Mutagenic potential of stereoisomeric bay region (+)- and (-)-cis-anti-benzo[a]pyrene diol epoxide-N2-2'-deoxyguanosine adducts in Escherichia coli and simian kidney cells

The mutagenic potential of site-specifically positioned DNA adducts with (+)- and (-)-cis-ante stereochemistry from the binding of r7,t8-dihydroxy-t9,10-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene (BPDE) to N2-3'deoxyguanosine was examined. Results showed that the two cis adducts were less mutagenic than the trans adducts in the COS cells. An association between the high mutagenicity of the 10S-(+)-trans adduct at G2, the 10S stereochemistry and the absolute configurations of the OH groups in the BPDE residue was observed.