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  • 2000-2004  (27)
  • 1980-1984  (3,421)
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  • Organic Chemistry  (5,859)
  • transformation
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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    GeoJournal 50 (2000), S. 97-100 
    ISSN: 1572-9893
    Keywords: disease ; health ; morbidity ; mortality ; pollution ; transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geography
    Notes: Abstract In general, the health of Poles improved markedly in the thirty years after the Second World War, but there was some deterioration after 1989 before improvement resumed. Only in the case of cancer is there an upward trend and so Poles are now healthier than they have been at any time in the past. However there are sharp regional variations well exemplified by the incidence of tuberculosis, where there appears to be some correlation with poorer housing and atmospheric pollution. High death rates in Lodz (consistently the highest in the country at the voivodship level between 1989 and 1996), may also be linked with environmental pollution as well as the ageing of the population. Variations between town and country are small, but Poland shows up in a poor light when compared with other European countries. These are important issues for the administration and financing of the welfare services.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    GeoJournal 52 (2000), S. 253-262 
    ISSN: 1572-9893
    Keywords: map sheets ; GIS ; seamless spatial database ; transformation ; computational procedure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geography
    Notes: Abstract Map sheets have been often used as a basic spatial unit for managing spatial data produced from paper maps. This often results in incompatibility between adjacent map sheets, because spatial objects do not cross the boundaries smoothly and even the boundaries themselves do not match their neighbors exactly. To solve the problem this paper proposes a computational procedure for joining separate map sheets to obtain seamless spatial data. Line objects digitized separately in different map sheets are considered, which are frequently used to represent road networks, gas pipelines, and boundaries of polygon objects. The procedure consists of three steps: (1) extraction of end nodes, (2) detection of matching nodes, and (3) transformation of the map sheet. Each step goes interactively so that unexpected errors can be avoided by human observation. To test the validity of the procedure, map sheets are combined containing the road network data of Tokyo 23-ku area, Japan.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    GeoJournal 50 (2000), S. 151-155 
    ISSN: 1572-9893
    Keywords: demography ; experts ; rural ; Romania ; rural development ; social issues ; transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geography
    Notes: Abstract There is no standard model of transformation for post- socialist countries and each country encounters specific problems rooted in the geographical characteristics of the areas concerned. The human resources are of the greatest importance because it really matters how people (especially the decision-makers) perceive system change and continually reformulate their expectations and strategies; so investigations into the views of people caught up in the transformation can provide a deeper understanding of the background to structural change. Working the national, regional level and local levels in Romania, experts were asked to consider the advantages and disadvantages arising out of the transformation, the most important problems and constraints for future rural development and the policies needed. The paper examines the responses on demographic and social issues. It emerges the most detailed responses were supplied by local-level representatives while respondents at the regional level steered a middle course between the need to address local problems and the prime importance of stimulating the Romanian economy so as to generate resources for welfare programmes (with the latter issue the overriding concern of interviewees at national level). There was general agreement on the importance of foreign investment and European integration for economic development, with local actors taking only small steps in line with the existing opportunities.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Chemistry of natural compounds 36 (2000), S. 137-139 
    ISSN: 1573-8388
    Keywords: 1,1′,6,6′,7,7′-hexahydroxy-3,3′-dimethyl-5,5′-diisopropyl-2,2′-dinaphthylidene-8,8′-dibarbituric acid ; transformation ; DMSO
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Transformations of 1,1′,6,6′,7,7′-hexahydroxy-3,3′-dimethyl-5,5′-diisopropyl-2,2′-dinaphthylidene-8,8′-dibarbituric acid (batridene) in DMSO are studied.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    World journal of microbiology and biotechnology 16 (2000), S. 177-182 
    ISSN: 1573-0972
    Keywords: Conjugation ; metal resistance ; plasmid DNA ; transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Heavy metal concentrations in soil treated with industrial wastewater of Aligarh City (U.P.), India were determined. The analysis of test samples revealed high levels of Fe, Zn, Ni and Cu. A total of 45 Pseudomonas spp. were isolated from soil and were characterized on the basis of morphological, cultural and biochemical characteristics. MICs of Hg2+, Cd2+, Cu2+, Cr3+, and Zn2+ for each isolate were determined. Eighty percent of the strains isolated from soil harboured resistance to copper, whereas 73.3% of the isolates exhibited resistance to cadmium, 71.1% to chromium and zinc and 48.8% to mercury. A maximum MIC of 200 μg/ml for mercury and 1600 μg/ml for other metals was observed. Metal resistance was found to be plasmid mediated as evidenced by transformation studies. Further, the transmissible nature of chromium resistance was confirmed by conjugation. Agarose gel electrophoresis using the miniprep method for plasmid isolation revealed that these isolates harboured plasmids of molecular weights (45 & 47 kb) using EcoRI and HindIII digests of λDNA and undigested λDNA as standard markers.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 1573-5060
    Keywords: Barley ; Hordeum vulgare ; transformation ; particle bombardment ; particle gun
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Immature embryos of the spring barley variety GoldenPromise, were bombarded with three different particledelivery systems and both transient and stabletransformation examined. In addition, a range oftechniques for the preparation of the DNA coated goldparticles was examined. Fertile transgenic barleyplants were obtained using three particle preparationtechniques which differed in the amount of gold andDNA used for each bombardment. However, only one ofthe particle delivery systems, the PDS 1000/He device,appeared to be effective in yielding transformedbarley plants.
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 1573-5060
    Keywords: cell suspension ; monocotyledon ; selection ; somatic embryogenesis ; transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The successful application of plant biotechnology to Alstroemeria improvement will largely depend on the availability of an efficient regeneration/transformation system. Regeneration in Alstroemeria is accomplished from nodular embryogenic callus initiated from zygotic embryos. Histological studies of embryogenic callus initiation from 4-weeks old cultured ovules revealed that the outermost layers of the protoderm of the embryogenic nodules divided to form either a new nodule or aproembryo. Transient gene expression after particle bombardment of nodular embryogenic callus was optimized using DNA of pAHC25. The highest β-glucuronidase expression was found when the GUS gene was under control of the maize ubiquitin promoter, the target tissue was placed 5 cm below the microcarrier launch assembly and when the rupture disc-breakage point was between 650–900 psi. Kanamycin blocked regeneration of somatic embryos, however, did not block growth of nodular embryogenic callus. With phosphinothricin both callus growth and regeneration were blocked. Bombardment of nodular embryogenic callus with DNA of pAHC25 combined with selection on medium containing phosphinothricin resulted in putative transgenic chimeric. Friable calli were selected from nodular embryogenic callus and used to initiate suspensions. These cell suspensions were subjected to transformation by particle bombardment using DNA of pAHC25 and resulted in a stable transformed friable callus line after selection based on luciferase activity. Even after 2 years of maintenance this callus line was luciferase positive and the Polymerase Chain Reaction analysis demonstrated the presence of the introduced gene in this friable callus line.
    Type of Medium: Electronic Resource
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  • 8
    ISSN: 1573-5087
    Keywords: alfalfa ; cell division cycle ; somatic embryogenesis ; transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Two simple, rapid and efficient protocols for theregeneration of transformed tetraploid lines ofalfalfa (Medicago falcata L.) have beendeveloped and compared. Leaf explants fromembryogenic lines 47/1-150 and 47/1-5 were inoculatedwith Agrobacterium tumefaciens containingconstructs carrying the nptII selectable markergene and promoter:gusA gene fusions under thecontrol of the CaMV 35S or Arabidopsis cdc2a,CycB1 and CycA2 promoters. In the firstregeneration system (the MSH system), inoculated leafexplants were incubated on MS medium supplemented with2,4-D and kinetin and then subcultured onto plantgrowth regulator-free MS medium in order to inducedirect somatic embryogenesis. In the secondregeneration system (the B5h system), the inoculatedexplants were incubated on B5h medium to induceindirect production of somatic embryos viaembryogenic callus. In both systems, an effectivekanamycin selection regime was employed and wasmaintained when the embryos were subcultured onto arecovery medium (Boi2Y) to promote further embryodevelopment. The use of Boi2Y medium was particularlyimportant for shortening the regeneration time andpromoting a higher frequency of healthy plantletproduction from the somatic embryos. The maturesomatic embryos were finally transferred to plantgrowth regulator-free MS medium for plantletformation. Transgenic plantlets were produced within10–14 weeks in the MSH system and 12–16 weeks in theB5h system. The MSH system appears to be the fastesttransformation system reported for leguminous speciesto date. Confirmation of transformation was obtainedusing a re-callusing assay on kanamycin and subsequentSouthern blot hybridisation and PCR analysis. Theability to induce expression of GUS activity in leafexplants containing the cell division cycle genepromoter:gusA constructs by 2,4-D treatment alsoproved to be a reliable indicator of transformation.
    Type of Medium: Electronic Resource
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  • 9
    ISSN: 1573-4889
    Keywords: Fe–Cr–Al alloy ; oxidation ; molybdenum ; breakaway oxidation ; transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Thin foils of Fe–20Cr–5Al alloys are susceptible to breakawayoxidation once the aluminum content of the substrate has fallen below somecritical value. The combined addition of 0.1 wt.% lanthanum and 0, 1, or 2wt% molybdenum has a beneficial effect on the high-temperature oxidation ofsuch foils. Lanthanum has the well-known reactive-element effect on adhesionof the protective alumina scale, thereby increasing the time to onset ofbreakaway oxidation, while, for alloys containing molybdenum, breakawayoxide spreads relatively slowly over the specimen in comparison to alloysthat contain no molybdenum. In particular, molybdenum-containing alloys areable to develop a protective Cr2O3 layer at the breakawayoxide–substrate interface. Conversely, molybdenum-free alloys form aninternal-oxide zone in the substrate adjacent to this interface, rather thana Cr2O3 layer, so breakaway oxide spreads rapidly. A martensitic phase isobserved in the substrate adjacent to the breakaway oxide formed on Fe–20Cr–5Al–La specimens, which means that theα-phase has transferred to the γ -phase at the temperature ofthe oxidation test (1150°C). Conversely, α-phase is retained inthe molybdenum-containing alloy, even after breakaway takes place, sincemolybdenum, which is a strong ferrite former, is enriched in the alloyadjacent to areas of breakaway oxide. The diffusion rate of chromium isslower in the γ than in the α-phase so a continuouschromium-rich oxide layer, which is effective in inhibiting breakawayoxide from spreading, cannot be established at the breakawayoxide–substrate interface for the molybdenum-free alloys.
    Type of Medium: Electronic Resource
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  • 10
    ISSN: 1573-5060
    Keywords: conifers ; salgareño pine ; tissue culture ; transformation ; transient gene expression ; uidA expression ; vir gene
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Cotyledons from dissected sterile embryos of salgareño pine (Pinus nigra Arn. ssp. salzmannii (Dunal) Franco) were inoculated with different disarmed Agrobacterium tumefaciens strains harbouring the binary vector p35SGUSint. The transient expression of a β-glucuronidase gene (uidA) was studied, using a histochemical staining procedure. Nineteen days after inoculation, the activity of β-glucuronidase was detected in epidermal and subepidermal layers of cotyledonary explants. The EHA105 strain harbouring a disarmed agropine-type Ti-plasmid (pTiBO542) was the most effective for gene transfer of the uidA gene. The effects of exudates and extracts from 0-day-old embryos on induction of vir gene expression in A. tumefaciens were also examined. The results of this study showed that salgarño pine embryo exudates contain a substance(s) that induce vir gene expression, in similar way to that observed with 100 μM acetosyringone (AS).All these findings suggest that T-DNA processing and transfer might take place when Agrobacterium infects suitable tissues of salgareño pine.
    Type of Medium: Electronic Resource
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  • 11
    Electronic Resource
    Electronic Resource
    Springer
    Pituitary 3 (2000), S. 117-122 
    ISSN: 1573-7403
    Keywords: Cushing's disease ; silent ; pituitary ; tumour ; macroadenoma ; transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Silent pituitary adenomas occur in 25–40% of all clinically apparent pituitary tumours. However, the subsequent development of florid Cushing's disease in a patient with a previous non-functioning tumour is extremely rare. We describe a 47 year-old woman presenting initially with a large, invasive and recurrent, non-functioning pituitary tumour. Histopathologic study of the initial tissue did not stain for any hormones. Six years after the initial presentation, she manifested florid ACTH dependent Cushing's syndrome. A recurrent invasive pituitary macroadenoma necessitated a third transphenoidal surgery. The resected specimen, in this instance, revealed positive staining for ACTH, FSH, prolactin, and growth hormone on immunocytochemistry. An incomplete response to surgical, radiation and medical therapy necessitated a bilateral adrenalectomy to control the hypercortisolism, which resulted in remarkable clinical improvement. We also review five previous case reports from the revision literature of similar transformations from non-secreting pituitary adenomas to Cushing's disease. This subset of patients may represent yet another entity in the widening spectrum of Cushing's syndrome.
    Type of Medium: Electronic Resource
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  • 12
    Electronic Resource
    Electronic Resource
    Springer
    Transgenic research 9 (2000), S. 471-486 
    ISSN: 1573-9368
    Keywords: Arabidopsis thaliana ; Agrobacterium tumefaciens ; floral spray ; SOD ; transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In this study, floral spray and floral dip were used to replace the vacuum step in the Agrobacterium-mediated transformation of a superoxide dismutase (SOD) gene into Arabidopsis. The transgene was constructed by using a CaMV 35S promoter to drive a rice cytosolic CuZnSOD coding sequence in Arabidopsis. The transgene construct was developed in binary vectors and mobilized into Agrobacterium. When Arabidopsis plants started to initiate flower buds, the primary inflorescence shoots were removed and then transformed by floral spray or floral dip. More than 300 transgenic plants were generated to assess the feasibility of floral spray used in the in planta transformation. The result indicates that the floral spray method of Agrobacterium can achieve rates of in planta transformation comparable to the vacuum-infiltration and floral dip methods. The floral spray method opens up the possibility of in planta transformation of plant species which are too large for dipping or vacuum infiltration.
    Type of Medium: Electronic Resource
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  • 13
    Electronic Resource
    Electronic Resource
    Springer
    Transgenic research 9 (2000), S. 405-415 
    ISSN: 1573-9368
    Keywords: Manihot esculenta ; transformation ; Agrobacterium tumefaciens ; mannose ; hygromycin ; selection
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In order to improve the efficiency of cassava (Manihot esculenta Crantz) transformation, two different selection systems were assessed, a positive one based on the use of mannose as the selective agent, and a negative one based on hygromycin resistance encoded by an intron-containing hph gene. Transgenic plants selected on mannose or hygromycin were regenerated for the first time from embryogenic suspensions cocultivated with Agrobacterium. After the initial selection using mannose and hygromycin, 82.6% and 100% of the respective developing embryogenic callus lines were transgenic. A system allowing plant regeneration from only transgenic lines was designed by combining chemical selection with histochemical GUS assays. In total, 12 morphologically normal transgenic plant lines were produced, five using mannose and seven using hygromycin. The stable integration of the transgenes into the nuclear genome was verified using PCR and Southern analysis. RT-PCR and northern analyses confirmed the transgene expression in the regenerated plants. A rooting test on mannose containing medium was developed as an alternative to GUS assays in order to eliminate escapes from the positive selection system. Our results show that transgenic cassava plants can be obtained by using either antibiotic resistance genes that are not expressed in the micro-organisms or an antibiotic-free positive selection system.
    Type of Medium: Electronic Resource
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  • 14
    Electronic Resource
    Electronic Resource
    Springer
    Applied mathematics and mechanics 21 (2000), S. 1423-1431 
    ISSN: 1573-2754
    Keywords: nonlinear differential equations ; transformation ; algorithm ; analytical solution ; O175.29
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Mathematics , Physics
    Notes: Abstract The idea of AC=BD was applied to solve the nonlinear differential equations. Suppose that Au=0 is a given equation to be solved and Dv=0 is an equation to be easily solved. If the transformation u=Cv is obtained so that v satisfies Dv=0, then the solutions for Au=0 can be found. In order to illustrate this approach, several examples about the transformation C are given.
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  • 15
    ISSN: 1573-9368
    Keywords: inheritance ; Rubisco small subunit promoters ; sonication ; sulphur nutrition ; sunflower albumin ; transformation ; white clover
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract With the aim of increasing the rumen-protected level of the sulphur amino acids cysteine and methionine in Trifolium repens, we introduced the coding sequence of the sunflower seed albumin (SSA) into T. repens by Agrobacterium tumefaciens-mediated transformation. The SSA gene was modified such that the protein would be localised to the endoplasmic reticulum (ER). Four different T-DNA constructions all containing the SSA gene driven by either the promoter of a gene encoding the small subunit of ribulose bisphosphate carboxylase (Rubisco) from Arabidopsis thaliana (A ssu), the promoter of the gene encoding the small subunit of Rubisco of Medicago sativa (L ssu), or the Cauliflower Mosaic Virus 35S promoter (CaMV35S), were transferred to T. repens cv. Haifa. Transgenic T 0-plants and inter-transgenic hybrids were analysed for the level of SSA accumulation in the leaves by western blotting. The highest observed level of SSA accumulation was 0.1% of total extractable leaf protein. We observed that the promoter had a substantive effect on the level of SSA accumulation with A ssu〉CaMV35S〉L ssu. Results from the inter-transgenic hybrids showed that the capacity to synthesise SSA was inherited. However the level of SSA accumulation in the leaves generally appears not to be additive with extra transgenic loci. During this work, we attempted to improve the efficiency of A. tumefaciens-mediated transformation of T. repens using the SAAT-method (Sonication Assisted Agrobacterium-mediated Transformation) on cotyledons of T. repens. T-DNA transfer was in general not enhanced by sonication compared to traditional A. tumefaciens-mediated transformation. Furthermore, Southern blot analyses of plants regenerated from the same cotyledon after A. tumefaciens treatment and under selection, indicated that multiple shoots were usually derived from the same transformation event. We concluded from these results that only one plant from each A. tumefaciens-treated cotyledon should be taken to avoid transgenic clones.
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  • 16
    ISSN: 1573-9368
    Keywords: Hyoscyamus muticus ; particle bombardment ; transformation ; tropane alkaloids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We report an efficient whole plant transformation system for Hyoscyamus muticus, an important medicinal plant of the Solanaceous family. We developed a system using a plasmid carrying the nptII and gusA genes, which was delivered into leaf explants by particle bombardment. Ten percent of bombarded leaf explants formed kanamycin-resistant callus, from which putative transgenic plants were recovered. The nptII gene conferring kanamycin resistance was found to be incorporated into the genome of all transgenic plants screened. Over 50% of the kanamycin resistant plants showed strong expression of the non-selected gusA gene. The majority of transgenic plants reached maturity, could be self pollinated, and produced fertile seed. A simple and efficient whole plant transformation system for this medicinal plant is an important step in furthering our understanding of tropane alkaloid production in plants.
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  • 17
    ISSN: 1573-6776
    Keywords: casein hydrolysate ; Coleus forskohlii ; forskolin ; transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Casein hydrolysate at 2.0 g l−1 significantly enhanced forskolin content (2.3 mg g−1 cell dry wt) in a rhizogenic tumourous line, GCO-RCH-2 of Coleus forskohlii. In rooty teratoma line, RC-ST-2/4, forskolin content enhanced to 1.7 mg g−1 cell dry wt in presence of 2.5 g l−1 casein hydrolysate. Unlike untransformed calli and rhizogenic/root cultures, all the forskolin yielding transformed cultures of C. forskohlii have been maintained for over 5 years.
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  • 18
    ISSN: 1573-5028
    Keywords: Agrobacterium tumefaciens ; sorghum ; transformation ; transgenic plants
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Agrobacterium tumefaciens was used to genetically transform sorghum. Immature embryos of a public (P898012) and a commercial line (PHI391) of sorghum were used as the target explants. The Agrobacterium strain used was LBA4404 carrying a `Super-binary' vector with a bar gene as a selectable marker for herbicide resistance in the plant cells. A series of parameter tests was used to establish a baseline for conditions to be used in stable transformation experiments. A number of different transformation conditions were tested and a total of 131 stably transformed events were produced from 6175 embryos in these two sorghum lines. Statistical analysis showed that the source of the embryos had a very significant impact on transformation efficiency, with field-grown embryos producing a higher transformation frequency than greenhouse-grown embryos. Southern blot analysis of DNA from leaf tissues of T0 plants confirmed the integration of the T-DNA into the sorghum genome. Mendelian segregation in the T1 generation was confirmed by herbicide resistance screening. This is the first report of successful use of Agrobacterium for production of stably transformed sorghum plants. The Agrobacterium method we used yields a higher frequency of stable transformation that other methods reported previously.
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  • 19
    Electronic Resource
    Electronic Resource
    Springer
    Journal of applied psychoanalytic studies 2 (2000), S. 109-115 
    ISSN: 1573-3459
    Keywords: James Joyce ; “The Dead” ; fiction ; reading ; transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Psychology
    Notes: Abstract The author offers a personal reading of James Joyce's “The Dead.” She focuses on how the sounds of the language are used to portray the main character's deadness and his beginning to come to life once the barriers to inner self and self-knowledge are broken.
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  • 20
    ISSN: 1573-4986
    Keywords: Cancer ; caveolae ; caveolin ; cholesterol ; glucosylceramide ; multidrug resistance ; rafts ; transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The carcinogenic process involves a complex series of genetic and biochemical changes that enables transformed cells to proliferate, migrate to secondary sites and, in some cases, acquire mechanisms that make cancer cells resistant to chemotherapy. This phenomenon in its most common form is known as multidrug resistance (MDR). It is usually mediated by overexpression of P-glycoprotein (P-gp) or other plasma membrane ATPases that export cytotoxic drugs used in chemotherapy, thereby reducing their efficacy. However, additional adaptive changes are likely to be required in order to confer a full MDR phenotype. Recent studies have shown that acquisition of MDR is accompanied by up-regulation of lipids and proteins that constitute lipid rafts and caveolar membranes, notably glucosylceramide and caveolin. These changes may be related to the fact that in MDR cells a significant fraction of cellular P-gp is associated with caveolin-rich membrane domains, they may be involved in drug transport and they could have an impact on drug-induced apoptosis and on the phenotypic transformation of MDR cancer cells.
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  • 21
    Electronic Resource
    Electronic Resource
    Springer
    Molecular breeding 6 (2000), S. 185-194 
    ISSN: 1572-9788
    Keywords: Agrobacterium ; transformation ; pea ; Pisum sativum L. ; PCR analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Factors influencing the efficiency of Agrobacterium-mediated transformation of pea were tested using highly efficient, direct regeneration system. The virulence of three Agrobacterium strains (octopine LBA 4404, nopaline C58C1 and succinamopine, hypervirulent EHA 105) clearly varied giving 1 transgenic plant per 100 explants for LBA 4404, 2.2 for C58C1 and 8.2 for EHA 105. To test the efficacy of selection agents we used the hypervirulent EHA 105 strain carrying pGPTV binary vector with one of four different selection genes: nptII, hpt, dhfr or bar. The mean number of transgenic, kanamycin-resistant plants for two cultivars tested was 4.2 per 100 explants and was slightly higher than the number of phosphinothricin-resistant plants (3.6 plants per 100 explants). The proportion of transgenics among kanamycin-selected plants was also higher than among phosphinothricin-resistant plants (35% and 28% respectively). There was no regeneration on hygromycin or methotrexate media (transformation with hpt and dhfr genes). Acetosyringone had no apparent influence on efficiency of transformation with hypervirulent EHA 105 strain, however it did affect the rate of transformation when moderately virulent C58C1 was used. Recovery of transgenic plants was enhanced after application of 5-azacytidine. The presence of integrated T-DNA was checked by PCR and confirmed by Southern hybridization. T-DNA was stably transmitted to the next generation.
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  • 22
    ISSN: 1572-9788
    Keywords: antisense DNA ; co-transformation ; nucleocapsid gene ; pathogen-derived resistance ; somatic embryogenesis ; transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Peanut (Arachis hypogaea L.) lines transgenic for the antisense nucleocapsid (N) gene of a Tomato spotted wilt virus (TSWV) strain isolated from peanut were generated by microprojectile-mediated transformation of repetitive somatic embryos of cultivars VC1 and AT120. The selectable marker (hygromycin resistance) and the N gene were on separate plasmids. A total of 207 VC1 and 120 AT120 hygromycin-resistant lines were produced. Of all the VC1 plants recovered 71% were cotransformed with the N gene (N+), but all plants were sterile. For AT120, 48 of the transgenic cell lines converted into plants. Polymerase chain reaction (PCR) screening showed 15 of the lines were transgenic for the N gene (N+), and two of these lines were fertile. A field test was conducted in 1998 at Ashburn, GA, using seeds from each fertile line, along with segregated and non-transgenic controls. Plants from four randomly selected field plots were examined for symptoms and analyzed by double-antibody sandwich enzyme-linked immunoabsorbent assay and PCR at 10 and 14 weeks after planting. At 14 weeks, 76% of the N+ plants were symptomless, while 2% were severely symptomatic or dead. In contrast, only 42% of the plants lacking the N gene were symptomless and 50% were severely symptomatic or dead. Northern blot analysis of selected field-resistant plants detected transgene RNA, and the transcript level appeared undiminished after viral exposure.
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  • 23
    ISSN: 1572-9788
    Keywords: bar ; cry3A ; Eucalyptus ; transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Transgenic Eucalyptus camaldulensis containing both the insecticidal cry3A gene and the bar gene (conferring tolerance to the herbicide glufosinate ammonium) have been produced by Agrobacterium tumefaciens-mediated transformation of seedling explants. Transgenic plants from two lines tested were resistant to first instars of chrysomelid beetles that are important pests of commercial Australian eucalypt plantations. Both lines also exhibit tolerance to the broad-spectrum herbicide Liberty® at 6 l/ha (1.2 kg active ingredient per hectare), twice the field application rate. Transgenic insect- and herbicide-resistant eucalypts like these are likely to provide better insect and weed control options in plantations, particularly during the vulnerable establishment phase, provided that any adverse ecological impacts of releasing transgenic trees into the environment can be assessed and minimized.
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  • 24
    ISSN: 1572-9788
    Keywords: choline oxidase ; glycinebetaine ; Japanese persimmon ; salt tolerance ; transformation ; woody plant
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract This report describes the first successful genetic engineering of tolerance to salt in an agriculturally important species of woody plants by Agrobacterium-mediated transformation with the codA gene of Arthrobacter globiformis. This gene encodes choline oxidase, which catalyzes the oxidation of choline to glycinebetaine. The binary plasmid vector pGC95.091, containing a kanamycin-resistance gene (nptII), a gene for β-glucuronidase (gusA) and the codA gene in its T-DNA region, was used with a disarmed strain of Agrobacterium tumefaciens, EHA101, to transform Japanese persimmon (Diospyros kaki Thunb. `Jiro') by the leaf disk transformation method. The pRS95.101 plasmid that included only nptII and gusA in the T-DNA region was used as a control. We selected eight transgenic lines with one or two copies of the T-DNA after transformation with pGC95.091 (PC lines) and three lines after transformation with pRS95.101 (PR lines). The eight PC lines produced choline oxidase and glycinebetaine whereas neither was found in untransformed `Jiro' and in the control PR lines. Transgenic plants grew normally, resembling wild-type plants both in vitro and ex vitro. The activity of photosystem II in leaves of the transgenic Japanese persimmon plants under NaCl stress was determined in terms of the ratio of the variable (F v) to the maximum (F m) fluorescence of chlorophyll (F v/F m). The rate of decline in (F v/F m under NaCl stress was lower in the PC lines than in the control PR lines. These results demonstrated that genetic engineering of Japanese persimmon, which allowed it to accumulate glycinebetaine, enhanced the tolerance to salt stress of this plant.
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  • 25
    ISSN: 1572-9788
    Keywords: heterologous protein accumulation ; phytate phosphorus digestibility ; phytase ; phytic acid ; transformation ; Triticum aestivum L.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The Aspergillus niger phytase-encoding gene (phyA) has been constitutively expressed in wheat. Transgenic wheat lines were generated by microprojectile bombardment of immature embryos, using the bar-Bialaphos selection system. The bar and the phyA gene expression were controlled by the maize ubiquitin-1 promoter. To ensure secretion and glycosylation of the microbial phytase, an expression cassette was designed (Ubi-SP-Phy) where an α-amylase signal peptide sequence was inserted between the promoter and the phytase coding region. A similar cassette was constructed without the signal peptide sequence (Ubi-Phy). Five lines of fertile wheat transformed with the Ubi-SP-Phy were generated and two lines with the Ubi-Phy construct. The inheritance of the phyA gene was monitored through three generations. Western blotting of leaf and seed derived protein revealed the presence of an immunoreacting polypeptide of the size expected for the Aspergillus phytase. Up to 25 days after pollination, the heterologous phytase was exclusively present in the pericarp-seed coat-aleurone fraction. Thereafter, it accumulated in the endosperm in amounts exceeding that found in the seed coat and aleurone. The phyA mRNA and derived protein could at no stage be detected in the embryo. The Ubi-SP-Phy transgenic seeds exhibited up to 4-fold increase of phytase activity while up to 56% increase was found in Ubi-Phy plants. It is concluded that a functional Aspergillus phytase can be produced in significant amounts in wheat grains. This may be of relevance for improving the phytate-phosphorus digestibility when wheat grains are used for non-ruminant animal feed.
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  • 26
    ISSN: 1572-9788
    Keywords: Choline oxidase ; glycinebetaine ; transformation ; Brassica juncea ; salt stress
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The codA gene for biosynthesis of glycinebetaine from Arthrobacter globiformis was used for transforming Brassica juncea cv. Pusa Jaikisan (which lack any means to synthesize glycinebetaine) through Agrobacterium mediated transformation. The stable insertion of the codA gene in the shoots obtained on medium with kanamycin and hygromycin was confirmed by PCR analysis of the nptII gene. Southern hybridization with a codA probe further demonstrated its successful integration. Immunoblot analysis revealed the presence of choline oxidase demonstrating that the bacterial codA gene had been successfully transcribed and translated. The seeds of transgenic lines showed enhanced capacity to germinate under salt stress as compared to that of the wild type. Further, the seedlings of transgenic plants that expressed codA gene showed significantly higher growth than that of the wild type under salt stress conditions. These results demonstrated that the introduction of a biosynthetic pathway for glycinebetaine into Brassica juncea significantly enhanced their salt tolerance. Hence, homozygous genotypes of selected transformed lines can be exploited for improving the salt tolerance of the desirable cultivars of Brassica juncea through breeding programmes.
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  • 27
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    Systemic practice and action research 13 (2000), S. 475-501 
    ISSN: 1573-9295
    Keywords: reflection ; transformation ; self-society dynamics ; critical systems thinking ; systemic intervention ; critical self-reflection ; ideology-critique ; critical appreciation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Sociology
    Notes: Abstract This paper sets out to uncover some relationships between reflection, discourse and action. By challenging and synthesizing some polemical arguments concerning the creation, maintenance, and transformation of self and society, a model of self-society dynamics that operates through reflection, discourse, and action is developed. The model of self-society dynamics brings together aspects of self-reflection and ideology-critique (explored in the paper), which it is suggested are required for any intervention (transformative action) to be grounded in locally meaningful ways. By creating a dialog community in which self- and group assumptions can be subjected to validation through discourse, it is proposed that a dynamic balance between individual needs and broader societal aims may be achieved. If individuals can be open to such discourse (i.e., they can become critically self-reflective), then it is argued that possibilities for achieving sustainable change will be significantly enhanced.
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  • 28
    ISSN: 1432-1424
    Keywords: cell junction ; cell-to-cell communication ; cell-to-cell channel ; gap junction ; simian virus 40 ; DNA virus ; tumor antigens ; transformation ; cancer
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Summary We studied the action of temperature-sensitive mutant simian virus 40—a transformation-inducing DNA virus—on the junctional permeability to mono-, di- and triglutamate in rat embryo-, pancreas islet (epithelia)-, and 10T1/2 cell cultures. Junctional permeability was reduced (reversibly) in the transformed state. To dissect the genetics of this alteration, we used two kinds of mutant virus DNA. One kind had a temperature-sensitive mutation on theA gene, rendering the largeT antigen (the gene product) thermolabile (T + ⇆T −). The other had a deletion on theF gene, in addition, abolishing (permanently) the expression of the littlet antigen (t −). The junctional alteration occurred in the conditionT + t +, but not in the conditionsT − t +,T + t − orT − t −. Both antigens, thus, are necessary for this junctional alteration—a genetic requirement identical to that for decontrol of growth (but distinct from that of the cytoskeletal alteration).
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  • 29
    ISSN: 1432-1424
    Keywords: cell-to-cell communication ; cell-to-cell channel ; cell junction ; communicating junction ; gap junction ; Rous sarcoma virus ; transformation ; cancer ; growth control ; tyrosine phosphorylation ; src gene ; protein kinase ; pp60src ; cytoskeleton
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Summary To learn whether the reduction of cell-to-cell communication in transformation is a possible primary effect of pp60src phosphorylation or secondary to a cytoskeletal alteration, we examined the junctional permeability in transformed cells with normal cytoskeleton. The permeability to fluorescentlabelled mono- and diglutamate was compared in clones of Faras' vole cells—clones transformed by Rous sarcoma virus and reverted from that transformation. One revertant clone (partial revertant), had the high levels of pp60src kinase activity and tumorigenicity of the fully transformed parent clone, but had lost the cytoskeletal alterations of that clone. Another revertant clone (full revertant) had lost the tumorigenicity and most of the pp60src kinase activity, in addition (J.F. Nawrocki et al., 1984,Mol. Cell Biol. 4:212). The junctional permeability of thepartial revertant with normal cytoskeleton was similar to that of the fully transformed parent clone with abnormal cytoskeleton. The permeabilities of both were lower than those of thefull revertant and the normal uninfected cell, demonstrating that the junctional change by thesrc gene is independent of the cytoskeletal one.
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  • 30
    ISSN: 1432-1424
    Keywords: cell junction ; cell-to-cell communication ; cell-to-cell channel ; gap junction ; Rous sarcoma virus ; transformation ; cancer ; growth control ; tyrosine phosphorylation ; src gene ; protein kinase ; pp60src
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Summary To study changes of junctional membrane permeability associated with transformation, the junctions and the nonjunctional membranes of quail embryo-, chick embryo- and mouse-3T3 cell cultures, infected with temperature-sensitive mutant Rous sarcoma virus, were probed with fluorescent-labelled glutamate. Junctional permeability fell in the transformed state. In the quail cells, the fall was detectable within 25 min of shifting the temperature down to the level (permissive) at which tyrosine-phosphorylation by the viralsrc gene product is expressed. This reduction of junctional permeability is one of the earliest manifestations of viral transformation. Normal permeability was restored within 30 min of raising the temperature to the nonpermissive level, a reversibility that could be displayed several times during the span of a cell generation. The reversal seems to reflect a reopening of cell-to-cell channels rather than a synthesis of new ones; it is not blocked by protein-synthesis inhibition. Treatments with cyclic AMP and phosphodiesterase inhibitor or with forskolin, which stimulate serine and threonine phosphorylation—the type of phosphorylation on which normal junctional permeability depends (Wiener & Loewenstein, 1983,Nature 305∶433)—did not abolish, in general, the junctional effect of the virus;src tyrosine-phosphorylation apparently overrides the junctional upregulation mediated by cyclic AMP. Nonjunctional membrane permeability was not sensibly affected by the virus. It was affected, however, by temperature: lowering the temperature from the nonpermissive to the permissive level caused the nonjunctional permeability to fall, andvice versa. This change was unrelated to transformation. Its secondary effect on junctional transfer is in the opposite direction to that produced by the temperature-activated viral transformation.
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  • 31
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    Cancer and metastasis reviews 3 (1984), S. 265-296 
    ISSN: 1573-7233
    Keywords: bladder cells ; urothelial cell lines ; markers for invasiveness ; transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The invasiveness of bladder tumors has been studied in man, experimental animals, and in tissue culture by numerous authors. The prognostic importance of cellular markers for invasiveness is stressed, and the usefulness of histopathological and cytologic grading, cytogenetic studies, antigenic investigations, and enzymatic characterization is discussed. The invasiveness of bladder cells has frequently been examined in transplantation and explantation experiments. In human urothelial cell cultures three grades of transformation are defined, and a correlation has been established between the invasiveness of these cell lines in a three-dimensional in vitro model and their tumorigenicity in nude mice. The mechanism of tumor invasion is discussed, and it is recommended in future research to make a distinction between invasion en bloc and cellular infiltration.
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  • 32
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    Plant cell, tissue and organ culture 3 (1984), S. 175-188 
    ISSN: 1573-5044
    Keywords: Agrobacterium tumefaciens ; crown gall ; transformation ; lysopine dehydrogenase ; cell wall ; cell cycle
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Agrobacterium has been used to transform zero to six-day-old cell wall nonregenerating (CWNR) and cell wall regenerating (CWR) leaf protoplasts of tobacco. Transformed cells were selected by phoytohormone autotrophic growth and were verified by detection of the presence of lysopine dehydrogenase. Transformation frequencies in CWNR protoplasts were at least as high as those in CWR protoplasts, indicating that a plant cell wall is not required for the process of crown gall tumorigenesis. Transformation frequencies were highest in two-day-old protoplasts. This age coincides with the onset of DNA synthesis and the first mitosis within the cell populations. We suggest that the initiation of cell cycle activity may be important for the transformation process.
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  • 33
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 279-286 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Convenient Synthesis of 4-Oxo-tetrahydropyrimidinesEnamino-nitriles as 6 or 11 yield 4-oxo-pyrimidines (2; 2a; 10; 12a-c) on treatment with cyclohexanone in basic media. Analogous compounds are obtained using acetone, butyraldehyde, benzaldehyde or substituted benzaldehydes.
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  • 34
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The “Normalizing Factor” for the Tomato Mutant chloronerva. XV. Peptide Analogues of the Phytosiderophore NicotianamineSome peptide analogues of the phytosiderophore nicotianamine, (2S, 3′S, 3″S)-N-[3-(3-amino-3-carboxypropylamino)-3-carboxypropyl]-azetidine-2-carboxylic acid, have been synthesized from protected amino acids by the EEDQ or the DCC method. They exhibited no biological effect with regard to the phenotypical normalization of the tomato mutant chloronerva.
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  • 35
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 2-Aza-3-chloro-2-propeniminium salts 5, which are easily available by the addition of formamide chlorides 1 to nitriles 2 react smoothly with hydrazines 9 giving rise to 1,3-disubstituted 1,2,4,-triazoles 11. When the 2-aza-3-chloro-2-propeniminium salts 5 are hydrolysed first the resulting N-acyl-formamidinium salts 6 react with hydrazines 9 to 1,5 disubstituted 1,2,4-triazoles 13 via isolable N-acyl-formamidrazones 12.
    Additional Material: 4 Tab.
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  • 36
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 303-310 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Quantum Chemical Investigations of the Molecular and Electronic Structure of Simple Azomethine Imines and Related CompoundsThe molecular and electronic structure of simple azomethinimines are investigated by means of MINDO/3 and CNDO/2 calculations. The calculated molecular geometry is compared with X-ray results obtained for these compounds. Except for the NN-bond lengths MINDO/3 satisfactorily describes the molecular structure of azomethinimine and related π-electronic systems. The charges at the atoms along the conjugated chain are alternating as in polymethines. The terminal carbon atom carries a negative charge. This charge brings about an appreciable shielding of this carbon atom such as found in the 13C-n.m.r. spectrum. This result does not contradict a stabilization of azomethinimines in the crystal via = CH…O=C interactions.
    Additional Material: 2 Tab.
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  • 37
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 320-328 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Synthesis of Oligodeoxyribonucleotides on a Polystyrene Grafted Polytetrafluorethylene Support via Phosphotriester Intermediates
    Additional Material: 5 Ill.
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  • 38
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 342-348 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Quinazolincarboxylic Acids. I. Quinazolin-4-on(2,4-dion)-3-acetic Acids and Esters
    Additional Material: 6 Tab.
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  • 39
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 374-380 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The effects of temperature, structure and sulphuric acid concentration on the selectivity of the oxidation of aliphatic ketones (R1COR2) (1a-g) by thallic sulphate have been investigated. With increasing temperature the quantity of internal α-hydroxyketone (3a-d) decreases and the quantity of 1-hydroxyketone (2a-d) increases in the oxidation of methyl alkyl ketones (R2〉CH3) (1a-d). The same concerns to the oxidation products of hexan-3-one (1e): 2-hydroxy-hexan-3-one (2e) and 4-hydroxy-hexan-3-one (3e), respectively. “The inverse selectivity temperature” (IST) for oxidation of linear methyl alkyl ketones (1a-c) and hexan-3-one (1e) has been found. With the use of the linear free-energy relationship it has been found that the selectivity of the reaction decreases with increasing the polar and steric effects of substituents R1, R2. With increasing the sulphuric acid concentration the selectivity of the oxidation of methyl alkyl ketones (1a, 1d) increases.
    Additional Material: 3 Ill.
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  • 40
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 401-406 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Electrophilic Reactions on the Maleimide Double BondThe aminosubstituted maleimides 1 are deprotonated to the anions 2, which are reacted with various electrophiles. By this way with heterocumulenes, acid chlorides and vinylogous acid chlorides the new acylated maleimides 3-6, 9, 10 are isolated. This reaction presents a method of direct acylation on the maleimide double bond.
    Additional Material: 1 Tab.
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  • 41
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Light Induced Polymer and Polymerization Reactions. 14. Radical Photopolymerization by Potassium Trisoxalato Cobaltate Arylonium Salts Systems.The photopolymerization of acrylamide (AA) by trisoxalato cobaltate ([Co(ox)3]3⊖) is inefficient because the produced nucleophilic ·CO2⊖-radicals are oxidized or they terminate with polymer radicals. If onium compounds are added to this system the initiation efficiency is increased as follows : p-CH3OC6H4N2⊕〉Ph2I⊕〉PhCOCH2S(CH3)2⊕〉Ph3S⊕. By means of quantum yield measurements a mechanism was proposed including the electron transfer from ·CO2⊖ to onium compounds. The produced radicals also initiate the polymerization of AA. The exponent m of the polymerization rate (vp ≍ [AA]m) is decreased from 1.4 to 1.1 in the presence of Ph2I⊕, deciding the decrease of termination reaction between ·CO2⊖ and polymer radicals. In comparison with K3[Fx(ox)3] the corresponding cobalt complex possesses higher polymerization quantum yields for AA.
    Additional Material: 6 Ill.
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  • 42
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 505-510 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Hammett-like Correlations between 13C-NMR Chemical Shifts and Substituent Constants on Aniles of p-Nitrocinnamaldehyde
    Additional Material: 1 Ill.
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  • 43
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 849-852 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Cyanoethylation of HydroquinazolinonesBy the reaction of acrylonitrile with octahydroquinazolinone-spirocyclohexane (1), cyanoethyl-octahydroquinazolinone-spirocyclohexane (2) is formed. Compound 2 and hydrogen-peroxide yield 5a-cyanoethyl-5-oxo-perhydro-oxaziridino[3,2-j]-quinazolin-2-spirocyclohexane (5). 2-Phenyl-octahydroquinazolinone (7) and acrylonitrile form 3,5a-biscyanoethyl-2-phenyl-octahydroquinazolinone-(4) (8). Compound 8 and hydrogenperoxide yield 3-phenyl-4,5a-biscyanoethyl-4-oxoperhydro-oxaziridino[3,2-j]-quinazoline (9). Compound 9 rearranges with ferrous sulphate to 3,4a-bis-cyanoethyl-4-oxo-8a-hydroxy-2-phenyl-octahydro-quinazoline (10).
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  • 44
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 876-892 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: About the Photochromic and Thermochromic Effect of Benzil PhenylhydrazonesBenzil phenylhydrazone 1 synthesized from benzil and phenylhydrazine possesses s-trans-E configuration detected by means of quantum chemical calculations and its spectral data. Upon irradiation a photochromic process proceeds with a λ-shift Δ λ ≈ 80 nm. The photoproduct has an s-cis-Z configuration. The quantum yields of the EZ-isomerization measured by spectroscopic methods depend on solvent (ΦEZ= 0,077 in CH3OH, ΦEZ= 0,22 in n-hexane), but are independent of the excitation wavelengths and O2. Benzil N-methylphenylhydrazone 2 is inactive under stationary irradiation. Both the Z/E-isomerization of 1 and 2 are be sensitized by benzil and m-methoxyacetophenone. On the basis of kinetic measurements the quantum yields of sensitized reactions of 1 are calculated (ΦEZsens = 0,43; ΦZEsens = 0,57). In protic solvents benzil phenylhydrazone 1 has thermochromic properties caused by E/Z-isomerizations. The measured activation parameters of these reactions are small. It is assumed that both the photoinduced and thermal isomerizations proceed via azo intermediates, as indicated by flash photolysis experiments.
    Additional Material: 5 Ill.
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  • 45
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 899-909 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Photooxidation of Leuco Dyes. VIII. Time Resolved Investigations of the Mechanism of the Photooxidation of Leucocrystal VioletThe photooxidation of leucocrystal violet has been reexamined by means of conventional and laser flash photolysis as well as spin trap experiments. Three radical transients have been observed and assigned to the cation radical (λmax ≈ 490, 530 nm), the neutral radical with one—NCH3—CH2 moiety (λmax ≈ 480 nm) and the triphenyl methyl radical derivative (λmax ≈ 400 nm).
    Additional Material: 10 Ill.
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  • 46
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 47
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 360-366 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Preparation of β-Substituted trans-Ethylene Diphenylphosphines and Sulphides by P(0) and P(S)-activated OlefinationMethylene bis-diphenylphosphine monoxide (3c) in tuluene reacts regiospecifically and stereoselectively with aldehydes in the presence of potassium tert-butoxide to ß-substituted transethylene diphenylphosphines 6, which can be oxidized to the sulphides 2 by sulphur in acetone. These sulphides 2 are to be obtained also directly from methylene bis-diphenylphosphine oxide sulphide 3b and methylene bis-diphenylphosphine disulphide 3d, respectively, under the same olefination conditions. But the yields are smaller and the purification of the raw products is much more difficult, if 3d is used.
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  • 48
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 599-604 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The present work deals with the synthesis of 6-aryl-2-ethoxycarbonyl pyridazin-3(2H)-ones (2) as useful synthetic intermediates because they allow formation of a new hydrazides (3), hydrazidoyl chlorides (4) and the highly reactive nitrile imine species (5). Dimerization and reaction of the latter species with benzonitrile, benzaldehyde and their p-methoxy and p-nitro derivatives provides a convenient method for the synthesis of substituted 1, 2, 4, 5-tetrazines (6), 1, 2, 4-triazoles (7) and 1, 3, 4-oxadiazoles (8), respectively, with pyridazin-3(2H)-one moiety.
    Additional Material: 1 Tab.
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  • 49
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 737-746 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Cyanic Acid Esters. 35. On Formation and Consecutive Reactions of N-Cyanato Phthalimide. New Specifically Activated and Blocked Isatoic Acid DerivativesDepending on the reaction conditions N-hydroxy-phthalimide affords on treatment with cyanogen bromide via N-cyanato phthalimide 2 the iminocarbonate 3 and isatoic acid derivatives 7 and 16. Both the latter react with nucleophiles as isatoic acid derivatives activated on the carboxylic group and protected on the carbamic group or vice versa, furnishing N,N-bis alkoxycarbonyl anthranilic acid amides 9, N-alkoxycarbonyl anthranilic acid amides 12, o-alkoxycarbonyl phenyl ureas 17 and the benzotriazepin-2,5-dione 14. The structures of the new compounds are proved by 1H-n.m.r. and 13C-n.m.r. measurements as well as independent synthesis.
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  • 50
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Deactivation Behaviour of Arenes and Heteroarenes. XLI. Structural and Environmental Effects on the Intramolecular [π4s + π4s]- Photocycloaddition Reaction of α, ω-Bis-(9-acridiziniumyl) - alkanes.Fluorescence characteristics, including quantum yields and decay times, and quantum efficiencies for the reversible intramolecular [π4s + π4s]- photocycloaddition reaction for a series of α, ω-bis-(9-acridiziniumyl)-alkanes have been measured in several solvents and they have been compared with those of the model compounds acridizinium-ion. and 9-methyl-acridizinium-ion. These parameters of the bichromophores depend on the number of CH2-groups of chromophor linkage. The title compounds investigated were divided into groups of common behaviour, and differences are due to increasing bond angle strain and coulomb-repulsion in the photocyclomer state.
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  • 51
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 779-790 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: On the Catalytic Dimerization of Acrylic Acid Derivatives by Palladium Complexes. IV. The Dimerization of Methyl Methacrylate.Methyl methacrylate has been dimerized to a mixture of 2.5-di(methoxycarbonyl)-hex-1-ene(1) and (E)-2.5-di(methoxycarbonyl)-hex-2-ene (2) by catalytic systems containing dichlorobis (nitrile)-palladium (II) complexes and silver tetrafluoroborate, Codimerization experiments with methyl acrylate show a lower reactivity of methyl methacrylate. Oxidative addition of ß-chloro methyl methacrylate to tetrakis (triphenylphosphine) palladium (O) gave ß-polladio methyl methacrylates (8, 9) suitable for model investigations of the catalytic reaction. A proposal is given for a mechanism via pd(IV) intermediates.
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  • 52
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 811-816 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 7 Tab.
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  • 53
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 804-810 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Mass Spectrometric Fragmentation of 4-Substituted 5-Hydroxynaphth[2,1-d]1,3-oxathiol-2-onesThe mass spectra of 5-hydroxynaphth[2,1-d]1,3-oxathiol-2-ones 1a-1x have been studied. They show characteristic fragmentations with participation of neighbouring groups. Investigations of isotopically labelled 4-alkyl and 4-acyl derivatives give evidence for the formation of cyclic ionic structures.
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  • 54
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 823-828 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The Dependence of UV-Spectra of Substituted Naphthalenesulfonic Acids upon the pH-Value - A Contribution in Order to Elucidate the Structure of Acid Azo Dyes
    Additional Material: 2 Ill.
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  • 55
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 910-916 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A detailed kinetic analysis is presented of the transient sultone (A2) formation which proceeds thermally from a photogenerated intermediate species after flash excitation of bromo thymol blue and bromo xylenol blue in the presence of quinoline, pyridine and 4-methyl pyridine in toluene solution. The sultone ring cleavage is a bimolecular reaction with the base resulting in a hydrogen-bridged molecular complex (A1) which equilibrates consecutively with the most stable rotamer of the ion pair (A3). The rate constants for the latter reaction are controlled essentially by conformational changes rather than by the proper proton transfer.
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  • 56
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 924-934 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Diels-Alder-Reactions. IX. On the Formation and the Thermolysis of Isomeric TricyclopentadienesThe formation of isomeric tricyclopentadienes by codimerisation of cyclopentadiene with endo- and exo-dicyclopentadiene between 100 and 140°C in the liquid phase, and the retrodiene reaction of the main isomeres of the tricyclopentadiene fraction by gas phase thermolysis were studied kinetically between 230 and 310°C. The rate constants and the parameters of activation were determined.
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  • 57
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 941-946 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 10β;-Chloro-estra-1,4-dienes as Intermediates of the Introduction of a 9(11)-Double Bond in Estra-1,3,5(10)-trienesThe synthesis of 9(11)-didehydro-estra-1,3,5(10)-trienes 5 starting from estra-1,3,5(10)-trienes 1 is described. 1 can be transformed into the ketals 2 and 3 by means of isocyanuric acid chloride and an alcohol such as methanol or ethylene glycol in the absence of moisture.The ketals 2 and 3 are sensitive against hydrolysis and react in the presence of water and traces of acid under formation of chlorodienone 4. Dehydrochlorination of 2, 3 and 4 with potassium-tert.-butylate in dimethylsulfoxide gives the 9(11)-didehydro compounds 5. The reaction mechanism of the electrophilic addition of positive chlorine and alcohol to the aromatic A-ring of 1 is discussed.
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  • 58
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 955-961 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Pyrylium Compounds. XXV. Quantum Chemical Calculations Concerning the Valence Isomerization of 2-Amino-2H-pyran and -thiopyranThe equilibrium 2-amino-2H-pyran 6 ⇌ 5-amino-2,4-dien-1-one 7 was investigated using the semi-empirical MINDO/3 and MNDO methods. In accordance with experimental findings for the substituted derivatives 1/2a-d, the introduction of a methyl group into the position 3 of 6 or the exchange of oxygen by sulfur shifts the equilibrium towards the cyclic structures 8 and 10, respectively. Polar solvents, the influence of which was estimated applying the reaction field approach as well as the solvaton theory, and entropy effects are calculated to favour the ring-open valence isomer 7. These results also correspond to experimental results.
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  • 59
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    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Photocatalytical Systems. LXIV. Theoretical Investigations of the Charge Transfer and of the Photochemical Reactivity of d6 Transition Metal Complexes with π Acceptor LigandsQuantum chemical investigations concerning the charge transfer interactions between a d6 complex fragment and heterocyclic nitrogen ligands are reported. The influence of inductive, mesomeric and steric effects on the π acceptor ability of the isolated ligand and on the electronic structure of the pentacyano-ferrate(II) mixed ligand compounds has been investigated and possibilities to sensitize spectrally the Fe(CN)5L3- system (L= pyridine-type ligand) with regard to their photochemical reactivity are discussed.
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  • 60
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    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Investigations of the Photo-Fading of Tautomeric Azo Dyes. VI. The Photochemical Oxidation by Singlet Oxygen of Phenylazoacetylacetones and PhenylazopyrazolonesThe dye-sensitized photo-oxidation by singlet oxygen of phenylazoacetylacetones (1) and Phenylazopyrazolones (2) has been investigated. The photo-fading of dyes is accelerated in the presence of Methylene Blue, a sensitizer of singlet oxygen, in airsatured methanolAn excellent relationship exists between the fading-rate of a series of dyes (1) and Hammett-σ-constants. An unexpected trend was found for photo-fading of a series of dyes (2). The Hammett plot consists of two parts, with a negative slope derived from electron-releasing substituents and a positive slope derived from electron-withdrawing substituents. The anomalous photo-fading is due to an attack of singlet oxygen on the more reactive anion of the phenylazopyrazolones in the case of electron-withdrawing substituents. In methanol containing acetic acid the dyes (2) exist only as the hydrazone tautomers. Under these conditions the fading-rate show a linear relationship with σ-constants.
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  • 61
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 994-998 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 3 Tab.
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  • 62
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 1008-1010 
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    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Tab.
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  • 63
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 1016-1020 
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    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Prostaglandins and Prostaglandin Intermediates. XI. Synthesis of Optically Active Bicyclic Lactones - Convenient Intermediates for 8-Methyl Prostaglandins
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  • 64
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 1027-1033 
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    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Quinazoline Carboxylic Acids. III. Quinazolin-4-on-3-benzoic Acids and Esters
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 1034-1036 
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    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Fluorescence Properties of Polymethine Dyes with Bridged Chains
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  • 66
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    Keywords: Chemistry ; Organic Chemistry
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  • 67
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984) 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 68
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 1-11 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Complex Catalysis. XV. Cationic η3-Allyl-bis(triorganylphosphite)nickel(II) Complexes as Catalysts for the Stereoregular Butadiene PolymerisationSynthesis and catalytic properties of [C3H5NiL2]PF6 complexes 1a-f with L = tri-ethyl-, -isopropyl-, -phenyl-, -o-tolyl-, -thymyl- and o-biphenylylphosphite are described. It is shown how electronic and steric effects of the phosphite ligands in these complexes control their catalytic activity and selectivity in 1,4-polymerization of butadiene.
    Additional Material: 7 Tab.
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  • 69
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 12-22 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Polyfunctionalized N-Tensides. VII. Substitution and Elimination in the Reaction of 1,2-Dihalogenoalkanes with Amines1, 2-Dichloroalkanes, 1, 2-dibromoalkanes and mixtures of 1-bromo-2-chloroalkanes and 1-chloro-2-bromoalkanes react with primary or secondary amines and give both elimination and substitution products, often in a nearly 1:1 proportion.The elimination products are the cis and trans-1-halo-1-alkenes, the 2-halo-1-alkenes, the 1,3-and 2, 4-dienes and the 1-alkenes. The main substitution products are the 1, 2-bis-aminoalkanes. Physical dates, 1H-n.m.r.-spectra, surface tension values and CMC-dates are given.
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 23-28 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Kinetik der Dimerisierung von Aminen durch Wasserstoffperoxid in Gegenwart von Fe(II)SO4 als KatalysatorDie Kinetik der Dimerisierung von Diethyl, n-Butyl- und tert.-Butylamin durch Wasserstoffperoxid in Gegenwart von Fe(II)-Ionen wurde untersucht. Die Reaktion ist bezüglich Fe(II)-Ionen und der Amine 1. Ordnung und 0. Ordnung betreffs Wasserstoffperoxid. Produkte der Dimerisierungsreaktionen sowie einige ihrer kristallinen Derivate wurden erhalten und identifiziert. Die Aktivierungsenergien für Diethyl-, n-Butyl- und tert.-Butylamin betragen 153, 130 bzw. 105 KJ mol-1. Ein Reaktionsmechanismus wurde aufgrund der experimentellen Beobachtungen vorgeschlagen.
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 29-34 
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    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Configurational Assignment of Steroids with Primary and Secondary Amino Groups by CD Measurements of the Copper Succinimidate complexesThe CD spectra of the copper succinimidate complexes of 9 different steroids with a primary and 3 steroids with a secondary amino group were investigated. A good correlation between the sign of the Cotton effects in visible range and the chirality of the immediate neighbourhood of the nitrogen atom was observed. The results obey the earlier established octant rule for this chromophor.
    Additional Material: 6 Ill.
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 35-40 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Thermitase - A Thermostable Serine Protease. I. Synthesis of Alanine Peptide Esters as Substrates of the EnzymeThe synthesis of N-acetylated and N-succinylated peptide esters of alanine is described. The peptides are built up from the Z-Abkürzung: Z = Benzyloxycarbonyl, Ac = Acetyl, Suc = Succinyl, OMe = Methylester, MA = Mischanhydridmethode, E = Ether, PE = Petrolether, Etac = Ethylacetat, AcOH = Essigsäure, Dibu = n-Dibutylether, DMSO = Dimethylsulfoxid, DMF = Dimethylformamid, TEA = Triethylamin, Ac2O = Essigsäureanhydrid protected peptides by liquid phase fragment condensation and by acylation of the deprotected peptide esters. The kinetic parameters K m and K cat of some compounds are presented.
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 41-47 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Thermitase - A Thermostable Serine Protease. II. Synthesis of Substrate Analogous Peptide Chloromethyl Ketones as Irreversibly Acting InhibitorsThe preparation of dipeptide to pentapeptide chloromethyl ketones of alanine wth variation of the amino acid in the P1 and P2 positionNomenklatur für die individuellen Aminosäurereste der Peptide nach I. Schechter u. A. C. Berger, Biochem. Biophys. Res. Commun. 27, 157 (1967). of the peptides is described. The synthesis is performed by fragment condensation of N-acylated amino acids or peptides with the unprotected chloromethyl ketone derivatives of amino acids and peptides, respectively. Some examples of enzyme inactivation by peptide chloromethyl ketones are discussed.
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 54-62 
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    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 13C-N.M.R. Investigation of Interannular Conjugation in Substituted PyrazolesThe correlation of the 13C-chemical shifts with the Hammet values for substituted 3-anilino-1, 5-diphenylpyrazoles (1a-k) and substituted 3-methyl-1, 5-diphenylpyrazoles (2a-g) provides evidence for extensive interannular conjugation only between the N-benzene-and the pyrazole rings, whereas in the capto-dative disubstituted system 1 extensive conjugation through the whole molecule is possible. The chemical shifts correlate well with the HMO-calculated π-electron densities. From a comparison of the chemical shifts of unsubstituted 1 and diphenylamine it can be concluded that the 1,5 -diphenylpyrazol-3-yl group has the same electronic effect as the phenyl group.
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 48-53 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Thermitase - A Thermostable Serine Protease. III. Synthesis of N-Acylated Peptide Methyl Ketones as Inhibitors Reversibly Bound to the EnzymeMethyl ketone derivatives of dipeptides to pentapeptides are used as suitable tools in the investigation of the non-covalent binding for subsite mapping of the active site of the enzyme. The synthesis is mainly performed by fragment condensation of N-acylated peptides or amino acids with methyl ketone derivatives of amino acids. These are prepared from the Z-protectedAbkürzungen: Ac = Acetyl, Z = Benzyloxycarbonyl, Boc = t-Butyloxycarbonyl, Suc = Succinyl, Glp = Pyroglutamyl, OBz = Benzylester, pNA = p-Nitranilid, CH3 = Methylketon, CH2Cl = Chlormethylketon, MA = Mischanhydridmethode, TEA = Triethylamin, NEM = N-Ethylmorpholin, CKEE = Chlorkohlensäureethylester, CKBE = Chlorkohlensäurebutylester, MeOH = Methanol, EtOH = Ethanol, AcOH = Essigsäure, Ac2O = Acetanhydrid, Etac = Ethylacetat, THF = Tetrahydrofuran, E = Ether, PE = Petrolether, DMF = Dimethylformamid, DMSO = Dimethylsulfoxid, DMAP = 4-(Dimethylamino)-pyridin cloromethyl ketones by catalytic hydrogenation. For the coupling steps the Z-protection is preferred. The peptide methyl ketones used in kinetic studies were N-protected by the Z, acetyl, Boc or pyroglutamyl residue.
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 73-80 
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    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In the autoxidations of 1-phenylprop-1-yne, 1-phenylbut-1-yne, and 1-phenyl-3-methylbut-1-yne a considerable attack at the C≡C triple bond takes place. Both products of the oxidative cleavage of the C≡C bond and products formed through the corresponding oxirenes were detected. The oxirenes rearrange via the isomeric ketocarbenes to ketenes, which yield the corresponding carboxylic acids or their esters. A part of the intermediate ketenes is oxidized with decarboxylation to lower ketones. All products were identified and quantitatively determined after LiAlH4 reduction to the corresponding alcohols.
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 63-72 
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    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Solvatochromism of 4′-Dialkylamino-α-Cyano-Stilbene-4-Diazonium-Salts4′-Dialkylamino-stilbene-4-diazonium-salts are deep coloured compounds and give strong solvatochromism. 4′-Diethylamino-α-cyano-stilbene-4-diazonium-tetrafluoroborate was investigated in 52 different solvents and 3 binary solvent mixtures. With increasing solvent basicity the longest wave lenght absorption maximum (\documentclass{article}\pagestyle{empty}\begin{document}$ \nu^{\hspace{-5pt}\sim}_{\rm max} $\end{document}) decrease. Complex formation by crown ethers causes a decrease of \documentclass{article}\pagestyle{empty}\begin{document}$ \nu^{\hspace{-5pt}\sim}_{\rm max}$\end{document}, too. In solvents with dielectricity constants higher than about 15 dissociation effects superpose solvatochromism. The summary of experimental dates support the approach of specific nucleophilic solvatation of diazonium ions.
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 81-86 
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    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Ionization and Dissociation of Triphenylmethyl Halides in MethylendichlorideThe Winstein scheme is valid for triphenylmethyl halides in methylendichloride. The equilibrium of ionization and dissociaton has been determined by investigation of the ratio between the sum of concentrations of ionic species and the covalent form. Tritylbromide in methylendichloride shows an exothermic ionization but endothermic dissociation. In the case of tritylchloride ionization and dissociation are nearly independent on the temperature.
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 87-91 
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    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Influence of Styren Addition on the Ionization-Dissociation Equilibrium of Trityl Halides in Methylene DichlorideThe ionization-dissociation equilibrium in solutions of trityl halides in methylene dichloride is effected by the addition of π-donors as a function of the temperature. The intensity of the trityl absorption of trityl fluoride and trityl chloride is decreased as it can be shown by u.v.-spectroscopy. The trityl absorption of trityl bromide solutions in methylene dichloride is very sensitive towards temperature changes. Measurements of the equilibrium constants for the ionization - dissociation-equilibrium, when styrene is added to the solution, indicate a specific solvation effect by the styrene molecules, however, a stabilization of ion pairs by specific solvation due to styrene molecules does not occur.
    Additional Material: 3 Ill.
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  • 80
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 101-110 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A New Synthesis of 6H-1,3-ThiazinesA new method for the synthesis of 1,3-thiazines is described. The addition of nucleophiles to γ-isothiocyanatoallylchlorides (1a-j) leads to functionalisation and subsequent cyclisation (nucleophilic cyclofunctionalisation). Reaction of secondary amines or alcohols under catalysis by tert. amines gives numerous 2-dialkylamino- (3a-w) or 2-alkoxy-6H-1,3-thiazines (4a-p).
    Additional Material: 4 Tab.
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  • 81
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Photoinduced Electron Transfer-Reactions of Arenediazonium Ions Complexed with Crown EthersThe photolysis (full light of a medium pressure Hg-lamp) of p-methylbenzenediazonium-tetrafluoroborate in the presence of the crown ether 18-crown-6 (1) yields mainly the products of a heterolytic dediazoniation via arene cations as intermediates. The quantum yield ϕges of the photolysis from p-methoxybenzenediazonium-tetrafluoroborat in CH2Cl2 decreases in the presence of 18- crowns-6 (1) from 0.66 to 0.08. In contrast to 1, the photolysis of arenediazonium salts in the presence of dibenzo-18-crown-6 (3) yields mainly the products of a homolytic dediazoniation as a consequence of an electron transfer from 3 to the diazonium ion. ϕges of this reaction increases with decreasing wavelength of the exciting light from 0.09 (436 nm) to 0.32 (366 nm). this wavelength dependence is explained by formation of a correlated radical pair after excitation. In agreement with this situation a photo-CIDNP-effect is observed in the 15N-n.m.r.-spectra of isotopically labeled arenediazonium salts complexed by 3 and benzo-18-crown-6(2). No photo-CIDNP-effect is observed in the presence of 1. This different behaviour of the EDA-complexes formed by arenediazonium salts with the two different groups of crown ethers 1 and 2, 3 is discussed as a control of the electron transfer-reaction by the structure of the frontier orbitals.
    Additional Material: 3 Ill.
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  • 82
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 121-128 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Dicyclopentadiene Oxidation. IV. Oxidation of 4,5- and 8,9-Dihydro-dicyclopentadieneA mixture of exo- and endo-4,5-dihydro-dicyclopentadiene 5 and also pure endo-8,9-dihydro-dicyclopentadiene 7 and pure exo-dicyclopentadiene 10 was oxidized in the absence and in the presence of catalysts. The compounds containing the norbornene structure mainly gave the corresponding exo-epoxides. No catalytic effects were observed in the formation of these nor-bornene epoxides. Compound 7 containing only the cyclopentene structure mainly yielded the corresponding hydroperoxide 9. In this case a catalytic effect of epoxidation catalysts was observed: in the presence of such catalysts the epoxide was increased.The results obtained prove the mechanism of dicyclopentadiene oxidation proposed by us.
    Additional Material: 4 Tab.
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  • 83
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 129-138 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Acylation of Heterocycles with Carbonic Acid Derivatives. IV. Reaction of Benzoxazolin-2-thione with Aryl Cyanates. Kinetics and MechanismThe arylcyanate benzoxazoline-2-thione (1) reaction in the presence and absence of the tertiary amines yields 1-aryloxyiminocarbonylbenzoxazoline-2-thione (2) and 2-thiocyanatobenzoxazole (4). A mechanism is proposed based on the influences of the reactants concentration, the concentration and basicity of tertiary amines, the solvent-water concentration, the arylcyanate substituents electronic effects on the reaction rate and the apparent activation parameters. This mechanism consists in the nucleophilic attack of the benzoxazoline-2-thione S-atom on the cyanate, followed by rearrangement through a four-center transition state.
    Additional Material: 8 Tab.
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  • 84
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 145-147 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: INDO Calculation of 15N-13C Coupling Constants in Simple Cyanines and Merocyanines
    Additional Material: 1 Ill.
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  • 85
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 139-144 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Quantum-Chemical Calculations on Allyl-Type Radicals: Cycloalkenyl- and Cycloalk-1-enylmethyl RadicalsThe ability of the MINDO/3-HE-method for predicting various molecular properties was tested for cycloalkenyl- (1 to 4), cycloalk-1-enylmethyl-(5 to 8), and for the resonance-stabilized cyclic radicals (9 to 12). Close by it was established that the calculated heats of formation are largely correct. The electronic distribution in the allylic part of 1 to 12 is evidently too levelled.Based on the defination of allyl resonance energy (ARE - SZWARC (1948)) a mean value for the ARE of 1 to 8 is derived to 55 ± 12 kJ · mol-1.
    Additional Material: 3 Tab.
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  • 86
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 222-232 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Carbon-13 Nuclear Magnetic Resonance Spectra of PhenylfulgidesThe carbon-13 chemical shifts are determined in a series of phenylfulgides in order to investigate steric and electronic influences of substituents. By means of the shift differences between suitably substituted compounds results can be obtained as to the relative variation of the rotation angles of the phenyl rings as well as to te angle alterations between the exocyclic double bonds and the anhydride ring. Introducing 4-CH3O- and 4-NO2-groups at the phenyl rings the substituent induced alterations of the carbon-13 chemical shifts and the π-polarization effects related with it are discussed.
    Additional Material: 3 Ill.
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  • 87
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 233-247 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Electronic and Steric Substituent Influences on the U.V./VIS-Absorption Spectra of Phenylfulgide IsomersThe u.v./vis spectral data of a large number of phenylfulgides (E-, Z-, E-E-, E-Z-, Z-E-, Z-Z-isomers, 1.8a-dihydronaphthalenes) are presented. An increase of the number of phenyl rings as well as substitution of the phenyl rings cause correlatable bathochromic spectral shifts. Steric influences became obvious by introducing methyl groups, by coplanarization of phenyl groups and in the series of isomers. By means of PPP calculations shifts in position and/or intensity of absorption bands are ascribed to the substituent effects.The calculated band polarization of E(E-E)-isomers are in agreement with the results of polarization spectra in oriented liquid crystal mesophases. The polarization spectra allow the assignment of the longwave absorption band to the S2 ← S0 and S1 ← S0 electronic transitions for E-E-Isomers with a C2v-symmetry.
    Additional Material: 4 Ill.
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  • 88
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 248-252 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: α-Cyanochalcone reacted with thiourea and guanidine to yield the corresponding pyrimidine derivatives 2 and 4. On the other hand, urea reacted with the same reagent under the same experimental conditions to yield the known urea derivatives 3. A new synthesis of polyfunction pyridine via reaction of 1a with malononitrile in presence of aniline could be developed. Similar to the behaviour of 1a, Compounds 1b, c reacted with malononitrile in presence of aniline to yield compounds 8 and 9. In contrast to the behaviour of compounds 1a-c, 1d reacted with malononitrile to yield the malononitrile derivatives 10 or 11 based on the reaction conditions. Mechanisms to account for formation of the reaction products were suggested.
    Additional Material: 2 Tab.
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  • 89
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 253-258 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Gibberellins. CIII. Synthesis of 8-Amino-gibbanesFor investigations of the structure-activity relationships of gibberellin phytohormones the synthesis of 8-amino-gibbanes is described. The reaction pathway involves condensation of gibberellin C (1a) and its methylester 1b with primary amines to the corresponding azomethins 1c-11 followed by stereoselective NaBH4-reduction to 8α-amino gibbanes 2a-2r.
    Additional Material: 1 Ill.
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  • 90
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    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Studies on U.V./Vis Absorption Spectra of Azo Dyes. XI. General Relationships between Structure and Colour of Protonated Azo DyesThe U.V.-VIS spectra of a wide range of azo dyes having structural variations in both diazo and coupling components in acidic solution are discussed.The azonium cation can be regarded as a donor-acceptor chromophore. Thus, structural variations which give a bathochromic shift in λmax, are explained. The negative halochromism is also discussed with reference to this model.
    Additional Material: 1 Ill.
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  • 91
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 287-302 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Pyrylium Compounds. XXI. Structure and Tautomerism of Pseudobases of Unsymmetrically Substituted 2,4,6-Triarylpyrylium SaltsHydrolytic ring opening of unsymmetrically substituted 2,4,6-triarylpyrylium salts 11 results in a mixture of two tautomeric pseudobases, the penten-1,5-diones 13 and 14. In crystalline state as a rule one of these tautomers markedly predominates, whereas in solution a rapid equilibrium establishment occurs which can be followed by 1H-n.m.r. and u.v. spectroscopy (equilibrium ratio nearly 1:1). The 1H-n.m.r. spectroscopic structural assignment of the two isomeric forms was supported by u.v. spectroscopic studies using 1:1 mixtures of the chromophoric partial systems ArCOCH=CHPh and ArCOMe or the pseudobases 10 of symmetrically substituted 2,4,6-triarylpyrylium salts 9 as reference systems. From the mass spectra of the pseudobases 10 and 13/14 follows that - if hydrolysis of 11 is performed in media containing H218O - mass spectrometric isotopic analysis of the resulting 18O-labelled pseudobases allows no information to be made about the regioselectivity of the ring opening. - Novel starting pyrylium salts of type 9 and 11 are characterized by u.v./vis data and by transformation into the corresponding pyridine derivatives.
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  • 92
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    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 2, 2-Disubstituted Cyclopentane-1, 3-diones. IV. Synthesis of Prochiral Intermediates for the Synthesis of 8-Methyl-prostaglandin C2 by Alkylation of 2-Methyl-cyclopentane-1, 3-dione with 1-Bromo-alk-2-ynes.2-Methyl-cyclopentane-1, 3-dione (1) is preferentially C-alkylated by 1-bromo-alk-2-ynes in aqueous sodium hydroxide solution. By this method it is possible to prepare 2,2-disubstituted-1, 3-diones (3-8), which can be converted into prochiral intermediates for 8-methyl-PGC2, containing the complete carboxylic side chain.
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  • 93
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 457-466 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Synthesis and Properties of Liquid Crystalline Derivatives of RhodanineSubstituted benzylidene-rhodanines 3-8 were prepared both by condensation of 1 a-f with suitable aldehydes and by acylation of 2a-g with substituted benzoyl chlorides or cinnamoyl chlorid. The mesomorphic properties of the compounds are discussed in respect to molecular structure with the aid of i.r.-, Raman- and u.v./vis-spectra of 3d, 3k, 4, 5, 6g, 8a. We have investigated the dielectric and electrooptic behaviour of 31.
    Additional Material: 3 Ill.
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  • 94
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 515-518 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 3 Ill.
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  • 95
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 524-528 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Two Modified Pulse Sequences for the 13C NMR Spectroscopic Characterization of CHn Building Groups. An Effective Method for the Determination of n and for the Estimation of 1J(13C—1H)
    Additional Material: 3 Ill.
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  • 96
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    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Cationic Photopolymerization of Isobutylglycidyl Ether with Benzoine Derivatives/Arylonium Salts- or Benzildimethyl Ketal/Arylonium Salts-Initiator SystemsRadicals produced by photolysis of benzoine derivatives and benzile dimethylketale decompose arene diazonium salts (ArN2⊕), diphenyliodonium salts (Ph2I⊕) and triphenylsulfonium salts (Ph3S⊕), respectively. The carbenium ions or protons formed in this way can be used for the cationic polymerization of isobutylglycidyl ether (IBGE). The efficiency of this polymerization depends on the quantum yields of the onium salts decomposition. A reactivity ArN2⊕ 〉 Ph2I⊕ 〉 Ph3S⊕ was found. In the case of ArN2⊕ the salt decomposition is caused by electron transfer between the photolytically produced substituted benzylic radicals and the diazonium ions. It is assumed that by the decomposition of Ph2I⊕ and Ph3S⊕ intermediates occur, which give rise to some reversible reactions. Therefore, the quantum yields of onium salt decomposition are less than those of initiator photolysis. The rate of cationic polymerization of IBGE is also influenced by the anion of onium compounds. A sequence PF6⊖ 〉SbF6⊖ 〉BF4⊖ was found.
    Additional Material: 2 Ill.
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  • 97
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    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Complications in the Initiation of Cationic Polymerizations by Lewis Acids - Model Calculations for Antimony(V)halogenidsQuantum-chemical CNDO/2-calculations including geometry-optimization show that complex anions (X5Sb-Z-SbY5)⊖ are formed as a result of interaction between Lewis acids SbX5 and anions SbY5Z⊖ (X, Y, Z = F, Cl, Br). This interaction is very strong in the case of X, Z = F and Y = Br. When the complex anions decompose the simple anions with the greatest number of fluorine ligands are formed.The interaction between the two different Lewis acids SbX5 and SbY5 yields a random distribution of the ligands of both acids.During formation of the ions SbX4⊕ and SbXY5⊖ the anion with the greatest number of fluorine ligands is formed.The probability of the conversion Sb(V)-Sb(III) is higher for SbCl5 than for SbCl6⊖.
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  • 98
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 572-578 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Valeric, caproic, and heptanoic acid and their methyl esters were oxidized at 140°C by molecular oxygen. The oxidation mixtures were reduced by LiAlH4 and the mono- and dihydroxy compounds formed were analyzed gaschromatographically. From the results obtained one can conclude that nonbranched aliphatic acids and their methyl esters are attacked by the chain-carrying peroxy radicals at the different C—H bonds with almost the same regioselectivity as normal paraffins Only the ß- and to a smaller extent the α-positions are desactivated by the neighbouring carboxylic group.
    Additional Material: 9 Tab.
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  • 99
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 588-593 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Spin Trapping. I. Investigation of Radical Reactions of Some 3-Nitrono-6-oxocyclohexadienes by ESR-SpectroscopyThe title compounds (3, 4 and 5) add O- and C-centered radicals to the nitrono group to yield spin adducts containing a 4-oxo-cyclohexadienyl group in the α-position (6, 7 and 8). These new nitroxylradicals undergo α- and ß-scission. The nitroxyl radicals and the paramagnetic decomposition products were detected by esr-spectroscopy.Further, a more general way of radical-induced decomposition was discussed.
    Additional Material: 1 Ill.
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  • 100
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 594-598 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Reactions of 2-Cyano-3-methoxy-maleinimide with Methylene Active Compounds and EnaminesThe vinylogous ester 1 gives with methylenactive compounds 2 carbamoylmaleinimides 3, which cyclize to pyridonimides 4. Reactions of 1 with enamines form cyanomaleinimides 6-8 and aminopyridines 11.
    Additional Material: 1 Tab.
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