Hm. Chen et al., ANTIOXIDANT ACTIVITY OF DESIGNED PEPTIDES BASED ON THE ANTIOXIDATIVE PEPTIDE ISOLATED FROM DIGESTS OF A SOYBEAN PROTEIN, Journal of agricultural and food chemistry, 44(9), 1996, pp. 2619-2623
Antioxidative activities of 28 synthetic peptides, which were designed
based on an antioxidative peptide (Leu-Leu-Pro-His-His) derived from
proteolytic digests of a soybean protein, against the peroxidation of
linoleic acid in an aqueous system were measured by the ferric thiocya
nate method. The results for the hydroperoxide levels derived from lin
oleic acid agreed with those obtained by reversed-phase high-performan
ce liquid chromatography. The deletion of the C-terminal His decreased
the activity, whereas the deletion of the N-terminal Leu had no effec
t. In the peptide sequence, His and Pro played important roles in the
antioxidative activity and, among the peptides tested, Pro-His-His was
the most antioxidative. The activity decreased on substitution of the
second His with D-His. Introduction of Tyr to the positions of Pro or
His did not increase the activities of the corresponding peptides. An
tioxidative peptides showed synergistic effects with nonpeptidic antio
xidants as observed in soybean protein hydrolysates. The magnitude of
the effects, however, did not correlate with the antioxidative activit
ies of the peptides.