Study On Extraction,Structural Analysis And Active Function Of Polysaccharide Isolated From A Uricularia A Uric Ula-judae(Bull.)

Auricularia auricula-judae(Bull.)is the second largest edible fungus in China.At present,China's production accounts for more than 90%of the world's total output.However,due to the lack of in-depth systematic research on the edible function of Auricularia auricula-judae(Bull.)in the current industry,the emphasis is on the preliminary processing of Auricularia auricula-judae(Bull.),so the industry has not brought significant economic benefits.As the main component of Auricularia auricula-judae(Bull.),the polysaccharide is a kind of edible fungus polysaccharide which has potential effects.With the development and application,the research can promote the transformation and upgrading of the Auricularia auricula-judae(Bull.)industry.The functional activity of polysaccharides is closely related to its structures.In this study,the active polysaccharide from Auricularia auricula-judae(Bull.)was isolated and their structural characteristics were studied to verify their immunomodulatory activity.We combined the structures with its functions and mainly obtained the following conclusions:(1)Purification and separation of Auricularia auricula polysaccharide by ultrafiltration and optimization of its process parameters to obtain refined polysaccharide(AAP).The yield of AAP was 37.49±1.64%which is higher than the extraction yield in the literature(generally between 10-30%).The process was stable,the purification method was simple and efficient,and no chemical reagent was introduced,which laid a good foundation for subsequent research.(2)We explored the structure of AAP through the aspect of glycosidic bonds,sugar chains,functional groups,and monosaccharide composition.The main monosaccharide compositions were rhamnose,mannose and glucose.The main chain of AAP was ?-(1,3-)glycosidic linkages,it has triple-helical conformation.These typical structures are closely related to immunomodulation activity.(3)The antioxidant and immunomodulatory activities of AAP were verified.The results showed that AAP has strong reducing ability and scavenging ability of ABTS and DPPH free radicals.It can strongly stimulate macrophages,promote its proliferation,enhance the phagocytosis of macrophages,and significantly induce the secretion of nitric oxide and the release of cytokines IL-6 and TNF-? in cells.It was found that AAP resisted the immunosuppression of mice induced by cyclophosphamide through promoting the recovery of leukocyte levels,the development of immune organs and the proliferation of lymphocytes in mice.Based on the above conclusions,it is not difficult to find that Auricularia auricula polysaccharide has good prospects in immunoregulation and it can be used as a potential immune agent.At the same time,the optimization of Auricular ia auricula polysaccharide extraction method and structural analysis also provided theoretical basis and practical means which are convenient for the future development and application of Auricularia auricula polysaccharide products.