Extraction And Purification Of Polysaccharides From P. Sylvestris And Its Antioxidant Activity In Vitro

This article studied the extraction,purification and antioxidant activity of polysaccharide extracted from the Dioscorea nipponica, Optimizesed the extraction process of water soluble polysaccharide extraction and ultrasonic-assisted extraction,we got get a certain amount of purified polysaccharide. The main results of this study are as follows.1. The extraction process of polysaccharide from Dioscorea nipponica,Two different methods of water extraction, ultrasonic extraction were respectively adapted to extract polysaccharide.The article optimizesed the extraction process by one-factor-at-a-time experiment and the response surface optim ization method. The best extraction technology was selected by taking the extraction ratio of polysaccharide as index.(1) The water solution extraction methodBsed on the response surface optimization method,the best extraction method are as follows, extraction temperature 96 ?, liquid ratio 25:1 (mL/g) extraction time 106 min, extraction views 2 and the Polysaccharide extraction rate reached 2.115%.(2) The ultrasonic-assisted extractionBsed on the response surface optimization method,the best extraction method are as follows, extraction temperature72?, extraction time 41min, extraction power380W, liquid ratio 25:1 (mL/g), extraction views 2, and the Polysaccharide extraction rate reached 2.297%.2. This article studied separation and purification method and the result as follows:(1) Separation and purification of polysaccharide was remove protein at first. The method of Sevage was chosen. Bsed on the one-factor-at-a-time experiment and the response surface optimization method, the best extraction method was:Enzyme dosage of 2%, the temperature of 55 ?, enzymolysis time 122 min, pH 7. Under process of Sevage,the removal rate of protein was 91.24%, and retention of polysaccharides was 80.12%.(2) Decolorization process:Decoloration of polysaccharide of Dioscorea nipponica was studied with hydrogen peroxide solution method, With the single-factor and the response surface optimization method, the optimal technological conditions for Hydrogen peroxide solution method were determined as follows:follows:temperature 55 ?, time 60min, pH=7.5, sample liquid ratio 1:5.Under these conditions, the decoloration rate was 90.12%, the polysaccharides holding rate was 87.17%(3) Classification and purification processThis study got a polysaccharide components C through the DEAE - ecllulose column and column separation sephadexG-200. From the content detection, the biuret test, ultraviolet spectrum scanning, and the gel-chromatography column identification,the result showed that C polysaccharide was uniformity, and its average molecular weight of 5.513 KDal.3. Antioxidant activities of polysaccharide of Dioscorea nipponicapolysaccharide of Dioscorea nipponica as antioxidants have attracted much attentions nowadays due to their advantages of non-toxicity and excellent biocompatibility,the result as follows:(1) After purification polysaccharide C of Dioscorea nipponica was white powder, has certain moisture absorption; which can be soluble in water at Room temperature, insoluble in ethanol, ethyl ether, acetone and other organic solvents; polysaccharide C without protein, simple sugars, uronic acid, the impurities such as polyphenol compounds.(2) From the study of the antioxidant activities, we got the conclusion that Polysaccharide of Dioscorea nipponica has significant antioxidant activity, and has great potential as health food orantioxidant functional food ingredients.