Isolation, purification and characterization of polysaccharides from Morchella essulenta L.

The nutrient liquid of \%Morchella esculenta \%L. from liquid deep layer fermentation was treated by ultrafiltration to remove low molecular weight components, then defatted, decolorized and deproteinized and followed by concentration under reduced pressure and low temperature. It was further purified by ultracentrifuge and repeated precipitation and purification with ethanol to obtain the required polysaccharide components (MEP), in which MEP\|SP of molecular of 10 000～100 000 was purified and separated by DEAE\|cellulose ion exchange column and Sepharose CL\|6B gel chromatography, two soluble fractions (MEP\|SP2 and MEP\|SP3) were yielded. HPLC was used to obtain their molecular weight and gas chromatography was used to determine their monosaccharide constitution. The results showed that molecular weight of ME\|SP2 is 23 000, MEP\|SP3 is 44 000, the former is composed of four kinds of monosaccharides: mannose, glucose, arabinose and galactose in the mole ratio of 1.75∶4.13∶0.71∶0.68; the latter is composed of six kinds of monosaccharides, which contains xylose, glucose, mannose, fructose, arabinose and galactose in mole ratio of 3.58∶14.9∶3.85∶1.77∶51.3∶0.53. The structure of MEP\|SP2 was studied by means of elemental analysis, IR, NMR, etc. the result showed that main chains in MEP\|SP2 were composed of α\|pyranglycoside linkage.