The mutagenicity of some novel phenyl-imidazopyridines.
The mutagenicity of some novel 2-phenyl-imidazopyridines was investigated by the Ames test. Those with nitro substituents, and 2 related nitrophenylpurines, were frame shift mutagens without liver activation. Similar compounds without nitro groups had no activity. The mutagenic compounds were more active against TA1538 than against TA98, and were also active against TA100, a base-pair substitution mutant. This unusual pattern of activity is similar to that of 2-nitrosofluorene and related compounds. Calculations of molecular size showed a relationship between the 2 groups of compounds, suggesting similar modes of action. The more potent mutagens were toxic at high concentrations. Many of the non-mutagenic compounds were toxic, depending upon their substituents. In general, the imidazol[4,5-c]pyridines were more biologically active than the imidazo [4,5-b]pyridines.