title: Synthesis and properties of a new class of nucleosides with spin source.
abstract: Novel spin-labeled ribonucleosides 1-5 were synthesized to investigate stability and behavior of N-tert-butyl aminoxyl radical on nucleobase. Site selective lithiation of tri-O-protected ribonucleosides followed by the reaction with 2-methyl-2-nitrosopropane (MNP) resulted in introduction of N-tert-butylhydroxylamino group into various positions of purine or pyrimidine nucleus. Oxidation of the obtained hydroxylamines with Ag2O led to formation of 1-5. EPR study showed that the unpaired electron of the aminoxyl radical was delocalized into the nucleobase and hyperfine structures were dependent on the position of the radical.
authors.affiliation: Graduate School of Pharmaceutical Sciences, Kyushu University, Midashi, Higashiku, Fukuoka 812-8582, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Aso
authors.forename: T
authors.initials: T
authors.lastname: Ikeno
authors.forename: T
authors.initials: T
authors.lastname: Kaneko
authors.forename: N
authors.initials: N
authors.lastname: Koga
authors.forename: H
authors.initials: H
authors.lastname: Suemune
mesh_terms: D004578:Electron Spin Resonance Spectroscopy; D005609:Free Radicals; D009705:Nucleosides / Q000138:chemical synthesis* / Q000737:chemistry*; D011687:Purines / Q000138:chemical synthesis / Q000737:chemistry; D011743:Pyrimidines / Q000138:chemical synthesis / Q000737:chemistry; D013113:Spin Labels / Q000138:chemical synthesis*
chemical_list: D005609:Free Radicals; D009705:Nucleosides; D011687:Purines; D011743:Pyrimidines; D013113:Spin Labels