Mutagenic activity of some 9-aminoalkyl acridine derivatives on S. typhimurium.

The mutagenic potential of 9-(3'-dimethylaminopropylamino)-acridine and of its 1-nitro and 2-nitro derivatives was investigated by using histidine-requiring mutants of Salmonella typhimurium. The 9-(3'-dimethylaminopropylamino)-acridine exhibited a weak mutagenic activity only on one of the S. typhimurium tester strains, TA1537. The 1-nitro derivative induced mutations with high frequency in strains TA1537, TA1538 and TA98, whereas the 2-nitro derivative was substantially more mutagenic than the parent compound but it was much less mutagenic than the 1-nitro derivative. Pre-mutational damages made by the 1-nitro derivative were repaired by the uvrB gene-repair system, whereas those caused by the 2-nitro derivative could not be repaired by this system. Both the 1-nitro and 2-nitro derivatives induced some mutations in the base-pair substitution strain TA100 carrying a plasmid. The frequency of the his+ mutation induced both by 1-nitro and by the 2-nitro derivatives in strain TA101 lacking a nitro reductase was lower. These results emphasize the involvement of the nitro group in the interaction of acridine derivatives with the bacterial genome.