Isolation and purification of flower polysaccharides from Aloe vera and chemical analysis of their composition

Crude flower polysaccharides from Aloe vera were isolated by a series of sequential steps including precipitation with ethanol,removal of protein by Sevag method,dehydration by several organic solvents.Polysaccharides from Aloe vera flower obtained after DEAE Sephadex A-25 anion-exchange chromatography consist of neutral polysaccharide,weakly acidic and strongly acidic polysaccharides,largely composed of weakly acidic polysaccharides(87%),which was quite different from Aloe vera gel polysaccharides.For Aloe vera gel polysaccharides,neutral polysaccharides accounted for more than 95% of the total polysaccharides.The polysaccharides were further purified and their molecular weights were measured by Sepharose 4B gel permeation chromatography.Neutral sugar analysis was performed by gas liquid chromatography(GLC).