Characterization of Directly Acting Mutagens Produced from N-Nitroso-N- (formylmethyl) alkylamines : Their Possible Involvement in the Carcinogenesis of N-Nitrosamines Having a 2-Hydroxyethyl Group

Abstract

Directly acting mutagens formed from N-nitroso-N- (formylmethyl) alkylamines (3) were isolated and identified as N-nitroso-N-alkyl-1-hydroxyimino-2-oxoethylamines (4). Their structures were elucidated on the basis of nuclear magnetic resonance spectra and confirmed by derivatization to the crystalline 2, 4-dinitrophenylhydrazones (5). Compounds 4 (alkyl =ethyl and butyl) were strongly mutagenic to Salmonella typhimurium TA 1535 and Escherichia coli WP2 hcr^- without metabolic activation, while 4 with a tert-butyl group was not mutagenic. The formation of 4 is considered to proceed by the nitrosation of 3, indicating a possible involvement of the formylmethyl metabolite in carcinogenesis by N-nitrosamines with a 2-hydroxyethyl group.