Research On The Combined Antioxidant Activity Of Amino Acids And Phenolic Compounds

The potential synergistic antioxidant activity of different natural antioxidants is critical to the development and application of natural antioxidants.Similar to other natural antioxidants,some amino acids also exhibit good antioxidant activity.However,there are not many reports and papers published on the synergism of amino acids with other natural antioxidants.Therefore,this study aims to investigate the synergistic antioxidant activity of 20 amino acids and 9 phenolic compounds and vitamins using ABTS free radical scavenging activity,DPPH free radical scavenging activity and Ferric-reducing antioxidant power assay.The main research work and results were as follow:(1)The ABTS free radical scavenging activity,DPPH free radical scavenging activity and Ferric-reducing antioxidant power of 20 amino acids were determined.Results showed that cysteine,tyrosine and tryptophan exhibited the strongest ABTS free radical scavenging activity,followed by lysine,arginine,valine,histidine,phenylalanine and methionine.And the other 11 amino acids did not showed any ABTS free radical scavenging activity.Moreover,cysteine also exhibited high DPPH free radical scavenging activity and Ferric-reducing antioxidant power,while these two kinds of antioxidant capabilities of other 19 amino acids there were not detected.(2)The combined antioxidant activities of amino acids and some phenolic compounds and vitamins,such as cyanidin,catechin,quercetin,caffeic acid,EGCG BHA,rosmarinic acid,ascorbic acid and tocopherol,were determined using ABTS free radical scavenging activity assay.Results showed that tyrosine and tryptophan exhibited more antagonistic ABTS free radical scavenging activities with the all phenolic compounds and vitamins,but lysine,arginine,valine,histidine,phenylalanine and methionine had synergisms with the phenolic compounds and vitamins.The combined antioxidant activities of other amino acids and phenolic compounds and vitamins were complex.(3)The combined antioxidant activities of amino acids and some phenolic compounds and vitamins,cyanidin,catechin,quercetin,caffeic acid,EGCG BHA,rosmarinic acid,ascorbic acid and tocopherol,were determined using DPPH free radical scavenging activity assay.Results showed that cysteine had synergisms with cyanidin,catechin,quercetin,caffeic acid,EGCG BHA and rosmarinic acid,but antagonisms with ascorbic acid and tocopherol on DPPH free radical scavenging activity.The other 19 amino acids also exhibited synergisms with catechin,quercetin,caffeic acid,BHA,rosmarinic acid,ascorbic acid and tocopherol,but antagonisms with EGCG.However,their combined activities with catechin were complex.(4)The combined antioxidant activities of amino acids and phenolic compounds and vitamins,cyanidin,catechin,quercetin,caffeic acid,EGCG,BHA,rosmarinic acid,ascorbic acid and tocopherol,were determined using Ferric-reducing antioxidant power assay.Results showed that cysteine exhibited synergistic Ferric-reducing antioxidant power with cyanidin,catechin,quercetin,caffeic acid,EGCG,BHA and rosmarinic acid,but antagonisms with ascorbic acid and tocopherol.The other 19 amino acis all showed synergistic Ferric-reducing antioxidant power with cyanidin,caffeic acid,BHA,rosmarinic acid,and tocopherol.Bue their combined activities with catechin,quercetin,EGCG,and ascorbic acid were complex.