Structural elucidation of a novel mannogalactan isolated from the fruiting bodies of Pleurotus geesteranus

Carbohydr Polym. 2013 Jan 30;92(1):236-40. doi: 10.1016/j.carbpol.2012.08.105. Epub 2012 Sep 1.

Abstract

A novel water-soluble polysaccharide named PGPB-1, with a molecular weight of 1.3 × 10(4)Da as determined by high-performance liquid chromatography (HPLC), was isolated from the fruiting bodies of Pleurotus geesteranus by boiling water as well as DEAE-Sepharose Fast Flow and High-Resolution Sephacryl S-300. On the bases of compositional analysis, methylation analysis and NMR spectroscopy ((1)H NMR, (13)C NMR, 2D-COSY, TOCSY, HMQC, HMBC and NOESY spectra) analysis, the structural elucidation of PGPB-1 consisted of a α-D-(1→6)-galactopyranan and a α-D-3-O-Me-D-galactosyl unit backbone with a α-D-Mannosyl unit on O-2 of the 2,6-di-O-substituted-D-galactosyl units. The repeating unit of the polysaccharide was established as: [formula in text] PGPB-1 also contains a minor proportion of 6-linked-D-Glcp.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Fruit / chemistry*
  • Galactans* / chemistry
  • Galactans* / isolation & purification
  • Magnetic Resonance Spectroscopy
  • Mannose / chemistry*
  • Molecular Structure
  • Pleurotus / chemistry
  • Polysaccharides* / chemistry
  • Polysaccharides* / isolation & purification

Substances

  • Galactans
  • Polysaccharides
  • Mannose