Structural characterization and immunostimulatory activity of a glucan from natural Cordyceps sinensis.

A water-soluble polysaccharide, named NCSP-50, was obtained from natural Cordyceps sinensis by hot water extraction and ethanol fractionation precipitation. It was eluted as a single symmetrical peak and had an average molecular weight of 9.76 × 10 5 Da. The structure was determined by monosaccharide composition, methylation analysis, 1D/2D NMR spectroscopy, and enzymatic hydrolysis and characterization of the oligosaccharides by MALDI-TOF mass spectrometry. The repeating unit of this polysaccharide was proposed as follows: Image 2 This glucan showed potent immunostimulatory activity on the basis of its significant abilities to promote macrophage proliferation, enhance NO production, as well as and cytokines (IL-1β and TNF-α) secretion. [ABSTRACT FROM AUTHOR]