Molecular Structure and Antioxidant Activity of Polysaccharides from Phellinus vaninii Ljup

Abstract:

The molecular weight，structure and antioxidant activity of extracellular polysaccharide（EPS） from Phellinus vaninii Ljup was investigated in this study. The EPS was isolated and purified，and the molecular weight of EPS was determined by gel filtration. The type of anomeric carbon in the EPS structure was investigated by FT-IR，the carbohydrate composition of the EPS was determined by GC/MS，the molecular conformation of EPS was analyzed by SEC/MALLS binding viscosity method，the antioxidant activity of EPS was determined according to OH and DPPH radical scavenging activity. The results showed that：two EPS fractions（Fr-I and Fr-II） were obtained after separation and purification，and the relative molecular weight of Fr-I and Fr-II were 627 500 and 55 000 respectively. FTIR results showed that the Fr-I was coexistence of α- and β-configuration of mannopyranoside acidic polysaccharides，while Fr-II α-mannopyranoside acidic polysaccharides. GC/MS results showed that the monosaccharide components of Fr-I and Fr-II contained ribose，xylose，glucuronic acid，galactose，glucose，mannose and galactose；SEC/MALLS results showed that the dispersion of the EPS is very low，and the EPS kept spherical conformation in aqueous solution. The EPS is a highly compact aggregates with branch. The antioxidant activity tests showed that the ·OH scavenging rate was 38.58% when EPS concentration was 10 mg/mL，and the