Extraction,Purification,Structure And Activities Of Polysaccarides From Bachu Mushromm

Bachu mushroom(Helvella leucopus),grow in north edge of Tarium Basin in Xinjiang Province of China,is a Helvella fungus belonging to the Ascomycetes.At present,the research on Bachu mushroon was still concentration on nutrient components and the activities of their crude extracts,and there was no comprehensive research on some of their specific components.In this paper,optimum extraction,purification,structure,antioxidant activity and antitumor activity of polysaccharides from Bachu mushroom were studied.Results showed that the optimum extraction of Bachu mushroom polysaccharide was the extraction temperature of 84.9?,extraction time of 94 min,pH 7.1 and solid-liquid rate of 1:42(g/mL).Under these conditions,the yield of polysaccharides was 6.52%(w/w).The experimental results were reliable testified by the variance analysis.Various factors affected on the yield of polysaccharides in the order of pH>the ratio of material/liquid(g/m L)>extraction time> extraction temperature.Protease-Sevage reagent was found to be the best method for protein removal.After purification by DEAE-52 cellulose and Sephadex G-150 Sephadex,two kinds of polysaccharide components,HLP1-1 and HLP2-1(named by ourselves),were obtained.HLP1-1 was white floc,and HLP2-1 was light yellow powder.Two kinds of polysaccharides had good solubility in water,which were non-starch polysaccharides.Both of them didn't contain protein,polyphenol and reducing sugar.Tertiary structure analyses indicated that HLP2-1 had triple-helical conformation,but HLP1-1 not.The monosaccharide compositions of HLP1-1 included rhamnose,glucosamine and mannitose at a molar ratio of 11.8: 1: 78.6,and HLP2-1 included of rhamnose,glucosamine,glucose and mannitose at a molar ratio of 4.2: 1: 18.1: 27.3.The results of 1HNMR and HLP1-1 were similar to those of HLP2-1.There were two kinds of polysaccharides in the presence of rhamnose hydrogen signal and methyl hydrogen signal in the N-acetyl group of amino sugars.And,both two kinds of polysaccharides contained both alpha ?-pyranose and ?-pyranose,but they do not contain furanose.The GPC result showed that HLP1-1 and HLP2-1 had similar molecular weight(21382 Da and 23063 Da,respectively).The antioxidant activities of polysaccharides HLP1-1 and HLP2-1 were determined by three methods(ABTS method,FRAP method and pyrograllot autoxidation method).Both HLP1-1 and HLP2-1 showed some antioxidant activities,and HLP2-1 showed stronger antioxidant activities than HLP1-1.Inhibitory effects of two polysaccharides on human hepatocellular carcinoma cells(HepG-2)were determined by MTT method.The result showed that two kinds of polysaccharides could inhibitted the proliferation of human hepatoma cell(HepG-2).The inhibitory effect of HLP2-1 was stronger than that of HLP1-1.