Studies On The Polysaccharide Extraction,Separation,Composition And Antioxidant Activity In Leccinum Extrioemirientale

Leccinum extrioemirientale(L.Vass.)Sing is a kind of mushroom with edible and medicinal functions.Studies showed that pigment extraction and polyphenol extraction from L.extrioemirientale have chemical and biological functions,but the polysaccharide of it hasn't been studied.Therefore,in this paper,a water-soluble polysaccharide was obtained from the dried fruiting body of L.extrioemirientale,and then analysis the extraction conditions,Monosaccharide composition,and in vitro antioxidant activity.The main results are liseted as follows.1.The polysaccharide of L.extrioemirientale was extracted with hot water and optimizated extraction conditions by response surface methodology.The results of Box-Behnken design were listed as follows:ratio of water to material of 33 mL/g,extraction time of 3 h and extraction temperature of 75 ?,with the corresponding yield of 10.3 0%.2.The LEPS were fractionated on DEAE-52 and Sephadex G-100 to afford three purified fractions.Generally,we named the fraction eluted with distilled water was neutral polysaccharide as LEP-1,and fractions eluted with NaCl solutions were acidic polysaccharide(LEP-2 and LEP-3).3.Analysis of LEP-2 by Infrared Spectroscopy(FT-IR).The results showed that LEP-2 is not only ?-pyranoside bond,but also an acidic sugar,the presence of uronic acid.The main absorption peaks are listed as follows:3309.12 cm-1 2926.35 cm-1,1601.73 cm-1 1416.48 cm-1,1366.77 cm-1,1247.37 cm-1,1035.02 cm-1,918.89 cm-1,796.78 cm-1.The results mentioned above showed that LEP-2 contains O-H,C-H,carbonyl C=O symmetric and asymmetric regions,-OH angular vibration region in glucose,P-pyranoside bond and mannose.4.Molecular weight determination of LEP-2 was determined by the method High performance gel filtration chromatography.The results showed that the average molecular weight of LEP-2 was 342375 Da.LEP-2 was composed of six kinds of Monosaccharide,i.e.Fucose,Arabinose,Galactose,Glucose,Mannose and Xylose.And the molar ratio of them was 1.82:0.61:5.14:26:5.41:61.02,respectively.5.The anti-oxidant activity experiment in vitro of LEP,LEP-1,LEP-2 and LEP-3 displayed by the scavenging ability of free radical as ·OH,DPPH and O2-·.The results indicated that LEP,LEP-1,LEP-2 and LEP-3 had obvious antioxidant activity.When the concentration of LEPS was 1 mg/mL,the clearance rate of ·OH was LEP-1>LEP-2>LEP-3>LEP;the clearance rate of O2-· was LEP>LEP-2>LEP-1>LEP-3;the clearance rate of DPPH· was LEP>LEP-3>LEP-1>LEP-2.