Abstrait

Isolation, fractionation and modification of sulfated polysaccharides from Spirulina platensis and its antitumor activity

Mohsen Mohamed Selim Asker, Zeinab Ibrabim Khalil, Osama Hamed El-Sayed

The water-soluble polysaccharide obtained froma blue-green alga Spirulina platensis by boilingwater extraction and ethanol precipitation (118.25g kg- 1 on dryweight basis) was fractionated byDEAE-cellulose column chromatography, and purified by Sephacry S-300 giving two active fractions termed Ca-SPIIa and Ca-SPIIb. These fractions weremainly composed of glucose, galactose, rhamnose, fructose, glucouronic acid, mannose, xylose with the molar ratio(6.5:3.3:50.0:38.5:9.6:1.5:1.0) and(7.2:3.5:55.0:40.2:8.5:2.0:1.0) and sulfate percent (2.25% and 3.47%, respectively). Calcium ion binding with the anionic part of a molecule was replaced with various metal cation and their inhibitory effects on EhrlichAscites Carcinoma Cells (EACC) was determined. The Ca-SPIIbwas able to kill 95%of the tumor cells when they were incubated with 200µg. While, replacement of Ca+2 withNa+,Ag+, Cu+2 and H+ reduced the activity.