摘要
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。
Four flavonoids compounds from Artemisia Ordosica, which are Apigenin-7,4＇-dimelhylether, genkainin, Hydroxygenkwanin and Rhamnetin, were geometrically optimized and calculated by using density function theory （DFT） B3LYP/6-311G （d,p）//B3LYP 6-31G （d,p） method. The properties of the flavonoids have been discussed in detail based on their molecular structures, NBO charges on Phenolic hydroxyl hydrogen atoms, the dissociation enthalpy of O-H bonds, the energies of the highest occupied molecular orbital （HOMO） and the lowest unoccupied molecular orbital （LUMO）, the energy gap between HOMO and LUMO, and etc. The results showed that compounds having more Phenolic hydroxyl groups and intramolecular hydrogen bonds reveal higher antioxidant activity. The 4＇-OH has the highest antioxidation activity and the 5＇-OH reveal the lowest activity, the 3-OH is favorable for the molecule to form a conjugate system and improve its antioxidant activity. As a result, the antioxidant ability order of the four flavonoids compounds is Rhamnetin 〉 Hydroxygenkwanin 〉 genkainin 〉 Apigenin-7,4＇- dimethylether based on the work. In the end, the paper adopts the dynamic method analysis the Rhamnetin molecular activity of scavenging free radicals.
出处
《计算机与应用化学》
CAS
CSCD
北大核心
2013年第3期267-272,共6页
Computers and Applied Chemistry
基金
国家自然科学基金资助项目(20972042)
