知母宁清除自由基作用的量子化学研究(英文)  

Scavenging effect of chinonin on free radicals studied with quantum chemistry

作　　者：张红雨[1] 

机构地区：[1]山东师范大学生物系

出　　处：《中国药理学报》1999年第6期555-558,共4页Acta Pharmacologica Sinica

基　　金：Project supported by Doctoral Science Foundation of ShandongTeacher's University.

摘　　要：研究知母宁的　酮结构是否有利于提高其清除自由基活性并探讨知母宁酚羟基活性的顺序．方法：用半经验量子化学方法ＡＭＩ计算出知母宁不同状态的△ＨＯＦ值（母体化合物与其自由基生成热之差）和电子自旋密度分布，以△ＨＯＦ值作为衡量知母宁清除自由基活性的理论指标，观察结构因素对△ＨＯＦ值的影响．结果：计算得出不同酚羟基的△ＨＯＦ值为 Ｏ５－Ｈ６： １３９．０９ ｋＪ·ｍｏｌ－１； Ｏ４ －Ｈ５： １４１．４６ ｋＪ· ｍｏｌ－１； Ｏ２－Ｈ２： １８５．１４ ｋＪ·ｍｏｌ－１； Ｏ１－Ｈ１： １９５．７１ ｋＪ·ｍｏｌ－１，同时得到自由基的自旋密度分布．结论：知母宁的　酮结构使Ｃ环对Ｂ环有较强的钝化作用，降低了Ｂ环酚羟基清除自由基的活性．知母宁酚羟基活性的顺序为Ｏ５－Ｈ６＞Ｏ４－Ｈ５＞Ｏ２－Ｈ２＞Ｏｌ－Ｈｌ。AIM: To study whether the xanthonoid structure can enhance the ability of chinonin to scavenge free radicals and to understand the sequence of activity of chinonin hydroxyls. METHODS: Sendempirical quantum chemistry method AMI was employed to calculate △HOF values, the differences between heat of formations of mother molecule and its free radicals, and spin density distribution of different states of chinonin. △HOF values were used as theoretical indices to measure scavenging activity of chinonin on free radicals and effects of structure on △HOF values were investigated. RESULTS: △HOF values of different phenolics were calculated to be 139.09 kJ·mol-1 (O5 -H6), 141.46 kJ· mol-1 (O4-H5), 185.14 kJ· mol-1(O2- H2) and 195.71 kJ·mol-1 (O1-H1). Spin density distribution of free radicals were obtained as well. CONCLUSION: Xanthonoid structure of chinonin made ring C to display high passive effect on ring B, which reduced scavenging activity of phenolics of ring B on free radicals. The sequence of activities of chinonin hydroxyls was O5-H6>O4-H5> O2-H2>Ol-Hl.

关 键 词：知母宁 量子化学 抗氧化剂 计算机辅助设计 

分 类 号：R914[医药卫生—药物化学] R977.9[医药卫生—药学]