Synthesis of 6-methylchrysene-1,2-diol-3,4-epoxides and comparison of their mutagenicity to 5-methylchrysene-1,2-diol-3,4-epoxides.

The syn- and anti-isomers of 1,2-dihydroxy-3,4-epoxy-1,2,3,4-tetrahydro-6-methylchrysene (6-MeC-1,2-diol-3,4-epoxide) were synthesized and their mutagenic activities in Salmonella typhimurium were compared with those of the syn- and anti-isomers of 1,2-dihydroxy-3,4-epoxy-1,2,3,4-tetrahydro-5-methylchrysene (5-MeC-1,2-diol-3,4-epoxide). The most mutagenic compound was anti-5-MeC-1,2-diol-3,4-epoxide, followed by syn-5-MeC-1,2-diol-3,4-epoxide. At the same doses, neither of the 6-MeC-1,2-diol-3,4-epoxides was mutagenic. These results demonstrate the enhancing effect on mutagenicity of a methyl group in the same bay region as the epoxide ring of a diol epoxide.