REACTION OF FREE RADICAL METABOLITES WITH DNA

自由基代谢产物与DNA的相互作用一直是研究的一个重要领域 感兴趣和猜测，但以前的电子自旋共振（ESR） 对这一领域的调查非常有限。的反应 羟基自由基，由芬顿系统与嘧啶产生 用自旋共振技术研究了脱氧核糖核苷酸 诱捕采用自旋捕集器t-亚硝基丁烷捕集次级产物 由羟基自由基与这些反应形成的自由基 个核苷酸这里给出的结果表明，羟基自由基攻击 胸苷、2-脱氧胞苷5-单磷酸和2-脱氧尿苷 5-单磷酸产生核苷酸衍生的自由基。结果 表明OH自由基攻击主要发生在碳-碳 嘧啶碱基的双键。ESR研究显示， 与使用X射线或伽马射线的作者先前工作的相关性 照射以产生羟基自由基。硫代巴比妥酸测定 也被用来监测核苷酸产生的损害， 芬顿系统。这些结果与自旋定性一致 诱捕研究

The interaction of free radical metabolites with DNA has been a major area of interest and speculation, but previous electron spin resonance (ESR) investigations of this area have been very limited. The reaction of the hydroxyl radical, generated by a Fenton system, with pyrimidine deoxyribonucleotides was investigated using the ESR technique of spin trapping. The spin trap t-nitrosobutane was employed to trap secondary radicals formed by the reaction of the hydroxyl radical with these nucleotides. The results presented here show the hydroxyl radical attack on thymidine, 2-deoxycytidine 5-monophosphate and 2-deoxyuridine 5-monophosphate produced nucleotide-derived free radicals. The results indicate that OH radical attack occurs predominantly at the carbon-carbon double bond of the pyrimidine base. The ESR studies showed a good correlation with previous work produced by authors who used x- or gamma-ray irradiation to generate the hydroxyl radical. A thiobarbituric acid assay was also used to monitor the damage produced to the nucleotides by the Fenton system. These results showed qualitative agreement with the spin trapping studies.