Mechanism on Damage of the Purine Base in a Nucleic Acid Using the Electrogenerated Active Oxygen

电生活性氧损伤核酸嘌呤碱基的机理

• 批准号: 09672192
• 负责人: UNO Bunji
• 金额: $ 1.47万
• 依托单位: Gifu Pharmaceutical University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1997
• 资助国家: 日本
• 起止时间: 1997 至 1998
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09672192/
• 关键词: Superoxide anion radical; Guanosine; Cyclic voltammetry; Hydroperoxy radical; Active oxygen; Spectroelectrochemistry; Molecular orbital calculation

Active oxygens are generated in a body, coupled with derivation of the activated free radical from mutation substances. From the point of view considerable interest is devoted to mutation character of the active oxygens. In this work, I have investigated the mechanism on damage of the purine base in a nucleic acid in terms of interaction of the guanosine derivative with electrogenerated superoxide anion radical.A reversible cyclic voltammogram of oxygen in DMF came out to be irreversible in the presence of guanosine. This arises from not a one-electron transfer mediated by superoxide anion radical but the EC mechanism. The reaction products are identified as guanine and its analog damaged in the purine base by the spectroelectrochemical and chromatographic measurements. A proton transfer from guanosine to electrogenerated superoxide anion radical leads to hydroperoxy radical. Generation of guanine is caused by hydrogen peroxide derived from the disproportionation reaction of hydroperoxy radical. It seems that guanosine reacts with hydroperoxy radical, yielding the product damaged in the purine base. Molecular orbital calculations partially support these conclusions. It has been found that the key reaction for the damage of the purine base in a nucleic acid is the proton transfer from guanosine to superoxide anion radical.

体内产生活性氧，同时从突变物质中衍生出活化的自由基。从这个角度来看，人们对活性氧的突变特性非常感兴趣。在这项工作中，我从鸟苷衍生物与电产生的超氧阴离子自由基的相互作用的角度研究了核酸中嘌呤碱基损伤的机制。DMF中氧的可逆循环伏安图在鸟苷存在下是不可逆的。这不是由超氧阴离子自由基介导的单电子转移引起的，而是由 EC 机制引起的。通过光谱电化学和色谱测定，反应产物被鉴定为鸟嘌呤及其嘌呤碱基受损的类似物。从鸟苷到电产生的超氧阴离子自由基的质子转移导致氢过氧自由基。鸟嘌呤的产生是由氢过氧自由基的歧化反应产生的过氧化氢引起的。鸟苷似乎与氢过氧自由基反应，产生嘌呤碱基受损的产物。分子轨道计算部分支持这些结论。研究发现，核酸中嘌呤碱基受损的关键反应是质子从鸟苷向超氧阴离子自由基的转移。

项目成果

K.サンソBunji Uno: Transworld Research Network (印刷中), "Recent Research Developments in Pyre & Applied Chemistry" (1998)

K. Sanso Bunji Uno：跨世界研究网络（正在印刷中），“火葬和应用化学的最新研究进展”（1998 年）

Bunji Uno: "Molecular Scientific Approach in Electroorganic Chemistry" Recent Res.Devel.in Pure & Applied Chem.2. 83-99 (1998)

Bunji Uno：“有机电化学中的分子科学方法”最近的 Res.Devel.in Pure

Bunji Uno and Noriko Okumura: "Molecular Scientific Approach in Electroorganic Chemistry" Recent Res.Devel.in Pure & Applied Chem.2. 83-99 (1998)

Bunji Uno 和 Noriko Okumura：“有机电化学中的分子科学方法”最近的 Res.Devel.in Pure

Noriko Okumura: "Electronic Spectra of the Electrogenerated I,4-Benzoquinone π-Dianion and the Strongly Hydrogen-Bonded Charge-Transfer Complex with Methanol" Bull.Chem.Soc.Jpn.(印刷中).

Noriko Okumura：“电生成的 I,4-苯醌 π-二价阴离子和强氢键电荷转移络合物与甲醇的电子光谱”Bull.Chem.Soc.Jpn.（出版中）。

Noriko Okumura: "Electronic Spectra of the Electrogenerated 1, 4-Benzoquinone π-Dianion and the Strongly Hydrogen-Bonded Charge-Transfer Complex with Methanol" Bull.Chem.Soc.Jpn.印刷中.

Noriko Okumura：“电化学 1, 4-苯醌 π-二价阴离子和强氢键电荷转移络合物与甲醇的电子光谱”Bull.Chem.Soc.Jpn 正在出版。