Radical oxidation of the adenine moiety of nucleoside and DNA: 2-hydroxy-2'-deoxyadenosine is a minor decomposition product.
A method involving high performance liquid chromatography (HPLC) separation associated with tandem mass spectrometry (MS/MS) detection in the multiple reaction monitoring mode was set-up for the measurement of 2-hydroxy-2'-deoxyadenosine (2-OHdAdo). This modified nucleoside, arising from the radical oxidation of 2'deoxyadenosine (dAdo), has been described in the literature as a potential biological marker of the Fenton reaction. Using the specific and sensitive HPLC-MS/MS assay, 8-oxo-7,8-dihydro-2'-deoxyadenosine, 4,6-diamino-5-formamidopyrimidine and 2-hydroxy-2-deoxyadenosine (2-OHdAdo) were measured within 2'-deoxyadenosine and DNA solutions either exposed to gamma-rays or treated under Fenton reaction conditions. It was found that the yield of 2-OHdAdo was low compared to that of 8-oxodAdo under most of the oxidative conditions studied. In particular and in contrast to previous works, the formation of 2-OHdAdo was shown to be a minor process both upon gamma irradiation and under Fenton reaction conditions. However, a significant yield of formation of 2-OHdAdo was observed either upon incubation with high concentrations of Fe2+ ions in the absence of hydrogen peroxide or upon gamma-radiolysis of a nucleoside solution in the presence of the copper/ (o)-phenanthroline complex.
Frelon
Sandrine
S
Laboratoire Lésions des Acides Nucléiques, Service de Chimie Inorganique et Biologique, UMR 5046, Département de Recherche Fondamentale sur la Matière Condensée, CEA/Grenoble, France.
Douki
Thierry
T
Cadet
Jean
J
D000225:Adenine / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D004247:DNA / Q000737:chemistry*; D004249:DNA Damage; D003839:Deoxyadenosines / Q000032:analysis*; D005609:Free Radicals / Q000737:chemistry; D008401:Gas Chromatography-Mass Spectrometry; D006861:Hydrogen Peroxide; D007501:Iron / Q000494:pharmacology; D010084:Oxidation-Reduction; D010100:Oxygen / Q000378:metabolism; D012256:Riboflavin / Q000494:pharmacology
D003839:Deoxyadenosines; C045076:Fenton's reagent; D005609:Free Radicals; D004247:DNA; D006861:Hydrogen Peroxide; D007501:Iron; D000225:Adenine; C058118:2'-deoxyadenosine; D010100:Oxygen; D012256:Riboflavin