Application, Function, And Molecular Modification Of Auricularia Auricula Polysaccharide

Auricularia auricular (Lex Hook.) Underw.) is known to be a highly nutritious and officinal edible fungus. Polysaccharide, as one of main active components extracting from A. auricular, has various functions such as antitumor, antithrombus, anticoagulation, anticaducity, decreasing blood sugar and blood fat, and modulating immunity, and so on.This paper systematically studied that fractionation methods and molecule modification (Sulfated esterification and the interaction of ultrasonic radiation degradation and transition metal ions) of polysaccharide of A. auricula. Through studies on the functions of polysaccharide and molecule modified polysaccharide in A. auricula (antioxidation, antitumor and anticoagulation), their applications on membrane materials were studied, which established a basis for the applications of polysaccharide and modified polysaccharide of A. auricula initmedicine, health supplies, foodstuffs, and membrane materials, etc. The main results are as follows:1 The polysaccharides of A. auricula were fractionated by the cation surface active agent-CTAB, and the neutral (18.67%) and acid polysaccharides (80.33%) of A. auricula (AAP) were obtained. The polysaccharide of A. auricula was divided into three parts of AAP1, AAP2, and AAP3.2 The optimum sulfated esterifing technics was determined: the volume ratio of chlorosulfonic acid and pyridine is 5:1, the volume ratio of polysaccharide solution and esterifing reagents is 2:1, esterifing temperature is 50°C, and esterifing reaction time is 1.5h. FTIR spectra show that sulfate and AAP may form sulfated compounds. And the three AAP sulfates of AAP-S1, AAP-S2 and AAP-S3, whose substitutions are 0.32, 0.64 and 1.0, respectively, were prepared.3 The polysaccharide of A. auricular (AAP) has best chelation on the Zn (II) of ZnSO₄·7H₂O, and the optimum chelated technics: initial concentration of Zn (II) is 3mg/mL, pH value is 4.0, the volume ratio of polysaccharide and Zn (II) is 4:1, and chelating reaction time is 6h. The chelates of five kinds of transition metal ions (Fe²⁺, Co²⁺, Ni²⁺, Cu²⁺ and Zn²⁺) with AAP were prepared.4 After the AAP is degraded by ultrasonic radiation, and along with the increase of time, its viscosity reduces gradually, dissolving quality increases, and the content of glucose uronic acid keeps constant. AAP was radiated by ultrasonic for 20min, 40min, and 60min separately, and three polysaccharides of AAP-US1, AAP-US2 and AAP-US3 were gained.5 The antimicrobial tests indicate that sulfated AAP has a certain of inhibition for the yellow staphylococcus and E. coli, with an inhibiting time of 16²0h. Moreover, AAP also has a...