Purification, chemical characterization and antioxidant activities of polysaccharides of fruiting bodies of Pleurotus ferulae mushroom

Three water-soluble polysaccharides fractions (PFP1a, PFP2b and PFP3c) were isolated and purified from Pleurotus ferulae by DEAE-Sepharose CL-6B and Sepharose CL-6B column chromatography. Their chemical characterization was conducted by chemical methods, chromatography and Fourier transform infrared spectroscopy. Antioxidant activities of crude polysaccharides from P. ferulae (CPFP) and its purified fractions were investigated on the basis of superoxide anion, DPPH, hydroxyl radical scavenging activity and reducing power. The result indicated PFP1a, PFP2b and PFP3c had obvious characteristic peaks of polysaccharides and were mainly composed of six kinds of monosaccharides including rhamnose, arabinose, glucose, mannose, xylose and galactose. The average molecular weight of PFP1a, PFP2b and PFP3c were approximately 5.9x10(5)Da, 3.2x10(5)Da and 2.6x10(4)Da, respectively. PFP1a, PFP2b and PFP3c exhibited antioxidant activities in a concentration-dependent manner. The results demonstrated that the three polysaccharides had the potential to be new natural antioxidant in the food and pharmaceutical industry, especially the PFP2b and PFP3c containing more uronic acid.