Oxidative Demethylation and Carcinogenicity of 4-N-Dimethylaminoazobenzene Derivatives

Abstract

RECENT work on the hepatocarcinogenic amino-azo compounds has shown that the presence of at least one N-methyl group and the formation of a firmly bound compound between metabolites of the azo compound and rat-liver proteins are probably necessary for the strong activity¹. The biochemical behaviour of N-methyl groups with respect to the protein-bound polar dye formation has not yet been elucidated satisfactorily, because of the structural complexity and very little amounts of polar dye obtained. We showed that the N-¹⁴C-methyl group of 4-N-¹⁴C-methylaminoazobenzene was incorporated almost quantitatively into the polar dye². The N-methyl group of 4-N-methylaminoazobenzene (MAB), being one of the most reactive sites and rapidly demethylated to split formaldehyde, appears to be responsible for the polar dye formation in an active metabolic intermediate.