A water-soluble polysaccharide from the roots of Eremurus spectabilis M. B. subsp. spectabilis: Extraction, purification and structural features.

A heteropolysaccharide ESP, was separated from a water extract of dried roots of Eremurus spectabilis by column chromatographies on DEAE-cellulose A52 and Sephadex G-100. Specific optical rotation, molecular mass and total carbohydrate content of ESP were -36.3°, 43.8 kDa and 97.2%, respectively. Monosaccharide composition analysis showed that ESP consisted of glucose and mannose at a molar ratio of 1.0:2.9. Structural characterization of ESP was done by various chemical and instrumental techniques (methylation, partial acid hydrolysis, Smith degradation, periodate oxidation, GLC-MS and 1D/2D NMR). The repeating unit of ESP was determined as following.