Preparation And Characterization Of Water Soluble β-Glucans From Grifola Frandosa Mycelium

Grifola frondosa is an edible/medical fungus, with a renowned fame and it has anticancer etc. activities. It has been liquid cultured on a large-scale to acquire mycelium at present.This thesis involves in the preparation and characterization of the water-soluble polysaccharides from Grifola frondosa. The mycelium was extracted with 85% ethanol and then extracted sequentially with hot water, cold and hot sodium hydroxide. One water soluble heteropolysaccharide (GFM1) was acquired using hot water extraction, and two water soluble P -glucan (GFM3, GFM4) were acquired using cold and hot alkali extraction, respectively.GFM3 was further fractioned into GFM3P1 and GFM3P2. GFM3P1 is a -glucan and GFM3P2 is a 6-glycopeptides. The structure of GFM3P1 and GFM3P2 was similar to that of GFM4P2. The; linkage of glucan to peptide is O-linkage in GFM3P2 and the peptide contained 16 kinds of amino acid, and acid amino acid is very abundant. The super helix structure of GFM3P1 and GFM3P2 is easily destroyed by 0.2mol/lNaOH, but that of GFM4P2 is hardly destroyed by 2mol/L NaOH in the Congo red binding assay. The structure of GFM4P2 is proved to be beta-l,6-glucan with beta-1,3-branch, and the degree of branches is 36.4%, and this structure is first reported from Grifola frondosa mycelium.The antitumor activities of GFM3P1 and GFM4P2 were further evaluated. The inhibition rate to S180 of GFM3P1 and GFM4P2 was 65% and 73%, respectively. Their anti-tumor activities are better than lentinan (35%), which is widely used in the clinical as anticancer drug. These beta-glucans can also improve the immunity of mice, and these results revealed, that the polysaccharide would be potentially developed to be an anticancer drug.