title: The reactivity of the 5-hydroxy-5,6-dihydrothymidin-6-yl radical in oligodeoxyribonucleotides.
abstract: Hydroxyl radical can be induced from Fenton reaction or gamma radiolysis of water. It can add preferentially to the C5 position of thymidine to give the 5-hydroxy-5,6-dihydrothymidin-6-yl radical. In this report, we examined the independent generation and reactivity of this radical in oligodeoxyribonucleotides (ODNs). Our results showed that the major products originated from this radical in single- and double-stranded ODNs were thymidine glycol, 5-hydroxy-5,6-dihydrothymidine, thymidine, and abasic site lesion. A cross-linking lesion, where the C6 of 5-hydroxy-5,6-dihydrothymidine and the C8 of its neighboring guanine are covalently bonded, could be induced from the independently generated radical in dinucleoside monophosphate and trinucleoside diphosphates. The formation of this type of cross-link product in duplex ODNs from either the independently generated radical or gamma irradiation was near or below the detection limit of the LC-MS/MS method that we used.
authors.affiliation: Department of Chemistry-027, University of California at Riverside, Riverside, California 92521-0403, USA.
authors.forename: Qibin
authors.initials: Q
authors.lastname: Zhang
authors.forename: Yinsheng
authors.initials: Y
authors.lastname: Wang
mesh_terms: D005609:Free Radicals / Q000737:chemistry*; D005720:Gamma Rays; D017665:Hydroxyl Radical / Q000737:chemistry*; D015394:Molecular Structure; D009838:Oligodeoxyribonucleotides / Q000737:chemistry* / Q000528:radiation effects; D009943:Organophosphorus Compounds / Q000138:chemical synthesis; D015719:Single-Strand Specific DNA and RNA Endonucleases / Q000737:chemistry; D013237:Stereoisomerism; D013936:Thymidine / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry; D014466:Ultraviolet Rays
chemical_list: D005609:Free Radicals; D009838:Oligodeoxyribonucleotides; D009943:Organophosphorus Compounds; C434331:phosphoramidite; C029390:thymidine glycol; D017665:Hydroxyl Radical; C097218:thymidine C5-hydrate; C029950:5,6-dihydro-6-hydroxythymidine; D015719:Single-Strand Specific DNA and RNA Endonucleases; D013936:Thymidine