鸟嘌呤受羟基自由基损伤反应机理的量子化学研究  

Quantum Chemical Studies on the Damage Mechanism of Hydroxyl Radical to Guanine

作　　者：申勇立[1] 郝金库[1,2] 曹映玉[2] 杨恩翠[2] 刘书文[2] 

机构地区：[1]南开大学化学学院,天津300071 [2]天津师范大学化学与生命科学学院,天津300387

出　　处：《高等学校化学学报》2010年第2期379-382,共4页Chemical Journal of Chinese Universities

基　　金：天津市自然科学基金(批准号:023606411);教育部重点科研项目基金(批准号:03009)资助

摘　　要：用密度泛函理论(DFT)研究羟基自由基与鸟嘌呤分子加成反应的过渡态,并进行内禀反应坐标(IRC)反应路径解析,结果表明,羟基自由基加成到鸟嘌呤碳碳双键上.利用B3LYP/6-31++G**对反应物、反应物络合物、过渡态以及产物络合物等反应通道上各个能量驻点的能量进行了计算,得到反应活化能Ea=28.0867 kJ/mol.AIM计算结果显示,过渡态结构中鸟嘌呤分子碳碳双键结构被削弱,羟基自由基氧原子与鸟嘌呤分子碳碳双键中的C4原子具有较强的相互作用,双键中剩余的π电子离域到了环体系中.Optimize the molecular structure of guanine with B3LYP/6-31G,the result show that the molecular is a planar structure.Searching the transition state of guanine reacted with hydroxyl radical under UB3LYP/6-31G.Internal reaction coordinate（IRC） calculation was carried under the same theoretical level.The result show that the planar structure is broken by the hydroxyl radical,the hydroxyl radical is added to the carbon-carbon double bond.More exact energies of all the stationary points on the reaction path were calculated under B3LYP/6-31G＊＊.The activation energy was 28.0867 kJ/mol.AIM results showed that the carbon-carbon double bond became weaken in the transition state.The oxigon atom of the hydroxyl radical was bonded with C4 atom.

关 键 词：鸟嘌呤 羟基自由基 密度泛函理论 内禀反应坐标 

分 类 号：O641[理学—物理化学]