亚硝酸和NO.2 自由基被证明为致DNA突变因子 ,作为公认的氮原子中心的强氧化性亚硝基自由基NO.2 对DNA的作用引起为数众多的科学家的关注 ,但未观察到其直接作用的结果。利用脉冲辐解技术在碱性条件下观察到NO.2 直接氧化鸟嘌呤阴离子和鸟苷阴离子 ,并测定 pH1 2条件下NO.2 氧化鸟嘌呤阴离子反应的速率常数k =1 .3× 1 0 8dm3 mol-1s-1。但未观测到NO.2 与脱氧鸟苷 - 5 -磷酸及DNA的基他碱基的反应 ,说明NO.2 选择性氧化鸟嘌呤 ,糖基和磷酸根及其组成的链具有保护DNA不被NO.2 。氧化的作用 Nitrite and NO.2 free radicals have been shown to cause DNA mutagenesis, and the action of the strongly oxidizing nitrosyl radical NO. 2, which is a well-recognized nitrogen atom center, on DNA has attracted the attention of a large number of scientists but not observed The result of its direct effect. NO.2 direct oxidation of guanine anion and guanosine anion were observed under pulsed radiolysis technique under alkaline conditions and the rate constant of NO.2-oxidized guanine anion reaction at pH12 was determined as k = 1.3 × 10 8dm3 mol-1s-1. However, no reaction of NO. 2 with the base of deoxyguanosine-5-phosphate and DNA was observed, indicating that NO.2 selectively oxidizes guanine, glycosyl and phosphate and the chains of its composition have protective DNA from being NO.2. The role of oxidation