Abstract: In this work, in comparison to corn peptide (CP), we investigated the change in structural characteristics and antioxidant activity in vivo of corn peptide-Zn (CP-Zn) complex. The structures of CP and CP-Zn were investigated through amino acid analysis, ultraviolet (UV) spectroscopy and infrared spectroscopy. CP and CP-Zn (50, 150, 250 mg/(kg·d)) at different doses were administered intragastrically to mice. Two days later, malondialdehyde (MDA) content, superoxide dismutase (SOD) activity and glutathione peroxidase (GSH-Px) activity in serum and liver were measured to evaluate antioxidant activity in vivo of CP and CP-Zn. The results showed a significant change in amino acid content, and UV and FT-IR spectra between CP and CP-Zn. Zn2+ was coordinated with the –COOH, –NH2 and C＝O groups of corn peptide. Compared with the control group, high-dose CP and high- and middle-dose CP-Zn could reduce MDA level (P < 0.05 or P < 0.01), and improve SOD (P < 0.01) and GSH-Px activity (P < 0.05 or P < 0.01) in serum and liver. The antioxidant activity of CP-Zn was better than that of CP.

Key words: corn peptide-Zn complex, structure, antioxidant activity