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  • 1
    Electronic Resource
    Electronic Resource
    N6-Adenyl arylation of DNA by aristolochic acid II and a synthetic model for the putative proximate carcinogen (1991)
    s.l. : American Chemical Society
    Chemical research in toxicology 4 (1991), S. 581-586 
    Details
    ISSN: 1520-5010
    Source: ACS Legacy Archives
    Topics: Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/tx00023a015
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  • 2
    Electronic Resource
    Electronic Resource
    DNA methylation in various rat tissues by the esophageal carcinogen N-nitrosomethyl-n-amylamine and six of its positional isomers (1991)
    s.l. : American Chemical Society
    Chemical research in toxicology 4 (1991), S. 77-81 
    Details
    ISSN: 1520-5010
    Source: ACS Legacy Archives
    Topics: Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/tx00019a010
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  • 3
    Electronic Resource
    Electronic Resource
    Benzenediazonium Ion Derived from Sudan I Forms an 8-(Phenylazo)guanine Adduct in DNA (1995)
    s.l. : American Chemical Society
    Chemical research in toxicology 8 (1995), S. 489-498 
    Details
    ISSN: 1520-5010
    Source: ACS Legacy Archives
    Topics: Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/tx00046a002
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  • 4
    Electronic Resource
    Electronic Resource
    Interference of acetoxyalkyl-nitrosamines with limb bud differentiation in organ culture (1983)
    Springer
    Archives of toxicology 54 (1983), S. 109-129 
    Details
    ISSN: 1432-0738
    Keywords: Limb bud culture ; Acetoxyalkylnitrosamines ; Teratogenicity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract α-acetoxynitrosamines have been used as model compounds to study biological activity of N-nitrosamines. After hydrolytic cleavage they yield an “active intermediate” (the hydroxynitrosamine) which presumably also arises as metabolite of N-nitrosamines. We tested eight N-nitrosamines mono-substituted at theα-carbon with an acetoxy group for their teratogenic potential in a mouse limb bud culture system. The following results were obtained: 1. The methyl compound (MOAc-MNA) — a derivative of dimethynitrosamine — proved to be the strongest teratogen in this group of chemicals. 2. The tertiary-butyl derivative — releasing a carbonium ion of low chemical reactivity — possessed the lowest activity in our test system. 3. The primaryα-acetates with unbranched side chains (POAc-MNA or BOAc-MNA) were more active than the corresponding derivatives with branched side chains. 4. The secondaryα-acetate (EOAc-ENA) was clearly less active than the primaryα-acetate (EOAc-MNA). 5. A teratogenic potential could also be demonstrated in the organ culture system with the cyclic derivative: N-nitroso-α-acetoxy-pyrrolidine (NAPYR). 6. With the use of limb buds from 12-day-old mouse embryos the explants showed the highest susceptibility to the teratogens on the first day of culture. No effect could be produced if the substances were added to the culture medium at the third day of culture or later. 7. When initiating the culture with limb buds from 11-day-old mouse embryos the concentrations needed to induce typical effects were lower than those tested with 12-day-old explants. 8. Typical and pronounced impairment with morphogenetic differentiation could be induced by MOAc-MNA if the substance was present in the medium for less than 60 min — the shortest period tested was 15 min. 9. A different abnormality pattern could be induced with the various substances tested. This may partly be explained by a quite different stability of the compounds in the test system. 10. N-Nitrosamines must be expected to be highly teratogenic if they can be “activated” in embryonic tissues. Such an activation into potent electrophilic agents does not occur in rodents under normal conditions. It will be interesting to study if such activity can be “induced” in embryonic tissues of rodents or if it is already present in embryonic tissues of primates.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01261380
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  • 5
    Electronic Resource
    Electronic Resource
    Sugar-Linked Dithiocarbamates as Modulators of Metabolic and Genotoxic Properties of N-Nitroso Compounds (1994)
    s.l. : American Chemical Society
    Journal of medicinal chemistry 37 (1994), S. 3154-3162 
    Details
    ISSN: 1520-4804
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/jm00045a021
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  • 6
    Electronic Resource
    Electronic Resource
    Embryotoxicity induced by alkylating agents: left-sided preponderance of paw malformations induced by acetoxymethyl-methylnitrosamine in mice (1985)
    Springer
    Archives of toxicology 56 (1985), S. 139-150 
    Details
    ISSN: 1432-0738
    Keywords: Acetoxymethyl-methylnitrosamine ; Teratogen ; Sidepreference ; Limb bud culture ; DNA alkylation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract 1. The alkylating agent acetoxymethyl-methylnitro-samine (DMN-OAc) triggers preferential left-sided paw defects in mice following IP administration on either day 11 or 12 of pregnancy. Predominantly, ectrodactyly and hypoplasia of the left paws were found. 2. In an organ culture system, using limb buds of 11-day-old mouse embryos, differentiation is severly impaired following addition of 2 μM DMN-OAc to the culture medium. Left and right limbs are equally affected. In contrast, when DMN-OAc is administered in vivo to the dams with subsequent culturing of the limb buds, growth and differentiation of the left limb buds is more affected when compared to the right. 3. Furthermore, DNA alkylation experiments were performed: in vitro, following addition of (14C)-DMN-OAc (2.3 μM) to the culture medium, the DNA alkylation rate of the limb bud DNA is determined. In vivo, following IP administration of 10 mg/kg DMN-OAc to the dams on day 11 of pregnancy, the extent of DNA alkylation of whole-embryo DNA is similar. However, the DNA alkylation rate of separately pooled left and right limb buds exhibits a two-fold difference according to the different teratogenic susceptibility. The results obtained with both in vivo and in vitro systems are consistent with the thesis that a certain amount of DNA alkylation in the tissue of the embryos is the initial step of alkylating agent-induced teratogenicity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00333418
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  • 7
    Electronic Resource
    Electronic Resource
    N-Nitrosamino phosphates are unlikely transport forms for activated nitrosamines (1990)
    Springer
    Journal of cancer research and clinical oncology 116 (1990), S. 569-574 
    Details
    ISSN: 1432-1335
    Keywords: N-Nitrosodimethylamide ; N-Nitrosomethylbenzylamine ; Hepatocytes ; Organotropy ; Conjugates
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Some of the target organs for nitrosamine carcinogenicity have a low activating capacity but many carcinogenic nitrosamines can be activated in the liver. Conjugates, such as phosphates, are chemically accessible reaction products of 1-OH-nitrosamines, and are either potential detoxication products or potential transport forms for activated nitrosamines.14C-labeled 1-(N-ethyl-N-nitrosamino)ethyl phosphate was tested for its ability to enter primary rat hepatocytes but no uptake was detectable. No uptake was observable into fibroblasts and human leukocytes.N-Nitrosomethylbenzylamine is efficiently 1-C-hydroxylated by hepatocytes but the corresponding 1-C-phosphate was detectable neither in the cells nor in the surrounding medium.N-Nitrosamino-1-phosphates, unlike 1-glucuronides, therefore, do not seem to be important for nitrosamine toxicokinetics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01637076
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  • 8
    Electronic Resource
    Electronic Resource
    Beta-galactosidase catalysed synthesis of branched oligosaccharide analogues (1997)
    Springer
    Biotechnology letters 19 (1997), S. 269-272 
    Details
    ISSN: 1573-6776
    Source: Springer Online Journal Archives 1860-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Beta-galactosidase from bovine liver and from E. coli was successfully employed in the glycosylation of the monoallyl and monobenzyl ether (2 and 9, resp.) of 1,3,5-benzene-trimethanol. The monoglucoside of 2 was obtained in 65% yield. Galactosylation of the isopropylidene protected monoglucoside yielded the monoglucosyl monogalactosyl adduct (17%) and the monoglucosyl bisgalactosyl adduct (10%). 9 was converted into the bisarabinopyranosyl adduct (3%).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1018365809793
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  • 9
    Electronic Resource
    Electronic Resource
    One Step Isolation of Bovine Asialoglycoprotein Receptor and Its Characterization by Sequence Analysis and MALDI Mass Spectrometry (1999)
    Springer
    Bioscience reports 19 (1999), S. 115-124 
    Details
    ISSN: 1573-4935
    Keywords: Carbohydrate binding proteins ; liver ; plasma membrane ; MALDI-TOF mass spectrometry ; sequence analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The asialoglycoprotein receptor (ASGP-R), which is responsible for the uptake of partially deglycosylated serum glycoproteins was isolated from bovine liver. The receptor was purified in one step from solubilized plasma membranes by affinity chromatography on 6-(β-D-lactosyl)-n-hexylamine coupled to N-hydroxysuccinimide activated Sepharose with a coupling degree of 7.6 μmol/ml gel. The preparation yielded two distinct polypeptides with apparent molecular weights of 48 and 43 kDa as determined by sodium dodecyl sulfatepolyacrylamide gel electrophoresis. A polyclonal antibody raised against the human ASGP-R recognized the bovine 43 kDa protein in Western blot analysis. The 48 and 43 kDa polypeptides were digested by trypsin and the digests were subsequently analyzed by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry. Sequence analysis of four tryptic fragments, two each of the 48 kDa and of the 43 kDa polypeptides revealed that these were highly homologous to ASGP-R subunits from man, mouse and rat.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1020162527447
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  • 10
    Electronic Resource
    Electronic Resource
    Chemie der Nitrosamine, V. Synthesen von α-funktionellen N-Nitrosodialkylaminen: Dithioester und Thioether (1987)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1987 (1987), S. 583-588 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Chemistry of Nitrosamines, V. - Syntheses of α-Functional N-Nitrosodialkylamines: Thioethers and DithiocarbamatesThe in vivo reaction products of electrophilic compounds with glutathione are excreted as S-alkyl-N-acetylcysteins (mercapturates) after enzymatic degradation. The results clearly show that mercapturates as 1-substituted N-nitrosodialkylamines 11 are chemically stable enough to be isolated and characterized. The reactions of 1-chloro-N-nitrosodialkylamines 5 with 3,4-dichlorothiophenol, ethanethiol, and N,N-diethyldithiocarbamate illustrate the high tendency of formation of 1-thiosubstituted nitrosamines.
    Notes: S-Alkyl-N-acetylcysteine (Mercapturate) werden als enzymatische Abbauprodukte der Reaktion von Glutathion mit elektrophilen Verbindungen im Organismus ausgeschieden. Es wird gezeigt, daß Mercapturate als 1-substituierte N-Nitroso-Verbindungen 11 synthetisch zugänglich und stabil sind. Durch die Umsetzungen von 1-Chlor-N-nitrosodialkylaminen 5 mit weiteren Schwefelnucleophilen wie 3,4-Dichlorthiophenol, Ethanthiol und N,N-Diethyldithiocarbamat läßt sich die große Bereitschaft zur Bildung von 1-thiosubstituierten Nitrosaminen aufzeigen.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198719870704
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