Isolation Purification Structure Characterization And Hypoglycemic Activity Of Polysaccharides From Chicory Root

Chicory belongs to chrysanthemum in the compositae family.Chicory can be used as a medicinal and edible plant.The root of chicory,as a part of Chicory,contains carbohydrate,α-aromatic resin alcohol,corpus callosum decoction and other active substances.Polysaccharide is the main active ingredient in chicory root.Inulin has the highest content,followed by glucose,fructose and other polysaccharides.The roots of chicory have a series of biological activities,such as hypoglycemia,hypolipemia,anti-oxidation,immune regulation,antibacterial and so on.Active substances and biological activities in chicory root have become the research priorities in recent years.In this paper,an active substance-polysaccharide was extracted from chicory root,then the polysaccharide was separated and purified.The structure of this polysaccharide was analyzed,the hypoglycemic activity of this polysaccharide was studied.The specific research work was as follows:Crude polysaccharide was extracted from chicory root by water extraction and alcohol precipitation method.Four single factors,extraction time,extraction temperature,solidliquid ratio and extraction times was conducted to exploring the effect of polysaccharide extraction rate.Response surface experiment was further to determined the optimal process.The optimal extraction time was 2h,the optimal extraction temperature was 80℃,the optimal solid-liquid ratio was 1:20,and the optimal extraction times was 2.The crude polysaccharide was further isolated and purified by a series methods.The protein was removed by Sevag.The small molecular substances such as amino acids were removed by dialysis method.Then the crude polysaccharide was purfied by the column chromatography of DEAE-52 and Sephadex G-15.This new polysaccharide was named as CRP-L.The full wavelength scanning of CRP-L by UVspectra showed that there was no special absorption peak of CRP-L at 260-280 nm,this results indicated that protein and nucleic acid were completely removed.The molecular weight of CPR-L identified by HPLC was 2.71x104 Da.By using phenol-sulfuric acid method to test the content of polysaccharide,the rest showed that the content of CRP-L polysaccharide was 98.07±0.23%.The functional groups of CRP-L were determined by FI-IR.The results showed that CRP-L contained C-OH,C-H,not cotained C-OOH bond,indicating that CRP-L was neutral polysaccharide.The monosaccharide composition of CRP-L was mannose,glucose and galactose,and their mole ratio was 2.28:4.79:1.CPR-L consumed 0.78 mmol periodic acid.Smith degradation analysis of CPR-L showed that CPR-L contains glycerol and erythritol.NMR data analysis and methylation experiments showed that the glycosidic bond of CPR-L were →2,3,6)-α-D-Glc-(1→,→2)-β-D-Manp-(1→,→3)-β-D-Galp-(1→,T→Manp and T→Galp.The results of α-glucosidase inhibitor showed that the inhibitory rates of acarbose,crude polysaccharide from chicory root and CRP-L on α-glucosidase were 83.71% ± 0.32%,43.78%±0.51% and 52.99% ±0.33%,respectively,when the concentration of sample was 2 mg/m L.The inhibitory rate of acarbose and CRP-L on α-glucoside increased with the increasing of the concentration.The inhibitory rate was 71.25±5.23%,when the concentration reached 8mg/m L.Cell experiments showed that CRP-L could reduce the glucose consumption of Hep G2 cells.