Influence of the triazine ring on the mutagenicity of triazinoindoles and some congeners.

Three compounds, which could be considered as precursors or derivatives of the 3-(4'-substituted-benzylidenamino)5H- 1,2,3-triazin[5,4b]indol-4-one series, were selected from the study of their mutagenic activity. Ames tests were performed study of their mutagenic activity. Ames tests were performed using the Salmonella typhimurium strains TA97, TA98, TA100, and TA102, according to the preincubation procedure, both with and without metabolic activation. The 3-amino-5H-1,2,3-triazin[5,4b]indol-4-one has been shown to be a strong S9-independent mutagen, which reverts frameshift and substitution mutations. Nevertheless its potency increases with the addition of microsomal fraction. In contrast, the 2-benzyliden-1-(3-aminoindol)-2-carbohydrazide and the 3-aminoindol-2-carbohydrazide congeners were not mutagenic. These results suggest that the 1,2,3-triazine ring is the principle substructure responsible for the mutagenicity of the triazinoindole congeners studied.