Mechanisms for the formation of major oxidation products of adenine upon 365-nm irradiation with 2-methyl-1,4-naphthoquinone as a sensitizer.
Recently we reported the isolation and characterization of N6-formyl- and N6-acetyladenine from 365-nm irradiation of dinucleoside monophosphates d(ApA), d(ApC), and d(CpA) in the presence of 2-methyl-1,4-naphthoquinone (menadione) (Wang et al. Biochem. Biophys. Res. Commun. 2002, 291, 1252-7). In this article we investigated the mechanisms for the formation of the two major products by carrying out photoirradiation with isotopically labeled menadione and 2,3-dimethyl-1,4-naphthoquinone. HPLC and electrospray ionization (ESI)-mass spectrometry (MS) and tandem MS studies of the products unambiguously established that the carbonyl group in the products arises from the photosensitizer: The N6-formyl group comes from oxidation of the methyl group and the N6-acetyl group stems from the methyl group and the adjacent ring carbon in menadione. From above results, we proposed mechanisms for the formation of the two products.
Wang
Yinsheng
Y
Department of Chemistry-027, University of California at Riverside, Riverside, California 92521-0403, USA.
Liu
Zhenjiu
Z
D000225:Adenine / Q000032:analysis* / Q000737:chemistry; D002384:Catalysis; D002625:Chemistry, Organic / Q000379:methods*; D002851:Chromatography, High Pressure Liquid; D015226:Dinucleoside Phosphates / Q000737:chemistry* / Q000528:radiation effects; D009838:Oligodeoxyribonucleotides / Q000737:chemistry* / Q000528:radiation effects; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry; D010777:Photochemistry; D017319:Photosensitizing Agents / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization; D014466:Ultraviolet Rays; D024483:Vitamin K 3 / Q000737:chemistry*
D015226:Dinucleoside Phosphates; D009838:Oligodeoxyribonucleotides; D017319:Photosensitizing Agents; D024483:Vitamin K 3; D000225:Adenine; D010100:Oxygen