河北香菊中5种黄酮类化合物抗氧化活性的DFT研究  

Density functional theory investigation on antioxidant activity of five flavonoids from Hebei Xiangju

作　　者：胡栋宝[1] 李德良[1] 李明[1] 伍贤学[1] HU Dong-bao LI De-liang LI Ming WU Xian-xue(College of Resource and Environment, Yuxi Normal University, Yuxi 653100, China)

机构地区：[1]玉溪师范学院资源环境学院,云南玉溪653100

出　　处：《中国中药杂志》2017年第4期719-724,共6页China Journal of Chinese Materia Medica

基　　金：云南省教育厅资助性项目(2016ZZX200);国家自然科学基金项目(31560483)

摘　　要：运用密度泛函理论(DFT)方法在B3LYP/6-311G(d)水平研究了河北香菊中5种黄酮类化合物木犀草素、芹菜素、金合欢素、木犀草苷、金合欢苷的电子结构、酚羟基氢原子的自然轨道电荷布局数(NBO)、酚羟基氢氧键离解能(BDE)、酚羟基氢氧键键级大小以及分子前线轨道的能级差。通过数据分析发现,B环邻位酚羟基分子内氢键的形成有利于增强分子的抗氧化活性;糖苷上的羟基并不具有消除自由基的活性,但是由于分子失去了7位酚羟基,从整体上降低了分子的抗氧化括性。初步判断出这5种黄酮类化合物抗氧化活性的大小顺序为:木犀草素>木犀草苷>芹菜素>金合欢素>金合欢苷。理论预测结果与文献报道的实验结果一致。该研究结果表明DFT方法可为天然黄酮类抗氧化剂的筛选提供理论指导。Five main flavonoids of Hebei Xiangju were studied using the Density Functional Theory （DFT） B3LYP method with 6- 311 G （d） basis set. Their activities were analyzed based on molecular structure, bond dissociation energy （BDE）, natural orbital charge distribution （NBO） ,bond order and the energy gap between HOMO and LUMO. The results showed that the existing of intra molecular hydrogen bond in B ring can improve the antioxidant activity of the flavonoids, at the same time, the hydroxyl groups on the glycosides do not have the activity of eliminating free radicals, but decrease the total molecular antioxidant activity. As a result, the an- tioxidant ability order of the five flavonoids compounds is luteolin 〉 luteolin-7-O-glucoside 〉 apigenin 〉 acacetin 〉 aeacetin-7-O-glueose, which is agreement with the experimental conclusion reported in literature. The results showed that the DFT method can provide theoret- ical guidance for the selection of natural flavonoid antioxidants.

关 键 词：河北香菊 黄酮 DFT 键离解能(BDE) 抗氧化活性 

分 类 号：R284[医药卫生—中药学]