Preparation,Structure And Bioactivity Of Polysaccharides From Capparis Himalayensis

The plant of capparidaceae a variety of biologically active.In this experiment,the Xinjiang characteristic plant Capparis himalayensis(C.himalayensis)was used as raw material,and the polysaccharide was extracted in response to ultrasound-assisted extraction of C.himalayensis polysaccharides.The component content,structural characterization and biological activity of the purified polysaccharide were studied.Using the experimental design software "Design-Expert 8.0.6",the optimal ultrasonic assisted extraction process parameters were found:the ratio of water to raw material was 25:1,the ultrasonic time was 49.5 min,and the extraction temperature was 72?,respectively.The actual yield of crude polysaccharide was 4.437%.The molecular weight distribution of polysaccharides was analyzed by HPLC and then separated and purified by 30 kD ultrafiltration tube.Purified polysaccharide CHP-1 was obtained by repeated freeze-thaw to remove non-sugar impurities.The average molecular weight of CHP-1 calculated from the dextran standard curve is about 1.79×103 kDa.By analyzing the basic components of CHP-1,it was concluded that the total sugar content of CHP-1 was 93.25%,the protein content was 0.21%,the uronic acid content was 4.41%,and the sulfate group content was 5.42%.GC-MS analysis showed that the polysaccharides of CHP-1 were mainly composed of rhamnose,arabinose,xylose,mannose,glucose and galactose,the molar ratio of which was 0.33:0.65:0.53:3.15:1:1.51.Ultraviolet absorption spectrum of CHP-1 shows that the polysaccharide had no obvious absorption peak at 260-280 nm,indicating that the polysaccharide didn't contain binding protein and nucleic acid.The structure characteristics of polysaccharides was studied by FT-IR analysis,NMR,periodate oxidation,Smith degradation and methylation analysis.Due to the large molecular weight of the polysaccharide and the complicated structure,based on the existing experimental conditions,it is speculated that the CHP-1 glycosidic linkage is based on(1?4)linked mannose backbone.The analysis by Congo red experiment and SEM showed that the CHP-1 was found to have a triple helix structure in a weak alkaline solution,and the surface structure was smooth and filamentous,which was crosslinked into a network.The DSC results show that the polysaccharide has strong rigidity and high thermal stability.Furthermore,the antioxidant activity in vitro of CHP-1 was successfully proved by DPPH free radical scavenging test,ABTS radical scavenging test,Hydroxyl radical scavenging test and Ferric reducing power test.