Structural characterisation and antioxidant properties of polysaccharides from the fruiting bodies of Russula virescens

Water-soluble crude polysaccharide named as RVP was obtained from the fresh fruiting bodies of Russula virescens by boiling-water extraction. DEAE-Sepharose CL-6B column chromatography was used for the fractionation of polysaccharide RVP. Two fractions were obtained, namely RVP-1 and RVP-2. RVP-1 and RVP-2 were composed mainly of glucose, with the estimated equivalent dextran molecular weights of 3.1 × 105 and 4.2 × 105 Da, respectively. Analysis by Periodate oxidation–Smith degradation indicated that RVP-1 was composed of 68.3% (1 →)- or ((1 → 6)-glycosidic linkages and 31.7% (1 → 3)-glycosidic linkages, and RVP-2 7.9% (1 →)- or (1 → 6)-glycosidic linkages, 9.6% (1 → 2)-glycosidic linkages, 35.7% (1 → 4)-glycosidic linkages, and 46.8% (1 → 3)-glycosidic linkages. RVP-1 exhibited equivalent inhibiting power for self-oxidation of 1,2,3-phentriol to vitamin C (Vc), a little higher scavenging activity of superoxide radical and hydroxyl radical than Vc. The reducing power of RVP-1 at 20.0 mg/ml was 0.77, and RVP-1 was a good chelating agent for ferrous ions. Overall, RVP-1 possessed good antioxidant properties and should be developed as a novel potential antioxidant.