Structural elucidation of an exopolysaccharide from mycelial fermentation of a Tolypocladium sp. fungus isolated from wild Cordyceps sinensis

Jing Kun Yan, Lin Li, Zhao Mei Wang, Jianyong Wu

Research output: Journal article publicationJournal articleAcademic researchpeer-review

86 Citations (Scopus)

Abstract

A novel polysaccharide designated EPS-1A with an average molecular weight around 40 kDa was fractionated and purified by anion-exchange and gel-filtration chromatography from the crude exopolysaccharide (EPS) isolated from fermentation broth of Cs-HK1, a Tolypocladium sp. fungus isolated from wild Cordyceps sinensis. The structural characteristics of EPS-1A were determined with various methods (e.g. GC, GC-MS, FT-IR,1H NMR and13C NMR) and through acid hydrolysis, methylation, periodate-oxidation and Smith degradation. The results suggested that EPS-1A was composed of glucose, mannose and galactose at 15.2:3.6:1.0 M ratio. EPS-1A was a slightly branched polysaccharide and its backbone was composed of (1 → 6)-α-d-glucose residues (∼77%) and (1 → 6)-α-d-mannose residues (∼23%). Branching occurred at O-3 position of (1 → 6)-α-d-mannose residues of the backbone with (1 → 6)-α-d-mannose residues and (1 → 6)-α-d-glucose residues, and terminated with β-d-galactose residues.
Original languageEnglish
Pages (from-to)125-130
Number of pages6
JournalCarbohydrate Polymers
Volume79
Issue number1
DOIs
Publication statusPublished - 5 Jan 2010

Keywords

  • Cordyceps sinensis
  • Exopolysaccharide
  • Fractionation
  • Molecular structure
  • Mycelial fermentation

ASJC Scopus subject areas

  • Organic Chemistry
  • Polymers and Plastics
  • Materials Chemistry

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