Characterization of the Antioxidant Peptides Prepared From the Seed Kernel of <i>Xanthoceras sorbifolium</i> Using Enzymatic Hydrolysis: Molecular Docking Analysis and In Vitro Binding Studies

ABSTRACT In this study, the antioxidant peptides (XSPH) from Xanthoceras sorbifolium oleifera were extracted and purified. The peptides were separated by ultrafiltration into XSPH‐I (&lt; 3 kDa), XSPH‐II (3–10 kDa), XSPH‐III (&gt; 10 kDa), and XSPH‐0 (unfiltered). Among them, XSPH‐I showed the strongest antioxidant activity. XSPH‐I increased the activity of glutathione (GSH), catalase (CAT), and superoxide dismutase (SOD) while decreasing the reactive oxygen species (ROS) and malondialdehyde (MDA) levels in HepG2 cells. After determining XSPH‐I's amino acid sequence, computer‐aided screening and molecular docking technologies were used to identify four new antioxidant peptides: AKPAFFAPR, TKPFAWARR, PRESDNTMLF, and GVTASFGMLG. All four synthetic peptides exhibited a good antioxidant activity, with PRESDNTMLF showing the best DPPH scavenging rate (53.624 ± 1.124%, p &lt; 0.05) and ABTS scavenging rate (89.704 ± 2.004%, p &lt; 0.05). In conclusion, the potential application value of Xanthoceras sorbifolia peptide in functional foods warrants further investigation.