Chemical properties and biological activity of a polysaccharide from Cyrtopodium cardiochilum

A polysaccharide with an estimated weight-average molar mass of 4.6 x 10(5) 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 beta-D-mannopyranosyl residues and O-D-alucopyranosyl 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 P-D-Manp and beta-D-Glcp. The polysaccharide inhibits capillary permeability and demonstrates phagocytosis stimulating property. (c) 2005 Elsevier Ltd. All rights reserved.