Chemical structure of one low molecular weight and water-soluble polysaccharide (EFP-W1) from the roots of Euphorbia fischeriana

A water-soluble protein-bound polysaccharide (EFP-W1) was fractioned from roots of Euphorbia fischeriana and purified by gel-filtration chromatography. Its primary structural features were characterized by partial acid hydrolysis, Smith degradation-periodate oxidation, methylation analysis, high performance size exclusion chromatography (HPSEC), fourier transform infrared spectroscopy (FTIR), gas chromatography (GC), gas chromatography–mass spectrometry (GC–MS) analysis and nuclear magnetic resonance spectroscopy (NMR). The data obtained indicated that EFP-W1 contains about 91% of carbohydrate content, which was mainly composed of glucose (Glc), galactose (Gal), mannose (Man), arabinose (Ara) in a molar ratio of 6:1:1:1. Its average molecular weight was about 11,230 Da. The structure of the repeating unit of the polysaccharide was elucidated as follows: