A water-soluble polysaccharide (EFP-AW1) from the alkaline extract of the roots of a traditional Chinese medicine, Euphorbia fischeriana: Fraction and characterization

A water-soluble polysaccharide, designated as EFP-AW1, was isolated from the roots of Euphorbia fischeriana and purified to homogeneity by gel-filtration chromatography. Its carbohydrate content was up to 92.34%, which was composed of glucose (Glc), galactose (Gal), mannose (Man) and rhamnose (Rha) in a molar ratio of 14.1:1.9:2.0:1.9. The molecular weight was evaluated to be 10,830 Da as determined by high performance size exclusion chromatography (HPSEC). On the basis of sugar analysis, methylation analysis, periodate oxidation, Smith degradation, and nuclear magnetic resonance spectroscopy (NMR) studies (1H and 13C), the structure of the repeating unit of the polysaccharide was established as: