| | 1 | Author
| Heinz-Peter Schuchmann, Rita Wagner, Clemens Von Sonntag | Requires cookie* | | | Title
| 7-Radiolysis of 2'-Deoxycytidine-5'-phosphate in Deoxygenated Aqueous Solutions. OH Radical-Induced Alterations at the Sugar Moiety  | | | | Abstract
| In order to elucidate some aspects of the mechanism of radical-induced strand break formation in DNA, the y-radiolysis of N20-saturated aqueous solutions of 2'-deoxycytidine-5'-phosphate has been studied as a model system. At pH 4 it has been observed that upon OH attack at the sugar moiety phosphate (G ^ 0.6) and cytosine (G = 1) are released and the following cytosine-free sugars are formed: 2,5-dideoxypentos-3,4-diulose, 1 (G = O.22), 2-deoxy-pentos-4-ulose, 2 (G = 0.1s), 2-deoxy-pentos-4-ulose-5-phosphate, 3 (G=0.06), 2-deoxypentonic acid-5-phosphate and its lactone, 5 (G «0.5). Some 2-deoxyribose-5-phosphate, 4 is also formed. Upon addition of H2O2 (up to 10 -2 M) prior to irradiation, G(l) is drastically reduced without giving rise to another cytosine-free product. G(3) increases at the expense of G(2). G (4 + 5) also increase upon H2O2 addition. The formation of these products and the change of their G values as a function of H2O2 concentration are discussed in the light of well-documented radical reactions of carbohydrates and related compounds. The precursor of 1 has been considered to be the radical at C-3', that of 2 and 3 the radical at C-4' and that of 5 the radical at C-l'. Product 4 is thought to arise from a radical-induced destruction of the cytosine moiety. These primary radicals which may undergo rearrangement, or eliminate phosphate, are readily oxidised by H202, a reaction which leads to the change of product distribution mentioned above. | | | |
Reference
| Z. Naturforsch. 38b, 1213—1220 (1983); received June 27 1983 | | | |
Published
| 1983 | | | |
Keywords
| Free Radicals, Radical Cations, Carbohydrates, DNA Model | | | |
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| default:Reihe_B/38/ZNB-1983-38b-1213.pdf | | | | Identifier
| ZNB-1983-38b-1213 | | | | Volume
| 38 | |
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