Isolation and identification of antioxidative peptides from peptic hydrolysates of half-fin anchovy (Setipinna taty)

- Six peptides were identified from the peptic hydrolysates of half-fin anchovy.
- Synthetic EMSAGLHE and WRKKDPLND had strong DPPH radical scavenging activities.
- Synthetic NKVKGELD had stronger ferric reducing power ability than other peptides.
- Peptide mixtures had synergistic effects on scavenging DPPH radicals reducing power.

The objective of this study was to identify antioxidative peptides from peptic hydrolysates of half-fin anchovy (HAHp). Furthermore, the possible synergistic effects of identified peptides were evaluated. HAHp were separated using CM FF ion exchange and Sephadex G 25 chromatography. HAHp1-2, one peptide fraction with the highest 1, 1-diphenyl-2-pycrylhydrazyl (DPPH) scavenging activity, was subjected to RP-HPLC coupled with ESI under positive ionization mode. Six peptides, AGDDARPA (771.35 Da), ESAGLHE (741.33 Da), NKVKGELD (901.45 Da), TLWSGAGQTVNT (1233.63 Da), EMSAGLHE (872.37 Da) and WRKKDPLND (1171.60 Da), were identified by ESI-MS/MS analysis. Peptides AGDDARPA (HAHp1-2Ⅰ), ESAGLHE (HAHp1-2Ⅱ), NKVKGELD (HAHp1-2Ⅲ), EMSAGLHE (HAHp1-2Ⅳ) and WRKKDPLND (HAHp1-2Ⅴ) were synthesized to determine in vitro antioxidative activity. Results showed that HAHp1-2Ⅳ and HAHp1-2Ⅴ displayed higher DPPH radical scavenging activities than other three peptides and l-carnosine. Peptide HAHp1-2Ⅲ demonstrated similar reducing power ability as l-carnosine. All synthetic peptides had moderate or negligible metal chelating activities. Additionally, the enhanced DPPH radical scavenging activities or reducing power abilities were observed for the mixture of HAHp1-2Ⅲ, HAHp1-2Ⅳ or HAHp1-2Ⅴ, indicating the possible synergistic effects. These results suggested that the antioxidative peptides derived from HAHp could be used as potential antioxidants in functional foods and nutraceuticals.