Purification, characterization and antioxidant activity of polysaccharides from Flammulina velutipes residue

In this study, we isolated polysaccharides from Flammulina velutipes residue (FVRP) using microwave assisted extraction and then purified the polysaccharides by column chromatography to yield FVRP-1, FVRP-2 and FVRP-3. The structural characteristics of FVRP-1, FVRP-2 and FVRP-3 were investigated, and their antioxidant activities against ABTS(+), DPPH and hydroxyl radicals were also analyzed in vitro. FVRP-1 was found to be neutral and rich in galactose. However, FVRP-2 and FVRP-3 were acidic polysaccharides and were rich in glucose. The average molecular weight of FVRP-1, FVRP-2 and FVRP-3 were 29,930, 62,290, and 36,310 Da, respectively. The glycosyl residue of FVRP-1 was an alpha-type glycosidic linkage, whereas FVRP-2 and FVRP-3 were p -type glycosidic linkages. We found FVRP-1, FVRP-2 and FVRP-3 had strong potential antioxidant activities in the order of FVRP-1