Study On Purification And Antioxidant Activity In Vitro Of Nicandra Polysaccharides

Nicandra Physaloides(L.) Gaertn is mainly growing in the southern region of our country. It contains a lot of ingredients, such as flavone, alkaloid, oleic acid, fat and protein. In addition to these, It also contains mass of polysaccharide compounds. However, there is few study on nicandra polysaccharides in domestic and overseas.In this paper, the extraction, purification and properties of nicandra polysaccharides were studied. It intended to provide a basis for extraction and application of nicandra polysaccharides in the field of health care and food.To obtain right extraction conditions, different methods were applied respectively, including the methods of water extraction, ultrasonic extraction, and microwave extraction. According to their characteristics, the effects of different extraction conditions on nicandra polysaccharides extraction rate. Orthogonal experiments L9(34) was designed on the basis of the single factor. The optimal extraction method and the condition were determined.Polysaccharides solution extracted from the seed of Nicandra Physaloides(L.) Gaertn contained soluble impurities were chiefly fat, protein and pigment. They had an impact on properties of nicandra polysaccharides. Nicandra polysaccharides solution was purified to insure to study more effectively on its properties. In the process of ethanol precipitation, polysaccharides were separated from solvent. The methods of Sevag, TAC and HCl were adopted to clear protein out of polysaccharides solution. The optimal deproteinization method was picked up through comparing the differences of the three methods. After QAC precipitation, there were different hierarchical Nicandra Polysaccharide solutions. Sephadex gel and freeze-melt methods were applied to the identification of its purity.Scavenging effects of polysaccharides on free radicals were studied. Taking Vc as a positive control, this study measured scavenging effects of Hydroxyl free radials, superoxide anion free radicals and DPPH free radials.