MUTAGENIC ACTIVITY OF 6-AMINOQUINOXALINES IN SALMONELLA-TYPHIMURIUM

Mutagenicity of 6-aminoquinoxaline derivatives was tested with Salmone lla typhimurium strains TA98 and TA100 in the presence and absence of S9 mix from the viewpoint that the 6-aminoquinoxaline skeleton is a co mmon unit of mutagenic imidazoquinoxalines. We tested nine compounds: 5-methyl-6-methylaminoquinoxaline (1), 3,5,-dimethyl-6-methylaminoquin oxaline (2), 2,5-dimethyl-6-methylaminoquinoxaline (3), 6-methylamino- 2,3,5-trimethylquinoxaline (4), 2,3-diethyl-5-methyl-6-methylaminoquin oxaline (5), 5-methyl-6-methylamino 3-phenylquinoxaline (6), 6-amino-2 ,3,5-trimethylquinoxaline (7), 6-dimethylamino-2,3,5- trimethylaminoqu inoxaline (8), 6-amino-2,3-dimethylquinoxaline (9). These compounds sh owed the mutagenic activity for both TA98 and TA100 in the presence of S9 mix, where they were more sensitive for TA100 strain. Methyl group s at the 2, 3 and/or 5 positions increased the potency of mutagenicity (1 < 2 < 3 much less than 4, 9 < 7). However, ethyl groups at the 2 a nd 3 positions lowered the mutagenicity of the methyl substitute but e levated it of the parental compound (1 < 5 < 4). A methyl group at the N-6 position decreased the mutagenicity (7 > 4 > 8).