Preparation, Characterization And Activities Of Glycosaminoglycans From Apostichopus Japonicus

Sea cucumber has been used as a fundamental source of food and drug in traditional Chinese medicine for centuries. The sea cucumber Apostichopus japonicus is a species with high commercial value and is found along the coast of Russia, China, Japan and Korea. Qingdao is one of the main production places of A. japonicus, where the sea cucumber is regarded as high value seafood. The usage of A. japonicus ranched from the Qingdao sea area, however, is simple. And, the composition and characterization of its bioactive chemical components have not been fully investigated. Researches on the structure, anticoagulant and immune-regulation activities of glycosaminoglycan and its low molecular weight products will contribute to the findings of new marine polysaccharide-like drugs, which promises a good application prospect.In the present study, we isolated a novel fucosylated glycosaminoglycan from A. japonicus cultivated in marine area of Huanghai and Bohai seas and further investigated its structure, depolymerized products and activities, which mainly including the following sections:1) A method about isolation and purification of glycosaminoglycan from A. japonicus was firstly established, which provided a production of glycosaminoglycan with constant molecular weight and high purification. Its structure was further characterized using varieties of technical skills. The results indicated that the polysaccharide possessed a chondroitin sulfate like bone structure and sulfated fucose branches stretching from GlcUA or GalNAc, which can be presented by-[4GlcAβ(Fuc2,4Sα1-3)1-3GalNAc4,6Sβ1]n-.2) A method about depolymerization of glycosaminoglycan from A. japonicus using Cu2+ induced free radical degradation reaction was firstly built, which provided a serial low molecular weight glycosaminoglycan. The established method was of low cost and could be well applied in large scale production. The results indicated that 1/MW was of linear relation to the degradation time during the reaction, which offered a controllable depolymerization of glycosaminoglycan from A. japonicus.3) The anticoagulant activities of glycosaminoglycan from A. japonicus and its depolymerized products were investigated to find a novel polysaccharide drug which cauld be used to replace the medical role of heparin in clinical application. The results indicated that the glycosaminoglycan exhibited its activity through intrinsic pathway and blocking the fibrinogenase. DAHG-2 could be used as a new anticoagulant with low side effort.4) The immune-regulation activities of glycosaminoglycan from A. japonicus were discussed firstly. The research was mainly focusing on the dendritic cell and cytokine induced killer cells. The results showed that glycosaminoglycan from A. japonicus could up-regulate the proliferation and cell factor secretion of DC and CIK cells.The present research would greatly benefit the building of Ocean sugar library and the finding of new anticoagulant and immune-regulation drugs with novel structures and low side efforts, which offered a great value of application.