BENZO[C]PHENANTHRENE 3,4-DIHYDRODIOL 1,2-EPOXIDE ADDUCTS IN NATIVE AND DENATURED DNA

High performance liquid chromatography/UV-absorption and P-32-postlabe ling were used to quantitate adducts generated by reaction of the four configurationally isomeric benzo[c]phenanthrene 3,4-dihydrodiol 1,2-e poxides with native or denatured DNA in vitro. For both the 4R,3S-dihy drodiol 2S,1R-epoxide and the 4S,3R-dihydrodiol 2S,1R-epoxide, the amo unt of product resulting from trans-opening of the epoxide ring by the exocyclic amino group of deoxyadenosine in denatured DNA was much les s than the level found in native DNA, indicating that the native DNA s tructure probably intercalates the hydrocarbon residue in a fashion th at promotes adenine reaction for 2S,1R-epoxides.