Studies On Extraction,Purification And Antioxidant Of Ramaria Sp.

In this paper the extraction,isolation,purification and antioxidation capacity of polysaccharides from wild Ramaria sp.were studied to provide reference for utilization and exploration of Ramaria fungi.This study mainly composed of four aspects.First,optimization of extraction technology of crude polysaccharides from wild Ramaria sp.were discussed.Second,the separation and purification of polysaccharide.Third,the physical and chemical properties and composition of polysaccharides were analyzed.Fourth,antioxidant activity of purified polysaccharides were studied.The experimental results are as follows:(1)To optimize the extraction conditions for the polysaccharides from Ramaria sp.based on the single factor trials,the response surface methodology were applied.The results showed that the optimum extraction conditions were as follows:temperature 91 ℃,water-to-material ratio 32:1(mL/g),time 3.2 h.Under these conditions,the actual extraction rate was 1.97%.(2)The sevag method is used for deproteinization of crude polysaccharide,then,AB-8 macroporous adsorption resin was used for decoloring the polysaccharide.After dialysising,samples were lyophilized to obtain a more pure polysaccharide CRP.Next,the CRP were separated and purified using DEAE-52 cellulose ion-exchange column chromatography and glucan gel G-100 column chromatography.Three water-soluble polysaccharides RP-1,RP-2 and RP-3 were obtained.The ultraviolet spectrum scanning and high performance gel permeation chromatography resultes proved that each of the three components was homogeneous.(3)The basic physical and chemical properties of purified polysaccharide components were determined by solubility,molish reaction,iodine-potassium iodide reaction,ninhydrin reaction,ferric chloride reaction and fehling reagent reaction.The results showed that RP-1,RP-2 and RP-3 had the general properties of polysaccharides and did not contain protein and small molecule oligosaccharides.The molecular weight of the polysaccharides were determined by high performance gel permeation chromatography(HPGPC),the results showed that the relative molecular weights of polysaccharide RP-1,RP-2 and RP-3 were 1.38×104 Da,3098 Da and 2285 Da,respectively.Their monosaccharide composition and molar ratio were analyzed by high performance liquid chromatography(HPLC),the RP-1 is mainly composed of mannose(78.48%),the main monosaccharide of RP-2 and RP-3 were both glucose which account for 62.54%,58.06%,separately,and they also have other monosaccharide.The infrared spectrogram showed all of them had characteristic absorption peak of polysaccharide.(4)The antioxidant capacity assay results showed that the Ramaria sp.polysaccharide CRP,RP-2 and RP-3 had better antioxidant activities in vitro.In a certain concentration range,the reducing ability,total antioxidant capacity,hydroxyl radicals scavenging capacity and DPPH free radical scavenging ability were all enhanced with the increase of polysaccharide concentration.