量子化学计算研究4种黄酮类天然抗氧化物清除自由基活性的构效关系  

The study on the structure activity relationship of scavenging free radical activity of 4 kinds of natural antioxidants of flavonoids by quantum chemistry calculation

作　　者：刘科梅[1] 聂挺[1] 潘栋梁[1] 胡川[1] 陆豫[2] 余勃[2] 

机构地区：[1]南昌大学资源环境与化工学院,江西南昌330031 [2]南昌大学中德联合研究院,江西南昌330047

出　　处：《南昌大学学报（理科版）》2016年第3期250-256,共7页Journal of Nanchang University(Natural Science)

基　　金：国家自然科学基金项目(31301435)

摘　　要：黄酮类化合物是一种具有广泛生物活性的多酚物质,其显著的抗氧化活性常被应用于食品保健和医疗等方面。为从化学反应活性层面研究黄酮类化合物的构效关系。以柚皮素、柚皮苷、橙皮素及橙皮苷4种黄酮类分子作为研究对象,使用量子化学密度泛函DFT方法 B3LYP和6-31g(d,p)基组计算得出4种分子的原子电荷分布情况、分子前线轨道分布(HOMO&LUMO)、能级差△E,以及各羟基位O-H键解离焓△BDE等理论参数,同时实测4种化合物对DPPH自由基的清除活性。结果表明,前线分子轨道能级差能有效的表征4种黄酮类清除自由能力的活性顺序,各羟基位O-H键解离焓BDE则能有效表征同一分子中各羟基位O-H的活性顺序,柚皮苷及其糖苷(柚皮素)与橙皮苷及其糖苷(橙皮素)抗氧化活性最大的位点分别为4’-OH、5’-OH基团。通过计算所得理论数据预测的黄酮类化合物清除自由基活性与实验测定结果一致,提示今后可利用理论计算方法对高活性的黄酮类化合物进行高通量筛选和分子结构设计。Flavonoids are a kind of polyphenolic substances which have a wide range of biological activities,and their significant antioxidant activities are often used in food and medical care and so on.To study the structure-activity relationship of flavonoids from chemical reactivity levels,four kinds of falavonoids,naringenin,naringin,hesperetin and hesperidin,were investigated in this paper.We use quantum chemistry density functional theory（DFT）methods,such as B3 LYP and 6-31g（d,p）basis set,to calculate the theoretical parameters of the atomic charge distribution,the distribution of molecular frontier orbital（HOMO LUMO）,the energy difference△E,and the bond dissociation enthalpy△BDE of each hydroxyl site OH.Meantime,the DPPH radical scavenging activity of four compounds was detected by experiments.The results showed that（1）the frontier molecular orbital energy gap can characterize the order of free radical scavenging ability of the four kinds of flavonoids effectively;（2）bond dissociation enthalpy（BDE）of each hydroxyl site O-H is able to efficaciously characterize the active order of each hydroxyl site O-H in the same molecule,and（3）the largest antioxidant activity sites of naringin/naringenin and hesperidin/hesperetin are respectively within 4＇-OH and 5＇-OH groups.The consequence of the free radical scavenging activity of flavonoids obtained by theoretical date prediction is consistent with the experimental results.This suggests that theoretical calculation method can be used for high-throughput screening and molecular design for the high activity of flavonoids in the future.

关 键 词：量子化学计算 黄酮类化合物 自由基 密度泛函理论 

分 类 号：O641[理学—物理化学]