Comparison of mutagenicity and chemical properties of N-methyl- N′-alkyl- N-nitrosoureas

Abstract

Thed mutagenic activities of 11 N-methyl- N′-alkyl- N-nitrosoureas were tested on Samonella typhimurium TA1535 and compared with chemical properties (alkylating activity and decompostion rate). In their relative mutagenicities the N-nitrosoureas that had a cyclic N′-alkyl group showed far more mutagenic activity than those having a chain N′-alkyl group. M(1-A)NU and M(2-A)NU, which had the most bulky N′-alkyl group in this series, exhibited lethal effects at high concentrations. The mutagenicity showed a small positive correlation with decomposition rates but not with alkylating activities on 4-( p-nitrobenzyl_prridine. The highest mutagenicity in this series was observed in N-methyl- N′-cyclobutyl- N-nitrosourea. These results suggest that, in this series of N-methyl- M′-alkyl- N-nitrosoureas, structural differences in the N′-alkyl groups had great significance in mutagenicity.