Extraction And Antioxidant Activities Of Polysaccharide From Solanum Nigrum Fruit

Solanum nigrum fruit（Solanum nigrum Fruit common name Heitiantian）is a species of Solanum solanum,annual herbaceous plants,most provinces and regions of the country have distributed.The main components of the fruit can be divided into three categories:alkaloids,saponins and non-saponins.The main active component is alkaloids,followed by polysaccharides.As one of the main components of Solanum nigrum,polysaccharides have not been studied in China,and there are few reports on antioxidant activity in vitro.Therefore,the extraction,classification and purification of polysaccharides from Solanum nigrum were carried out,and their structure was preliminarily analyzed,and the antioxidant function in vitro was studied.For further development and utilization of Solanum nigrum fruit provide theoretical basis.The specific studies are as follows:（1）Extraction of Polysaccharide from Solanum nigrum fruitThe extraction of Solanum nigrum fruit polysaccharose by water-based alcohol sinking method was used,the process of Solanum nigrum fruit polysaccharose extraction was optimized by the response surface method on the basis of a single factor,and the best extraction conditions for Solanum nigrum fruit polysaccharose were:extraction time 5h,liquid ratio of 1:20g/m L,ethanol concentration of 94%,at this time,the polysaccharose yield in Solanum nigrum fruit was 4.07mg/g;Then,through the single-factor and response surface optimization experiment,it was determined that the best condition for the removal of protein in the Solanum nigrum fruit polysaccharide method was 6%,the number of removals was 2 times,the oscillation time was 20min,under which the removal rate of the protein in the polysaccharides of Solanum nigrum fruit reached 93.61%and the loss rate of polysaccharides was 16.46%.（2）Purification and Grading of Polysaccharide from Solanum nigrum fruitThe polysaccharides of Solanum nigrum fruit were refined by DEAE-cellulose ion exchange column chromatography and Sepharose CL-6B agarose gel column chromatography.The contents of glyoxylic acid and total sugar were determined by DEAE-cellulose purification SNFP-0、SNFP-1、SNFP-2、SNFP-3,and the contents of glyoxylic acid and total sugar were determined by interhydroxybenzidine method and phenol sulfuric acid method.Only the SNFP-0 did not contain glyoxylic acid as neutral sugar,SNFP-1-1、SNFP-2-1、SNFP-3-1 three main grades were obtained by Sepharose CL-6B agarose gel column chromatography.Through glyoxylic acid and Total sugar content detection.All three levels contain glyphonic acid as acid sugar.（3）Analysis of Four Structural Grades of Polysaccharide from Solanum nigrum fruitThe composition of polysaccharide was analyzed by HPLC.The compositi on of polysaccharide was as follows:glucose,arabinose,mannoseose,mannose and galactose were SNFP-0,and the molar percentage was 50.62:10.64:35.64:35.64:3.09,SNFP-1-1 was Made up of five monosaccharides,Glucose,galacturoni c acid,rhamnose,arabinose,galactose,The molar percentage was 52.01:1.36:13.87:4.32:28.43;SNFP-2-1 is composed of glucose,arabinose,mannose and galac tose,The molar percentage was 27.79:16.72:1.6:53.88;SNFP-3-1 monosaccharid es were glucose,arabinose,mannose,xylose and galactose in the molar percent age of 67.89:9.64:3.2:1.87:17.39.The results showed that the four grade polysa ccharides of Solanum nigrum fruit were pyran polysaccharides.The full wavele ngth scanning of the four grades of polysaccharides of Solanum nigrum fruit w as carried out by ultraviolet spectrophotometer.The results showed that the abs orption peak of polysaccharides was consistent with the characteristic absorption peak and there were no other heterogenous peaks,which indicated that the pu rification effect of the four polysaccharides of Solanum nigrum fruit was better.（4）Study on Antioxidant Activity of Solanum nigrum fruit Polysaccharide in VitroThe total antioxidant capacity,free radical scavenging ability,free radical scavenging ability and superoxide anion scavenging ability（O₂·）of DPPH polysaccharides were determined by in vitro antioxidant activity test.The ability of free radicals,the results showed that its antioxidant capacity showed a dose-dependent relationship,that is,with the increase of polysaccharide concentration,the antioxidant capacity also increased.The results showed that the polysaccharide had certain antioxidant effect.