-aminolevulinic acid but failed to exert a beneficial influence on the anemia and the lethal action of Pb. These negative results raise questions about the usefulness of chelation therapy in cases of acute Pb poisoning.
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    URL: http://dx.doi.org/10.1007/BF00353284
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  • 24
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    Electronic Resource
    Acrylonitrile biotransformation in rats, mice, and chinese hamsters as influenced by the route of administration and by phenobarbital, SKF 525-A, cysteine, dimercaprol, or thiosulfate (1975)
    Springer
    Archives of toxicology 33 (1975), S. 151-161 
    Details
    ISSN: 1432-0738
    Keywords: Acrylonitrile ; Phenobarbital ; SKF 525-A ; Dimercaprol (BAL) ; Thiosulfate ; Cyanide-Thiocyanate ; Route of Administration ; Drug Biotransformation ; Rat ; Mouse ; Chinese Hamster ; Acrylonitril ; Phenobarbital ; SKF 525-A ; Dimercaprol (BAL) ; Thiosulfat ; Cyanid ; Thiocyanat ; Applikationsart ; Biotransformation ; Ratte ; Maus ; Chinesischer Hamster
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Wistar Ratten, Standard-Albinomäuse und chinesische Hamster (Weibchen) erhielten eine einmalige Dosis von Acrylonitril, 0,5 oder 0,75 mmol/kg Gewicht. Die Ausscheidung des Thiocyanats, Hauptmetaboliten des Acrylonitrils, wies bei Ratten nach einer oralen (20 %), intraperitonealen und subcutanen (2 bis 5%) und intravenösen (1 %) Applikation einen sinkenden Umwandlungsanteil auf. Auch bei Hamstern und Mäusen rief die orale Verabreichung eine höhere Umwandlung hervor als bei der intraperitonealen Zufuhr. Die Vorbehandlung von Ratten mit Phenobarbital, SKF 525-A, Cystein oder Dimercaptopropanol, hatte keinen signifikanten Einfluß auf die Ausscheidung von Thiocyanat im Harn. Hingegen erhöhte die gleichzeitige Applikation von Thiosulfat bedeutend den Anteil von Thiocyanat, und zwar bei Ratten fast zweifach, bei Mäusen mehr als dreifach. Die Studie bestätigt den ausgeprägten Einfluß der Verteilung (first pass metabolic phenomenon) auf das metabolische Schicksal von Acrylonitril. Anscheinend ist die starke Bindung von Acrylonitril und die Cyanoethylierung für den so markanten Einfluß der Applikationsart verantwortlich. Nach oraler, intraperitonealer und intravenöser Applikation von Acrylonitril wurde dieser bei Mäusen effektiver in Thiocyanat metabolisiert als bei Ratten. Die größere Umwandlung von Acrylonitril in Thiocyanat und die stärkere Senkung seiner akuten Toxicität nach Thiosulfat deuten auf eventuelle Unterschiede im Mechanismus der toxischen Wirkung von Acrylonitril bei Mäusen und Ratten hin. In der Toxicität des Acrylonitrils für Ratten spielt Cyanid anscheinend eine kleine Rolle, wohl aber für Mäuse.
    Notes: Abstract Female Wistar rats, conventional albino mice, and Chinese hamsters were given a single dose of acrylonitrile, 0.5 or 0.75 mM/kg body weight. The elimination in the urine of thiocyanate, which is the main metabolite of acrylonitrile, indicated a decreasing proportion of biotransformation after oral (over 20 %), intraperitoneal, or subcutaneous (2 to 5 %), and intravenous (1 %) administration in rats. Oral administration of acrylonitrile in hamsters and mice was also followed by higher biotransformation than intraperitoneal administration. Pretreatment of rats with phenobarbital, SKF 525 A, cysteine, or dimercaprol did not significantly influence elimination of thiocyanate in the urine after the administration of acrylonitrile, but simultaneous administration of thiosulfate significantly increased the metabolized portion of acrylonitrile given intraperitoneally in rats (almost twice) and mice (more than three times). Acrylonitrile was found to be strongly bound in blood. The study confirmed the marked effect of distribution (first-pass metabolic phenomenon) on the metabolic fate of foreign compounds. The strong acrylonitrile binding and cyanoethylation are apparently responsible for the unusually high influence of the different routes of administration on the metabolic fate of acrylonitrile. Acrylonitrile was more effectively metabolized to thiocyanate in mice than in rats after oral, intraperitoneal, and intravenous administration. A greater response of acrylonitrile to thiocyanate metabolism and a larger decrease in its acute toxicity after thiosulfate in mice than in rats indicate possible differences in the mechanism of acrylonitrile toxicity in these animals. Cyanide apparently plays a minor role in the acrylonitrile toxicity in rats, but may play quite an important one in mice.
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    URL: http://dx.doi.org/10.1007/BF00353240
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  • 25
    Electronic Resource
    Electronic Resource
    Tierexperimentelles Modell einer Lungenfibrose bei der Ratte mittels Paraquatinjektion (1975)
    Springer
    Lung 152 (1975), S. 65-74 
    Details
    ISSN: 1432-1750
    Keywords: Lung fibrosis ; Rat ; Paraquat ; Lungenfibrose ; Ratte ; Paraquatlunge
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Es wird die Erzeugung einer Lungenfibrose bei Spraque-Dawley-Ratten mittels mehrfacher Injektion von Paraquat intraperitoneal beschrieben. Notwendige Dosierungen, Intervalle zwischen den Injektionen sowie der zeitliche Ablauf der histologischen Veränderungen werden dargelegt.
    Notes: Summary An experimental model of lung fibrosis by multiple i.p. injections of the herbicide Paraquat is described. The schedules, intervals between injections and histological changes are described.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02101575
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  • 26
    Electronic Resource
    Electronic Resource
    The relation between cerebral serotonin levels and conditioned behaviour in the rat following the administration of LSD-25 and UML (1975)
    Springer
    Psychopharmacology 41 (1975), S. 245-247 
    Details
    ISSN: 1432-2072
    Keywords: LSD-25 ; UML ; Acute ; Chronic ; Behaviour ; 5-HT ; Brain ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Successive daily injections of LSD-25 and UML (1-methyl-d-lysergic acid butanolamide) caused progressive depression of brain 5-HT levels in the rat. On the fourth day, the decrease was significant with respect to the highly significant fall observed after a single administration, whereas it had been shown earlier that conditioned behaviour is no longer affected by LSD-25 after 3 days and that simultaneous administration of a single dose of LSD-25 and UML is equally ineffective in this respect. Its depression of 5-HT levels, however, has now been shown to be equal to that of LSD-25 alone at doses that influence conditioned behaviour. The findings indicate that changes in such behaviour are not dependent on brain 5-HT levels and that no link exists between such levels and the psychotomimetic effect of LSD-25 in man.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00428931
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  • 27
    Electronic Resource
    Electronic Resource
    Hapten-immunological studies on mescaline (1975)
    Springer
    Psychopharmacology 41 (1975), S. 301-304 
    Details
    ISSN: 1432-2072
    Keywords: Mescaline ; Anti-Drug Antibody ; Hapten ; Immunopharmacology ; Rabbit ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Antibodies with mescaline binding specificity were raised in rabbits by immunization with conjugates of bovine serum albumin with mescaline or its analogue 3,4,5-trimethoxyphenylacetic acid. Immunized rats were given mescaline and their behavior was compared to that of non-immunized controls.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00428941
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  • 28
    Electronic Resource
    Electronic Resource
    The effects of nicotine on two-way avoidance conditioning in bi-directionally selected strains of rats (1975)
    Springer
    Psychopharmacology 42 (1975), S. 147-152 
    Details
    ISSN: 1432-2072
    Keywords: Nicotine ; Selection ; Avoidance Conditioning ; Rat ; Latency ; Freezing
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Rats of both sexes from the genetically selected Roman High Avoidance (RHA), the Roman Low Avoidance (RLA) and the Roman Control (RCA) strains were given one 30-min session of two-way escape-avoidance conditioning (30 trials) in a shuttle box with a buzzer as the conditioned stimulus and shock as the unconditioned stimulus in a factorial design involving three time intervals (0,15 and 30 min) following one subcutaneous injection of saline or of nicotine in five doses (0.05, 0.1, 0.2, 0.4, or 0.8 mg/kg of body weight). Six measures relating to performance were analysed in whole or part. While the number of avoidance responses showed the expected strain differences, no effect of dose or delay interval could be detected. Avoidance and escape latencies and intertriai activity showed some effects of these variables, especially in interaction with sex and strain. Dose determined pre-sessional activity, but its effect was strain dependent. The failure to confirm previous findings is discussed in the context of other instances in the literature, and the results of an operant experiment confirming the continuing sensitivity of the Roman strains to the effects of nicotine are reported.
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    URL: http://dx.doi.org/10.1007/BF00429545
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  • 29
    Electronic Resource
    Electronic Resource
    Effect of p-chlorophenylalanine on the acquisition of tolerance to ethanol and pentobarbital (1975)
    Springer
    Psychopharmacology 44 (1975), S. 247-252 
    Details
    ISSN: 1432-2072
    Keywords: p-CPA ; Ethanol ; Pentobarbital ; Tolerance ; Brain 5-HT ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Rats were rendered tolerant to ethanol or pentobarbital by daily oral administration. Motor impairments after test doses of ethanol or pentobarbital were measured prior to and at various times during chronic treatment in order to assess the degree of tolerance development. Chronic administration of p-chlorophenylalanine (p-CPA) in a dosage regimen which produced and maintained approximately 95% depletion of brain serotonin (5-HT) did not alter motor impairment after initial acute administration of ethanol or pentobarbital. However, the rate of tolerance development to the motor-impairing effects of both drugs was slowed down in p-CPA-treated rats. p-CPA did not appear to exert this effect by altering the disposition of ethanol or pentobarbital, since blood levels determined 20 min after administration of the test doses were similar in animals treated with p-CPA and in controls. These findings suggest that brain 5-HT may have a role in tolerance development to ethanol and pentobarbital.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00428901
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  • 30
    Electronic Resource
    Electronic Resource
    Effects of heroin on lever pressing for intracranial self-stimulation, food and water in the rat (1975)
    Springer
    Psychopharmacology 42 (1975), S. 231-234 
    Details
    ISSN: 1432-2072
    Keywords: Heroin ; Self-Stimulation ; Water Intake ; Food Intake ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Male rats maintained with continuous access to levers for intracranial self-stimulation (ICSS), water, and food were subjected to five consecutive daily injections of heroin (5 mg/kg). Rates of lever pressing for ICSS were increased in 8 rats, 2–6 hrs after administration of heroin. Rates of lever pressing for water and food were not significantly changed during this period. Naloxone (5 mg/kg) pretreatment attenuated by 82% the facilitative effect of heroin on ICSS. A second group of 8 rats maintained at reduced ICSS rates failed to show an increase in lever pressing for ICSS with heroin. The facilitative effect of heroin described in this study is consistent with previously reported studies describing the effects of morphine on ICSS.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00421261
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  • 31
    Electronic Resource
    Electronic Resource
    Methadone dependence in the rat (1975)
    Springer
    Psychopharmacology 42 (1975), S. 255-261 
    Details
    ISSN: 1432-2072
    Keywords: Methadone ; Mode of Withdrawal ; Body Weight ; Relapse ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Physical dependence on methadone was induced in rats by an initial “forced drinking” procedure and subsequently by i.p. administration of the drug. In a subsequent Experimental Phase of the study the physical dependence of one group was sustained by a “methadone maintenance” treatment, while two other groups were withdrawn from the drug, one gradually and one abruptly. When relapse trials were carried out during a Readdiction Phase it was found that the maintained group voluntarily consumed significantly greater amounts of methadone than did the two withdrawal groups. These groups did not differ between themselves but did in turn ingest significantly more methadone than a control group with no prior exposure to the drug. The characteristic loss of body weight reliably found during withdrawal from morphine was not demonstrated. This may have been due to the unexpected weight loss which occurred during the last stage of the initial Addiction Phase. The dependent variables of amount of methadone solution and the percentage of fluid consumed as methadone solution correlated highly. However the amount of methadone solution ingested was a better indicator of addiction liability as it was not influenced by fluctuations in the amount of water consumed by the animals.
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    URL: http://dx.doi.org/10.1007/BF00421265
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  • 32
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    Electronic Resource
    Effects of halothane and nitrous oxide anaesthesia on 5-HT turn-over in the rat brain (1975)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 288 (1975), S. 109-121 
    Details
    ISSN: 1432-1912
    Keywords: Halothane and Nitrous Oxide Anaesthesia ; 5-HT Turn-Over ; Brain ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effects of anaesthesia with halothane and nitrous oxide on the turn-over of 5-HT in the rat brain were analysed. The rate of 5-HT synthesis was estimated on the basis of 5-HTP accumulation following 5-HTP decarboxylase inhibition. Inhalation anaesthetics reduced the rate of 5-HT synthesis in the whole brain, this effect being particularly marked in the forebrain. In addition, the reduction of the rate of 5-HT synthesis was still detected after a large tryptophan loading indicating that halothane and nitrous oxide anaesthesia reduced the activity of tryptophan hydroxylase in vivo. The utilization of 5-HT was also delayed during anaesthesia since the rate of 5-HT disappearance following the inhibition of its synthesis at the decarboxylation step was decreased in the whole brain. In spite of this reduced turnover of 5-HT in the brain of rats exposed to inhalation anaesthetics, the 5-HIAA levels were permanently elevated. This was the result of a partial inhibition of the active elimination of the acidic metabolite from the brain during this kind of anaesthesia.
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    URL: http://dx.doi.org/10.1007/BF00500519
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  • 33
    Electronic Resource
    Electronic Resource
    Studies on the synthesis and subcellular distribution of dopamine in the rat adrenal medulla (1975)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 287 (1975), S. 1-10 
    Details
    ISSN: 1432-1912
    Keywords: Dopamine ; Adrenomedullary Hormones ; Synthesis ; Rat ; Adrenals ; Subcellular Distribution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Rats received intravenous injections of3H-tyrosine and were killed at various time intervals thereafter.3H-dopamine (DA) in the adrenals reached a maximum within 1.5 min after the administration of3H-tyrosine. From the 15th min it disappeared with an apparent half life of 90 min.3H-Adrenaline (A) +3H-noradrenaline(NA) increased much more slowly and reached a plateau 120–240 min after the injection. The approximate synthesis rate of adrenal A+NA, calculated from the specific activity curves, ranged from 9.3 to 2.2 nmoles/h per kg b.w. The highest value was noted the first few minutes, the lowest 1–2 hrs after the administration of3H-tyrosine. In some experiments subcellular fractionation of the adrenals was performed. In untreated animals the amount of DA and A+NA recovered from the supernatant fraction was about 10 and 8 per cent, respectively, of the total amount recovered from the supernatant and particulate fractions. In the adrenals of animals receiving3H-tyrosine 3.75 or 60 min beforehand these figures were significantly elevated whereas the DA and A+NA of the particulate fraction did not deviate significantly from control values. The specific activities of3H-DA were the same in the supernatant and particulate fractions within 3.75 min after the injection of3H-tyrosine.
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    URL: http://dx.doi.org/10.1007/BF00632633
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  • 34
    Electronic Resource
    Electronic Resource
    Adenylate cyclase and phosphodiesterase in the rat gastric mucosa after starvation, feeding and pentagastrin (1975)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 288 (1975), S. 147-153 
    Details
    ISSN: 1432-1912
    Keywords: Adenylate Cyclase ; Phosphodiesterase ; cAMP ; Gastric Mucosa ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effects of starvation, feeding and pentagastrin on gastric mucosal adenylate cyclase (AC) and phosphodiesterase (PDE) activity were studied in the rat. 1. Starvation for 24 hrs and 48 hrs reduced both NaF stimulated and basal AC activities. 2. Feeding of starved rats slowly raised the AC activity up to 430% within 4 hrs after feeding. This effect was more pronounced under basal conditions than with NaF stimulation. 3. A single i.p. injection of pentagastrin (125 μg/kg) caused a stimulation of basal AC lasting 45 min, which was followed by a subsequent decrease in the basal and NaF stimulated enzyme activity. 4. PDE activity was not influenced by starvation and feeding but underwent a transient inhibition by pentagastrin. Accordingly gastric mucosal cAMP levels after starvation, feeding and pentagastrin are regulated by changes in AC and not in PDE activity. The rise in AC activity after feeding appears to be related to functions other than H+ and pepsin secretion.
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    URL: http://dx.doi.org/10.1007/BF00500522
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  • 35
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    Electronic Resource
    Antagonism by d-amphetamine of learning deficits in rats induced by exposure to antipsychotic drugs during early postnatal life (1975)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 288 (1975), S. 185-193 
    Details
    ISSN: 1432-1912
    Keywords: Avoidance Acquisition ; Development ; Pimozide ; d-Amphetamine ; Catecholamines ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The acquisition of a conditioned avoidance response (CAR) was investigated in rats of nursing mothers given pimozide 0.5 mg/kg on days 1, 2, 3, 4, 5, 6, and 7 after delivery. Four weeks after birth, the male litter-mates were tested for CAR acquisition in a two-way avoidance situation or for correct CAR acquisition in a brightness discrimination situation. Offspring of mothers treated with pimozide were markedly inferior in the CAR acquisition in both behavioural situations as compared to those of mothers given glucose. The administration of d-amphetamine 15 min prior to the training session specifically counteracted the behavioural impairment obtained in the offspring of pimozide-treated mothers. The results obtained in the present investigation lend further support to the contention that the behavioural deficits in offspring of nursing mothers treated with neuroleptic agents are due to a developmental disturbance in central catecholamine neurones.
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    URL: http://dx.doi.org/10.1007/BF00500526
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    Electronic Resource
    Different populations of granules and their distribution in the hypothalamo-neurohypophysial tract of the rat under various experimental conditions (1975)
    Springer
    Cell & tissue research 160 (1975), S. 231-261 
    Details
    ISSN: 1432-0878
    Keywords: Median eminence ; Rat ; Populations of axonal granules ; Electron microscopy, morphometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung In Fortsetzung einer früheren Arbeit wurde die Eminentia mediana von männlichen und weiblichen Ratten, sowie die trächtiger und durstender Tiere auf die Fragestellung hin untersucht, ob 1. die Eminentia mediana der erste Ort ist, wo die beiden Neurohormone Oxytocin und Vasopressin freigesetzt werden, und 2. ob sich die Axone in der externen Schicht der Eminentia mediana aufgrund der mittleren Durchmesser ihrer Granula in verschiedene Populationen differenzieren lassen. Bei männlichen und weiblichen Kontrolltieren haben die Oxytocin-bzw. Vasopressin-granula in der Eminentia mediana bereits ihre endgültige Größe erreicht; ihr mittlerer Durchmesser ändert sich nicht mehr wesentlich bis zum Hypophysenhinterlappen. Allerdings gibt der unterschiedliche prozentuale Anteil beider Populationen in der Eminentia mediana, in Zusammenhang mit den früher bestimmten Werten für die jeweiligen Kerne und die Neurohypophyse, Hinweise auf gewisse Unterschiede im turnover beider Hormone bei männlichen und weiblichen Tieren. Bei graviden und durstenden Ratten findet sich eine scheinbare Abnahme der Granula Durchmesser in den oxytocin-bzw. vasopressinführenden Axonen. In Verbindung mit sehr charakteristischen morphologischen Befunden, besonders bei langdurstenden Tieren, sprechen die morphometrischen Ergebnisse dafür, daß in der Eminentia mediana bereits Neurohormon freigesetzt wird, wenn eine schnelle Deckung des peripheren Bedarfes notwendig ist. Die Axone mit Granula, die kleiner sind als 115 nm, lassen sich in der internen Schicht der Eminentia mediana aufgrund der mittleren Durchmesser ihrer Granula in vier Populationen aufteilen. Ihre mittleren Granula-Durchmesser liegen bei etwa 84 nm, 96 nm, 103 nm und 110 nm. Dieselben vier Populationen finden sich sowohl in der Zona palisadica als auch in der perikapillären Schicht der Eminentia mediana. Im Unterschied zur Zona interna findet sich aber in diesen beiden Schichten noch eine fünfte Population von Axonen mit einem mittleren Granula-Durchmesser von etwa 70–75 nm. Der mengenmäßige Anteil dieser fünf Populationen aber ist unterschiedlich in der Zona palisadica und in der perikapillären Schicht einerseits und in den verschiedenen Tiergruppen andererseits. Einige morphologische Befunde an den Tanycyten werden im Zusammenhang mit der neueren Literatur diskutiert.
    Notes: Summary In connection with previous studies (Krisch, 1974), a morphologic analysis of the median eminence of male, female, pregnant, and thirsting rats has been made, in order to evaluate: 1. whether the median eminence is an additional area where oxytocin and vasopressin may be released from neurosecretory axons in the zona interna; 2. whether it is possible to distinguish different populations of axons according to the mean diameters of their granules in the external zone of the median eminence. In the zona interna of the male and the female control animals, the oxytocin-and vasopressin-containing granules have already reached their final diameters, i.e. their size remains constant until they reach and are stored in the neurohypophysis. However, the relative proportions of these populations in the fibre layer of the median eminence indicate certain differences between male and female animals, concerning the turnover of oxytocin and vasopressin. In pregnant, as well as in thirsting animals, there is an apparent decrease of the mean granule diameters in oxytocin and vasopressin-containing axons. In particular in the latter group, ballooned axons in the fibre layer of the median eminence, containing disintegrating granules, tubular structures filled with electron dense material, and fine-flocculent material in the axoplasm, together with the morphometric results, support our concept that in case of highly increased peripheral demand the contents of the mature, large granules are released into the axoplasm of the fibre layer in the median eminence. In addition, axons containing granules smaller than 115 nm may be classified into four populations with mean diameters of 84 nm, 96 nm, 103 nm, and 110 nm. The same populations are found in the palisade zone of the median eminence as well as in the pericapillary zone, but in contrast to the zona interna there is a fifth population of axons containing very small granules with a mean diameter of about 70–75 nm. The relative proportions of these five populations differ between the zona palisadica and the pericapillary zone on the one hand and between the experimental groups on the other hand. Some morphological findings concerning the tanycytes are discussed with respect to previously published data.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00220580
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  • 37
    Electronic Resource
    Electronic Resource
    Rate of protein synthesis in rat salivary gland cells after pilocarpine or feeding (1975)
    Springer
    Cell & tissue research 164 (1975), S. 447-456 
    Details
    ISSN: 1432-0878
    Keywords: Protein secretion ; Protein synthesis ; Salivary glands ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The effect of pilocarpine and food uptake on the rate of incorporation of [3H]-leucine in vivo was measured by means of quantitative radioautography in three exocrine cells of the rat: the acinar and the granular duct cells of the submandibular and the acinar cells of the parotid gland. The three cell types react differently. The submandibular acinar cells showed a decrease in incorporation rate after pilocarpine administration but not after feeding. The incorporation rate of the granular duct cells of the submandibular gland remains constant after both stimulations. The acinar cells of the parotid gland show an increase in incorporation rate of [3H]-leucine in response to both. The contrast between the submandibular and the parotid gland could also be demonstrated radiobiochemically, the results reflecting the incorporation rates of the acinar cells of both glands, giving no information on the contribution of other cell types. The decrease in incorporation rate of the submandibular gland acinar cells is accompanied by a shift of polyribosomes towards monomers.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00219936
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  • 38
    Electronic Resource
    Electronic Resource
    Rate of protein synthesis in rat salivary gland cells after pilocarpine or feeding (1975)
    Springer
    Cell & tissue research 164 (1975), S. 457-466 
    Details
    ISSN: 1432-0878
    Keywords: Protein secretion ; Protein synthesis ; Salivary glands ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary After stimulation of the protein secretion by pilocarpine or feeding the rate of incorporation of [3H]-leucine increases in the acinar cells of the parotid gland of the rat while the secretory cells of the submandibular gland show a moderate decrease (Kuijper et al., 1975b). Since the rate of labelled amino acid incorporation depends on the specific radioactivity of the amino acid used, which is not easy to determine in vivo, experiments in vitro were performed to get an idea of the influence of this factor on the measured changes in [3H]-leucine incorporation. In vitro both cell types showed a more pronounced but essentially identical reaction as in vivo. Since in these experiments the specific radioactivity of the extracellular leucine is the same whether fragments of stimulated or unstimulated glands incorporate the radioactive amino acid, the increase of incorporation in the parotid and the decrease in the submandibular cells cannot be ascribed to differences in specific radioactivity of leucine, unless the intracellular leucine pool should show great differences between secreting and non-secreting cells. However, in vitro the submandibular gland cells under both conditions appear to use the extracellular leucine for their protein synthesis (or a small compartmentalized pool in rapid exchange with the extracellular pool). In the parotid cells the whole intracellular pool showed such a rapid exchange with the extracellular one that for practical reasons one may say that these cells, too, rely on the extracellular specific radioactivity of leucine in their protein synthesis. We conclude that the rat parotid gland cells show a rapid and substantial increase of protein synthesis after stimulation of their enzyme secretion, while the submandibular gland cells do not.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00219937
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  • 39
    Electronic Resource
    Electronic Resource
    Rate of protein synthesis in rat salivary gland cells after pilocarpine or feeding (1975)
    Springer
    Cell & tissue research 164 (1975), S. 435-446 
    Details
    ISSN: 1432-0878
    Keywords: Protein secretion ; Protein synthesis ; Salivary glands ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In untreated, fasting animals the cells of the serous demilunes of the sublingual gland incorporate [3H]-leucine at a higher rate than any other of the 5 main cell types of the 3 major salivary glands. The acinar cells of the submandibular and the mucous cells of the sublingual gland show intermediate values, while the cells of the granular ducts of the submandibular and the acini of the parotid gland have a low rate of incorporation. In fasting animals extrusion of newly synthesized protein starts early in the cells of the serous demilunes. It starts between 4 and 7 hrs after [3H]-leucine injection in the acinar cells of the submandibular gland, while the other cell types did not lose substantial amounts of labelled (glyco)protein within 7 hrs. The secretion of protein is stimulated by the cholinergic drug pilocarpine in all but one of the 5 types of salivary gland cells studied. The acinar cells of the submandibular gland react strongly, the granular duct cells less strongly. Still less are the reactions of the acinar cells of the parotid and of the mucous cells of the sublingual gland. The cells of the serous demilunes of the latter appear to be insensible to pilocarpine. The effect of food uptake on secretion does not differ from pilocarpine stimulation, with one exception: the acinar cells of the parotid gland react more strongly on food uptake than on cholinergic stimulation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00219935
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  • 40
    Electronic Resource
    Electronic Resource
    Ganglion cells and paraganglionic cells in the developing superior cervical ganglion of normal and p-chlorophenylalanine treated rats (1975)
    Springer
    Cell & tissue research 163 (1975), S. 249-262 
    Details
    ISSN: 1432-0878
    Keywords: Superior cervical ganglion ; Rat ; Catecholamines ; p-Chlorophenylalanine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Ganglion cells and paraganglionic (PG) cells in the developing rat superior cervical ganglion were studied following postnatal treatment with p-chlorophenylalanine (pCPA) for 5 to 8 days. Litter mates, injected with saline solution, served as controls. Ganglion cells of control animals were differentiated ultrastructurally according to L. Eränkö (1972 a) into late sympathicoblasts and young sympathetic nerve cells. In both maturation stages treatment with pCPA caused marked swelling of mitochondria, concomitant with minor changes of other cell organelles. Parallel to the ultrastructural alterations, fluorescence microscopy and cytophotometry revealed a slight diminution of diffuse fluorescence intensity in sympathetic neurons as the expression of a mainly extragranular amine depletion. In distinction from ganglion blocking agents the alterations are regarded as a general toxic effect of pCPA upon maturing sympathetic neurons, which secondarily influences catecholamine storage sites. Following treatment with pCPA, in PG-cells an alteration of mitochondria was scarcely to recognize. Specific granules were distinctly decreased in number, in some cases to an almost complete degree. Concordant to ultrastructural observations a marked diminution of fluorescence intensity was demonstrable in SIF-cells. In addition in these elements the fluorescence spectrum shifted towards the green field. Fluorescence cytophotometric evaluations confirmed the optical impression. Provided, that PG-cells, demonstrated with electron microscopy, are identical with SIF-cells in fluorescence microscopy, the results are discussed on the basis of a specific decrease of primary catecholamines due to an enzyme inhibition involved in catecholamine synthesis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00221731
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  • 41
    Electronic Resource
    Electronic Resource
    Radioautographic study of the rat brain and pituitary after injection of 3H dexamethasone (1975)
    Springer
    Cell & tissue research 161 (1975), S. 183-191 
    Details
    ISSN: 1432-0878
    Keywords: Hypothalamus ; Pituitary ; Rat ; Localization of 3H-dexamethasone ; Radioautography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The central nervous system and the pituitary of adrenalectomized male rats injected with 3H-dexamethasone were examined by radioautography. At 1 hr after the injection, radioactivity concentration was high in the medial basal hypothalamus, the pituitary and the pineal gland. In the hypothalamus, radioactive material was found to be selectively concentrated in neurons in the ventral part of nucleus arcuatus and in the infundibular region. In the anterior pituitary, a large proportion of cells showed silver grains both in the cytoplasm and over the cell nuclei. However, in a small number of cells, the radioactive material was associated with the cell nuclei. Less radioactivity was present in the intermediate and posterior lobes. The pineal gland contained more silver grains than did other regions of the brain. The results obtained in the present study suggest essentially an action of dexamethasone in the medial basal hypothalamus and at the level of the pituitary.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00220367
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  • 42
    Electronic Resource
    Electronic Resource
    Ultrastructure of cell surface coat (glycocalyx) in rat urinary bladder epithelium (1975)
    Springer
    Cell & tissue research 158 (1975), S. 281-283 
    Details
    ISSN: 1432-0878
    Keywords: Glycocalyx ; Urinary bladder ; Ruthenium red ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Earlier statements to the contrary, the present study demonstrates the presence of a cell surface coat (glycocalyx) on the luminal plasma membrane of the super ficial transitional epithelial cells lining the urinary bladder of male Buffalo rats. This coat was demonstrated with ruthenium red, an electron dense stain, which revealed a surface layer, 60–80 Å thick, separated from the outer leaflet of the plasma membrane by an electron lucent layer, approximately 30 Å thick. The structure of the glycocalyx was not affected by 12 weeks of treatment with dibutylnitrosamine, a known bladder carcinogen.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00219966
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  • 43
    Electronic Resource
    Electronic Resource
    The major ganglion in the pelvic plexus of the male rat (1975)
    Springer
    Cell & tissue research 159 (1975), S. 49-62 
    Details
    ISSN: 1432-0878
    Keywords: Autonomic ganglia ; Pelvic plexus ; SIF cells ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary To further evaluate the role of autonomic ganglia in the regulation of pelvic visceral activity, the neural elements in the major pelvic ganglion of the male rat have been studied with histochemical and electron microscopic techniques. The principal findings are that the ganglion is composed of cholinergic and adrenergic ganglion cells as well as small intensely fluorescent (SIF) cells. Polarity in the ganglion is indicated by clustering of small ganglion cells which stain intensely for acetylcholinesterase (AChE) along the pelvic nerve while larger cells, with weak to moderate AChE activity, collect near small branches of the hypogastric nerve. Some cholinergic ganglion cells are enclosed by a plexus of adrenergic terminals. SIF cells appear to be in contact with both cholinergic and adrenergic cells, although many of the fluorescent beads around adrenergic neurons may be short dendrites of ganglion cells, rather than processes of SIF cells. Two types of SIF cells may be distinguished on the basis of size and morphology of their granulated vesicles. Afferent synapses of the cholinergic type were common on SIF cells of the large granule and small granule type. Portions of SIF cells with large granules occur within the capsule of ganglion cells. Contacts seen here were interpreted as efferent synapses from SIF cells to the dendrites of ganglion cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00231994
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  • 44
    Electronic Resource
    Electronic Resource
    Identification of the vasopressin-neurophysin producing neurons of the rat suprachiasmatic nuclei (1975)
    Springer
    Cell & tissue research 156 (1975), S. 377-380 
    Details
    ISSN: 1432-0878
    Keywords: Vasopressin-neurophysin neurons ; Suprachiasmatic nuclei ; Immunoenzyme histochemistry ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Immuno-enzyme histochemical investigations on the hypothalamus of the normal rat showed (1) that the Suprachiasmatic nuclei produce vasopressin; (2) that it is highly probable that these nuclei do not produce oxytocin. From the present and previous investigations it may be concluded that the Suprachiasmatic neurons produce a vasopressin-neurophysin complex.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00225365
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  • 45
    Electronic Resource
    Electronic Resource
    Histochemical observations on uptake of L-dopa into endocrine cells of the rat pituitary gland during the postnatal development (1975)
    Springer
    Cell & tissue research 156 (1975), S. 451-461 
    Details
    ISSN: 1432-0878
    Keywords: Adenohypophysis ; Rat ; L-dopa ; Fluorescence histochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The uptake of L-dopa into the cells of the adenohypophysis of the rat was studied during the postnatal development and at adult age using the formaldehyde-induced fluorescence method (FIF). The cells taking up L-dopa were classified by Alcian blue-PAS-Orange G staining. The correlation between the cells taking up L-dopa and those containing tryptophyl-peptide was estimated during the postnatal period and in adult rats. The cells containing tryptophyl-peptide were demonstrated using fluorescence induced by treatment with combined formaldehyde and acetyl chloride vapour. The following observations were made: 1) Great majority of the cells taking up L-dopa did not contain tryptophyl-peptide. Thus the accumulation of L-dopa into the cells of pars distalis is not due to accumulation of L-dopa into the cells by the same transport mechanism as the amino acids for tryptophyl-peptide. 2) Of the cells taking up L-dopa in the adult rats 96% were chromophobes, 2.0% acidophilic cells (somatotrophs and cells producing prolactin), 0.9% R-mucoid cells (corticotrophs), and 1.2% S1- and S2-mucoid cells (gonadotrophs and thyrotrophs). At 10 and 25 days' age the relative numbers of the cells taking up L-dopa were about the same. 3) Pretreatment with nialamide caused only a slight increase in the number of the cells taking up L-dopa. The decrease in the number of the cells uptaking L-dopa of the pars distalis, which takes place after 5 weeks' age is thus not caused by the increased MAO-activity. 4) Strongly chromophilic cells did not take up L-dopa. At the light of our results it seems evident that L-dopa is taken up by the chromophobic cells when these differentiate into chromophilic cells. The accumulation of L-dopa may be a sign of an active transport of amino acids into the cells. The accumulation of L-dopa into the chromophobic stellate and follicular cells may reflect their metabolic activity. These cells probably have an important role in the production of the hormones of the pars distalis.
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    URL: http://dx.doi.org/10.1007/BF00225105
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  • 46
    Electronic Resource
    Electronic Resource
    Masthead (1975)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975) 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19751080101
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  • 47
    Electronic Resource
    Electronic Resource
    Zur Kenntnis des Narciclasins (1975)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 445-463 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Chemistry of NariciclasineFrom narciclasine (2a), the acetonide 8a and its oxidation product 10 are prepared. 10 isomerizes easily to give 11. Catalytic hydrogenation of 2a yields a mixture of dihydronarci-clasines from which the pure cis- and trans-isomers 14a and 15a can be obtained via the tetraacetates. As a by-product of the hydrogenation, isonarciclasine (16a) is isolated. The relative configuration of narciclasine (as represented by formula 2a) is established by the n. m. r. spectra of 15b and 16b. Lycoricidine and margetine are shown to be identical; their configuration is as shown in formula 2b. Some biological tests are reported.
    Notes: Aus Narciclasin (2a) wird das Acetonid 8a und dessen Oxidationsprodukt 10 dargestellt. 10 wird leicht zu 11 isomerisiert. Das bei der katalytischen Hydrierung von 2a anfallende Gemisch der Dihydronarciclasine wird über die Tetraacetate in die cis- und trans-Verbindungen 14a und 15a aufgetrennt. Als Nebenprodukt der katalytischen Hydrierung entsteht Isonarciclasin (16a). Mit Hilfe der NMR-Spektren von 15b und 16b läßt sich die relative Konfiguration des Narciclasins entsprechend 2a beweisen. Lycoricidin und Margetin sind identisch und haben die Konfiguration 2b. Über einige biologische Teste wird berichtet.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19751080210
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  • 48
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    Electronic Resource
    Komplexchemie reaktiver organischer Verbindungen, V. Reaktionen aliphatischer Diazoverbindungen mit thermolabilen Mangan-Komplexen (1975)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 486-499 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Complex Chemistry of Reactive Organic Compounds, V. Reaction of Aliphatic Diazo Compound with Thermolabile Manganese ComplexesAliphatic diazo compounds react with the manganese- tetrahydrofurane complexes 1 and 2, respectively, to yield olefine, ketimine or carbene complexes: 3-diazo-2- butanone (3b) reacts with 2 under intramolecular hydride transfer to give the buten-2- one complex 7, while 3-diazocamphor (3c) leads to the 3-iminocamphor complex 8. Benzolyphenyldiazomethane (3a), diphenyldiazomethane (9a), and its p-substituted derivatives 9b-f are shown to be preliminary stages for the stable carbene complexes 4, 10, and 11, the spectra of which are discussed. The diphenylcarbene ligand can be split off by triphenylphosphine, carbon monoxide, ammonium cerium(IV) nitrate, and by thermolysis.
    Notes: Aliphatische Diazoverbindungen reagieren mit den Mangan-THF- Komplexen 1 bzw. 2 zu Olefin-, Ketimin- oder Carben-Komplexen: Während 3-Diazo-2-butanon (3b) mit 2 unter intramolekularer Hydridverschiebung den Buten-2- on-Komplex 7 ergibt, bildet 3-Diazo-campher (3c) bei Umsetzung mit 2 den 3-Iminocampher-Komplex 8. Benzoylphenyldiazomethan (3a) sowie Diphenyldiazomethan (9a) und seine p- substituierten Derivate 9b-f verhalten sich gegenüber 1 und 2 als Vorstufen für die stabilen Carben-Komplexe 4, 10 und 11, deren Spektren diskutiert werden. Der Diphenylcarben-Ligand in 11a kann mit Triphenylphosphin, Kohlenmonoxid und Ammoniumcer(IV)-nitrat sowie durch Thermolyse abgespalten werden.
    Additional Material: 7 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19751080213
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  • 49
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    Electronic Resource
    Photochemische Dimerisierung von 1,4- Dialkinylbenzolen (1975)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 528-537 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Photochemical Dimerisation dof 1,4-DialkynylbenzenesOn irradiation with ultraviolet light 1,4-diethynylbenzene (4a) forms blue unstable 6-ethynyl-1-(4- ethynylphenyl)azulene (5) and 6-ethynyl-2-(4-ethynylphenyl)azulene (6) besides polymers. The photolysis of 1,4-bis(phenylethynyl)benzene (4b) yields stable green 2,3-diphenyl-6-phenylethynyl-1-[4- (phenylethynyl)phenyl]azulene (9) and the isomeric naphthalene 11. Products of catalytic reduction of 5, 9, and 11 are described.
    Notes: Aus 1,4-Diäthinylbenzol (4a) entstehen bei Bestrahlung mit ultraviolettem Licht das wenig beständige, blaue 6-Äthinyl-1-(4-äthinylphenyl)azulen (5) und 6-Äthinyl-2-(4-äthinylphenyl)-azulen (6) neben polymeren Produkten. Dagegen führt die Photolyse von 1,4-Bis(phenyl-äthinyl)benzol (4b) zu dem beständigen grünen 2,3-Diphenyl-6-phenyläthinyl-1-[4-(phenyl-äthinyl)phenyl]azulen (9) und dem isomeren Naphthalin-Derivat 11. Reduktionsprodukte von 5, 9 und 11 werden beschrieben.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19751080218
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  • 50
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    Derivate des Methylendioxybenzols, 40. Synthese des Ferrugons und des Pseudoferrugons (1975)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 561-568 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Derivatives of Methylendioxybenzene, 40. the Synthesis of Ferrugone and PseudoferrugoneThe isoflavones ferrugone (1a) and pseudoferrugone (1a) as well as their dihydro derivatives 2a and b are prepared from the apione derivatives 5f of 6f and the chromene or chroman derivatives 4d and 3p.
    Notes: Die Isoflavone Ferrugon (1a) und Pseudoferrugon (1b) sowie die Dihydroverbindungen 2a und b werden durch Reaktion der Apionderivate5f und 6f mit den Chromen- bzw. Chroman-derivaten 4d bzw. 36p dargestellt.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19751080221
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  • 51
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    Methylendioxyhetarene, 1. Zur Darstellung von 3,4- Methylendioxythiophen-, -furan- und pyrrol- abkömmlingen (1975)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 569-575 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Methylenedioxyhetarenes, 1. On the Preparation of 3, 4- Methylenedioxythiophene-, furan- and -pyrrole DerivativesMethylenation experiments with 3, 4-dihydroxy compounds of diethyl thiophene-, furan-, 1-phenyl-, and 1- (ethoxycarbonylmethyl)-2, 5-pyrroledicarboxylate are reported. Methylenations lead only with diethyl 3, 4-dihydroxy-2, 5- thiophenedicarboxylate (1) to the 3, 4- methylenedioxythiophene derivatives 2 and 3 with formation of diethyl dithieno[3, 4-b: 3′, 4′- g]tetroxecin-1, 3, 7, 9-tetracarboxylate (4) as by- product. The furan- (5a) and pyrrole derivatives 7a and b give the tetraethyl difuro- (6) and dipyrrolo[3, 4-b: 3′, 4′-g]tetroxecin- 1, 3, 7, 9-tetracarboxylates 8a and b, respectively.
    Notes: Es wird über Methylenierungsversuche an 3,4-Dihydroxy- Verbindungen der Thiophen-Furan-, 1-Phenyl- und 1- (Äthoxycarbonylmethyl)-2,5-pyrroldicarbonsäure- diäthylester berichtet. Die Methylenierungen führen nur beim 3,4-Dihydroxy-2,5-thiophendicarbonsäure-diäthylester (1) zu den 3,4-Methylendioxythiophen-Derivaten 2 und 3, wobei als Nebenprodukt der Dithieno[3,4-b: 3′,4′-g]tetroxecin-1,3,7,0-tetracarbonsäure- tetraäthylester (4) gebildet wird. Bei dem Furan- (5a) und den Pyrrol-Derivaten 7a und b entstehen die Difuro- (6) bzw. die Dipyrrolo[3,4- b: 3′,4′-g]tetroxecin-1,3,7,9- tetracarbonsäure-tetraäthylester 8a, b.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19751080222
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    Reaktionen von N, N-Dialkyl- und N, N-Diarylsulfamiden mit Chlorsulfonylisocyanat (1975)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 618-622 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reaction of N, N-Dialkyl- and N, N-Diarylsullfamides with Chlorosulfonyl IsocyanateChlorosulfonyl isocyanate reacts with N, N-dialkyl- or N, N-diarylsulfamides to give the so far unknown N-chlorosulfonyl-N′-(dialkyl- and -diarylsulfamoyl)ureas (3a-e), which may be hydrolysed to the corresponding N-(dialkyl- and -diarylsulfamoyl)ureas (4a-e). The pyrolysis of 3a-e leads to the formation of the known sulfamoyl chlorides.
    Notes: Durch Umsetzung von Chlorsulfonylisocyanat mit N, N-Dialkyl- oder N, N-Diarylsulfamiden erhält man die bisher unbekannten N-Chlorsulfonyl-N′-(dialkyl- und -diarylsulfamoyl)harnstoffe (3a-e), die sich zu N-(Dialkyl- und-Diarylsulfamoyl)harnstoffen (4a-e) hydrolysieren lassen. Die Pyrolyse von 3a-e liefert die bekannten Sulfamidsäurechloride.
    Additional Material: 1 Tab.
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    URL: http://dx.doi.org/10.1002/cber.19751080227
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    Zur Photochemie des Allens (1975)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 657-663 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On the Photochemistry of AlleneAcetophenone-sensitized irradiation of allene yields a complex mixture of products, from which the allene dimer 1, the trimers 2 and 3, and the ketones 4 and 5 have been isolated. This is in contrast to the reported thermal di- and trimerization of allene, which lead to products such as 1, 8-12. The planar allene triplet 13, derived by way of a nonvertical triplet-triplet energy transfer, presumably plays a key role in the photosensitized oligomerization of allene. Also, the formation of the ketone 5 is easily explained in terms of an attack of 13, through its central C-atom to the o-position of the acetophenone, to give 16, which cyclizes ultimately to yield 5. At 240°C, 5 undergoes fragmentation to the starting materials. The α,β-unsaturated ketone 4 arises through a [2 + 2]-photocycloaddition reaction of the 3(n,π*) state of acetophenone to methylacetylene via the oxetene intermediate 6, followed by ring-opening.
    Notes: Die acetophenon-sensibilisierte Belichtung von Allen liefert eine komplexe Produktmischung, aus der sich das Allendimere 1, die Trimeren 2 und 3 sowie die Ketone 4 und 5 isolieren lassen. Dieser Befund steht im Gegensatz zur beschriebenen thermischen Di- und Trimerisierung des Allens, die zu 1, 8-12 führt. Eine Schlüsselrolle bei der photosensibilisierten Allen-Oligomerisierung spielt vermutlich das durch nichtvertikale Triplett-Triplett-Energieübertragung gebildete planare Allen-Triplett 13. Auch die Entstehung des Bicyclo[4.2.0]octadien-Ketons 5 erklärt sich zwanglos durch einen Angriff von 13 mit seinem mittleren C-Atom in der o-Position des Acetophenons unter Bildung der Zwischenstufe 16, die Ringschluß zu 5 erfährt. Bei 240°C erleidet 5 Rückspaltung in die Ausgangskomponenten. Das α,β-ungesättigte Keton 4 ist dagegen Ergebnis einer [2 + 2]-Photocycloaddition des Acetophenons im 3(n,π*)-Zustand an Methylacetylen zum Oxeten 6 mit anschließender Ringöffnung.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19751080231
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  • 54
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    Organische Schwefelverbindungen, XI. Synthese von 1,3-Oxathiol-spirofuranonen und Furanon-spirodihy-drothiopyranen aus 4-Thioxo-tetrahydrofuran-3-onen (1975)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 673-682 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Organosulfur Compound, XI. Synthesis of 13-3-Oxathiol-spirofuranones and Furanone-spirodihydrothiopyrans from 4-Thioxotetrahydrofuran-3-onesHeterocyclic, non-enolisable α-oxo-thioketones of furan-type 9 have been prepared for the first time. These highly unstable compounds undergo dimerisation and subsequent elimination of sulfur to give 1,3-oxathiol-spirofuranones 11. In competition with this process reaction with the eliminated active sulfur can occur to yield a dispiro-1,2,4-trithiolan 10a. In the presence of dimethylbutadiene the new α-oxo-thioxofurans 9 react according to the Diels-Alder principle to form the furanone-spirodihydrothiopyrans 13. The reaction mechanisms are discussed.
    Notes: Es werden erstmals heterocyclische, nicht enolisierbare α-Oxo-thioketone vom Furantyp (9) hergestellt, die außerordentlich instabil sind und unter Dimerisierung mit anschließender Schwefeleliminierung reagieren, wobei die bisher unbekannten 1,3-Oxathiol-spirofuranone 11 entstehen. In Konkurrenz hierzu kann Reaktion mit dem bei der Fragmentierung gebildeten aktiven Schwefel unter Bildung eines Dispiro-1,2,4-trithiolans (10a) eintreten. In Gegenwart von Dimethylbutadien reagieren die neuen α-Oxo-thioxo-furane 9 ausschließlich nach dem Diels-Alder-Prinzip unter Bildung der Furanon-spirodihydrothiopyrane 13. Die Reaktions-mechanismen werden diskutiert.
    Additional Material: 2 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19751080233
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  • 55
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    Übergangsmetall-substituierte VB-Elementsysteme, V. Bis(VIA-metall)methylstibine - Darstellung, Quartärisierung und Oxidation (1975)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 700-715 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Transition Metal Substituted VB Element System. Bis(VIA metal)methylstibines-Preparation, Quaternization and OxidationCH3SbBr2 reacts with the transition metal anions of Na[Fe(CO)2π-C5H5] and Na[M(CO)3π-C5H5] (M=Cr, Mo, W) to give CH3Sb[Fe(CO)2π-C5H5]2 and CH3Sb[M(CO)3π-C5H5]2 (M=Cr, Mo, W). via stepwise metalation. Starting with the primary substitution products BrCH3Sb—M(CO)3π-C5H5 (M=Mo, W) the heteronuclear species π-C5H5(CO)3Cr—Sb-(CH3)—M(CO)3π-C5H5 (M=Mo, W) and π-C5H5(CO)3Mo—Sb(CH3)—W(CO)3π-C5H5 can be obtained. Reactions with alkyl halides result in the quaternization of the Sb-atom or the cleavage of the Sb—M bond. In the first case metal substituted Sb-cations of the type [{π-C5H5(CO)3M}2Sb(CH3)R]⊕ (M=Mo, W; R=CH3, C2H5, C6H5CH2) are formed, which can also be synthesized by reaction of monometalated stibines with metal halides [{e. g. π-C5H5(CO)3Mo—Sb(CH3)2 and π-C5H5(CO)3MoBr]. Bromine adds on VB element, to yield transition metal derivatives with presumable pentacoordinated antimony ([π-C5H5(CO)3W]2SbCH3Br2). The chemical and spectroscopic properties of the new antimony transition metal complexes are reported.
    Notes: Die Umsetzung von CH3SbBr2 mit den Übergangsmetall-Anionen von Na[Fe(CO)2π-C5H5] und Na[M(CO)3π-C5H5] (M=Cr, Mo, W) führt unter stufenweiser Metallierung zur Bildung von CH3Sb[Fe(CO)2π-C5H5]2 und CH3Sb[M(CO)3π-C5H5]2 (M=Cr, Mo, W). Ausgehend von den primären Substitutionsprodukten BrCH3Sb—M(CO)3π-C5H5 (M=Mo, W) Können die heteronuclearen Spezies π-C5H5(CO)Cr—Sb(CH3)—M(CO)3π-C5H5 (M=Mo, W) und π-C5H5(CO)3Mo—Sb(CH3)—W(CO)3π-C5H5 erhalten werden. Reaktionen mit Alkylhalo-geniden verlaufen unter Quartärisierung am Sb-Atom oder Spaltung der Sb—M-Einheit. Im ersten Fall werden metallsubstituierte Sb-Kationen der Form [{π-C5H5(CO)3M}2Sb(CH3)R]⊕; (M=Mo, W; R=CH3, C2H5, C6H5CH2) gebildet, die auch aus monometalliertem Stibin und komplexem Metallhalogenid zugänglich sind [z. B. π-C5H5(CO)3MoSb(CH3)2 und π-C5H5(CO)3MoBr]. Die Einwirkung von Brom verläuft unter Addition am VB-Element und liefert Übergangsmetallderivate mit vermutlich pentakoordiniertem Antimon([π-C5H5(CO)3W]2sbCH3Br2). Die chemischen und spektroskopischen Eigenschaften der neuen Antimon-Übergangsmetallkomplexe werden beschrieben.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19751080236
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  • 56
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    Übergangsmetall-substituierte VB-Elementsysteme, VI. Bis(VIA-metall)methylstibine als monofunktionelle Ligandsysteme in Übergangsmetallkomplexen (1975)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 716-723 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Transition Metal Substituted VB Element System. Bis(VIA metal)methylstibines as Monofunction Ligands in Transition Metal ComplexesThe photochemical or thermal reaction of the metal corbonyls M(CO)6 (M=Cr, Mo, W), π-C5H5Mn(CO)3, and Fe2(CO)9 with the dimetalated stibines CH3Sb-[M′(CO)3π-C5H5]2 (M′=Cr, Mo, W) proceeds with elimination of CO or Fe(CO)5, yielding the neutral single antimony-bridged trinuclear complexes (CO)5M—Sb(CH3)[M′L4]2, π-C5H5(CO)2Mn—Sb(CH3)[M′L4]2, and (CO)4Fe-Sb(CH3)[M′L4]2. The new compounds are characterized by means of spectroscopy.
    Notes: Die photochemische bzw. thermische Umsetzung der Metallcarbonyle M(CO)6 (M=Cr, Mo, W), π-C5H5Mn(CO)3 und Fe2(CO)9 mit den dimetallierten Stibinen CH3Sb-[M′(CO)3π-C5H5]2 (M′=Cr, Mo, W) liefert unter Eliminierung von CO bzw. Fe(CO)5 die neutralen, einfach antimonverbrückten Dreikernkomplexe (CO)5M—Sb(CH3)[M′L4]2, π-C5H5(CO)2Mn—Sb(CH3)[M′L4])2 und (CO)4Fe—Sb(CH3)[M′L4]2, Die neuen Verbindungen werden spektroskopisch charakterisiert.
    Additional Material: 3 Tab.
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    URL: http://dx.doi.org/10.1002/cber.19751080237
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    Polyacetylenverbindungen, 232. Weitere Inhaltsstoffe der Gattung Dendranthema (1975)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 735-738 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Polyacetylenic Compounds, 232. Further Constituents of the Genus DendranthemaThe genus Dendranthema, also listed as a section of Chrysanthemum, is characterized by the occurrence of 6-ring-enol ether polyynes. The structure of three new compounds has been elucidated (10-12).
    Notes: Die auch als Sektion von Chrysanthemum geführte Gattung Dendranthema ist durch das Vorkommen von 6-Ring-enolätherpolyinen charakterisiert. Drei neue Verbindungen werden in ihrer Konstitution geklärt (10-12).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19751080304
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  • 58
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    Die Ozonolyse von 3,4-cis-Diacetyl-1,2,3,4-tetramethyl-1-cyclobuten (1975)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 749-753 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Ozonolyse of 3,4-cis-Diacetyl-1,2,3,4-tetramethyl-1-cyclobuteneThe ozonolysis of the title compound 3 gives an ozonide (9) with trans-acetyl groups in high yield. Only a two step transformation of the primary ozonide to the final ozonide via a well defined intermediated (5) can explain this result.
    Notes: Die Tasache, daß die Ozonolyse der Titelsubstanz 3 in CFCl3 in hoher Ausbeute ein Ozonid (9) mit trans-ständigen Acetylgruppen liefert, bewiest, daß der Übergang vom Primärozonid zum Ozonid nicht einstufig, sondern über ein definiertes Zwischenprodukt (5) verläft.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19751080307
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    Untersuchungen an Stoffwechselprodukten von Mikroorganismen, VIII. Aldgamycin F, ein neues Antibiotikum aus Streptomyces lavendulae (1975)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 780-789 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Investigation on Metabolites of Microorganisms, VIII. Aldgamycin F, a New Antibiotic from S. lavendulaeThe new antibiotic aldgamycin F was isolated from cultures of S. lavendulae, for which we suppose structure. 7.
    Notes: Aus Kulturen von S. lavendulae wurde das neue Antibiotikum Aldgamycin F isoliert, für das wir Struktur 7 vorschlagen.
    Additional Material: 5 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19751080311
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  • 60
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    Die Stereochemie der Spaltung chiraler acyclischer quartärer Phosphoniumsalze zu tertiären Phosphinoxiden mit Alkalialkoholat (1975)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 803-812 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Stereochemistry of the Alkali Alcoholate-induced Fission of Chiral Acyclic Quaternary Phosphonium Salts to Tertiary Phosphine OxidesThe stereochemical course of the sodium ethanolate-induced fission of chiral acyclic quaternary phosphonium salts 1-5 to tertiary phosphine oxides 6-10 is (with one exception) the same as that of the cleavage of these salts by sodium hydroxide. However, in most cases the stereoselectivity is remarkably lower in the alcoholate-induced fission than in the reaction with sodium hydroxide.
    Notes: Die beobachtete Brutto-Stereochemie der Spaltung chiraler acyclischer quartärer Phosphoniumsalze 1-5 zu tertiären Phosphinoxiden 6-10 mittels Natriumäthylat ist  -  mit einer Ausnahme  -  prinzipiell die gleiche wie bei der Spaltung der betreffenden Salze mit Natrium-hydroxid. Die Stereoselektivität ist dagegen bei der Spaltung mit Alkoholat meist deutlich geringer als bei der Reaktion mit Natriumhydroxid.
    Additional Material: 3 Tab.
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    URL: http://dx.doi.org/10.1002/cber.19751080313
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    Die Primärprodukte der Carbonsäurehydrazid/Chlorphosphoran-Reaktion: 1,3,4,2λ5-Oxadiazaphospholine (1975)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 820-830 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Primary Products of the Carbohydrazide/Chlorophosphorane Reaction:. 1,3,4,2λ5-OxadiazaphospholinePhosphorus pentachloride and other at least difunctional chlorophosphoranes react with acylhydrazines and with N-acyl-N′-phenylhydrazines to give 1,3,4,2λ5-oxadiazaphospholines 3. Pentacoordination at phosphorus is unexpected stable in these rings. The compounds are characterized by n. m. r. and mass spectrometry. They are more or less thermolabile and decompose eliminating phosphine oxide or a phosphorus oxide chloride. Electron releasing substituents at the phosphorus and electron withdrawing substituents at the nitrogen atom increase the rate of decomposition. With triethylamine the compounds 3 loose hydrogen chloride and yield the dimers 4 of 1,3,4,2λ5-oxadiazaphospholes.
    Notes: Phosphorpentachlorid und andere mindestens difunktionelle Chlorphosphorane reagieren mit Acylhydrazinen sowie N-Acyl-N′-phenylhydrazinen zu den 1,3,4,2λ5-Oxadiazaphospholinen 3 mit unerwartet stabiler Pentakoordination am Phosphor. Die Verbindungen werden NMR- und massenspektrometrisch charakterisiert. Sie sind mehr oder weniger thermolabil und zerfallen unter Abspaltung von Phosphinoxid bzw. eines Phosphoroxidchlorids. Der Einfluß der P-, C- und N-ständigen Substituenten auf die Zerfallsgeschwindigkeit wird diskutiert. Triäthylamin spaltet aus 3 Chlorwasserstoff ab; es entstehen Dimere 4 der 1,3,4,2λ5-Oxadiazaphosphole.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19751080315
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    Vier Synthesewege zu (2-Pyrimidinylamino)-n-alkansäuren (1975)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 862-874 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Four Routes for the Synthesis of (2-Pyrimidinylamino)-n-alkanoic AcidsNucleotide analogues of amino acids with variously substituted 2-pyrimidinyl side chains are available by four synthetic routes. 1) The cyclocondensation of 2-alkyl-3-aminoacroleins (4) with amino acids containing guanidino functions (5b) gives Nδ-(5-alkyl-2-pyrimidinyl)ornithine derivatives (7). 2) Cyclocondensations of 1,3-diketones of (9) with C-(guanidino)amino acids or N-(amidino)amino acids (5a-d) yield (4,6-dialkyl-2-pyrimidinylamino)-n-alkanoic acids (10). 3) (4-Alkyl-6-oxo-1,6-dihydro-2-pyrimidinylamino)-n-alkanoic acids (13) are obtained by way of cyclocondensation of ethyl acetoacetate (12) with 5a-c. 4) The nucleophilic substitution of 2-ethylthio-6-oxo-1,6-dihydropyrimidines (14, 17) by mono- and diamino acids (15) yields (5-alkyl-6-oxo-1,6-dihydro-2-pyrimidinylamino)- and (4-alkyl-6-oxo-1,6-dihydro-2-pyrimidinylamino)-n-alkanoic acids (16, 18).
    Notes: Nucleotid-analoge Aminosäuren mit verschieden substituierten 2-Pyrimidinyl-Seitenketten sind auf vier Wegen zugänglich: Die Cyclokondensation von 2-Alkyl-3-aminoacroleinen (4) mit Aminosäuren mit Guanidinofunktion (5b) führt zu Nδ-(5-Alkyl-2-pyrimidinyl)ornithin-Derivaten (7). Cyclokondensationen von 1,3-Diketonen (9) mit C-(Guanidino)aminosäuren bzw. N-(Amidino)aminosäuren (5a-d) liefern (4,6-Dialkyl-2-pyrimidinyiamino)-n-alkansäuren (10). Durch Cyclokondensationen von Acetessigester (12) mit 5a-c sind (4-Alkyl-6-oxo-1,6-dihydro-2-pyrimidinylamino)-n-alkansäuren (13) darstellbar. Aus 2-Äthylthio-6-oxo-1,6-dihydropyrimidinen (14, 17) lassen sich durch nucleophile Substitution mit Mono- und Diaminosäuren (15) (5-Alkyl-6-oxo-1,6-dihydro-2-pyrimidinylamino)- sowie (4-Alkyl-6-oxo-1,6-dihydro-2-pyrimidinylamino)-n-alkansäuren (16, 18) erhalten.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19751080319
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    Photoelektronenspektren und Moleküleigenschaften, XLV. Schwefelsäure-Derivate : Alkyl-, Vinyl- und Arylsulfone, Alkylsulfoimide und Sulfurylhalogenide (1975)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 897-913 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Photoelectron Spectra and Molecular Properties, XLV. Sulfuric Acid Derivatives : Alkyl, /Vinyl, and Aryl Sulfones, S,S-Dialkylsulfoimides and Sulfuryl HalidesThe photoelectron (PE) spectra of the following sulfuric acid derivatives are discussed comparatively using qualitative MO models supported by modified CNDO calculations. The substituent effects  -  including the isoelectronic exchange S=O → S=NH and structural modifications  -  can be summarized in correlation diagrams and rationalized as perturbations of the ++ group.
    Notes: Die Photoelektronen(PE)-Spektren der folgenden Schwefelsäure-Derivate werden mit qualitativen MO-Modellen, gestützt auf modifizierte CNDO-Rechnungen, vergleichend diskutiert. Die Substituenten-Effekte - den isoelektronischen Austausch S=O → S=NH und Strukturänderungen eingeschlossen  -  lassen sich in Korrelationsdiagrammen zusammenfassen und als Störungen der -Gruppe betrachten.
    Additional Material: 11 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19751080322
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    Gekoppelte Elektrodenreaktionen, II. Benzonitril als Reaktionsmedium für anodisch erzeugte Carbeniumionen (1975)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 967-972 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Coupled Electrode Reaction, II. Benzonitrile as a Reaction Medium for Anodically Generated Carbenium IonsBy electrolysis of pivalic acid and isobutyric acid in benzonitrile/isopropyl alcohol in undivided cells N alkylated benzylamines and N,N′-diisopropyl-1,2- diphenylethylenediamine are isolated in a total yield up to 60 percent of the condensed reaction products. The reaction path is explained by anodically generated carbenium ions which react with bezonitrile forming nitrilium ions 3. These are reduced at the cathode (6, 8) or are hydrodimerized (7). The details and the formation of by-products are discussed.
    Notes: Bei der Elektrolyse von Pivalinsäure und Isobuttersäure in Benzonitril/Isopropylalkohol in ungeteilten Zellen werden in einer Gesamtausbeute bis zu 60% der kondensierten Reaktions-produkte N-alkylierte Benzylamine und N,N′-Diisopropyl-1,2-dipnhenyläthylendiamin isoliert. Der Reaktionsverlauf wird über anodisch erzeugte Carbeniumionen erklärt, die mit Benzonitril zu Nitriliumionen 3reagieren. Diese werden an der Kathode reduziert (6, 8) oder hydrodimerisiert (7). Die Einzelheiten und die Bildung von Nebenprodukten werden besprochen.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19751080329
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    Masthead (1975)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975) 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19751080401
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    Natürlich vorkommende Terpen-Derivate, XLIII. Neue Sesquiterpenlactone aus Athanasia-Arten (1975)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 357-361 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Naturally Occurring Terpene Derivatives, XLIII. New Sequiterpene Lactones from Athanasia SpeciesThe investigation of four further Athanasia species shows that furansesquiterpenes of the type 1-4 are characteristic for this genus. Besides known compounds five new sesquiterpene lactones have been isolated and their structures elucidated (6, 7, 9, 10 and 13). The close biogenetic relationships of these lactones to already known sesquiterpenes are apparent.
    Notes: Die Untersuchung von vier weiteren Athanasia-Arten zeigt, daß Furansesquiterpene vom Typ 1-4 für diese Gattung charakteristisch sind. Neben bereits bekannten Verbindungen werden fünf neue Sesquiterpenlactone isoliert und in ihrer Konstitution aufgeklärt (6, 7, 9, 10 und 13). Die engen biogenetischen Beziehungen dieser Lactone zu bereits bekannten Sesquiterpenen sind offensichtlich.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19751080144
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  • 67
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    Hydrogenolyse kleiner Kohlenstoffringe, II. Über die Hydrierung von Basketan- und Snoutanderivaten (1975)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 337-356 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Hydrogenolysis of Small Cycloalkanes, II. hydrogenation Basketane- and Snoutane-Derivativescis- and both trans-dimethyl twistane-4,5-dicarboxylates (9 and 11, 13) are formed via the dihydro intermediates 4-7 by hydrogenation of cis- and trans-dimethyl basketane-9,10-dicarboxylates (1 and 3) over Pd/C under normal conditions. During the uptake of the first mole-equivalent of hydrogen all the basketane derivatives were rearranged to snoutane derivatives (22 and 24) to some extent. The second C—C bond is cleaved on that side of the basketane skeleton, which is opposite to the first hydrogenated one. cis- and trans-dimethyl snoutane-9,10-dicarboxylates (22 and 24) were hydrogenated under the same conditions but more slowly via the dihydro derivatives (25, 27 and 29, 31) to yield cis- and trans-dimethyl isotwistanedicarboxylates (33 and 35). In snoutane derivatives the second cyclopropane ring is cleaved exclusively from the same side of the molecule as the first one. This is shown by separate hydrogenations of dihydro snoutane derivatives (27, 37 and 38). Hydrogenation of basketene (21) provides a mixture containing 70-75% of twistane (17) and 25-30% of isotwistane (39). The reasons for the different ways of hydrogenation in both systems are discussed. The configurations of all dihydro intermediates and endproducts have been established.
    Notes: cis- und trans-Basketan-9,10-dicarbonsäure-dimethylester (1 und 3) werden unter Normal-bedingungen mit Pd/C in Methanol über die isomeren Dihydrozwischenstufen (4-7) zu cis- und den beiden trans-Twistan-4,5-dicarbonsäure-dimethylestern (9 und 11, 13) hydriert. Bei der Hydrogenolyse der ersten C—C-Bindung erfolgt teilweise Umlagerung zu Snoutanderivaten (22 und 24). Die Öffnung der zweiten Bindung am Basketangerüst geschieht ausschließlich an der zur ersten hydrierten Bindung gegenüberliegenden Molekülseite. cis- und trans-Snoutan-9,10-dicarbonsäure-dimethylester (22 und 24) reagieren unter den gleichen Bedingungen ebenfalls, aber langsamer, über die Zwischenstufen (25, 27 und 29, 31) zu cis- und trans-Isotwistan-dicarbonsäure-dimethylester (33 und 35). An den getrennt untersuchten Zwischenstufen 27, 37 und 38 wird gezeigt, daß im Snoutangerüst beide Cyclopropanringe ausschließlich von der gleichen Molekülseite angegriffen werden. Aus Basketen (21) erhält man bei der Hydrierung ein Gemisch von 70-75% Twistan (17) und 25-30% Isotwistan (39). Die Ursachen für den verschiedenen Hydrierungsverlauf in beiden Systemen werden erörtert, und die Konfiguration aller Zwischenstufen und Endprodukte wird aufgeklärt.
    Additional Material: 2 Tab.
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    URL: http://dx.doi.org/10.1002/cber.19751080143
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    Die Synthese von 5α-Stigmasta-22,25-dien-3β-ol, 5α-Stigmast-22-en-3β-ol und 5α-Stigmastan-3β-ol und ihren 24-Epimeren (1975)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 1101-1110 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Synthesis of 5α-Stigmasta-22,25-dien-3β-ol, 5α-Stigmast-22-en-3β-ol und 5α-Stigmastan-3β-ol and their 24-EpimersThe synthesis of the title compounds from butynylcarbinols 5 with 1-dimethylamino-1-methoxy-1-propene in a Claisen rearrangement via the amides 7 is described. An effective preparation of the starting materials is given and the data of the products are compared with those from natural sterols.
    Notes: Die Synthese der Titelverbindungen aus den Butinylcarbinolen 5 mit 1-Dimethylamino-1-methoxy-1-propen in einer Claisen-Umlagerung über die Amide 7 wird beschrieben. Eine effektive Darstellung der Ausgangsverbindungen wird angegeben, und die Daten der Produkte werden mit den aus Naturstoffen gewonnenen verglichen.
    Additional Material: 2 Tab.
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    URL: http://dx.doi.org/10.1002/cber.19751080415
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    Aromatische Diazoniumsalze, VI; Nitroso-acyl-amine und Diazoester, XIV Eine neue Reaktionsweise des N-Nitrosoacetanilids (1975)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 1027-1035 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Aromatic Diazonium, VI; Nitrosoacylamines and Diazoesters, XIV A New Reaction Mode of N-NitrosoacetanilideA side reaction in the decomposition on N-nitrosoacetanilide in ethanol/potassium acetate, which has been described to produce a salt K[C8H8N3O3]6), was reinvestigated. It is probale that this compound is formed by a free radical addition of NO to the nitroso group of N-nitrosoacetanilide and subsequent reduction. The potassium salt and the corresponding silver salt are considered to be derived from N-nitroso-N-(N-phenylacetamido)hydroxylamine (7) in agreement with spectroscopic data. Dynamic n. m. r. allows to measure a rotation process with ΔG≠ = 16.0 and ΔG° = 0.6 kcal/mole.
    Notes: Eine früher beschriebene6) Nebenreaktion beim Zerfall des N-Nitrosoacetanilids in Äthanol/Kaliumacetat, die zur Bildung eines Salzes K[C8H8N3O3] führte, wurde erneut untersucht. Es ist wahrscheinlich, daß diese Verbindung durch radikalische Addition von NO an die Nitrosogruppe des N-Nitrosoacetanilids und anschließende Reduktion entsteht. Das Kaliumsalz und ein entsprechendes Silbersalz werden in Übereinstimmung mit spektroskopischen Daten als Salze des N-Nitroso-N-(N-phenylacetamido)hydroxylamins (7) formuliert. Die NMR-Linienformanalyse gestattet die Messung einer Rotationsschwelle mit ΔG≠ = 16.0 und ΔG° = 0.6 kcal/ mol.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19751080407
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    Reaktionen mit Derivaten aus der (CH)8CH2-Reihe; der dirigierende Einfluß von Substituenten bei der Photolyse einiger cis-3a, 7a-Dihydroindene (1975)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 1052-1073 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions with Derivatives of the (CH)8CH2-Family; the Governing Influence of Substituents on the Photolysis of Several cis3a,7a-DihydroindenesOn photochemical or thermal activation the tricyclo[4.3.0.02,5]nonadienes 10, 12, 14a, b, 16 are transformed to the cis-dihydroindenes 11, 13, 15a, b, 17. As determined by the reaction halflives at 120 and 153°C, respectively, the thermal stability of the starting compounds decreases in the order 14b 〉 14a ⋍ 16 〉 12 〉 10; steric reasons are discussed as a possible explanation for this sequence. Cycloaddition reaction of 11, 13, 15a, b, (17 is unreactive) with maleic anhydride and 4-phenyl-1,2,4-triazoline-3,5-dione, respectively, yield the adducts 21(21′)a, b, 22a, b, 24 and 25 for which the endo-configuration of the carbocyclic five-membered ring with respect to the C-8/C-9 double bond is unambigously proven at least in the case of 22a, b by formation of the cagephotoproducts 23a, b. Irradiation of the dihydroindenes involves different pathways: while excitation of 13 leads back to the tricyclic diene 12 the tetraesters 15a, b are converted to the intramolecular cyclization products 28a, b, and the diphenyl-compound 17 undergoes phenyl migration affording the di-π-methane isomer 30; all reactions proceed in a specific manner and only under direct irradiation conditions.
    Notes: Die Tricyclo[4.3.0.02,5]nonadiene 10, 12, 14a, b, 16 wandeln sich bei photochemischer oder thermischer Aktivierung in die cis-Dihydroindene 11, 13, 15a, b, 17 um. Aus den bei 120 bzw. 153°C ermittelten Halbwertszeiten der Isomerisierungen ergibt sich für die Ausgangsverbindungen eine in der Reihenfolge 14b 〉 14a ⋍ 16 〉 12 〉 10 abnehmende thermische Stabilität; als Ursache hierfür werden sterische Faktoren diskutiert. Cycloadditonen von Maleinsäureanhydrid bzw. 4-Phenyl-1.2.4-triazolin-3.5-dion an 11, 13, 15a, b (17 reagiert nicht) liefern die Addukte 21(21′)a,b, 22a,b,24 und 25 für welche die endo-Anordnung des carbocyclischen Fünfrings bezüglich der C-8/C-9-Doppelbindung zumindest für 22,a b duch die photochemische Bildung der Käfigverbindungen 23a, b, gesichert ist. Ber der Belichtung der Dihydroindene ist das Ergebnis sehr unterschiedlich: während der Diester 13 den Tricyclus 12 zurückbildet, werden die Tetraester 15a, b in einer intramolekularen Cyclisierung zu 28a, b und das Diphenyl-Substrat 17 in einer Di-π-Methan-Umlagerung zu 30 umgewandelt; alle Reaktionen verlaufen spezifisch und nur unter direkten Bestrahlungsbedingungen.
    Additional Material: 6 Tab.
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    URL: http://dx.doi.org/10.1002/cber.19751080411
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    Neue Derivate des Fluorenon-hydrazons (1975)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 1138-1141 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: New Fluorenone Hydrazone DerivativesThe triaminoguanidines 3a and b and N-[bis(methylthio)methylene]-N′-fluorenylidenehydrazine (4) have been synthesized. Compound 4 reacted with amines and hydrazine hydrate to give S-methylisothioureas (5), aminoguanidines (6), and triaminoguanidines (7), respectively.
    Notes: Es wurden die Triaminoguanidine 3a und b sowie das N-[Bis(methylthio)methylen]-N′-fluorenylidenhydrazin (4) synthetisiert. Die Reaktion von 4 mit Aminen bzw. Hydrazinhydrat führte in die Reihe der S-Methylisothioharnstoffe (5), Aminoguanidine (6) und Triaminoguanidine (7).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19751080420
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    Umsetzungen N-substituierter Amidine mit Heterokumulenen, V. Umsetzungen mit Isothiocyanaten und Isocyanaten (1975)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 1142-1155 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reaction of N-Substituted Amidines with Heterocumulenes, V. Reactions with Isothiocyanates and IsocyanatesN1, N2-Dialkyl-substituted amidines (e.g. 1) react with methyl isothiocyanate at room temperature to give thiocarbamoylamidines (e. g. 6) without an intramolecular hydrogen bond, whereas at elevated temperatures cyclic 1: 2-adducts (30-32) are formed. Aromatic isothiocyanates yield exchange products (34-37), whereas cyclic amidines (15-17) yield thiocarbamoylamidines (20, 26, 27) with intramolecular NH…N-bridges because of lower steric hindrance around R2. - The reaction between N1, N2-dialkyl-substituted amidines and isocyanates in the presence of larger groups R2 or strongly electron-withdrawing groups R5 yields only instable carbamoylamidines. The zwitter-ion intermediate (4) then undergoes an intramolecular reaction to give exchange products or adds a dipolarophile to yield 1,3,5-triazacyclohexane derivatives (46, 47, 51-54). These products are not formed when attack on C-2 is rendered considerably more difficult by R2 (tert-C4H9) (43, 56) or when R2=CH3 favours the formation of a very strong hydrogen bond (55).
    Notes: N1, N2-Dialkylsubstituierte Amidine (z. B. 1) reagieren mit Methylisothiocyanat bei Raumtemperatur zu Thiocarbamoylamidinen ohne intramolekulare Wasserstoffbrücke (z. B. 6), bei höheren Temperaturen zu cyclischen 1:2-Addukten (30-32). Aromatische Isothiocyanate führen zu Austauschprodukten (34-37), cyclische Amidine (15-17) geben dagegen Thiocarbamoylamidine (20, 26, 27) mit intramolekularen NH…N-Brücken infolge sterischer Entlastung um R2.  -  Die Umsetzung N1, N2-dialkylsubstituierter Amidine mit Isocyanaten führt in Gegenwart größerer Reste R2 oder stark elektronenabziehender Substituenten R5 nur zu instabilen Carbamoylamidinen. Das intermediär entstehende Zwitterion (4) reagiert dann intramolekular zu Austauschprodukten oder unter Anlagerung eines Dipolarophils zu 1,3,5-Triazacyclohexanderivaten (46, 47, 51-54). Diese Produkte werden nicht gebildet, wenn R2 (tert-C4H9) den Angriff an C-2 beträchtlich erschwert (43, 56) oder R2=CH3 die Ausbildung einer besonders festen Wasserstoffbrücke begünstigt (55).
    Additional Material: 5 Tab.
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    URL: http://dx.doi.org/10.1002/cber.19751080421
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    Lichtreaktionen mit Carbonsäurederivaten, IX. Abfangversuche mit photochemisch erzeugtem monoatomarem und diatomarem Schwefel. Schwefeladdition an 1,2-Dimethylencyclohexan. - Synthese von 1,4,5,6,7,8-Hexahydrobenzo[d][1,2]dithiin und 1,3,4,5,6,7-Hexahydrobenzo[c]thiophen (1975)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 630-639 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Photoreactions with Carbonic Acid Derivatives, IX. Experiments on the Capture of Photochemically Produced Monoatomic and diatomic sulfur-Sulfur Addition on 1,2-Dimethylenecyclohexane.-Synthesis of 1,4,5,6,7,8-Hexahydrobenzo-[d][1,2]dithiin and 1,3,5,6,7-Hexahydrobenzo[c]thiopheneIn addition to cis- and trans-2,3-diethoxy-2-butene (3) small amounts of 2,3-diethoxy-1-butene (6), 2,3-diethoxy-1,3-butadiene (7) and 1-ethoxy-1-ethanethiol (5) were found in the irradiation product of O-ethyl thioacetate. The produced sulfur adds to a slight extent to 1,2-Dimethylenecyclohexane giving 1,4,5,6,7,8-hexahydrobenzo[d][1,2]dithiin (8), 1,3,4,5,6,7-hexahydrobenzo-[c]thiophene (9) and 4,5,6,7-tetrahydrobenzo[c]thiophene (10). For definite identification of the reaction products 8, 9 and 10 were synthesized.
    Notes: Im Bestrahlungsprodukt von Thionessigsäure-äthylester (1) wurden neben cis- und trans-2,3-Diäthoxy-2-buten (3) in geringen Mengen noch 2,3-Diäthoxy-1-buten (6); 2,3-Diäthoxy-1,3-butadien (7) und α-Mercaptodiäthyläther (5) nachgewiesen. - Der gebildete Schwefel addiert sich in geringem Ausmaß an 1,2-Dimethylencyclohexan unter Bildung von 1,4,5,6,7,8-Hexahydrobenzo[d][1,2]dithiin (8), 1,3,4,5,6,7-Hexahydrobenzo[c]thiophen (9) und 4,5,6,7-Tetrahydrobenzo[c]thiophen (10). Zur sicheren Identifizierung der Reaktionsprodukte wurden 8, 9 und 10 synthetisiert.
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    URL: http://dx.doi.org/10.1002/cber.19751080229
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    Acylgruppenwanderung, V. Kinetische Daten der Acylgruppenwanderung von 2-Benzoyl-3-indenyl-acetat und 3-Benzoyl-2-indenyl-acetat (1975)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 683-692 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Acyl Group Migration, V. Kinetic Parameters of Acyl Group Migration in 2-Benzoyl-3-indeny Acetate and 3-Benzoyl-2-indenyl Acetate2-Acyl-1-indanones 6 and 8, obtained by ester condensation from 1-indanone, react with acetyl chloride to form the corresponding enolesters 7 and 9. In solution the Z-isomers, (Z)-2-(1-acetoxyethylidene)-1-indanone (7B) and (Z)-2-(1-acetoxybenzylidene)-1-indanone (9aB) as well as 9bB and 9cB show a rapid equilibrium by acetyl group migration with the 2-acyl-3-indenyl acetates 7C and 9C:7B ⇄ 7C, 9B ⇄ 9C. The isomerisation of the semicyclic C=C double bond 7B ⇄ 7A or 9B ⇄ 9A is catalysed photochemically. The kinetic parameters of the acetyl group migration have been determined by n. m. r. line-shape analysis for the isomeric enol esters 2-benzoyl-3-indenyl acetate (9aC) and 3-benzoyl-2-indenyl acetate (10C).
    Notes: Die durch Esterkondensation aus 1-Indanon erhaltenen 2-Acyl-1-indanone 6 und 8 werden mit Acetylchlorid in die zugehörigen Enolester 7 und 9 übergeführt. Die Z-Isomeren, (Z)-2-(1-Acetoxyäthyliden)-1-indanon (7B) und (Z)-2-(1-Acetoxybenzyliden)-1-indanon (9aB) sowie 9bB und 9cB liegen in Lösung durch schnelle Acetylgruppenwanderung im Gleich-gewicht mit den 2-Acyl-3-indenyl-acetaten 7C und 9C vor: 7B ⇄ 7C bzw. 9B ⇄ 9C. Die Isomerisierung der semicyclischen C=C-Doppelbindung 7B ⇄ 7A bzw. 9B ⇄ 9A wird photochemisch erreicht. Durch eine NMR-Linienformanalyse wurden die kinetischen Daten der Acetylgruppenwanderung am Beispiel der beiden isomeren Enolester 2-Benzoyl-3-indenylacetat (9a C) und 3-Benzoyl-2-indenyl-acetat (10 C) ermittelt.
    Additional Material: 2 Tab.
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    URL: http://dx.doi.org/10.1002/cber.19751080234
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    Notiz über Donor-Akzeptor-komplexe zwischen Organylhalogenboranen und Diorganylchalkogenen (1975)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 724-726 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Tab.
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    URL: http://dx.doi.org/10.1002/cber.19751080238
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    Abfangreaktionen kurzlebiger Radikale, XII Über die radikalische substitution am Schwefel: Induzierter Zerfall von (Thio)Carbonyldisulfiden (1975)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 1339-1345 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions of Short-Life Radicals, XII. Free Radical Substitution at the Sulfur Atom: The Induced Degradation of (Thio)Carbonyl DisulfidesDibenzoyl, diacetyl, bis(thiobenzoyl) disulfide (1, 2, 7), and benzoyl 4-tolyl disulfide (11) are degradated by hydrides R3SnH at 60°C about 103 times faster than in the spontaneous degradation. The products and following reactions have been established. In all cases, SH2 mechanisms are found, with attack of stannyl radicals at the (acyl bound) sulfur atom. In the case of 1, 2 and 11, ΔHspont.≠ is 35 or 34 ± 2 kcal/mole at 150°C.
    Notes: Dibenzoyl-, Diacetyl-, Bis(thiobenzoyl)disulfid (1, 2, 7) und Benzoyl(4-tolyl)disulfid (11) werden durch Hydride R3SnH bei 60°C im Verhältnis zum Spontanzerfall etwa um den Faktor 103 rascher abgebaut. Produkte und Folgereaktionen werden sichergestellt. Es liegen jeweils SH2-Mechanismen mit Angriff von Stannyl-Radikalen am (acylseitigen) Schwefel vor. Bei 1, 2 und 11 ist ΔH spont.≠ = 35 bzw. 34 ± 2 kcal/mol bei 150°C.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19751080439
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    Kristall- und Molekülstruktur von Bis(triphenylphosphin)iminium-tetracarbonylpropylferrat,[{(C6H5)3P}2N] [Fe(CO)4C3H7] (1975)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 1373-1383 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Crystal and Molecular Structure of Bis(triphenylphosphine)iminium Tetracarbonylpropyliron, [{(C6H5)3P}2 N] [Fe(Co)4C3H7]The crystal and molecular structure of the title compound has been determined by X-ray diffraction methods. The yellow salt crystallizes in the monoclinic space group C2/c with 8 molecules per cell. The structure was solved by conventional methods (agreement factor R1 = 0.07). Within the trigonal bipyramidal coordination polyhedron of the [Fe(CO)4C3H7] anion, the propyl group occupies an axial position. The bond length Fe-Cpropyl is 220(2) pm, the Fe-Cco distances are equal within experimental error (mean value 175(2) pm). The distances within the [{(C6H5)3P}2N] cation are similar to those found for the same ion in different crystalline salts. However, unexpectedly, an hitherto unknown new conformation is observed for the cation.
    Notes: Die Kristall- und Molekülstruktur der Titelverbindung wurde durch Röntgenbeugungsanalyse bestimmt. Das gelbe Salz kristallisiert in der monoklinen Raumgruppe C2/c mit 8 Molekülen in der Elementarzelle. Die Lösung der Struktur erfolgte mit konventionellen Methoden (Übereinstimmungsfaktor R1 = 0.07). Im [Fe(CO)4C3H7]-Anion besetzt die Propylgruppe eine axiale Position des trigonal-bipyramidalen Koordinationspolyeders um das Eisen. Die Fe-CPropyl-Bindungslänge beträgt 220(2) pm, die Fe-Cco-Abstände sind innerhalb der Fehlergrenzen gleich lang (Mittelwert: 175(2) pm). Die Abstände innerhalb des [{(C6H5)3P}2N]-Kations unterscheiden sich nicht von denen, die für das gleiche Ion in verschiedenen kristallinen Salzen gefunden wurden; unerwarteterweise liegt das Kation jedoch in einer neuen, bislang unbekannten Konformation vor.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19751080504
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    Reaktionen mit Cyclobutendionen, XXXVII. Umsetzungen des (2,5-Dimethoxyphenyl)phenyl- und des Diphenylcyclobutendions mit Diazoalkanen. Ein Beitrag zur Isomerie der möglichen 1-Pyrazoline (1975)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 1413-1420 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions with Cyclobutenediones, XXXVII. Reactions of (2,5-Dimethoxyphenyl)phenyl-and Diphenylcyclobutenedione with Diazoalkanes. A Contribution to the Study of Isomerism of Possible 1-Pyrazolines(2,5-dimethoxyphenyl)phenylcyclobutenedione (7) reacts with diazomethane to give only 3a-(2,5-Dimethoxyphenyl)-4-methoxy-6-oxo-6a-phenyl-3,3a,6,6a-tetrahydrocyclopentapyrazole (8a). In glacial acetic acid 8a isomerizes to the 2-pyrazoline 9a. Diphenylcyclobutenedione (1) reacts with diazoethane to yield the diastereomeric 1-pyrazolines 10 and 11. These two compounds isomerize in glacial acetic acid to form the same 2-pyrazoline 12 and react with acetyl chloride to give the same N-acetyl derivative 13. In xylene 10 reacts to form the 4-ethoxy-3,6-dimethyl-1,5-diphenylbicyclo[3.1.0]hex-3-en-2-one (14), while in boiling tetrahydronaphthalene 10 gives two isomeric phenols 16 and 18.
    Notes: (2,5-Dimethoxyphenyl)phenylcyclobutendion (7) reagiert mit Diazomethan in Benzol ausschließlich zu 3a-(2,5-Dimethoxyphenyl)-4-methoxy-6-oxo-6a-phenyl-3,3a,6,6a-tetrahydrocyclopentapyrazol (8a). Dieses kann in Eisessig zum 2-Pyrazolin 9a umgelagert werden. Diphenylcyclobutendion (1) reagiert mit Diazoäthan zu zwei diastereomeren 1-Pyrazolinen 10 und 11. Beide ergeben in Eisessig das gleiche 2-Pyrazolin 12 sowie mit Acetylchlorid das N-Acetyl-Derivat 13. In Xylol wird 10 in das 4-Äthoxy-3,6-dimethyl-1,5-diphenylbicyclo[3.1.0]hex-3-en-2-on (14) und in Tetralin in die isomeren Phenole 16 und 18 übergeführt.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19751080508
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  • 79
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    Über Phosphazene, LII. Disproportionierung von PCl3 und CH3PCl2 bei der Cyclokondensation mit einem Amino-di(phosphazen) (1975)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 1454-1459 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Phosphazenes, LII. Redox Disproportionation of PCl3 and CH3PCl2 during the condensation with an Aminodi(phosphazene)In a condensation and concomitant redox disproportionation CH3PCl2 and PCl3 convert the NPNPN chain of bis(aminodiphenylphosphorus) nitride chloride 6 into six-membered rings. 2-Chloro-2-methylcyclotri(phosphazene) 12 and spirobi[cyclotri(phosphaza)]pentaene 8 (as hydrochloride 7, X = Cl) are obtained, respectively. An intermediate of the spirophosphazene formation is the chloro-hydrido-λ5- or the λ3-phosphazene 4, X = Cl, or 5, respectively. It is of importance, that the second rings starts to form before the spiro center is oxidized. Competing oxidation by CCl4 leads to the gem. dichlorophosphazene 13, which enters no further reaction.
    Notes: Unter gleichzeitiger Redoxdisproportionierung schließen CH3PCl2 und PCl3 die NPNPN-Kette von Bis(aminodiphenylphosphor)nitridchlorid 6 zum Sechsring. Es entsteht das 2-Chlor-2-methyl-cyclotri(Phosphazen) 12 bzw. das Spirobi[cyclotri(phosphaza)]pentaen 8 (als Hydrochlorid 7, X = Cl). Zwischenstufe der Spirophosphazen-Bildung ist das Chlor-hydrido-λ5-oder das λ3-Phosphazen 4, X = Cl, bzw. 5. Wesentlich ist, daß die Angliederung des zweiten Rings noch vor der Oxidation des Spirozentrums eingeleitet wird. Die konkurrierende Oxidation mit CCl4 führt zum gem. Dichlorphosphazen 13, das nicht mehr weiterreagiert.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19751080513
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  • 80
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    Gehinderte Ligandbewegung in Übergangsmetallkomplexen, IV. 13C-NMR-Studien an Tricarbonyl-η6-cyclopolyen-Komplexen der Elemente der VI. Nebengruppe (1975)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 1502-1510 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Hindered Ligand motion in Transition Metal Complexes, IV 13C N.M.R. Studies on Tricarbonyl-η6 -cyclopolyene complexes of the VIB ElementsThe 13C n.m.r. spectra of some tricarbonyl-n6-cyclopolyene complexes of the VIB elements with the cyclopolyenes 1,3,5-cycloheptatriene, 1,3,5-cyclooctatriene, and 1,3,5,7-cyclooctatetraene are reported. Two novel ligand movements have been detected in this group of half-sandwich complexes: 1. A hindered rotation of the cyclopolyene ligands around the prolonged threefold axis of the tricarbonylmetal groups with free energies of activation from 11.3 to 12.7 ± 0.3 kcal/mole. 2. The 1,3,5-cyclooctatriene ligand in C8H10Cr(CO)3 is frozen at - 120°C into a chiral conformation. The enantiomers can be interconverted over an energy barrier of 8.3 ± 0.1 kcal/mole.
    Notes: Die 13C-NMR-Spektren einiger Tricarbonyl-η6-cyclopolyen-Komplexe der Elemente der VI. Nebengruppe mit den cyclopolyenen 1,3,5-Cycloheptatrien, 1,3,5-Cyclooctatrien und 1,3,5,7-Cyclooctatetraen werden beschrieben. Zwei neuartige Ligandbewegungen konnten an dieser Gruppe von Halbsandwichkomplexen nachgewiesen werden: 1. Eine gehinderte Rotation der Cyclopolyenliganden um die verlängerte dreizählige Achse der Tricarbonylmetallgruppen mit freien Aktivierungsenthalpien von 11.3 bis 12.7 ± 0.3 kcal/mol. 2. Der.1,3,5-Cyclooctatrienligand in C8H10Cr(CO)3 ist bei - 120°C in einer chiralen Konformation eingefroren. Die beiden Enantiomeren können über eine Energiebarriere von 8.3 ± 0.1 kcal/mol ineinander übergeführt werden.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19751080518
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  • 81
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    Heterocyclisierungen, XV. Über die Reaktion von 2,3,3-Trimethylindoleninen und 1-Methyl-3,4-dihydroisochinolin mit Acyliso(thio)cyanaten (1975)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 1541-1547 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Heterocyclizations, XV. The Reaction of 2,3,3-Trimethylindolenines and 1-Methyl-3,4-dihydroisoquinoline with Acyliso(thio)cyanates5-Methoxy- and 5-nitro-2,3,3-trimethylindolenines (7a, b) react with dielectrophilic iso(thio)cyanates to give the pyrimido[3,4-a]indoles 14, 15. Furthermore, 7a affords a dicarbamoylmethylene derivative 16, which undergoes cyclization to the pyrimidinylidene indole 17. 1-Methyl-3,4-dihydroisoquinoline (21) condenses with dielectrophilic iso(thio)cyanates to the pyrimido[6,1-a]isoquino-lines 24, hitherto unknown in this stage of saturation.
    Notes: 5-Methoxy- und 5-Nitro-2,3,3-trimethylindolenin (7a, b) reagieren mit dielektrophilen Iso(thio)-cyanaten zu den Pyrimido[3,4-a]indolen 14, 15. Darüber hinaus bildet 7a ein Dicarbamoyl-methylenindol 16, das zum Pyrimidinylidenindol 17 cyclisiert. 1-Methyl-3,4-dihydroisochinolin (21) liefert mit dielektrophilen Iso(thio)cyanaten die in der vorliegenden Sättigungsstufe noch nicht beschriebenen Pyrimido[6,1-a]isochinoline 24.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19751080523
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    Alkylierung von Polyphenolderivaten, III. 2,6-Di-n-alkyl-1,4-benzochinone mit langen Alkylketten (1975)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 1570-1579 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Alkylation of Polyphenol Derivatives, III. 2,6-Di-n-alkyl-1,4-benzoquinones with Long Alkyl ChainsThe syntheses of 1,4-benzoquinones 7, 13, and 23, substituted in the 2,6-positions with dodecyl residues, are described. The corresponding phenol ethers were acylated with dodecanoic acid/boron trifluoride and/or metalated and then alkylated with 1-bromododecane. The dialkylated phenol ethers 5, 11, and 20 were demethylated with boron tribromide and dehydrogenated to the corresponding benzoquinones with nitric acid or iron(III) sulfate, respectively.
    Notes: Es wird die Synthese der 2,6-Dodecyl-1,4-benzochinone 7, 13 und 23 beschrieben. Die Einführung der Dodecylreste erfolgte durch Acylierung entsprechender Phenoläther mit Dodecansäure/Bortrifluorid und/oder Metallierung der Phenoläther mit anschließender Alkylierung durch 1-Bromdodecan. Die dialkylierten Phenoläther 5, 11 und 20 wurden mit Bortribromid entmethyliert und mit Salpetersäure bzw. Eisen(III)-sulfat zu den Chinonen dehydriert.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19751080526
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  • 83
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    Ein einfacher Zugang zu 1-Azaspiro[5.5]undecanen (1975)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 1623-1629 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: A Simple Aproach to 1-Azaspiro[5.5]undecanesThe chemical behaviour and the synthesis of 1-azaspiro[5.5]undecane-2,7-diones 5 by Schmidt-reaction of alkyl 1-alkyl-2-oxo-1-cyclopentane carboxylates 3 to alkyl 2-alkyl-6-oxo-2-piperidine-carboxylates 4 and their cyclisation is described.
    Notes: Das chemische Verhalten und die Synthese der 1-Azaspiro[5.5]undecan-2,7-dione 5 durch Schmidt-Reaktion von 1-Alkyl-2-oxo-1-cyclopentancarbonsäure-alkylestern 3 zu 2-Alkyl-6-oxo-2-piperidin-carbonsäure-alkylestern 4 und deren Cyclisierung werden beschrieben.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19751080531
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  • 84
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    1,2,3-Butatrien durch Diels-Alder-Spaltung (1975)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 1655-1658 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 1,2,3-Butatrien durch Diels-Alder RetrogressionThe pyrolysis of 1 leads to indane (6), whereas 2,3, and 4 yield 1,2,3-butatriene (5) by a Diels-Alder-retrogression.
    Notes: Die Pyrolyse von 1 führt zu Indan (6), während 2,3 und 4 unter Diels-Alder-Spaltung zerfallen und 1,2,3-Butatrien (5) liefern.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19751080534
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  • 85
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    Umsetzungen von Ketonen mit azavinylogen Säureamiden (1975)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 1756-1767 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions of Ketones with Azavinylogue CarboxamidesKetones with a methyl or methylene group in the α-position react with monohydrazones of glyoxal in the presence of bases to give hydrazonoethylidene derivatives (16 + 12, 13 or 15 → 19 or 17). From these compounds 4-ketocarboxylic acids 22, 4-ketoaldehydes 27, pyrroles 28, 29, and N-aminopyrroles 31, 35, 37 can be prepared.
    Notes: Ketone mit α-ständiger Methyl- oder Methylengruppe reagieren mit Monohydrazonen des Glyoxals in Gegenwart von basen zu den entsprechenden Hydrazonoäthyliden-Derivaten (16 + 12. 13 oder 15 → 19 bzw. 17). aus diesen Verbindungen lassen sich durch Hydrolyse bzw. Reduktion 4-Ketocarbonsäuren 22, 4-Ketoaldehyde 27, Pyrrole 28, 29 oder N-Aminopyrrole 31, 35, 37 darstellen.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19751080542
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  • 86
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    Über die Reaktion von Diphosphanen mit Tetrachlorkohlenstoff (1975)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 1783-1790 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Reaction of Diphosphanes with Carbon TetrachlorideTetraphenyl- and tetracyclohexyldiphosphane as well as the long chain tetraalkyldiphosphanes are easily cleaved by CCl4 leading to the chlorophosphines R2PCl (2a-d) and (trichloromethyl)- phosphines R2PCCl3 (3a-d). The diphosphane monoxide 4 and the diphosphacyclohexane 7 decompose in the same manner. The reaction is reversible at temperatures above 100°C. Tetramethyl- and tetraethyldiphosphane react in substance or in unpolar solvents to form the diphosphanium(1+) chlorides 9e and 10f; the careful hydrolysis of the latter gives the (chloromethyl)-diphosphanium(1+) chlorides 11 e and f.
    Notes: Tetraphenyl- und Tetracyclohexyldiphosphan sowie die längerkettigen Tetraalkyldiphosphane werden durch CCl4 glatt zu den Chlorphosphinen R2PCl (2a-d) und(Trichlormethy1)phosphinen( R2PCCl3 3a-d) gespalten. In gleicher Weise wird auch das Diphosphanmonoxid 4 sowie das Diphosphacyclohexan 7 abgebaut. Die Reaktion ist bei Temperaturen über 100°C reversibel. Tetramethyl- und Tetraäthyldiphosphan reagieren in Substanz oder unpolaren Lösungsmitteln zu den Diphosphanium(1 +)-chloriden 9e und 10f. Die vorsichtige Hydrolyse von 9e und 10f führt zu den (Chlormethyl)diphosphanium(1 +)-chloriden 11e und f.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19751080602
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    Stereochemie aliphatischer Carbokationen, 9. Substituenteneffekte bei der 1,2-Wasserstoffverschiebung (1975)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 1839-1854 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Stereochemistry of Aliphatic Carbocations, 9. Substituent Effects in 1,2 Hydride ShiftsThe sterochemistry at the origin of 1,2 hydride shifts has been studied with 2-methylbutylamines which were substituted at the 2-methyl site by isopropyl (10), isopropenyl (26), phenyl (32) and methoxy groups (50), respectively. The deamination of these amines afforded tertiary alcohols (3) as the major products. Predominant retention of configuration at the chiral center was observed which increased from 7 to 27% in the order of substituents given above. The results may be attributed to partial delocalization of the incipient positive charge by π- and n-donors.
    Notes: Die Stereochemie am Ausgangspunkt von 1,2-Wasserstoffverschiebungen wurde an 2-Methylbutylaminen untersucht, deren 2-Methylgruppe Isopropyl-(10), Isopropenyl-(26), Phenyl-(32) oder Methoxy-Substituenten (50) trug. Die Desaminierung dieser Amine lieferte tertiäre Alkohole (3) als Hauptprodukte. Wir beobachteten überwiegende Konfigurationserhaltung am chiralen Zentrum, die in der oben angegebenen Reihenfolge der Substituenten von 7 auf 27% zunahm. Dieses Ergebnis kann mit einer partiellen Delokalisierung der entstehenden positiven Ladung durch π- und n-Donatoren erklärt werden.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19751080608
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    Torfmoosmembranochrome, 2. Die Struktur des Sphagnorubins (1975)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 1166-1181 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Cell Wall Pigments of Peat Mosses, 2. The Structure of SphagnorubinThe structure of the red cell wall pigment sphagnorubin has been elucidated. It is the anhydro-base of an anthocyanidin with a 2-phenylphenanthro[2,1-b]pyran skeleton which is hitherto unknown for flavonoids.
    Notes: Die Struktur des roten Torfmoosmembranochroms Sphagnorubin wurde aufgeklärt. Es ist die Anhydrobase eines Anthocyanidins mit einem für Flavonoide bislang unbekannten 2-Phenyl-phenanthro[2,1-b]pyran-Ringgerüst.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19751080423
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  • 89
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    Die Ozonisierung von Alkyliden- und Benzylidenadamantanen (1975)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 1198-1206 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Ozonolysis of Alkyliden- and BenzylidenadamantanesFrom the adamantane derivatives 4-7 normal ozonides could be obtained by treatment with ozone in pentane. The olefines 9 and 10 do not react with ozon. Methanol and tetracyanoethylene respectively interfere in the known manner. 4 and 8 form primary ozonides, which are stable at -78°C.
    Notes: Die Adamantanderivate 4-7 geben bei der Ozonbehandlung in Pentan normale Ozonide, während die stark sterisch gehinderten Olefine 9 und 10 nicht mit Ozon reagieren. Sowohl Methanol wie Tetracyanäthylen greifen in bekannter Weise in die Ozonolyse ein. Nur bei der Ozonisierung von 4 und 8 konnten bei -78°C Primärozonide nachgewiesen werden.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19751080426
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    Phosphorhaltige Kohlenhydrate, X. Reaktion von Carbonylzuckern mit Lithio-methanphosphon-säureestern. Darstellung von 1-Desoxy-D-fructose-1-phosphonsäure-dimethylester (1975)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 1229-1238 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Phosphorus-containing Carbohydrates, X. Reaction of Carbonyl Sugars with Lithio Methanephosphonic Esters. Preparation of Dimethyl 1-deoxy-D-fructose-1-PhosphonateLithio-methyl-methanephosphonate (5) reacts with 2,3:4,5-di-O-isopropylidene-D-arabinose (4) to form gluco-and manno-compounds 6 + 8 which can be oxidized to the 1-deoxy-D-fructose-1-phosphonate derivative 10. Substituted uloses react with 5 to give phosphonomethyl branched sugars. 3-ulose 11 yields the allo-compound 12, hydrolysis of which leads to the aldehyde 14 which in turn yields an oxaphosphorinane 16 after reduction with sodium borohydride and ester exchange. Uloses 17 and 21 can be transformed to branched sugar phosphonates with ribo configuration.
    Notes: Lithio-methanphosphonsäure-methylester (5) reagiert mit 2,3:4,5-Di-O-isopropyliden-D-arabinose (4) zur gluco-und manno-Verbindung 6 + 8, die mit Rutheniumtetroxid zum 1-Desoxy-D-fructose-1-phosphonsäure-Derivat 10 oxidiert werden können. Blockierte Ulosen reagieren mit 5 zu phosphonomethyl-verzweigten Zuckern. Die 3-Ulose 11 ergibt eine allo-Verbindung 12, die nach Hydrolyse zum Aldehyd 14 gespalten werden kann, der nach Reduktion mit Natriumborhydrid durch Umesterung. ein Oxaphosphorinan 16 liefert. Die Ulosen 17 und 21 lassen sich in verzweigte Zuckerphosphonate der ribo-Konfiguration überführen.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19751080430
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  • 91
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    Sterischer Verlauf des thermischen und photochemischen Zerfalls bicyclischer Vinyl-1-pyrazoline (1975)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 1271-1284 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Stereochemistry of the Thermal and Photochemical Decomposition of Bicyclic Vinyl-1-pyrazolinesThe 1,3-dipolar cycloaddition of diazomethane, diazoethane, and 3-diazo-1-propene to cyclic olefines results in the formation of the bicyclic 1-pyrazolines 8, 11-18, which form upon thermal and photochemical decomposition the hydrocarbons 9, 10, 19-32. The thermal decomposition reactions form mainly products which show inversion of configuration in reference to the starting pyrazolines, whereas the photochemical decompositions result predominantly in products where the stereochemistry of the starting materials is retained. The possibly occurring intermediates are discussed. The properties and further reactions of the resulting products are described.
    Notes: Durch 1,3-dipolare Cycloaddition von Diazomethan, Diazoäthan und 3-Diazo-1-propen an Cyclene entstehen die bicyclischen 1-Pyrazoline 8, 11-18, deren thermischer und photochemischer Zerfall die bicyclischen Kohlenwasserstoffe 9, 10, 19-32 liefert. Die entstandenen Produkte zeigen bei der thermischen Reaktion gegenüber den Ausgangsverbindungen Inversion der Konfiguration, während die Photoreaktion zu Produkten mit überwiegender Retention führt. Die bei den Reaktionen möglicherweise auftretenden Zwischenstufen werden diskutiert und die Folgereaktionen der Zersetzungsprodukte beschrieben.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19751080434
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  • 92
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    Oxidative Kupplung von N-Methyl-Säureamiden über Kupfer-Komplexe, I. Synthese eines Piperazins aus Dimethylformamid und Kupfer(I)-cyanid (1975)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 991-996 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Oxidative Coupling of N-Methylcarboxamides via Copper Complex Forming, I. Synthesis of a Piperazine with Dimethylformamide and Cuprous CyanideDry dimethylformamide reacts with cuprous cyanide in the presence of acetyl chloride and aerial oxygen to give 1,4-dimethyl-2,2,3,3-piperazinetetracarbonitrile (1). In 1 the 4 nitrile groups in C-2 and C-3 react, each group with a vicinal one, with methanolic ammonia to yield 2′,5′-diiminopyrrolidine rings (2). The saponfication reaction of 1 with sodium ethoxide solution with formation of 3 is described.
    Notes: Wasserfreies Dimethylformamid reagiert mit Kupfer(I)-cyanid in Gegenwart von Acetylchlorid und Luftsauerstoff zum 1,4-Dimethyl-2,2,3,3-piperazintetracarbonitril (1). In 1 reagieren je 2 vicinale Nitrilgruppen an C-2 und C-3 mit methanolischem Ammoniak zu 2′,5′-Diiminopyrrolidiniringen (2). Die Verseifung von 1 mit Natriumäthylat zu 3 wird beschrieben.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19751080402
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  • 93
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    Zur Konjugation in makrocyclischen Bindungssystemen, XXI. Kristall- und Molekularstruktur der Käfigverbindung 2,3;6,7;10,11-Tribenzotetracyclo[6.4.0.04,12.05,9]dodeca-2,6,10-trien (1975)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 1017-1026 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Conjugation in Macrocyclic Systems, XXI. The Crystal and Molecular Structure of the Cage Compounds 2,3;6,7;10,11-Tribenzotetracyclo[6.4.0.04,12.05,9]dodeca-2,6,10-trienThe crystal structure of the title compound has been solved by direct methods and has been refined to R = 0.05. The cage compound contains the structure elements of bicyclo[2.2.2]octene, 1,5-cyclooctadiene, and cyclopentene. These subunits show deformations and sterical strain because they are forced into a cage system. Therefore long Csp3—Csp3 bond distances of 1.570 and 1.592 Å have been found. The corresponding bond angles are deformed up to 97.1°.
    Notes: Die Kristallstruktur der Titelverbindung wurde mit direkten Methoden gelöst und bis zu einem R-Wert von 0.05 verfeinert. In der Käfigverbindung sind die Strukturelemente von Bicyclo[2.2.2]-octen, 1,5-Cyclooctadien und Cyclopenten enthalten, die im Vergleich zum freien Zustand durch die Verklammerung mit Benzolkernen deformiert und sterisch gespannt sind. Daher treten besonders lange Csp3-Csp3-Bindungsabstände mit Werten von 1.570 und 1.592 Å auf. Die zugehörigen Bindungswinkel sind bis zu 97.1° deformiert.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19751080406
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  • 94
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    Lupinen-Alkaloide, XLI. 13C-NMR-Spektren von Lupinen-Alkaloiden (1975)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 1043-1051 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Lupin-Alkaloids, XLI. 13C-N.M.R.-Spectra of Lupin-AlkaloidsThe analysis of the 13C-n.m.r.spectra of 47 quinolizidines and piperidines as well as some deuterated derivatives give the possibility to coordinate the found signals of the spectra of several lupin-alkaloids. The observed chemical shifts follow in general the common rules. However several particular effects can be recognized mainly due to special steric situations. The usefullness of 13C-n.m.r. spectroscopy for lupin-alkaloids has been shown.
    Notes: Die Analyse der 3C-NMR-Spektren von 47 Chinolizidinen und Piperidinen sowie einiger deuterierter Derivate gibt die Möglichkeit, die gefundenen Signale der Spektren mehrerer Lupinen-Alkaloide zuzuordnen. Die beobachteten chemischen Verschiebungen folgen im allgemeinen den übliche Regeln. Jedoch werden besondere Effekte beobachtet, die vor allem auf spezielle sterische Situationen zurückzuführen sind. Die Brauchbarkeit der 13C-NMR-Spektroskopie für Lupinen-Alkaloide wird gezeigt.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19751080410
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  • 95
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    16,17-Dihydroxy-9(11)-Kauren-18-säure - ein Bestandteil des Röstkaffees (1975)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 1093-1100 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 16,17-Dihydroxy-9(11)-Kauren-18-oic acid  - a Compound of Roasted CoffeeAtractyligenin (1) is a compound isolated from roasted coffee beans (Coffea arabica)1). 1 kg of roasted coffee contains further C19- and C20- acids up to 20 mg of each compound. It is very difficult to separate and purify these acids. One of these acids was identified as 16,17-dihydroxy-9(11)-kauren-18-oic acid (2). Its structure was confirmed by partial synthesis starting from 9(11), 16-kauradien-18-oic acid (5)2).
    Notes: Das im Röstkaffee (geröstete Bohnen von Coffea arabica) enthaltene Atractyligenin (1)1) wird von Säuren mit 19 und 20 Kohlenstoffatomen begleitet. 1 kg Röstkaffee enthält maximal bis zu 20 mg von jeder Säure, die sich dünnschichtchromatographisch nur sehr schwer trennen und reinigen lassen. Die Struktur einer dieser Verbindungen wurde als 16,17-Dihydroxy-9(11)-kauren-18-säure (2) bestimmt und durch Partialsynthese aus der 9(11),16-Kauradien-18-säure (5)2) abgesichert.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19751080414
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  • 96
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    Synthese optisch aktiver α-Aminosäuren mit 8-Azapurinyl-Seitenkette (1975)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 1111-1117 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis of Optically Active α-Amino Acids Substituted in the Side Chain with an 8-Azapurinyl Residue4-Amino-6-chloro-5-nitropyrimidine (1) or 4-chloro-5-nitro-6-oxo-1,6-dihydropyrimidine (4) react with Nα-benzyloxycarbonyl-L-lysine (2a) or 6-aminohexanoic acid (2b) to give 6-(4-pyrimidinyl-amino)hexanoic acids (3a, b, 5a, b). Reduction of their nitro group and subsequent cyclization with sodium nitrite in acidic medium yields the corresponding (triazolo[4,5-d]pyrimidine-3-yl)hexanoic acid derivatives (7a, b, 9a, b). The amino acid derivatives 7a and 9a are hydrogenated to optically active 8-azapurinyl substituted α-amino acids (10, 11).
    Notes: Durch Umsetzung von 4-Amino-6-chlor-5-nitropyrimidin (1) bzw. 4-Chlor-5-nitro-6-oxo-1,6-dihydropyrimidin (4) mit Nα-Benzyloxycarbonyl-L-lysin (2a) bzw. 6-Aminohexansäure (2b) lassen sich 6-(5-Nitro-4-pyrimidinylamino)hexansäuren (3a, b, 5a, b) darstellen. Nach Reduktion der Nitrogruppe mit Natriumdithionit werden diese mit Natriumnitrit in essigsaurem Medium zu (Triazolo[4,5-d]pyrimidin-3-yl)hexansäure-Derivaten (7a, b, 9a, b) cyclisiert. Die Aminosäure-derivate 7a und 9a können zu optisch aktiven, 8-azapurinyl-substituierten α-Aminosäuren (10, 11) hydriert werden.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19751080416
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  • 97
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    Zum Mechanismus der Friedel-Crafts-Alkylierung mit Allylalkohol (1975)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 1182-1187 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On the Mechanism of Friedel-Crafts Alkylation with Allyl AlcoholThe reaction between benzene and allyl alcohol in the presence of AlCl3 leads via 2-phenyl-1-propanol to 1,1-and1,2-diphenylpropane. The mechanism is investigated with the aid of deuteriated materials.
    Notes: Die Umsetzung von Benzol mit Allylalkohol in Gegenwart von AlCl3 führt über die Stufe des 2-Phenyl-1-propanols zu 1,1- und 1,2-Diphenylpropan. Der Reaktionsablauf wird vor allem mit Hilfe deuterierter Vorstufen untersucht.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19751080424
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  • 98
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    Untersuchung chromatographischer Racemattrennungen, IV Trennwirkung optisch aktiven Poly [N-((S)-1-phenyläthyl)acryl-amids] in Abhängigkeit vom Polymerisationsverfahren (1975)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 1188-1197 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Investigation of Chromatographic Resolutions of Racemates, IV. Separation Efficiency of Optically Active poly [N-((S)-1-phenylethyl)acrylamide] Depending on the Polymerisation ProcedureThe optically active suspension polymers 2a-o were synthesized from N-[(S)-1-phenylethyl]-acrylamide [(S)-1] by systematic variation of the polymerisation procedure. These adsorbents whose separation efficiencies were determined by chromatography of racemic mandelic acid separated the enantiomers with very different results. Depending on the synthesis of 2, the optical yields were between 0(2e, f, n, o) and 43% (2i, j). Additionally, 2d separated the enantiomers of mandelamide, the optical yield being 35%. Furthermore, investigations on the particle structure of these adsorbents and the preparative partial separation of 3 are reported.
    Notes: Die optisch aktiven Suspensionspolymerisate 2a-o wurden aus N-[(S)-1-Phenyläthyl]acrylamid [(S)-1] unter systematischer Variation der Versuchsbedingungen hergestellt und auf ihre Trennwirkung durch Chromatographie racem. Mandelsäure geprüft. Die Enantiomeren wurden sehr unterschiedlich getrennt. Je nach Herstellung von 2 schwankten die optischen Ausbeuten von 0 (2e, f, n, o) bis 43% (2i, j). Bei der Trennung von racem. Mandelamid an 2d betrug sie 35%. Ferner wird über Untersuchungen zur Kornstruktur der Polymeren sowie über die präparative Anreicherung der Enantiomeren von 3 berichtet.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19751080425
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  • 99
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    Phosphorhaltige Kohlenhydrate, XI Darstellung von α-Hydroxy- und α-Amino-phosphonaten acyclischer Monosaccharide (1975)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 1239-1245 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Phosphorus-containing Carbohydrates, XI. Synthesis of α-Hydroxy- and α-Amino-phosphonates of Acyclic Monosaccharides2,3:4,5-Di-O-isopropylidene-D-xylose (1) reacts with dimethyl phosphite to yield homogeneous dimethyl 2,3:4,5-di-O-isopropylidene-D-xylitol-1-phosphonate (2a). The reactions of 2,3-O-isopropylidene-D-glycerinaldehyde (4) and 2,4-O-ethylidene-D-erythrose (8) with dimethyl phosphite proceeds without stereoselectivity to yield mixtures of the S- and R-forms of the α-hydroxyphosphonates 5a and 9 in the ratio 1:1. From benzylamine and 2,3:4,5-di-O-isopropylidene-D-arabinose (15) the azomethine 16 is obtained, which adds dimethyl phosphite to give 17. Hydrogenation of 17 yields the crystalline dimethyl 1-amino-1-deoxy-2,3:4,5-di-O-isopropylidene-D-arabitol-1-phosphonate (18).
    Notes: 2,3:4,5-Di-O-isopropyliden-D-xylose (1) reagiert mit Dimethylphosphit zu einheitlichem 2,3:4,5-Di-O-isopropyliden-D-xylit-1-phosphonsäure-dimethylester (2a). Die Reaktion von 2,3-O-Isopropyliden-D-glycerinaldehyd (4) bzw. 2,4-O-Äthyliden-D-erythrose (8) mit Dimethylphosphit erfolgt nicht stereoselektiv zu Gemischen von S- und R-Form der α-Hydroxyphosphonate 5a bzw. 9 im Verhältnis 1:1. 2,3:4,5-Di-O-isopropyliden-D-arabinose (15) reagiert mit Benzylamin zur Schiffschen Base 16, die Dimethylphosphit addiert zu 17. Hydrogenolytische Spaltung von 17 liefert kristallinen 1-Amino-1-desoxy-2,3:4,5-di-O-isopropyliden-D-arabit-1-phosphonsäure-dimethylester (18).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19751080431
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  • 100
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    Stereochemie aliphatischer Carbokationen, 10. Umlagerungen von 3-Methyl-2-butyl-Kationen (1975)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 1855-1863 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Stereochemistry of Aliphatic Carbocations, 10. Rearrangements of 3-Methyl-2-butyl CationsThe deamination of (R)-[2-D]-1,2-dimethylpropylamine (5) in acetic acid at 50°C afforded alkenes, cyclopropanes and acetates in ratios very similar to those obtained with the undeuteriated amine. The 1,2 hydride shift leading to the tert amyl cation proceeds with 66% inversion (34% racemization) at the migration terminus, as judged from the optical rotation of [3-D1]-2-methyl-1-butene (15). The formation of [2-D]-3-methyl-2-butanol-acetate (8b) discloses a previously undetected 1,2 methyl shift which was studied in more detail by means of [1-CD3]-1,2-dimethylpropylamine (23). The stereochemistry of the products is best explained by the assumption of „open“ carbocations with insufficient lifetime for conformational equilibration.
    Notes: Die Desaminierung von (R-[2-D]-1,2-Dimethylpropylamin (5) in Eisessig bei 50°C ergab Alkene, Cyclopropane und Acetate in Mengenverhältnissen, die denen des undeuterierten Amins weitgehend gleichen. Die zum tert-Amylkation führende 1,2-Wasserstoffverschiebung verläuft mit 66% Inversion (34% Racemisierung) am Endpunkt der Umlagerung, wie die optische Drehung des [3-D1]-2-Methyl-1-butens (15) zeigt. Die Bildung von [2-D]-3-Methyl-2-butanol-acetat (8b) macht eine bisher nicht festgestellte 1,2-Methylwanderung deutlich, die mit Hilfe von [1-CD3]-1,2-Dimethylpropylamin (23) näher untersucht wurde. Die Stereochemie der Produkte wird am besten erklärt durch die Annahme „offener“ Carbokationen, deren Lebensdauer zu einer vollständigen Äquilibrierung der Konformeren nicht ausreicht.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19751080609
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