[Extraction and purification of acidic polysaccharide from Moerella iridescens].

OBJECTIVE: To optimize extraction and purification methods of acidic polysaccharide from Moerella iridescens (MIAP). METHODS: With alkali extraction process and orthogonal experiment,the time consumption,temperature,pH value of the solution and alcohol concentration during the extraction were optimized. The crude products were deprived of protein,pigment and ion,then were purified with DEAE-cellulose ion-exchange chromatography and verified with Sephadex G-100 and cellulose acetate membrane electrophoresis,and examined with infrared spectrum. RESULTS: The optimized extraction conditions were as follows: extraction time 6 h,extraction temperature 70 degree,the solution pH 8.0 and the concentration of alcohol precipitation 70%. Intuitive features showed that the MIAP was pure white crystalline granular with slight dark brown color. The purification results demonstrated that the target MIAP was eluted and identified as a homogeneous components by DEAE-cellulose ion exchange column,Sephadex G-100 and cellulose acetate membrane electrophoresis. Infrared spectral scanning suggested that MIAP was α-D-type terminated glucopyranose. Intuitive features showed that MIAP was soft and cottony white. CONCLUSION: The extraction process with orthogonal test has been optimized and the acidic polysaccharide from Moerella iridescens is successfully isolated.