title: Structure and chain conformation of a neutral polysaccharide from sclerotia of Polyporus umbellatus.
abstract: A water-soluble heteropolysaccharide (PUP60W-1) was purified from the hot water extract of sclerotia of P. umbellatus by chromatography with DEAE Sepharose Fast Flow and Sephacryl S200 High-Resolution. The primary structure of PUP60W-1 was elucidated by GC, GC-MS and NMR. PUP60W-1 was identified as a highly branched polysaccharide composed of fucose, glucose and galactose in a ratio of 1.0:0.9:13.3. The main repeating unit was identified as α-(1→6)-d-galactopyranan backbone with substitution of terminal α-galactopyranosyl residues at O-2 for two out of every three main chain galactose residues. Its chain conformation was studied by atom force microscopy and size exclusion chromatography coupled with multiple detectors. The results revealed that PUP60W-1 had a molecular weight of 2.47×104Da with a polydispersity index of 1.04, and existed in water as compact sphere structures which could be disrupted into smaller spherical chain blocks after dispersion with sodium dodecyl sulfate.
authors.affiliation: College of Biological and Environmental Engineering, Zhejiang University of Technology, Hangzhou 310014, China; Department of Food science and Technology, Zhejiang University of Technology, Hangzhou 310014, China.
authors.forename: Peng-Fei
authors.initials: PF
authors.lastname: He
authors.affiliation: The Key Laboratory of Biological and Chemical Utilization of Zhejiang Province, Zhejiang Forestry Academy, Hangzhou 310023, China.
authors.forename: Liang
authors.initials: L
authors.lastname: He
authors.affiliation: Department of Food science and Technology, Zhejiang University of Technology, Hangzhou 310014, China. Electronic address: zhanganqiang@zjut.edu.cn.
authors.forename: An-Qiang
authors.initials: AQ
authors.lastname: Zhang
authors.affiliation: Hangzhou Baishanzu Biotech Co. Ltd., Hangzhou 310052, China.
authors.forename: Xing-Li
authors.initials: XL
authors.lastname: Wang
authors.affiliation: Hangzhou Baishanzu Biotech Co. Ltd., Hangzhou 310052, China.
authors.forename: Liang
authors.initials: L
authors.lastname: Qu
authors.affiliation: Department of Food science and Technology, Zhejiang University of Technology, Hangzhou 310014, China. Electronic address: sun_pl@zjut.edu.cn.
authors.forename: Pei-Long
authors.initials: PL
authors.lastname: Sun
mesh_terms: D002236:Carbohydrate Conformation; D002850:Chromatography, Gel; D008970:Molecular Weight; D055492:Polyporus / Q000737:chemistry*; D011134:Polysaccharides / Q000737:chemistry*
chemical_list: D011134:Polysaccharides
keywords: AFM; Chain conformation; NMR; Polyporus umbellatus; Polysaccharide; Structural analysis