Studies On Separation, Purification And Charictrization Of Polysacchriade Isolated From The Wild Morchella Esculenta (L.)Pers.Grown In YunNan

The Morchella esculenta (L.)Pers. is one kind of precious medical food fungus, which has high nutritional value and contains various function components, such as polysaccharide. In this paper, the wild Morchella esculenta (L.)Pers .from Yunnan province was used as material and its water-soluble polysaccharide was studied in the following respects, including content determination, extraction process, conditions of separation and purification, physical and chemical characteristic. The following results were obtained.(1)The preliminary experiment discovered that extracting temperature, extracting time, extracting cycle and material to water ratio were the major factors affecting the extraction process. The single factor experiment indicated that the polysaccharide yield rate gradually increased with the extraction temperature increment. It increased and then decreased with the extraction time increased or material to water ratio decreased. It became less obvious after a sharp increase with the extraction cycle folded. With extraction time 2-3 h, material to water ratio 1:40, the extraction process had a reasonable result. The residual of water extraction further extracted with 0.5mol/L NaOH at normal temperature over night, which obtained the alkaline-extracted-water-soluble polysaccharide and the alkaline-extracted-alkaline-soluble polysaccharide. Unfortunately, the recoveries of these two kinds of alkaline-extracted polysaccharides were extremely low, 0.82% and 0.54% respectively. In terms of polysaccharide recovery, the optimum conditions of extraction process through orthogonal experiment were gained with material to water ratio 1:50, extraction time 2 h, extraction cycle 3 and extracting temperature 95℃. Meanwhile, when the Morchella esculenta (L.)Pers concentrated extracts mixed with 95% cold alcohol at a ratio of 1:4 (v/v), the polysaccharide yield rate is 4.96 %.(2) The Morchella esculenta (L.)Pers. crude polysaccharide carried on the DEAE-52 cellulose ionic exchange column chromatographic analysis after dissolved used distilled water. Using the distilled water, the 0.1mol/LNaOH solution and the 0.2mol/LNaOH solution stage gradient elution separately, it will obtain three kinds of elution products, MEP-1, MEP-2 and MEP-3; their yield rate will respectively be 12.40%, 3.10% and 5.94%. Then the Morchella esculenta (L.)Pers. polysaccharide MEP-1 after double steams the water dissolution carried on glucosan gelatin SephadexG-100 molecular sieve column chromatographic analysis(16×1000mm), on the quantity 20mg, with double steams the water elution, the speed of flow was 2ml/5min, each tube collected 2ml, collecting 34-48 eluents, drying and concentration, the Morchella esculenta (L.)Pers. polysaccharide MEP-1 purely can be obtained; its yield rate was 1.58%.(3) The elution curve obtained through glucosan gelatin Sephadex G-100 chromatographic analysis of the Morchella esculenta (L.)Pers. polysaccharide MEP-1 pure was the sole symmetrical peak. On the gelatin seepage chromatograph analysis on the room temperature(Highly effective liquid chromatography system, TSK-Gel G4000PWXL柱(7.8×300mm, 4um) ), taking the pure water as flowing, Speed of flow being the 0.3 ml/min, column pressure being the 1.5MPa, temperature being the 25℃, refractire index detector detection, the Morchella esculenta (L.)Pers. MEP-1 pure only appears the sole peak. Therefore, overpass the experiment; we can obtain that the Morchella esculenta (L.)Pers. MEP-1 pure was the sole component polysaceharide.(4) The pure the Morchella esculenta (L.)Pers. MEP-1 product assumes white powder which is no smell, ratio whorl luminosity [a]⁰⁰_D is + 257.0 (C =0.001, 1120); Water-solubility is easy and belongs to the neuter polysaccharide. The pure Morchella esculenta (L.)Pers. MEP-1 product does not contain amylum, is non-starch class polysaccharide, and does not contain monosaccharide, uronic acid, protein, polyphenols material, nucleic acidaverage and so on. Mean molecule quality is 43.625KD. Through paper chromatographic analysis, it is found that the Morchella esculenta (L.)Pers. MEP-1 pure composition monosaccharide possibly includes the glucose, the mannose, the pectin sugar and the galactose. Through infrared chromatograph analysis, the Morchella esculenta (L.)Pers. MEP-1 is by beta - the sugar glucoside keying mixed polysaccharide, in the monosaccharide composition possibly also includes the xylose.