Mutagenicity of some benzidine congeners and their N-acetylated and N,N′-diacetylated derivatives in different strains of Salmonella typhimurium

The Ames Salmonella/microsome test was used to compare the mutagenic response of Salmonella typhimurium TA100, TA98, TA1538, and TA1535 to 12 benzidine derivatives, ie, benzidine, 3,3′-dimethoxybenzidine, 3,3′-dimethylbenzidine, 3,3′-dichlorobenzidine, and the corresponding N- and W,W-diacetylated derivatives. With a few exceptions, the mutagenic response to this series of compounds varied in the order TA98 > TA1538 > TA100 > TA1535 = 0, and the N-monoacetylated derivatives were more mutagenic than either the parent diamines or the N,N′-diacetyl derivatives. The relative mutagenicities of the parent amines for TA98 were 3,3′-dichlorobenzidine > > 3,3′-dimethoxybenzidine > benzidine > 3,3′-dimethylbenzidine.