多黄酮混合物抗氧化活性的协同与拮抗作用

Synergism and Antagonism of Flavonoid Mixtures on Antioxidant Capacities

以DPPH自由基清除能力、·OH清除能力、总抗氧化性、还原能力等不同机理的氧化还原反应为评价指标,分析7种黄酮类化合物中的3种以质量比1∶1∶1混合后,混合物体外抗氧化活性的协同与拮抗作用;用高效液相色谱(high-performance liquid chromatography,HPLC)测定黄酮两两混合物与DPPH自由基反应过程中的结构变化。结果表明:4-羰基与2,3-双键对多黄酮混合物相互作用的影响大于B环邻二羟基,B环邻二羟基对多黄酮混合物相互作用的影响大于B环仅有一个酚羟基的结构。黄酮之间相互作用的发生,与氧化还原反应中氧化剂的比例和反应时间有关,只有当氧化剂比例以及反应时间达到某一程度,黄酮之间的相互作用才开始发生。在此之前,抗氧化性更强的黄酮组分先被氧化。

This study investigated antioxidant activities of 1：1：1 （m/m） mixtures of three selected from seven flavonoid compounds to evaluate their synergism and antagonism in vitro. 2,2-Diphenyl-l-picrylhydrazyl （DPPH） radical scavenging activity, hydroxyl radical scavenging activity, total antioxidant activity and reducing power were used as evaluation indicators under different redox reaction mechanisms. HPLC method was used to analyze the structural change of binary flavonoid mixtures during DPPH scavenging reaction. The results indicated that the 2,3-double bond and the 4-oxo had stronger influence on the interactions of mixed flavonoids than the o-dihydroxy structure in the B-ring, and this o-dihydroxy structure had stronger influence than single hydroxy structure in the B-ring. HPLC analysis indicated that the occurrence of interaction among flavonoids was related to reaction time and the ratio of reducing agents in the redox reaction, which can happen only when both conditions reach the required levels. Before that, the component with stronger antioxidant activity in flavonoid mixtures was firstly oxidized.