Mutagenic effect of 1.1'-hexamethylene-bis-[(5-p-chlorophenyl)-biguanide].

The strongly effective bactericidal compound 1.1'-hexamethylene-bis-[(5-p-chlorophenyl)-biguanide] (HCG) induces mutations with a slight inactivation rate in the auxotrophic strains Salmonella typhimurium TA 1535 and TA 1538 in 0.4 microM solution. The mutagenic effect could be confirmed by using the plate incorporation test and the repair test. As phenylethylbiguanide at different inactivation rates does not show any mutagenic effect, the biguanide structure does not seem to be responsible for chemical mutagenesis. A hypothetic mutation mechanism is proposed and compared with the corresponding reaction mechanism of N-methyl-N'-nitro-N-nitro-soguanidine (MNNG).