Research on Water Soluble Polysaccharides Separated from Skin Juice, Gel Juice and Flower of Aloe ferox Miller

Abstract

Crude water-soluble polysaccharides were isolated from gel juice, skin juice and flowers of Aloe ferox Miller. Result indicated that skin juice contained 15 fold the level of polysaccharides in gel juice from one plant, strongly suggesting the potential industrial application of A. ferox skin as the resource of polysaccharides, rather than discarded. The amount of polysaccharides in the flower of A. ferox was about 2 fold compared with those of A. arborescens and A. vera. After fractionation by anion-exchange chromatography and gel permeation chromatography, gel juice polysaccharide was separated into three neutral (GN1, 1.7%; GN2, 17.6% and GN3, 0.4%) and one acid (GA1, 19.7%) fractions. Skin juice polysaccharide consisted of one neutral (SN1, 25.2%) and two acid (SA1, 7.2%; SA2, 18.0%) fractions. Flower polysaccharide consisted of one neutral (FN1, 1.6%) and one acid (FA1, 26.4%) fractions. All the subfractions have relatively high polydispersity indices (1.0 to 2.5). Sugar analysis shows that the subfractions are constituted predominantly by galactose, glucose and mannose with different mole percentages, except that acidic flower polysaccharide was composed of two more monosaccharides, rhamnose and xylose, and neutral skin juice polysaccharide yielded glucose as the sole monosaccharide. Galacturonic acid was identified as the sole uronic acid in all acidic polysaccharides from different tissues.Keywords: Aloe ferox, skin juice, gel juice, flower, polysaccharides, composition *To whom correspondence should be addressed. E-mail: yongmeif@126.com IntroductionThere are over 250 species of aloe grown world over. Out of wide range of aloe species, A. vera industry is a wellresearched, well-established, multi-billion dollar industry (Reynolds and Dweck, 1999). A. arborescens is much used in Japan in a way similar to A. vera, although in these studies it appears that the whole leaf was used in the preparation rather than the isolated gel (Reynolds and Dweck, 1999). A. vera and A. ferox are economically important with a significant international trade (Oldfield, 1993). A. ferox, the Cape Aloe or Bitter Aloe, is used to produce bitters as laxative in South Africa which had an estimated export value of approximately $1.2 million in 1996, now close to $2 million (Dickson, 2008). The mucilaginous gel is used in skin preparation and cosmetics (Sachedina and Bodeker, 1999).It has multiple pharmacological effects on healing wounds (Jia et al., 2008), skin cancer, burns and psoriasis (Maliehe, 1997;Van Wyk et al., 2009;Loots et al., 2007), eczema (Van Wyk and Gericke, 2000), constipation (Wintola et al., 2010). Currently, value adding such as the production of cosmetics or beverages is done mainly in export destinations (Melin, 2009). Kleinschmidt (2004) described the health benefits of beverages and fortified food products containing the leaf parenchyma of A. ferox, although it has been difficult to compete with the A. vera products available in the international market. Locally, the production of aloe drinks from polysaccha...

Extraction, Purification, Structural Characteristics, Biological Activities and Pharmacological Applications of Acemannan, a Polysaccharide from Aloe vera: A Review

“…As such polysaccharides usually contain proteins, pigments and small molecular substances, further separation and purify is necessary to get acemannan. Separation and purification of crude extracts by anion exchange chromatography coupled with gel permeation chromatography (DEAE-Sephadex A-25 column) [38,39,40] and normal membrane separation were done [41]. However, considering the long fractionation time, low cost, membrane vulnerability, gradient ethanol precipitation method and gradient ammonium sulfate precipitation method were adopted in recent years.…”