基于新型互作模型的多酚不同羟基的抗氧化性评价

Antioxidative evaluation of different hydroxyl groups of polyphenols based on a novel interaction model

目的揭示咖啡酸(caffeic acid,CA)和绿原酸(chlorogenic acid,CGA)不同酚羟基抗氧化活性的构效关系及内在规律。方法建立CA和CGA与功能小分子的复合物作用模型,然后计算互作模型下的分子间氢键,比较分子中间位酚羟基与对位酚羟基的抗氧化性强弱。结果CA和CGA的间位酚羟基氧原子电荷为-0.486和-0.483,对位酚羟基氧原子电荷为-0.441和-0.445,表明酚羟基氧原子电荷绝对值与酚羟基抗氧化性存在正相关性;酚羟基与功能小分子互作模型显示分子间氢键键长与抗氧化性存在负相关性。结论酚羟基氧原子电荷和分子间氢键互作模型,可以快速、准确评价同一分子酚羟基中的关键活性位点,同时,理论模型评价与酶抑制实验结果一致。该新型互作模型的建立,有望为天然抗氧化剂开发、酚类化合物调控酶活性的研究提供新的理论参考。

Objective To reveal the structure-activity relationship and internal rules of the antioxidant activities of different phenolic hydroxyl groups of caffeic acid(CA)and chlorogenic acid(CGA).Methods The interaction model of CA and CGA with small functional molecules was established,and then the intermolecular hydrogen bonds under the interaction model were calculated to compare the antioxidant activity of the meta and the paracentric phenolic hydroxyl groups.Results The results showed that the oxygen atom charges of the m-phenolic hydroxyl group of CA and CGA were-0.486 and-0.483,respectively,and that of the p-phenolic hydroxyl group were-0.441 and-0.445,respectively.The absolute value of the oxygen atom charge of the phenolic hydroxyl group had a positive correlation with the antioxidant activity of the phenolic hydroxyl group;the interaction model between the phenolic hydroxyl group and the small functional molecule showed that there was a negative correlation between the intermolecular hydrogen bond length and the antioxidant activity.Conclusion The phenolic hydroxyl group oxygen atom and the interaction model of intermolecular hydrogen bonds can quickly and accurately evaluate the key active sites in the phenolic hydroxyl group of the same polyphenol.Meanwhile,the theoretical model evaluation is consistent with the experimental results of enzyme inhibition.The established new model is expected to provide a theoretical reference for the development of natural antioxidants and the regulation of enzyme activity by phenolic compounds.