Isolation, Purification And Physicochemical Analysis Of The Polysaccharides In Agaricus Blazei Murill

The isolation and purification of polysaccharides in Agaricus blazei were studied. The physicochemical properties and antibacterical activities of the polysaccharides also been discussed. Based on the establishment of the best conditions on the phenol-sulfate method, the optimum conditions on the methods of extraction, precipitation, removal of protein etc. were developed to find a simple and easy way obtaining the high ratio of crude sugar products. The crude polysaccharides products were further purified by Column Chromatography on DEAE ion-exchange colluluse and Sepharose CL-4B into three main fractions: AB-I~ AB-II-b~ AB-III-b. Each of them contained about 87.3%~ 79.5%., 68.8% of total sugar, with 20.l%~ l6.3%~ 25.6% protein and showed no nucleic acid in it. The results of I-IPLC, Sephadex G- 100 and Cellulose acetate film electrophoresis proved the homegeneity of AB- I AB- II -b and AB-III-b. Infrared spectroscope analysis determination indicated that these three fractions were made up of ~3-glucosidic bonds. By means of GC, Sepharose 4B, optical rotation etc., it was estimated that the obtained polysaccharides have some properties as follows: AB-J: [a ]20D = ~44?30 ([120); Mw = 20.8kd; component sugars (in a molar ratio): Gal: Man: Glc 1.43:2.02:5.57. AB-II-b: [a ID = +3.700 ([120); Mw 33.9kd; component sugars (in a molar ratio): Rha: Gal: Man: Glc 1.00: 1.26: 2.75: 4.26 AB-HI-b: [a ]20D = +5.040 ([120); Mw = 6.3kd; component sugars (in a molar ratio): Pha: Xyl: Gal: Man: Glc=1.49: 0.37: 0.84: 1.86: 4.05. AB-I.. AB-II-b~ AB-III-b were found to possess with excellent thickening and thixotropic properties, thermal stability and stabal to the variation of Salt content and pH value. The antibacteria effects of the fruit bodies of A. blazei were discussed by testing the MIC against 8 species of spoilage organisms. The results showed that both the water and alcohol extract have the antibacteria activities, which the latter showed better inhibition abilities than the former.