Study On The Extraction,Purification Of Polysaccharide From Thelephora Ganbajun Zang And Its Antioxidant Activity

Polysaccharide has become one of research focuses for both domestic and overseas researchers,since it displayed some bioactivities,such as regulating immunological mechanism,anti-aging.Thelephora ganbajun Zang is one of rare wild edible mushroom as well as contains polysaccharide.So far,the report concerning about extraction,purification and structure identification of polysaccharide of Thelephora ganbajun Zang are very few.In this study,Thelephora ganbajun Zang were selected as materials,the extraction thechnology of Thelephora ganbajun Zang cruds extracts were optimized,then the extracts were deproteined persistently,afterwards,the polysaccharides were separated,purified as well as its structures were identified preliminarily,furthermore,the antioxidant activity of the polysaccharide was evaluated finally.The results were as follows: 1.Four extraction methods for crude extracts of polysaccharide were employed and compared,they were hot water extraction,alkali extraction,ultrasound-assisted extraction and compound enzymatic extraction methods.Their extraction rates were 8.18±0.091(%)?13.89±0.945(%)?8.79%±0.603(%)?17.12%±0.721(%)respectively.The compound enzymatic extraction method demonstrated higher rate.The optimal conditions for compound enzyme extraction of polysaccharides of thelephora ganbajun zang were optimized by Box-Behnken design;the results showed that the optimal extraction conditions were compound enzyme 0.47%,hydrolysis time 64 min.material-liquid ration 1:40mg/L.Under these conditions,the extraction rate of polysaccharides could be up to 17.55%.2.The deproteinization technologies of crude extracts of Thelephora ganbajun Zang polysaccharide were compared and selected.The polysaccharide was isolated and purified as well as its structure was analyzed preliminarily.Three deproteinization methods(enzyme method,sevage method and enzyme-sevage method)were compared.The results indicated that enzyme-sevage method was optimal with 71.25% deproteinization rate and 91.36% polysaccharide reservation rate.Furthermore,the crude extracts were isolated and purified by DEAE-52 and Sephadex G-100,and then the polysaccharide was obtained.3.The monosaccharide components were analyzed by HPLC and showed they were mannose,glucose,galactose and xylose,and their contents were 0.17mg/g?0.21mg/g?0.95mg/g?0.33mg/g,respectively.The analysis of IR spectrum indicated that the polysaccharides of Thelephora ganbajun Zang contained glycosidic bond of pyranoid ring.4.The crude extracts and purified polysaccharides were used as samples groups,meanwhile ascorbic acids were positive group,their antioxidant capacities were evaluated by several experiments(reducing power and DPPH radical scavenging capacity,total antioxidant capacity,hydroxyl free radical scavenging ability),the results suggested that the antioxidant capacities of polysaccharides were increased with dose-dependent,the purified polysaccharides displayed better antioxidant activity.