Extraction And Purification Of Polysaccharide From Quercus Acutissima And Property Analysis Of Its Pure Polysaccharide

Quercus acutissima,also known as oak and quercus,is a deciduous tree of Quercus in Fagaceae.Its thicker branches can be used as a substrate for cultivation of edible fungi.Compared with substitute cultivation,Quercus acutissima has obvious advantages in yield,appearance and quality,which are closely related to the nutrients in the original wood of Quercus species.Up to now,there are relatively few studies on polysaccharides from Quercus species,and there are no reports on the isolation,purification and activity of Polysaccharides from Quercus species.Therefore,in order to exploit and utilize the polysaccharide resources in Quercus acutissima wood,this paper discussed the technological parameters of hot water extraction of Polysaccharide from Quercus acutissima,the optimum conditions of protein removal by dialdehyde cellulose method,and preliminarily analyzed the properties of pure polysaccharide.Taking the yield of crude polysaccharides from Quercus acutissima as an index,the extraction time,temperature,ratio of material to liquid and extraction times were investigated by single factor test.Box-Benhnken central combination test and response surface analysis were used to optimize the extraction conditions.The optimum conditions for hot water extraction of crude polysaccharides from Quercus acutissima were obtained as follows:extraction time 3 h,extraction temperature 90? ratio of material to liquid 1:25 g/mL,extraction times 2 times under these conditions.The yield of polysaccharide was 2.65%.The optimum conditions for protein removal by dialdehyde cellulose method were as follows:aldehyde content was 4.68±0.07 mmol/g,temperature was 40?,liquid-to-material ratio was 1:20 mL/mg,time was 4 h,pH was 8,and compared with Sevage method.After being decolorizing by AB-8 macroporous resin,the crude polysaccharides of Quercus macrocarp were separated and purified by two steps of DEAE-52 cellulose ion exchange column and Sephadex G-200 gel column,and four pure polysaccharides were obtained(labeled OPA-D,OPB-D,OPA-S and OPB-S,OP stands for Oak Polysaccharide,respectively).UV and high performance liquid chromatography analysis showed that OPA-D,OPB-D,OPA-S and OPB-S had single absorption peaks and were pure polysaccharides.Pre-column Derivatization-High Performance Liquid chromatography analysis showed that OPA-D and OPA-S were neutral heteropolysaccharides composed of xylose and glucose with a molar ratio of 0.86:0.7;OPB-D and OPB-S were homologous compounds composed of ribose,glucuronic acid and arabinose.The molar ratio of acid Heteropoly saccharide was 0.42:0.21:0.56.The average molecular weight of OPA-D and OPA-S was 444.836 kDa by high performance gel permeation chromatography(HPGPC),and the average molecular weight of OPB-D and OPB-S was 121.238 kDa.These results provide a basis for the preparation,structure characterization and pharmacological activity evaluation of the pure product of Quercus acutissima polysaccharide.