Isolation And Purification Of A Mycelium Polysaccharide From Grifola Frondosa And Its Biological Activity On Hypoglycemic

Grifola frondosa as a kind of precious edible-medicinal fungi, It has been highly been concerned by scientists. GFP is a kind of high value of biological active component, it also is the focus of scientific research. In this paper, carbon and nitrogen source control of liquid fermentation, the submerged fermentation and extraction of GFP were studied.Meanwhile, The structure of pure polysaccharide and the activity on hypoglycemic activity were discussesed. The results are as follows:1.With glutinous rice powder, potato starch, corn starch, maltose, cane sugar and soluble starch as a source of carbon, comprehensive optimal carbon source is glutin-ous rice powde. With ammonium chloride, urea,ammonium sulfate,yeast and bran as a source of nitrogen, comprehensive optimal nitrogen source is bran.2. With glucose, peptone, VitB1 and KH2PO4 as the investigation factors and ta-ke the exopolysaccharide as the investigation index. The optimal liquid fermentation condition is glucose 30g/L, peptone 5g/L,VitBl 1.5mg/L,KH2PO4 1.5g/L. In this condition, the yield of exopolysaccharide is 32.13mg/mL.3. With microwave power, microwave radiation time, solid-liquid ratio and ex-traction time as the investigation factors and take the yield of polysaccharides. The optimal liquid fermentation condition is microwave power 450W, microwave radiat-ion time 4min, solid-liquid ratio 1:45, extraction time 4.5h. In this condition, the yield of polysaccharide is 3.21%.4. The hypoglycemic activity of polysaccharides from Grifola frondosa alloxan-induced mice was investigated. It was found that all the treatment group The prepared peptide could improve the syndromes of polyphagia, drinking more water and lossing weight of the alloxan induced diabetic rats. Low-dose group of GFP and traditional Chinese medicine compound high dose group could markedly decrease blood glucose (P<0.05) compared with model control group. Blood glucose value of traditional Ch-inese medicine compound high dose group down to 10.94 mmol/L on the 28th day.It reached the standard of diabetes mellitus.5. The GFP was purified by DEAE Sephadex A-50, and gained three main components of the polysaccharide, named GFP1,GFP2 and GFP3.The result of GFP1 and GFP2 200-700nm scanning exhibited that GFP1 and GFP2 almost does not contain nucleic acid, protein and pigment.GFPl and GFP2 were further purified by Sephadex G-200 chromatography, showed that GFP1 is a single absorption peak. It indicated that GFP1 was a single component polysaccharide. Then the molecule structure of GFP1 was studied by infrared spectrum and nuclear magnetic resonance(400M). The results showed GFP1 has the typical character of polysaccharides.