Study on Extraction, Purification and Immunomodulatory Effect of Cordyceps Polysaccharide of Cordyceps militaris

Objective To extract and purify the cordyceps polysaccharide of Cordyceps militaris and preliminarily investigate its molecular structure and immunomodulatory effect on macrophage.Methods The pure cordyceps polysaccharide was obtained by alcohol precipitation,deproteinizing by Sevag method,removal of small molecules by dialysis and CM-52 cellulose column chromatography.The purity of cordyceps polysaccharide was determined by UV spectra;the relative molecular mass was analyzed by gel chromatography;the molecular structure was determined by high performance capillary electrophoresis and infrared spectroscopy analysis.The effect of cordyceps polysaccharide was also investigated on NO production by RAW 264.7 macrophage.Results The pure cordyceps polysaccharide with a single symmetrical peak was obtained by a series of steps of purification.Its relative molecu-lar mass was 3.49 × 104 with hydroxy,furaldehyde,carbonyl groups and mannose structure.The pure cordyceps polysaccharide could stimulate RAW 264.7 macrophage to excrete NO,so it had an immunomodulatory effect on macrophage function.Conclusion The cordyceps polysaccharide of Cordyceps militaris with high purity can be produced by the above methods,and the polysaccharide can activate macrophage and improve immunity.