Structure and antioxidant activity of a novel poly-N-Acetylhexosamine produced by a medicinal fungus

Shiguo Chen, Ka Chai Siu, Wen Qiang Wang, Xing Xun Liu, Jianyong Wu

Research output: Journal article publicationJournal articleAcademic researchpeer-review

32 Citations (Scopus)


A novel poly-N-Acetylhexosamine (polyhexNAc) about 6 kDa average molecular weight (MW) was isolated from the low-MW fraction of exopolysaccharide produced by liquid fermentation of a medicinal fungus Cordyceps sinensis Cs-HK1. The composition and linkage of sugar residues were determined by mass spectrometry and methylation analysis, and the anomeric configuration and chain linkage were confirmed by NMR. From the analytical results, the molecular structure was elucidated as a [-4-β-d-ManNAc-(1→3)-β-d-GalNAc-(1→] disaccharide repeating unit in the main chain with a Gal branch occurring randomly at the 3-position of ManNAc. This polyhexNAc showed notable antioxidant activities with a Trolox equivalent antioxidant capacity of 330 μmol Trolox/g, a ferric reducing ability of plasma of 45.7 μmol Fe(II)/g, and significant cytoprotective effect against H2O2-induced PC12 cell injury. This is the first report on the structure and bioactivity of an extracellular amino-polysaccharide from the Cordyceps species.
Original languageEnglish
Pages (from-to)332-338
Number of pages7
JournalCarbohydrate Polymers
Issue number1
Publication statusPublished - 15 Apr 2013


  • Antioxidant activity
  • Cordyceps sinensis
  • Exopolysaccharide
  • MS
  • NMR
  • Poly-N-Acetylhexosamine

ASJC Scopus subject areas

  • Organic Chemistry
  • Materials Chemistry
  • Polymers and Plastics

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