RADIOPROTECTION OF PYRIMIDINES BY OXYGEN AND SENSITIZATION BY PHOSPHATE - A FEATURE OF THEIR ELECTRON ADDUCTS
RADIOPROTECTION OF PYRIMIDINES BY OXYGEN AND SENSITIZATION BY PHOSPHATE - A FEATURE OF THEIR ELECTRON ADDUCTS
复制标题
DOI：
10.1080/09553008714551081
复制
发表时间：
1987-05-01
影响因子：
2.6
通讯作者：
VONSONNTAG, C
中科院分区：
文献类型：
--
作者：
DEEBLE, DJ;VONSONNTAG, C
研究了胸腺嘧啶、尿嘧啶和1，3-二甲基胸腺嘧啶的电子加合物在磷酸盐缓冲溶液和低氧浓度下的反应。氧与嘧啶电子加合物及其O(4)质子化形式反应，还原嘧啶，生成O2-/HO2。因此，氧气起到了辐射防护剂的作用。在缓冲浓度较高的情况下，电子加合物在C(6)处发生不可逆质子化。当这个自由基与氧反应时，不会恢复原来的嘧啶，并破坏了嘧啶。因此，磷酸盐缓冲液起到了辐射增敏剂的作用。对这些反应与生物系统的可能相关性进行了一些推测。
The reactions of the electron adducts of thymine, uracil and 1,3-dimethylthymine in the presence of phosphate buffer and low oxygen concentrations have been investigated. Oxygen reacts with the pyrimidine electron adducts and their O(4)-protonated forms to restore the pyrimidine and produce O2-/HO2.. Thus oxygen acts as a radiation protector. In the presence of high buffer concentrations the electron adducts are irreversibly protonated at C(6). On reaction of this radical with oxygen no restitution of the original pyrimidine occurs and the pyrimidine is destroyed. Thus phosphate buffer acts as a radiation sensitizer. Some speculations are made as to the possible relevance of these reactions to biological systems.