The Extraction And Purification Of Polysaccharides From Potentilla Anserina L. And The Monosaccharide Constitute Of Polysaccharides

Potentilla anserina L., one traditional Tibetan medicine, has been used in food and medicine. Like other polysaccharides, the polysaccharides of Potentilla anserina L. have some special functional properties. The paper focuses on the extraction and purification of polysaccharides original from Tibet. And the paper also involves the structure analysis of monosaccharide and the antibacterial properties of polysaccharides.The polysaccharides were extracted by water. According to the results of single factor and orthogonal experimental design, the optimum extraction conditions were that the ratio of water and powder of Potentilla anserina L., extraction time and temperature were 1:25, 1h and 90℃, respectively. The production of crude polysaccharides was 6.97±1.02%.Compared with protease and Sevage, the protein in crude polysaccharides can be efficiently hydrolyzed by proteases. In all selected proteases, trypsin is an ideal protease. According to the results of single factor and orthogonal experimental design, the optimum hydrolysis condition for removing protein were that trypsin, hydrolysis time, pH and temperature were 250U/mg, 4h, pH 7.8 and 30℃, respectively. At this condition, 73.2±1.21% protein was removed from crude polysaccharides.Active carbon, hydrogen peroxide and iron-exchange resins were choose to decolorization of polysaccharides. The results shown that hydrogen peroxide was best decolourant among them. At pH 9.0 25% (V/V) hydrogen peroxide (30%) was added into the 2% polysaccharides and the mixture was heated 60 min at 60℃. The decoloring rate was 89.92±0.53%.In order to determinate the monosaccharides of Potentilla anserina L. polysaccharides, the polysaccharides were hydrolyzed into monosaccharide, and then applied TLC and GC to analyze the monosaccharide. The main monosaccharides in polysaccharides were arabinose, D-glucose and galactose, and the ratio of relative mass of them was 6:17:1 (arabinose : D-glucose : galactose).The purified polysaccharides were investigated its antibacterial properties. The reproduction of Shigella can be inhibited by 0.5% polysaccharides in 24h. Also the reproduction of Salmonella and E. Coli also can be inhibited by 1% and 3% polysaccharides in 8h.