酚酸及黄酮醇结构对其二元复合体系抗氧化效应的影响

将抗氧化活性相对较好的19种酚酸和7种黄酮醇分别进行二元组合,利用FRAP(铁离子还原法)和DPPH(1,1-二苯基-2-三硝基苯肼)自由基清除法测定133种酚酸-黄酮醇二元组合的抗氧化活性。以实验值与理论值的差值及差值率为衡量指标,研究酚酸及黄酮醇结构与二元复合体系抗氧化效应(协同、拮抗和加成)之间的关系。结果表明:酚酸和黄酮醇的结构对二元组合的抗氧化效应有明显的影响。在FRAP抗氧化模型中,肉桂酸型或有间苯二酚基结构的酚酸,其二元组合表现出协同效应;黄酮醇B环上的甲氧基结构可增强其二元组合协同效应,而酚酸或黄酮醇连接3,4-二联羟基结构不利于二元组合的协同效应;酚酸苯环上甲氧基数量越多其二元组合中表现的拮抗效果越显著(P<0.05)。在DPPH抗氧化模型中,对位羟基结构的酚酸其二元组合协同效应强于间位和邻位,酚酸连接位阻结构促使二元组合协同效应降低。本实验可以为设计新型膳食补充剂或强化食品时,选择多酚类化合物的最佳组合提供理论基础。

Effects of Structures of Phenolic Acids and Flavonols on Antioxidant of the Binary Composite System

19 phenolic acids and 7 flavonols with relatively good antioxidant activity were selected for binary combination. Iron ion reduction assay(FRAP)and 1,1-diphenyl-2-picrylhydrazyl(DPPH)radical scavenging were established in vitro to determine the antioxidant activity of 133 phenolic acid-flavanol binary combinations. The relationship between the structure of phenolic acid and flavonol and the antioxidant effect(synergistic,antagonistic and additive)of binary composite systems were studied by differences and difference rates between experimental and theoretical values. The results showed that the structure of phenolic acid and flavonol had significant effects on the antioxidant of binary combination. In the FRAP antioxidant assay,or cinnamic acid phenolic acid with resorcinol structure showed synergistic effect in the binary combination. The methoxyl structure on the B ring of flavonol enhanced the synergistic effect of the binary combination,while flavonol with the steric resistance structure weakened the synergistic effect of the binary combination. The more methoxyl group on overring of phenolic acid,the more significant antioxidant activities of the binary combination would be. In the DPPH antioxidation assay,the synergistic effect of the binary combination with phenolic acid of para-hydroxyl structure was stronger than that of ortho-hydroxyl structure phenolic acid,and the phenolic acid binding steric resistance structure decreased the synergistic effect of binary combination. The results could provide a theoretical basis for choosing the best combination of polyphenols when designing new dietary supplements or fortified foods.