1124-84-1Relevant academic research and scientific papers
Hydroxyl radical-induced cross-linking of thymine and lysine: Identification of the primary structure and mechanism
Morimoto, Syota,Hatta, Hiroshi,Fujita, Shin-Ichi,Matsuyama, Tomochika,Ueno, Toru,Nishimoto, Sei-Ichi
, p. 865 - 870 (2007/10/03)
Hydroxyl radical-induced formation of a cross-link of thymine (Thy) and lysine (Lys) in the γ-radiolysis of N2O-saturated aqueous solution was studied. A Thy-Lys cross-link (I) of the formal structure that OH radical and 4-carbon-centered Lys radical added respectively to C(5) and C(6) positions of Thy was isolated by a preparative HPLC and identified by a FAB-HRMS. The primary cross-link I was dehydrated by treatment with HCl at 120°C to yield the secondary structure (II) possessing a C(5)-C(6) double bond in the Thy moiety: the latter structure II was reported previously (Dizdaroglu, M.; Gajewski, E. Cancer Res. 1989, 49, 3463-3467). A pulse radiolysis study with a redox titration method indicated that 4-carbon centered Lys radical intermediate was of neutral redox reactivity in contrast to reducing reactivity of 5-hydroxy-5,6-dihydrothymin-6-yl radical intermediate. The cross-link I could be formed by a conventional radical recombination mechanism, but not by an ionic recombination mechanism involving a redox reaction between the radical intermediates.
Radiation-Induced Degradation of Purine and Pyrimidine 2'-Deoxyribonucleosides in Aqueous KBr Solutions
Cadet, J.,Voituriez, L.,Berger, M.,Myers, L. S., (Jr.)
, p. 1643 - 1651 (2007/10/02)
Steady-state γ-radiolysis of 5E-4 M pyrimidine and purine 2'-deoxyribonucleosides in aqueous solutions saturated with N2, N2O and O2, respectively, have been carried out in the presence of 0.1 M KBr.The main final degradation products have been isolated and characterised by various spectroscopic measurements including 1H and 13C NMR, UV, C.D. and mass spectrometry.The radiation-induced decomposition of thymidine is mostly accounted for by an ionic mechanism involving Br2, the decay product of Br2, as the reactive oxidising specie.On the other hand the degradation of the purine ring of 2'-deoxyadenosine and 2'-deoxyguanosine may be accounted for by the action of Br2 or Br3. - Keywords: 2'-Deoxyribonucleosides, Inorganic Radical, γ-Irradiation, Radical Reactions, Thymidine Oxidation
Steady State Radiolysis of Aqueous Aerated Solutions of 5,6-Dihydrothymine. Identification of the Major Degradation Products
Cadet, J.
, p. 1579 - 1583 (2007/10/02)
The major radiation-induced degradation products of 5,6-dihydrothymine (1) in aqueous solutions saturated either with O2 or N2O/O2 (75/25 v/v) were identified as thymine (10), the trans- and cis-isomers of 6-hydroperoxy-5,6-dihydrothymine (5, 7), 5-hydroperoxy-5,6-dihydrothymine (9), and their corresponding hydroxy derivatives (4, 6, 8).The formation of these compounds is explained in terms of initial H-abstraction from the C(5) and C(6) carbons which gives rise respectively to the transient 5-yl and 6-yl radicals.Thymine hydroxy-hydroperoxides (11-14) and their decomposition products (17-20), which are derived from hydroxyl radical attack at the 5,6-ethylenic bond of thymine (10), were also characterized. - Keywords: 5,6-Dihydrothymine, Hydroperoxides, Dihydropyrimidyl Radicals
