Radiation chemistry of nucleic acids: Characterization of thymine hydroxy-hydroperoxides
1974; Elsevier BV; Volume: 59; Issue: 3 Linguagem: Inglês
10.1016/s0006-291x(74)80085-9
ISSN1090-2104
Autores Tópico(s)Photochromic and Fluorescence Chemistry
ResumoThe four hydroxyhydroperoxides of thymine produced at pH 6.5 under γ irradiation of thymine in an aerated aqueous solution (10 mM) i.e. cis 6-hydroperoxy-5-hydroxy-5,6-dihydrothymine 1 (G = 0.22); cis 5-hydroperoxy-6-hydroxy-5,6-dihydrothymine 2 (G = 0.04); trans 6-hydrperoxy-5-hydroxy-5,6-dihydrothymine 3 (G = 0.42); trans 5-hydroperoxy-6-hydroxy-5,6-dihydrothymine 4 (G = 0.08) have been isolated, synthesized and unambiguously characterized. The cis peroxides gave by H2S or DMSO reduction cis thymine glycol and, in the same way, trans peroxide yielded trans thymine glycol. NMR spectra of 1, 3, 4 enabled us to determine unambiguously the position of the OOH group on the pyrimidic ring. When the hydroxyl group was located at position 6 a doublet JOH6-H6 was observed. This doublet collapsed into a singlet when H-6 proton was irradiated in double resonance experiments.
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