Separation and Identification of Peptides Derived from Soybean Protein, and Their Active Oxygen Scavenging Activity

Abstract

Peptides having strong superoxide scavenging activities were separated from a soybean protein digest by chromatographic methods such as ion-exchange and gel-filtration. The most potent fraction (SP-1) obtained by SP-Sephadex C-25 chromatography was further separated into peptide components using ODS HPLC. The amino acid sequences of these peptides were: Ala-Val-Pro-Tyr-Asn-Leu (AVPYNL) and Leu-Val-Pro-Pro-Gln-Glu-Glu-Gln-Lys (LVPPQEEQK). The IC₅₀ values of AVPYNL and LVPPQEEQK for superoxide scavenging activity were 126μM and 186μM, respectively, determined by the tetrazolium salt XTT method. The IC₅₀ values of AVPYNL and LVPPQEEQK for hydroxyl radical scavenging activity were 6.1μM and 9.2μM, respectivity.