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采用量子化学密度泛函理论(DFT)的B3LYP/6-311G(d,p)//B3LYP/6-31G(d,p)方法对黑沙蒿中已分离得到的4种黄酮类化合物芹菜素-7,4’二甲醚、芜花素、羟基芜花素、鼠李素进行了优化及单点能计算。从黄酮分子的几何构型、酚羟基H的NBO电荷数、不同位置酚羟基解离焓、HOMO和LUMO及其能级差分析所得:黄酮类化合物的羟基数目和形成的分子内氢键数目越多,抗氧化活性越强;不同位置酚羟基的活性不同,B环4’位酚羟基的活性最强,A环5位酚羟基的活性最弱,C环3位酚羟基的存在有利于鼠李素分子形成良好的共轭体系,提高了该化合物的抗氧化活性。结果表明,四种黄酮类化合物的抗氧化活性顺序为鼠李素>羟基芜花素>芜花素>芹菜素-7,4’二甲醚;文章最后对鼠李素分子清除羟基自由基的反应历程进行了动态模拟分析。
The four flavonoids, apigenin, were isolated from the leaves of Artemisia lanceolata by B3LYP / 6-311G (d, p) // B3LYP / 6-31G (d, p) method using quantum chemical density functional theory (DFT) -7,4 ’Dimethyl ether, toxanthin, hydroxyguanidin, rhamnolide were optimized and single point energy calculation. From the geometric configuration of flavonoids, NBO charges of phenolic hydroxyl group H, enthalpies of dissociation of phenolic hydroxyl groups at different positions, HOMO and LUMO and their energy difference analysis, the number of hydroxyl groups of flavonoids and the number of intramolecular hydrogen bonds formed are more , The stronger the antioxidant activity. The activity of phenolic hydroxyl groups at different positions was different. The phenolic hydroxyl group at the 4 ’position of B ring had the strongest activity. The phenolic hydroxyl group at position 5 of A ring had the weakest activity. Supramolecular molecules form a good conjugated system and increase the antioxidant activity of the compound. The results showed that the order of the antioxidant activities of the four flavonoids was rhamnoides> hydroxyvascorubicin> oxaliplatin> apigenin-7,4’-dimethyl ether. Finally, The reaction process was simulated dynamically.