Study On Extraction, Isolation And Anti-Oxidative Activity Of Polysaccharides From Melaleuca Ahemifolia

The extraction of polysaccharides from was investigated in this article. The determination conditions of polysaccharide content were optimized. The main affecting factors on the extraction process of polysaccharides from were studied and the optimal extraction conditions were obtained by response surface methodology (RSM). The crude polysaccharides were purified and the structure and compositions were analyzed. The antioxidation activities of purified polysaccharides were also evaluated.1. The content of polysaccharides can be determined by the Anthrone sulfuric Acid colorimetric method. The accuracy of determination can be improved by adding3mL of2g/L anthrone in concentrated sulfuric acid into lmL polysaccharide solution and heating for5min at100℃. After cooling the polysaccharides solution naturally for10min, the absorbance can be read on a spectrophotometer at620nm, with glucose as the standard. The experimental precision (RSD) was0.96%and the average recovery for the determination of the polysaccharides was87.8%with a RSD of4.75%.2. An ultrasonic-assisted procedure for the extraction of polysaccharides from was investigated using response surface methodology (RSM). The statistical analysis indicated that the independent variables such as extraction time, ratio of water against raw material and ultrasonic power exhibit significant effects on the yield of polysaccharides (p<0.05). The experimental data obtained were fitted to a second-order polynomial equation using multiple regression analysis and further analyzed by appropriate statistical methods (ANOVA). The optimum extraction conditions were as follows:extraction time of21min, ratio of water to raw material of40, ultrasonic power of170W. Under the optimization conditions, the experimental yield was6.194%, which was agreed closely with the predicted value (6.288%).3. The structures of purified polysaccharides were characterized by IR and HPLC. The results showed that polysaccharides exhibit the characteristic infrared absorption peaks of polysaccharide. HPLC analysis indicated that the main components in the purified polysaccharides (MAP-2) are fructose and galacturonic acid with molar rations of1.000:1.614.4. The free radical scavenging capacities of polysaccharides against DPPH、 ABTS+·and·OH.MAP-2were also evaluated. The median inhibition concentrations (IC50) against·OH, ABTS+·and DPPH radical are0.373mg/mL,0.092mg/mL and0.018mg/mL, respectively. The results demonstrated that polysaccharides exhibit significant scavenging activities against DPPH、ABTS+·and·OH radicals.The research work and the conclusions in this article have established a theory foundation for the further research and application development of in the future.