Study on the separation, purification and molecular structure characterization of Phyllanthus emblica L. polysaccharide

The refined polysaccharide fractions were conducted from Phyllanthus emblica L., then characterized their physiochemical and structural properties. The P. emblica polysaccharide was extracted with hot water, purified sequentially by DEAE- Sephadex A- 25 column chromatography then obtained two different polysaccharides. With analyzed for physical and chemical properties by chemical analysis, such as sulphuric acid-phenol, sulphuric acid-carbazole, I-KI. Homogeneity and relative molecular weights (Mw) tested by high performance liquid chromatography (HPLC) and monosaccharide composition which was determined by gas chromatography. Structural characterizations were carried out by ultraviolet spectroscopy and infrared spectroscopy (FT-IR) . The result showed that the fractional purification included Pe Ps Ⅰand Pe PsⅡ. Pe PsⅠ was neutral sugar with pyran, then Pe Ps Ⅱ was pyran acidic polysaccharide containing uronic acid. Both of them were heat-stable, insoluble in organic solvents and free of proteins and amino acids. The specific rotation of Pe Ps Ⅰ and Pe Ps Ⅱ were +68° and +108°, relative molecular mass were 1.49 ×105u and 1.51 ×105u, respectively. Pe Ps Ⅰ were constituted mainly by five monosaccharide residues, including L- rhamnose, L- arabinose, D- xylose, then Pe Ps Ⅱ were constituted mainly by three monosaccharide residues, such as L-rhamnose, L-arabinose, D-galactose.