Water-Soluble Polysaccharides Isolated from Skin Juice, Gel Juice and Flower of Aloe Vera Miller

Crude water-soluble polysaccharides were isolated from gel juice, skin juice and flowers of Aloe vera. Results indicate that skin juice contained similar amount of polysaccharides to gel juice, suggesting the potential industrial application of A. vera skin rather than discarded. After anion-exchange chromatography, neutral polysaccharides account for more than 95% of the crude polysaccharides from skin juice and gel juice, whereas, the crude flower polysaccharides are largely composed of weakly acidic polysaccharides (88.7%). Sugar analysis of the polysaccharides after gel-permeation chromatography shows that the neutral polysaccharides from skin juice and gel juice consist of mannose and glucose in a similar ratio of (4.7–5.0):1; whereas the acidic polysaccharides from skin juice are composed mainly of glucose (42.5–45.3%), appeared to be different to those of gel juice, which are constituted predominantly mannose, glucose and galactose. Except a high content of glucuronic acid (20.8%) in flower acidic polysaccharide, the flower neutral and acidic polysaccharides had similar sugar compositions, with galactose, glucose and mannose being the main sugar components, quite different from those of skin juice and gel juice polysaccharides. Glucuronic acid was as the major uronic acid in all acidic polysaccharides from different tissues.