文摘
The properties of 22 synthetic peptides containing histidine, which weredesigned on the basis ofthe antioxidative peptide (Leu-Leu-Pro-His-His) derived fromproteolytic digests of a soybean protein,were examined with regard to their antioxidative activity against theperoxidation of linoleic acidand the scavenging effects on active oxygen and free radical species.The antioxidative activities ofthese peptides in an emulsion oxidation system using2,2'-azobis(2-amidinopropane) dihydrochlorideas a radical initiator correlated well within an aqueous system.Although the histidine-containingpeptides had a quenching activity on singlet oxygen, they did not showantioxidative activity in an2,2'-azobis(2,4-dimethylvaleronitrile)-induced oxidation system orscavenging effects on 1,1-diphenyl-2-picrylhydrazyl radical and superoxide. The metal-ion chelatingactivities and the hydrophobicitiesof these peptides showed no direct correlation with their antioxidativeactivities. Leu-Leu-Pro-His-His was modified with a hydroxyl radical in an aqueous ethanolsystem during the peroxidationof linoleic acid.Keywords: Antioxidative peptide; histidine; antioxidant; metal chelate;radical scavenger