Study on the Preparation,Structure,Properties and Antioxidant Activity of New Polysaccharides from Russula aeruginea Lindb.: Fr

Using the fruiting bodies of Russula aeruginea Lindb.:Fr as raw materials,the water extraction and alcohol precipitation process of its polysaccharides were established by single factor experiments and response surface method. Two kinds of polysaccharides were obtained from the crude extracts by DEAE-cellulose-52 and Sephadex G-150. The relative molecular weight and monosaccharide composition were determined by high performance gel filtration chromatography and monosaccharide precolumn derivatization. And their structure and properties were studied by infrared scanning and Congo red experiment. The morphology was observed by scanning electron microscope and atomic force microscope,and their antioxidant activities were preliminarily studied. The results showed that the yield of polysaccharides from Russula aeruginea Lindb.:Fr reached 4.30% under the optimum conditions of extraction temperature 84℃,extraction time 2.6 h and solid-liquid ratio 1:23 g/mL.The relative molecular weight of the two new polysaccharides after purification was 18.05 kDa and 2398.83 kDa,respectively;They had typical characteristic absorption peaks of polysaccharides,one of which has three helix structures. The scavenging rates of DPPH free radicals by Crude RLP,RLP-1-1 and RLP-2-1 were 41.19%,38.97% and 39.27%,while their metal ions chelating rates were 29.83%,27.81% and 51.96%,respectively. The polysaccharides from Russula aeruginea Lindb.:Fr showed certain antioxidant activity.