Extraction, Characteristic And Antioxidant Activities Of Polysaccharides By Flammulina Velutipes SF-07

Flammulina velutipes(Fr.) Singer, namely as collybia, belonged to Eumycophyta, Basidiomycotina, Hymenomycetes, Agaricales, Tricholomataceae, Flammulina or Collybia, was a delicious and nourishing fungus contained many biological active components, such as polysaccharides, vitamins, protein, polyphenol, flammulin and dietary fiber. Polysaccharides from the fruiting body of F. velutipes possessed beneficial activities including antioxidant, immunomodulatory, antitumor etc.. However, scarce studies concerning intracellular polysaccharides(IPS) and exopolysaccharides(EPS) from F. velutipes had been processed.The extraction conditions of IPS and EPS from F. velutipes SF-07 were optimized by Plackett-Burman(PB) design and response surface method(RSM). The enzymatic- and acdic-hydrolysis of IPS and EPS were processed. Both the unhydrolyzed and hydrolyzed polysaccharides were purified by DEAE-52 cellulose column and Sephadex G-100 column chromatography. The molecular weights, monosaccharide compositions, bond types and antioxidant properties of all fractions were investigated.(1) The extraction optimization of polysaccharides by F. velutipes SF-07Three most significant factors for the extraction of polysaccharides from F. velutipes SF-07 were determined according to the PB design and further analyzed by the RSM. Under the optimum conditions, the theoretically maximum yields of IPS and EPS were 5.74% and 2.78mg/m L. As for the reliability compliance test, the actual yields of IPS and EPS were 5.88% and 2.82mg/m L. The results indicated that the models were adequate for IPS and EPS extraction process.(2) Enzymatic and acidic hydrolysis of polysaccharides by F. velutipes SF-07IPS and EPS were hydrolyzed by enzyme and acid, gaining enzymatic hydrolysis intracellular polysaccharides(EIPS), enzymatic hydrolysis exopolysaccharides(EEPS), acidic hydrolysis intracellular polysaccharides(AIPS) and acidic hydrolysis exopolysaccharides(AEPS), respectively.(3) Separation and purification of polysaccharides from F. velutipes SF-07The separation and purification of polysaccharides from F. velutipes SF-07 were operated, and two fractions(IPS-1 and IPS-2) of IPS, two fractions(EIPS-1 and EIPS-2) of EIPS, one fraction(AIPS-1) of AIPS, two fractions(EPS-1 and EPS-2) of EPS, two fractions(EEPS-1 and EEPS-2) of EEPS, and one fraction(AEPS-1) of AEPS were obtained.(4) Molecular weightThe results of high performance liquid chromatography(HPLC) analysis indicated that the number-average molecular weight(Wn) of IPS and EPS were 5.77×104Da and 4.58×103Da, and the other types of molecular weights of IPS were also higher than that of EPS.(5) Monosaccharide compositionsThe results of gas chromatography(GC) showed that the monosaccharide compositions of polysaccharides by F. velutipes mainly contained rhamnose, mannose, glucose and galactose. However, the monosaccharide compositions and contents of the tested polysaccharides and fractions revealed non-consistent in present study.(6) The bond types of IPS and EPS fractionsThe results of infrared spectrum(IR) analysis revealed that three fractions(IPS-2, EPS-1 and EPS-2) were furanose and IPS-1 was pyranose.(7) The antioxidant activities in vitro of IPS and EPSThe experimental results showed that both IPS and its fractions exhibited higher antioxidant activities on reducing power, and the scavenging activities against hydroxyl radicals, superoxide anion radicals and DPPH radicals. The results also indicated that the EIPS-2 had stronger antioxidant activities than other fractions in vitro. Equally, the in vitro antioxidant analysis of EPS and its fractions showed that EEPS-2 had potential antioxidant activity on increasing reducing power and the scavenging activities against hydroxyl radicals, superoxide anion radicals and DPPH radicals. Based on the analysis of monosaccharide composition, we concluded that the contents of rhamnose had positive effects on enhancing antioxidant activities of IPS and EPS in vitro.(8) The antioxidant activities in vivo of IPS and EPSThe animal experiments indicted that IPS and EPS expressed potential antioxidant activities on decreasing the contents of malondialdehyde(MDA), and increasing the actvities of glutathione peroxidase(GSH-Px), superoxide dismutase(SOD), catalase(CAT) and total antioxidant capacity(T-AOC) in kidney, heart, liver and blood of mice.