Isolation, purification and structural elucidation of polysaccharide from Saccharum Alhagi / 中国药学杂志

ABSTRACT

OBJECTIVE: To isolate and purify the polysaccharide from Saccharum Alhagi, and to clarify its chemical structure. METHODS: Water extracting-alcohol precipitating method was applied to extract polysaccharide from Saccharum Alhagi. Macro-porous adsorption resin chromatography, DEAE cellulose chromatography and Sephadex gel chromatography were applied to fractionalize and purify the polysaccharide. The homogeneity and molecular weight of the polysaccharide were determined by gel filtration. The monosaccharide composition of the polysaccharide was identified by gas chromatography (GC). Partial acid hydrolysis, periodate oxidation, smith degradation and NMR were used to analyze the chemical structure of the polysaccharide. RESULTS: Polysaccharide fraction AP1-1 was got from Saccharum Alhagi. The analysis results show that APl-1was a homogeneous polysaccharide and its molecular weight was 99.7 × 10. AP1-1 was composed of mannose, glucose, galactose with molar ratio of 1.10:2.19:4.32.The main chain of AP1-1was mainly made up of →4)-β-D-GalpA-(1→, →4)-β-D-Galp-(1→ and →4, 6)-α-D-Glcp-(1 →. The side chain was composed of →6)-α-D-Glcp and 2-OCH3-α-D-Man. CONCLUSION: Saccharum Alhagi polysaccharide AP1-1 is a complicated hetero-polysaccharide with multi-branches.