ISSN:
1617-4623
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Summary 1. A homologous series of N-nitroso-N-methylcarbonamides was synthesized. These substances in aqueous solution decompose into a fatty acid-residue and diazomethane. The intact molecule is considered as a transport-form generating the active form, diazomethane. The fatty acid residue was varied from a chain length of 3 to 14. The chain length of the fatty acid residue determines largely the lipophilic properties; the rate of hydrolysis and generation of the active form, diazomethane, being almost the same for all these compounds. 2. These N-nitroso-N-methylcarbonamides were tested for their mutagenic efficiency in a reverse mutation system in a haploid, adenine-requiring strain ofSaccharomyces cerevisiae. The mutagenic efficiency was defined by the concentration which under standard conditions induced the mutation frequency of 200 mutants per 106 survivors. 3. The mutagenic efficiency increased at first slowly than more rapidly with the chain length of the fatty acid residue and reached a maximum at 10 C-atoms per chain. The difference in mutagenic efficiency between the most inefficient and the most efficient agent amounted to a factor of about 300. 4. The chemical reactivities in vitro of the different compounds, and generation of the active form, were roughly the same in spite of a 300 fold difference of the mutagenic efficiency. This suggests that in mutation induction other parameters play a more important rôle than the mere in vitro reactivity. 5. The mutagenic efficiency is interpreted to result from a localized, intracellular accumulation of the transport-form against a steep concentration gradient. It is considered that strong lipophilic properties are the reason for such an intracellular accumulation.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00895261
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