Separation,Purification And Structure Analysis Of Opuntia Dillenii Haw. Polysaccharides

Extraction, purification and preliminary structure analysis of Opuntia dillenii Haw. polysaccharides (ODP) were studied in this work, The results were as follows:1. Single factor and the response surface analysis (RSA) were used to optimize the extraction conditions of ODP. The extraction conditions optimized were as follows: extraction temperature93℃; extraction time3.5h; ratio of water to raw material60:1(mL/g); and extraction2times. The yield of polysaccharides was up to24.97%.2. Trichloroacetic acid method, Sevag method and the protein isoelectric point method were used to remove protein from Opuntia dillenii Haw. crude polysaccharides. And the deproteinization effects of this three methods were compared by the loss of protein, the loss of polysaccharides and the loss of inoxidizability. The results showed that the deproteinization effection was the most with3%trichloroacetic acid. In this condition, the loss of protein was80.28%, the loss of polysaccharides was5.98%and the loss of inoxidizability was34.56%.3. Opuntia dillenii Haw. polysaccharides was purified on DEAE Sepharose Fast Flow column, and tested the effects of the different elution mode and different elution velocity on purification of the polysaccharides. The experimental results showed that, the sample quantity of6mL, sample concentration of15mg/mL, elution velocity of2mL/min, and in this condition, with0.02mol/L sodium chloride,0.1mol/L sodium chloride,0.3mol/L sodium chloride eluted the column separately. Two main components, ODP-I and ODP-II named respectively, were got.4. ODP-II was further purified with Sephacryl S-400by column chromatography experiments, and tested the effections of the flow rate, the amount of sample and the concentration of sodium chloride on purification were tested. The results showed that the concentration of sodium chloride was0.015mol/L sodium chloride, sample concentration5mg/mL, sample quantity1mL, flow rate0.4mL/min, On this condition, two components of ODP-II were got, ODP-II a and ODP-II b named respectively. The homogeneity of ODP-II a was evaluated by ultraviolet-visible light spectrophotometer and Sephacryl S-400.5. The molecular weight of ODP-II a is934kD tested by Sephacryl S-400gel-filtration chromatography, and contained30.25%uronic acid. From I2-KI experiment and Congo experiment, it’s known that ODP-II a does not have the triple helix conformation, and there are many branched chains attached to its backbone chain.6. Paper using the hot water to extraction the Opuntia dillenii Haw. polysaccharides, and the response surface analysis (RSA) was used to optimize the extraction conditions. On the basis of this, compared the deproteinization effects of three methods, using column chromatography to get a homogenous polysaccharides, and preliminary analysis its property. Providing a theoretical basis for the further study of the Opuntia dillenii Haw. polysaccharide, has important significance for promoting the polysaccharides of health care products and medicine development and accelerating the pace of the cactus industrial application.