Preparation, characterization and antioxidant activity of acetylated garlic polysaccharide, and garlic polysaccharide‐Zn (II) complex

Abstract Garlic polysaccharide (PS) was extracted from garlic by hot‐water extraction. Acetylated garlic polysaccharide (AcPS) and garlic polysaccharide‐zinc complex (ZnPS) were synthesized. The results of Fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy analysis showed that the modifications were successful. The antioxidant activities of PS, AcPS, and ZnPS were further investigated in vitro, including scavenging superoxide anion and hydroxyl radicals, antilipid peroxidation capacity, and reducing power. The results showed that the scavenging abilities of AcPS and ZnPS on hydroxyl radical (The IC 50 of PS, AcPS, and ZnPS were 2.86, 1.62 and, 1.49 mg/ml, respectively,) and superoxide anion radical (The scavenging rate of PS, AcPS, and ZnPS were 1.5% and 1.8%, and 2.3%, respectively, when concentration was at 1.0 mg/ml.) were stronger than that of PS, and the inhibitory effect of AcPS on lipid peroxidation was significantly stronger than that of PS (The IC 50 of PS and AcPS were 1.05 and 0.53 mg/ml, respectively.). It indicated that the acetylation was a favorable way to enhance the antioxidant activity of garlic PS; ZnPS complex could be applied as potential candidate for antioxidant and Zn supplement.