title: Nucleoside adducts from the in vitro reaction of benzo[a]pyrene-7,8-dihydrodiol 9,10-oxide or benzo[a]pyrene 4,5-oxide with nucleic acids.
abstract: The covalent binding of benzo[a]pyrene 4,5-oxide and benzo[a]pyrene-7,8-dihydrodiol 9,10-oxide isomer I and isomer II to nucleic acids in aqueous acetone solution has been investigated. Benzo[a]pyrene 4,5-oxide reacted preferentially with guanosine residues. On the other hand, benzo[a]pyrene-7,8-dihydrodiol 9,10-oxide isomer I and II reacted extensively with guanosine, adenosine, and cytidine residues. Time course studies showed that the reactivity of isomer I or isomer II with homopolyribonucleotides followed the order poly(G) greater than poly(A) greater than poly(C). Alkaline or enzymatic hydrolysis of the modified nucleic acids and subsequent chromatography on Sephadex LH-20 columns yielded benzo[a]pyrene-nucleotide adducts. These were enzymatically converted to the corresponding nucleosides which were resolved into several distinct components by high-pressure liquid chromatography. Evidence was obtained for the presence of multiple nucleoside adducts of guanosine, adenosine, cytidine, deoxyguanosine, deoxyadenosine, and deoxycytidine. The HPLC profiles of adducts formed with isomer I were different from the corresponding profiles of adducts formed with isomer II. Structural aspects of these nucleoside adducts are discussed.
mesh_terms: D000438:Alcohols; D001580:Benzopyrenes; D001665:Binding Sites; D004247:DNA; D003854:Deoxyribonucleotides; D006150:Guanine Nucleotides; D007536:Isomerism; D010087:Oxides; D011119:Polynucleotides; D013056:Spectrophotometry, Ultraviolet; D013329:Structure-Activity Relationship
chemical_list: D000438:Alcohols; D001580:Benzopyrenes; D003854:Deoxyribonucleotides; D006150:Guanine Nucleotides; D010087:Oxides; D011119:Polynucleotides; D004247:DNA