Das S, Deeble D J, von Sonntag C
Z Naturforsch C Biosci. 1985 Mar-Apr;40(3-4):292-4. doi: 10.1515/znc-1985-3-425.
Hydrogen atoms from the radiolysis of water at pH 1.6 add to the 5,6-double bond of pyrimidines. The preferential site of attack is the C(5) position (values in brackets) in the case of 6-methyluracil (87%), 1,3-dimethyluracil (71%), uracil (69%) and poly(U) (60%). This reaction yields a radical of reducing properties which can be monitored by its reaction with tetranitromethane in a pulse radiolysis experiment. In thymine (37%), thymidine (32%) and 1,3-dimethylthymine (25%) H-addition no longer preferentially occurs at C(5), but addition is now mainly at C(6). Hydrogen abstraction from the methyl groups or the sugar moiety is negligible (less than or equal to 5.5%). A comparison is made with literature values for the equivalent reactions of OH radicals.
在pH 1.6条件下，水辐射分解产生的氢原子会加成到嘧啶的5,6-双键上。对于6-甲基尿嘧啶（87%）、1,3-二甲基尿嘧啶（71%）、尿嘧啶（69%）和聚尿苷酸（60%），优先攻击位点是C(5)位（括号内数值）。该反应产生具有还原性质的自由基，可在脉冲辐射分解实验中通过其与四硝基甲烷的反应进行监测。在胸腺嘧啶（37%）、胸苷（32%）和1,3-二甲基胸腺嘧啶（25%）中，氢加成不再优先发生在C(5)位，而是主要发生在C(6)位。从甲基或糖部分夺取氢的情况可忽略不计（小于或等于5.5%）。还与文献中关于OH自由基等效反应的值进行了比较。
