Study On Separation,Purification,Structure,Hypoglycemic Activity And Pd Nanoparticle Synthetic Application Of Cynomorium Polysaccharide

Cynomorium songaricum Rupr.is a plant fresh stem in the genus of Songaricum(Cynomoriaceae family).It is also a herbal Traditional Chinese Medicine which contains plenty of polysaccharides,mainly distributed in the gobi desert of the Hexi Corridor in Gansu or Inner Mongolia.The study of it's hypoglycemic activity would provide a reference for seeking some novel hypoglycemic drugs.And further research of its polysaccharide extracts would have a positive impact on the full development and comprehensive utilization of it.In this paper,four Cynomorium polysaccharide components were purified by water extraction,salt extraction and high temperature / pressure process,respectively.And their monosaccharide compositions and primary structure were determined.Firstly,established a Hep G2 cell insulin resistance model,the structure-activity relationship of improved insulin resistance by Cynomorium polysaccharide was studied.The hypoglycemic effects of Cynomorium polysaccharide with different extraction methods,different molecular weights,containing or free protein were observed.Secondly,induced a diabetic rat model by streptozotocin,the hypoglycemic effect of water-extracted Cynomorium polysaccharide was investigated.Lastly,the Pd-CSP composites was prepared by reduction with salt-extracted Cynomorium polysaccharide under microwave irradiation and applied in glucose detection.Above all,this thesis is consists of five parts as follows: Part I: The extraction,separation and purification of Cynomorium polysaccharidesCynomorium polysaccharide components were obtained by water extraction,salt extraction and high temperature/pressure process,respectively.And the decolorization process which is the key step of purification was optimized.The optimal decolorization process is 2 mg m L-1 polysaccharide,1 % activated carbon,40 ? and p H=4.Under these conditions,the retention and decolorization rates of polysaccharides can be reached to 76.45 ± 0.67 % and 86.84 ± 2.10 %,respectively.Finally,the CSP-SA?,CSP-SA?,CSP-WA? and CSP-HT? were obtained after decolorization,protein removing,alcohol precipitation,dialysis and column chromatography.Its molecular weights and molecular weight distributions were also investigated.Part ?: The characterization of Cynomorium polysaccharides structureFour obtained Cynomorium songaricum polysaccharides were characterized by the FT-IR,GC-MS,1D-NMR,2D-NMR,AFM and TGA-DSC,respectively.The results show that the CSP-SA? is made up of the straight chain glucan and its possible primary structure was determined.The CSP-SA ? is a heterosaccharide,consists of rhamnose,arabinose,mannose,glucose and galactose.And its degree of branching(21 %)and possible primary structure were also determined.The CSP-WA?is a heterosaccharide mainly contains glucose.It also contains a little of arabia sugar,xylose and galactose.Its possible primary structure was also determined.As to the CSP-HT?,it contains some nonsugar compounds besides rhamnose,arabinose,glucose and galactose.Part ?: The structure-activity relationship of improved insulin resistance by Cynomorium polysaccharide on Hep G2 cellsThe cytotoxicity and hypoglycemic effect of Cynomorium polysaccharide with different extraction methods,different molecular weights,containing-or freeprotein were observed in cells levels.By establishing a Hep G2 cell insulin resistance model,the structure-activity relationship of improving insulin resistance by Cynomorium polysaccharides was studied.In the cytotoxicity aspect,the saline-extracted Cynomorium polysaccharide(CSP-SA)has high cytotoxicity on cells.Especially,the middle-molecular-weight Cynomorium polysaccharide(CSPM-SA)can affect Hep G2 cell viability significantly on medium and high doses.And the protein-containing Cynomorium polysaccharide(CSPpro-WA)also has a significant cytotoxicity.In promoting glucose consumption aspect,the water-extracted Cynomorium polysaccharides(CSP-WA)can improve the Hep G2 cell insulin resistance significantly,which is equivalent or even better compared with metformin(positive control drug).The study shows that,among different extractions,the hot water extraction is the best one and its promotion effect on glucose consumption is dose-related.Addtionally,the promoting glucose consumption of the low molecular weight polysaccharide is better than others.At the same time,the freeprotein Cynomorium polysaccharide can promote glucose consumption effectively in Hep G2 cells compared to containing-protein ones.Part ?: The hypoglycemic effect of Cynomorium polysaccharide on diabetic ratsA streptozotocin induced diabetic rat model was established.And the hypoglycemic effect of water-extracted Cynomorium polysaccharide(CSP-WA)was investigated by determination of blood glucose,body weight,drinking water volume,feed intake,TC levels,TG levels and LDL/HDL levels.It was found that the CSP-WA can decrease the blood glucose of diabetic rats significantly and improve polydipsia,polyphagia,polyuria and weight loss caused by diabetes.Furthermore,it can reduce the high level of insulin and make the level of metabolism to normal.At the same time,it also can significantly reduce the serum cholesterol,triglyceride and low density lipoprotein.Therefore,the levels of lipid metabolism were improved and the symptoms of diabetes were relieved.Part ?: Preparation of nano-sized Pd by Cynomorium polysaccharide under microwave irradiation and application in glucose detectionNano-sized Pd was prepared by reduction of palladium acetate with salineextracted Cynomorium polysaccharide(CSP-SA)under microwave irradiation and applied in non-enzymatic glucose detection.It was found that the CSP-SA has reducing and stabilizing effects of Pd nanoparticles.The obtained Pd nanoparticles are a composite structure(Pd-CSP),which adsorbed on Cynomorium polysaccharide.And as-prepared Pd nanoparticles have a high dispersion and small diameter.Its prepared blood glucose monitor shows a good response,high sensitivity,excellent anti-interference ability and stability.