Study On Polysaccharides From The Fruits Of Siraitia Grosvenorii And Their Activities(Ⅰ)

The Siraitia grosvenorii is the mature fruit of Siraitia grosvenorii(Swingle) C.Jeffrey. Components of Siraitia grosvenorii,such as mogroside III,mogroside IV,mogroside V,mogrol ,siamenoside and so on,have been isolated. Their structure and activities have been studied in many papers. But research on polysaccharides of Siraitia grosvenorii(SGPS) has not been found,so the study on the extraction technology ,purifiction and pharmacological activities about SGPS was done in thispaper. The SGPS were extracted with heating in a water bath,or a microwave oven,or a ultrasonic instrument. Through orthogonal experiments,the optimum conditions of water bath extracting were as follows:extracting temperature 100C,extracting 3 times,each time 1.5 hour,Siraitia grosvenorii I water 1 :2 (W V);the optimum conditions of microwave extracting were as follows:microwave heating 15 min,extracting 7 times,Siraitia grosvenorii I water 1 :6(W V);the optimum conditions of ultrasonic extracting were as followed;the ultrasonic time 60 min,extracting 7 times,Siraitia grosvenorii I water 1:6(W V). Under these optimum conditions,the yield of polysaccharides was 0.60%,1.24% and 0.741%,respectively.The crude polysacharides were deproteinzated by Sevag method. Then they were purified on DEAE-cellulose,followed by an elution with water,aqueous sodium chloride(0.1M,0.5M). Fractions were examined with phenol-sulfuric acid method. The fractions were divided into three groups,named as PS1,PS2,PS3. The PS1 and PS2 were further purified by a column chromatogram of DEAE-cellulose,Sephadex G-200 to get the SGPS1 and SGPS2 respectively. Their homogenity were proved and their molecular weights were measured by HPLC on DIOL-150 column. Their Mw. were 470000 ,790000 respectively. According to TLC,the SGPS1 was composed of D-galactose ,D-xylose,D-mannose,L-arabiose,L-rhamnose and two unkowed uronic acid. The SGPS2 was composed of L-rhamnose and unkowed uronic acid. UV,IR and NMR were used to analyse structure of SGPS 1 and SGPS2 in this paper .The pharmacological experiment showed that crude polysaccharides could promote immune system.