Separation, Purification And Structure Analysis Of Water-Soluble Polysaccharide From The Fruiting Body Of Pleurotusostreatus

Pleurotusostreatus (PO) belongs to Tricholomataceae and Basidiomycetae. Theseyears, scholars lay particular emphasis on the research of its chemical composition,pharmacological function , high quality culture and so on. It is extremely important to find outthe pharmacological activity and structure of Pleurotusostreatus for its better utilization. Inthis paper, the structure feature of water soluble polysaccharide isolated from the fruitingbody of Pleurotusostreatus is reported. The results may provide an academic basis for thepharmacological function and clinic application of Pleurotusostreatus.The crude polysaccharide was abtained by boiling and exacting the fruiting body ofPleurotusostreatus. Then the water soluble crude polysaccharide POP was fractionated byethanol. The gas chromatography (GC) indicated that POP was a kind of neutralheteropolysaccharide and composed of glucose, mannose, galactose and fucose. The molarratio is 3.88:2.28:3.28:1.00.The crude polysaccharide was freezed-melted repeatedly and deprotinized by protenaseand Sevage method.. Furthermore,the classifying precipitation in ethanol and SepharoseCL-6B gel chromatography was used to obtain the fraction of POP₃. By means of HPLC andspecific optical rotation measurement,it was proved to be homogeneous on molecular weight.Its molecular weigh was about 24,000. The totle content of POP₃ is 95%.The gaschromatography (GC) indicated that POP₃ was composed of glucose,mannose, galactose andfucose. The molar ratio is 17.50:4.42:39.88:1.00. By means of HPLC, cellulous acetateelectrophoresis and specific optical rotation measurement,it was proved to be homogeneouson molecular weight and polar as well.The IR,GC,partial hydrolysis with acid,periodate oxidation,Smith degradation,¹³CNMR,methylation and GC-MS analysis of POP₃ show that the nonreduced end is composedof glucose and fucose and the main chain is made up of 1→6Gal. 1→2,6Gal residues aresubstituted at 2-O. 1→3,6Man residues are substituted at 3-O on the side chain. On average,there are 4 branches among 10 main chain residues.