title: Chemical components and molecular mass of six polysaccharides isolated from the sclerotium of Poria cocos.
abstract: Six polysaccharides were extracted sequentially from the fresh sclerotium of Poria cocos cultivated in China using 0.9% NaCl (PCS1), hot water (PCS2), 0.5M NaOH (PCS3-I and PCS3-II), and 88% formic acid (PCS4-I and PCS4-II). Their chemical and physical characteristics were determined using infrared spectroscopy (IR), gas chromatography (GC), GC-MS methylation analysis, 13C NMR spectroscopy, elementary analysis (EA), protein analysis, size exclusion chromatography combined with laser light scattering (SEC-LLS), light scattering (LS), and viscometry. The results indicated that the polysaccharides PCS1, PCS2, and PCS3-I were heteropolysaccharides containing D-glucose, D-galactose, D-mannose, D-fucose, and D-xylose; the predominant monosaccharide was D-glucose except for PCS1 where it was D-galactose. PCS3-II, the main component of the sclerotium of P. cocos, was a linear (1-->3)-beta-D-glucan of high purity. PCS4-I consisted of (1-->3)-beta-D-glucan with some beta-(1-->6) linked branches. PCS4-II was mainly composed of (1-->3)-beta-D-glucan containing some glucose branches. The M(w) values of the six polysaccharides PCS1, PCS2, PCS3-I, PCS4-I in 0.2M NaCl aqueous solution, PCS3-II, and PCS4-II in dimethyl sulfoxide (Me(2)SO) were determined to be 11.6 x 10(4), 20.8 x 10(4), 17.1 x 10(4), 9.1 x 10(4), 12.3 x 10(4), and 21.1 x 10(4), respectively. The six polysaccharides in aqueous solution or Me(2)SO exist as flexible chains.
authors.affiliation: Department of Chemistry, Wuhan University, 430072, Wuhan, China.
authors.forename: Yifeng
authors.initials: Y
authors.lastname: Wang
authors.forename: Mei
authors.initials: M
authors.lastname: Zhang
authors.forename: Dong
authors.initials: D
authors.lastname: Ruan
authors.forename: Alexander S
authors.initials: AS
authors.lastname: Shashkov
authors.forename: Michelle
authors.initials: M
authors.lastname: Kilcoyne
authors.forename: Angela V
authors.initials: AV
authors.lastname: Savage
authors.forename: Lina
authors.initials: L
authors.lastname: Zhang
mesh_terms: D005656:Fungal Proteins / Q000032:analysis / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008970:Molecular Weight; D020072:Polyporales / Q000737:chemistry* / Q000166:cytology*; D011134:Polysaccharides / Q000737:chemistry* / Q000302:isolation & purification*; D014783:Viscosity
chemical_list: D005656:Fungal Proteins; D011134:Polysaccharides