Isolation, Purification And Antioxidant Activity Of Polysaccharides From Pleurotus Geesteranus

Pleurotus geesteranus also known as Lentinus sajur-caju (Fr.). It has high quality delicious taste, nutritious characteristics. It provides eight kinds of essential amino acids and rich in protein. This paper foused on the extraction, purification, analyses initially thestructure, antioxidant activity assay of polysaccharides from Pleurotus geesteranus. This study provided the basic date and scientific for the application of Pleurotus geesteranus polysaccharides.(1) Optimization of aqueous extract with ethanol precipitation techlnology. The optimum technological parameters of aqueous extract with ethanol precipitation techLnology were as follows:temperature82℃, solid-liquid ratio1:30(g/mL), time4h and ethanol concentration90%. The yield of polysaccharides was7.33%under the optimum experiment parameters.(2) Optimization of ultrasonic and high hydrostatic pressure extraction techlnology. The optimal conditions of ultrasonic extraction were gained as following:the solid-liquid ratio1:30(g/mL), time50min, extraction temperature55℃, ultrasonic power210W, and that extraction rate could reach to7.53%. The optimal conditions of high hydrostatic pressure extraction were gained as following:extraction temperature35℃, the solid-liquid ratio1:35(g/mL),550Mpa holding25min. under the optimum experiment parameters the yield of polysaccharides was8.56%.(3) Purification of Pleurotus geesteranus polysaccharides and structural analysis preliminary. The optimal conditions of deproteinized were gained as following:the content of enzyme110U/mL, enzymatic hydrolysis time120min, Ph5.0and enzyme temperature40℃, then treated polysaccharides with Sevag three times. The rate of removed protein could reach to93.43%, the rate of losing polysaccharides was18.24%. The polysaccharides of Pleurotus geesteranus was extracted in hot water and was isolated/purified by DEAE-52, and Sephadex G-150, which contained three components:PGP1, PGP2, and PGP3. The analysis of infrared spectra fingerprint characteristic absorption peak showed that the four components of PGP contain carboxyl, monosaccharide residues was consited by pyran ring form. (4) Antioxidant activity research. Making aseorbic acid as control, the antioxidant activity of the above four different extracts from Pleurotus geesteranus were determined by scavenging hydroxyl radical (-OH), superoxide anion radical (O2-·),1,1-diphenyl-2-picrylhydrazyl radical (DPPH-) and radicals of total flavonoids. PGP, PGP1, PGP2and PGP3have certain total antioxidant capacity and Has a capacity to scavenging-OH, DPPH,·O2-.Concentration of antioxidant capacity and polysaccharides in a dose dependent manner. PGP antioxidant capacity which is better than others.