One-Electron Oxidation of the Guanine Moiety of 2‘-Deoxyguanosine:  Influence of 8-Oxo-7,8-dihydro-2‘-deoxyguanosine

• Published in: Journal of the American Chemical Society 2003-02, Vol.125 (8), p.2030-2031
• Main Authors: Ravanat, Jean-Luc, Saint-Pierre, Christine, Cadet, Jean
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Chemical Sciences; Chemistry; Chromatography, High Pressure Liquid; Deoxyguanosine - analogs & derivatives; Deoxyguanosine - chemistry; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; General and physical chemistry; Guanine - chemistry; Kinetics; Mass Spectrometry; Molecular biophysics; Organic chemistry; Oxidation-Reduction; Photochemistry; Photochemistry. Photosynthesis. Bioluminescence; Physical chemistry of induced reactions (with radiations, particles and ultrasonics); Radiation-biomolecule interaction
• ISSN: 0002-7863; 1520-5126
• DOI: 10.1021/ja028608q

The influence of 8-oxo-7,8-dihydro-2‘-deoxyguanosine (8-oxodGuo) on riboflavin and UVA-mediated one-electron oxidation of an aqueous aerated solution of 2‘-deoxyguanosine (dGuo) has been studied. Using labeled experiments, we have demonstrated that, despite not being able to detect significant amounts of 8-oxodGuo upon one-electron oxidation of dGuo, 8-oxodGuo is indeed produced but is further rapidly degraded to oxidized nucleosides. Evidence is provided showing that an efficient electron transfer reaction from 8-oxodGuo to the guanine radical cation or rather its deprotonated form occurs, giving rise to the specific decomposition of 8-oxodGuo together with the restitution of dGuo. It could be concluded that 8-oxodGuo efficiently protects dGuo from decomposition by the one-electron oxidation reaction.