Purification, Characterization and Antioxidant Activities of Enzymolysis Polysaccharide from Grifola frondosa

Our previous study revealed that the antioxidant activity of polysaccharide (coded as FGFP) extracted from Grifola frondosa by enzymolysis treatment was significantly superior than that (coded as GFP) extracted by boiling-water. In this study, one purified polysaccharide fractions (coded as FGFP-11) was obtained from FGFP by purified using DEAE-52 column and Sephacryl S-500HR column. Results indicated that FGFP-11 with MW of 59.82 kDa consisted of mannose, glucose and galactose with a molar ratio of 1.00: 16.36: 5.25. Fourier Transform Infrared Spectroscopy (FTIR spectrum) of FGFP-11 was similar with that of polysaccharide extracted by boiling-water from Grifola frondosa. These indicated the enzymolysis did not destroy the polysaccharide structure. NMR spectrum showed that FGFP-11 possess alpha-(1 -> 6) glycosidic bond and alpha-(1 -> 3) glycosidic bond configuration. The experiment of Congo red also revealed that FGFP-11 had triple helix stereo-configuration. Moreover, the antioxidant activities of FGFP-11 were improved compared with that of GFP, especially in scavenging of hydroxyl radical and diphenyl picryl hydrazinyl (DPPH) radical.