Extraction, Separation, Purification And Bioactivity Of Aloe Vera Polysaccharides

High-speed countercurrent chromatography (HSCCC) is a continuous liquid-liquid distribution of chromatography without solid-phase carrier, sample pretreatment strictly etc. Now it is widely applied in biological technology, medicine, natural products, environmental monitoring, food. However, the existing research basic confined by high-speed countercurrent chromatography organic phase-aqueous solvents system to separate natural products, it is restricted largely in the polysaccharide separation, protein study because of organic solvents can dissolve biological macromolecules. But with the development of aqueous two-phase system, high-speed countercurrent chromatography in polysaccharide separation, protein in biological macromolecules research shows its unique advantage. Therefore, this article provide mainly a new method to separate and purify aloe polysaccharides from the preparation of high-speed countercurrent chromatography with aqueous two-phase system of solvent.In China, the traditional, classic methods of separation and purification the aloe polysaccharides is mostly using gel column chromatography technology. This method is convenient, selective, low requirements for experimental skills, but it also exists a lot of shortcomings, for example low degree of mechanization, long preparation time and the less of preparation. the high-speed countercurrent chromatography connect with gel column chromatography technology will be studied to separate and purify aloe polysaccharide in this article, it can not only overcome the long time of consuming, the low of mechanization degree and low quantity of preparation, but also it is a kind of innovation method in using high-speed countercurrent chromatography technology. Aloe vera has much important medicinal value, but the medicinal chemical composition quite complicated. At present, it are common in multiple components, but we can not know which component is the leading role, Aloe polysaccharide is present most important bioactive components, enhance immunity, anti-tumor, cholesterol-lowering physiological function, etc. They are extremely important in the natural raw material medicine and cosmetics. the purpose of this study mainly discusses the important parameters, for example the solvent composition, the distribution coefficient ratio for high-speed countercurrent chromatography.First, the content of moisture in Aloe gel is over 98.74%, the content of sugar in leaves is higher than the gel, it is for 1.164%, it is almost not the content of protein in their skins, the content of minerals is only 0.156% in aloe gel.Second, response surface methodology (RSM) was applied to optimize the ultrasonic assisted extraction conditions of polysaccharides from Aloe vera (APS) gel. The results indicated that the optimum extraction conditions of the Aloe vera polysaccharides were as follows: ultrasonic extraction time 45.85 minutes, pH value 8.74, ratio of water to material 29.84 mL/g. Under the optimized condition, the predicted yield of polysaccharides extracted was 11.453mg/g and the content of polysaccharide is 51.49%.Third, the solvent system of Aloe polysaccharides separation by HSCCC was studied with UV-Vis Spectrophotometer, the result showing that the best ratio of the solvent system was w(PEG600):w(KH₂PO₄):w(K₂HPO₄):w(H₂O)=5:15:15:65 as well as 2 %(w/w) NaCl. The raw polysaccharide was separated successfully by HSCCC under the conditions of bath temperature 30℃, 600 r/min and 2 mL/min, and APS-1 and APS-2 were accessible. It is further purified for APS-1 using Sephadex G-150 gel chromatography technology, we can gain the homogenous separately(APS-1-1) by changing the constituent separation condition, its purity is over 98% and the molecular weight is 1300 Dalton.Finally, by the study of high fat mouse model, aloe polysaccharide APS-1-1 play the more important role in reducing weight at the same time lowering cholesterol, the effect of TC and TG is 27mg/Kg for the best. But when the polysaccharide concentration in 9mg/Kg, it is the best for the effect of LDL-C.