Aloe Polysaccharides Sulfated Modified

At present, there are some disadvantages in the production process of aloe polysaccharides, such as higher energy consumption, pollution of used organic solvent and so on. As a novel separation technique, aqueous two-phase system (ATPS) has many advantages such as easily being operated, shorter phase-separation time, lower investment cost, bigger separation coefficent and so on. In this paper, a new type of separation system for aloe polysaccharide was designed, the component of aloe polysaccharide was analyzed and the inoxidizability was studied, in addition, the method of sulfating polysaccharide and the inoxidizability of sulfated polysaccharide were investigated.Firstly, a ATPS based on Triton X-114 was established. The aloe polysaccharides was measured by the colorimetry of phenol-sulferic acid method and the protein was measured by the colorimetry used coomassie brilliant blue (CBB) respectively. The affecting parameters to the recovery of aloe polysaccharide and protein of Triton X-114 concentration, pH, temperature and inorganic salt concentration were investigated in details. Under the optimal conditions, the content of 85.72% and 85% for aloe polysaccharide were obtained with 4% (w/w) Triton X-114,0.3 mol/L inorganic sodium chloride at pH 3.0 and 50℃, the recovery of 89.7% and 99% for aloe polysaccharide were obtained with 4% (w/w) Triton X-114,0.3 mol/L inorganic ammonia sulfate at pH 3.0 and 50℃.Secondly, the polysaccharides was analysed by IR, UV and HPLC. The UV spectrum showed that there were no protein and nucleic acid in aole polysaccharides due to no characteristic absorption peak at 260 nm and 280 nm. The result of analysis of polysaccharides manifested that the major component of aloe polysaccharides were malmose and a few glucose, there were no xycose and galaetose.Thirdly, polysaccharide was sulfated with chlor sulfonicacid-pyridine. The reagent proportion, reaction temperature and reaction time were selected with substitution degree and yield as index by L9(34) orthogonal design. The results showed that the optimum conditions are the volume ratio of pyridine and chlorine sulfonic acid was 1:3, the reaction temperature was 60 and reaction time 2 h. The structure of sulfated polysaccharide was proved by UV spectrum and IR spectrum. The results indicated that synthesis of the sulfate is achieved because absorption peak of stretching vibration at 1230-1260 nm by sulfate and at 815 nm by C-O-S.Fourthly, the ability to remove hydroxyl radical and superoxide anion was tested. The results showed that sulfated polysaccharide had the strongest in vitro antioxidant activities while the crude polysaceharides has the weakest in vitro antioxidant activities. The antioxidant activities increased with the polysaceharides concentration.