REACTION OF FREE RADICAL METABOLITES WITH DNA

自由基代谢物与DNA的相互作用一直是 感兴趣和推测的主要领域，但之前的电子自旋 对这一地区的共振(ESR)研究非常有限。 由Fenton体系产生的羟基自由基的反应， 用电子自旋共振(ESR)研究了含嘧啶脱氧核糖核苷酸 自旋捕获技术。自旋陷阱t-亚硝基丁烷是 用来捕获次生自由基，这些自由基由 羟基自由基与这些核苷酸结合。研究结果如下： 这是羟基自由基对胸腺嘧啶核苷2-脱氧胞苷的攻击。 生产5-单磷酸和2-脱氧尿苷5-单磷酸 核苷酸衍生的自由基。结果表明，哦 自由基攻击主要发生在碳-碳双键上 嘧啶碱的键。ESR研究表明， 与使用x-or的作者之前的工作的相关性 用伽马射线照射产生的羟基自由基。一个 硫代巴比妥酸测定也被用来监测损伤 由Fenton系统产生的核苷酸。这些结果 显示出与自旋捕获研究的定性一致。

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.