Isolation, purification and partial properties of polysaccharides from Angelica sinensis

OBJECTIVE To isolate and purify the polysaccharides fractions from Angelica sinensis(ASP), and to determine the partial characters. METHODS Hot water extracting and ethanol precipitating method were employed to isolate polysaccharides from fresh Angelica sinensis. After the removal of protein by Sevag method, the purified ASP was dried by frozen drier. The amount of total carbohydrates of ASP was measured with phenol-sulfuric acid method. FT-IR spectrometry, UV-spectrophotometer, and automatic spectropolarimeter were used to determine the characteristic absorption and optical rotation of the polysaccharides, respectively. Size exclusion chromatography with laser light scattering (SEC-LLS) technology was employed to measure the molecular masses . The monosaccharides contained in ASP were analysed by HPLC. RESULTS The amount of total carbohydrates in ASP was 96.8%. Both UV and IR displayed representative polysaccharides properties. The molecular weight distribution was 1×10 4-1.1×10 5, and eight percent was distributed in 4.3×10 4. The monosaccharides constituent of ASP were glucose, arabinose, galactose, rhamnose and xylose, and their molar proportions were 17.8∶5.8∶12∶1∶2.2. CONCLUSION The amount of total carbohydrates is high in ASP distilled by this method. The range of molecular weight and monosaccharides constituents of ASP are affirmed.