Absolute stereochemistry of the major 7,12-dimethylbenz(a)anthracene-DNA adducts formed in mouse cells

Abstract
In recent work we assigned partial structures to individual 7, 12-dimethylbenz[a]anthracene (DMBA) - deoxyribo-nudeoside bisphosphates separated by TLC after postlabel-ing with [32P]ATP. We have now been able to postlabel DNA adducts formed in cells exposed to either the (4R, 3R)- or (4S, 3S)-dihydrodiol of DMBA and thereby to assign absolute stereochemistry to the 2-, 3- and 4- positions in the major DMBA-DNA adducts. It is found that the major and dihydrodiol epoxide-DNA adducts arise from the (4R, 3S)-dihydrodiol (2S, lR)-epoxide and that the major syn dihydrodiol epoxide-DNA adducts arise from the (4S, 3R)-dihydrodiol (2S, 1R)-epoxide.