Preparation And Antioxidant Activity Of Garlic Polysaccharide Derivatives

Garlic has always had important medicinal value,and garlic polysaccharide is the main component of garlic,and its various functions are inextricably linked to it.Molecular modification can greatly improve the biological activity of polysaccharide and can produce many new medicines.Garlic polysaccharide was extracted from fresh garlic.Chemical modification of garlic polysaccharide yielded sulfated garlic polysaccharide,phosphorylated garlic polysaccharide,carboxymethylated garlic polysaccharide,carboxymethyl sulfated garlic polysaccharide and carboxymethyl phosphorylated garlic polysaccharide.The experiment also tested the hydroxyl radical scavenging ability,superoxide anion scavenging ability,reducing ability and anti-lipid peroxidation of garlic polysaccharide and its derivatives.The main contents of lipid peroxidation were as follows:1.The advantages and disadvantages of different methods for extracting garlic polysaccharide were compared,and the existing conditions in the laboratory were taken into consideration to determine the extraction of garlic polysaccharide.In the experiment,the extraction solution of garlic polysaccharide was optimized from the extraction temperature,the ratio of material to liquid and the extraction time.The optimal conditions for the extraction of garlic polysaccharide in this experiment were determined as follows: the extraction temperature was 80℃,the material-liquid ratio was 1: 7,and the extraction time was 150 min.The fat in garlic polysaccharide was removed with Ether,and the protein was removed with the Sevage method,and the small molecular impurities were removed by dialysis.2.Five kinds of garlic polysaccharide derivatives were obtained by chemical modification of garlic polysaccharide.In the experiment,the phenol-sulfuric acid method was used to test the sugar content of the garlic polysaccharide and its derivatives.The sugar content of P was 76.67%,the sugar content of SP was 41.02%,the sugar content of PP was 40.38%,the sugar content of CM was 60.27%,the sugar content of CMS was 30.60%,and the sugar content of CMP was 41.20%.The degree ofsubstitution of garlic polysaccharide derivatives was also determined.The derivatives were tested by infrared spectrum and nuclear magnetic carbon spectrum.The test results showed that chemical modification of garlic polysaccharide was successful.3.The antioxidant activity of garlic polysaccharide and its derivatives was tested.The hydroxyl radical scavenging ability of phosphorylated garlic polysaccharide and carboxymethyl phosphorylated garlic polysaccharide was greater than that of garlic polysaccharide,the superoxide anion scavenging ability of carboxymethylated garlic polysaccharide was greater than that of garlic polysaccharide,the reducing ability of carboxymethyl phosphorylated garlic polysaccharide was greater than that of garlic polysaccharide,and the anti-lipid peroxidative ability of the five derivatives of garlic polysaccharide were greater than that of garlic polysaccharide.Chemical modification can change the biological activity of polysaccharides.In the study on the antioxidant activity of five derivatives of garlic polysaccharide,the antioxidant activity of phosphorylated garlic polysaccharide,carboxymethylated garlic polysaccharide and carboxymethyl phosphorylated garlic polysaccharide was better,the antioxidant activity of sulfated garlic polysaccharide and carboxymethyl sulfated garlic polysaccharide in vitro was general.