Chemical properties and biological activity of a polysaccharide from Cyrtopodium cardiochilum

A polysaccharide with an estimated weight-average molar mass of 4.6×105 was obtained from an aqueous extract of pseudobulbs of Cyrtopodium cardiochilum Lindl. by fractionation on Sephacryl S-300 HR and Sephadex G-25. Chemical and spectroscopic studies indicated that it has a backbone of (1→4)-linked β-d-mannopyranosyl residues and β-d-glucopyranosyl residues, and is demonstrated to be composed of d-mannose and d-glucose in 2:1 molar ratios. It was found to contain 4.2% of acetyl groups substituted at O-2 of (1→4)-linked β-d-Manp and β-d-Glcp. The polysaccharide inhibits capillary permeability and demonstrates phagocytosis stimulating property.