Extraction, Separation,Determination Of Molecular Weight And Structural Research Of Polysaccharide From Bletilla Striata

Objective:Bletilla is one kind of commonly used traditional Chinese medicine, which is orchid Bletilla striata’s(Bletilla striata (Thunb) Reichb. f.) dry tuber. Mainly produced in south China region Bietilla polysaccharide is extracted from the tuber of a polysaccharide substance, detumescence muscles, promote blood clotting, anticancer effect. Reports study found that in recent years, bletilla mainly as a vascular embolization agent and gene delivery carrier, in targeting effect at the same time also can exert its anti-tumor effect, has a good application prospect. This experiment by bletilla tuber as the research object, to extract the polysaccharide content, and the molecular weight of polysaccharides and the structure of the system research, provide a basis for further development and utilization of bletilla polysaccharide.Method:This experiment with water formulation, alkaline formulation, cellulose enzyme method, ultrasonic extraction four extraction experiment. Phenol-sulfuric acid method for polysaccharides content determination to the highest polysaccharides content method as a base for process optimization, to determine the best extraction process.The best extraction technology to extract the polysaccharide with Sevag method to take off the protein, ultrafiltration treatment, column separation and purification method, the obtained bletilla striata polysaccharide is tasted. And the structure of the polysaccharide from the extracted bletilla striata polysaccharide were characterized by I3C-NMR, IR, methylation and other methods; Gel column chromatography and high gel permeation chromatography detect its molecular weight size.Results:1The ultrasonic extraction of polysaccharide extraction yield and sugar content is highest. Determine the best extraction technology conditions:temperature80℃, feed liquid ratio1:20, extracting time10min, Bletilla striata polysaccharide content is above60%.2Polysaccharide from Bletilla striata1sample molecular weight for460KDa,2 sample molecular weight for390KDa, mixed sample molecular weight for620KDa.3Polysaccharide from Bletilla striata is mainly composed of glucose and mannose composition, the mole ratio of1:6.0, monosaccharide residue to β-1,4-glycosidic bond connection, there is acetyl replace.Conclusion:In this experiment, bletilla striata polysaccharide for the extraction of raw materials, and the molecular weight of the polysaccharide and structure characterization, the experiment scheme design is reasonable, the method is feasible, high reliability, basically reached the experimental design purpose.