Study on Extraction and Purification of Polysaccharides from Morinda officinalis How

The polysaccharides were extracted from Morinda officinalis How by pretreatment of cellulose,and were further purified by ion exchange and gel filtration chromatography. The optimal conditions for pretreatment of cellulose are determined by orthogonal test as follows:amount of cellulase 8 mg/g,pH 5.0,hydrolysis temperature 40 ℃ and hydrolysis time 2 h. Three fractions,namely MOPI-1,MOPI-2 and MOPI-3 are obtained using the step gradient elution manner on DEAE-Sephrose CL-6B column,and then the MOPI-2 and MOPI-3 fractions were purified by the gel filtration chromatography with Sephadex G-50. An uniform fraction named as MOPI-3a is obtained from MOPI-3,while two fractions named as MOPI-2a and MOPI-2b are obtained from MOPI-2.