Studies On The Synthesis And Some Bioactivities Of Ce-polysaccharide Complexes

Rare earth elements (REE) and their complexes have speeial physical and chemieal properties have been widely applied in nearly eveyr aspect.Whereas, a great deal of steady gelatinous REE-OH deposit will be formed at physiological pH so as to reduce the solvency of REE.Therefore, one suitable ligand which can react with REE must be found in order to broaden its purpose. Ce-complexes which have a great deal of hydroxyl groups can be formed in the neutral condition,beacause cerium ion has smaller ionic radius and higher ionic potential than other metal ion. Polysaccharides can be as supporting ligand to combine lanthanide ions because of having many active groups such as hydroxyl groups.The paper showed that the polysaccharides which extracted from Ganoderma atrun,Camellia sinensis, Plantago asiatica L, Herba moslae could coordinate with Ce(NH4)2(NO3)6 to prepare the complexes, and the bioactivities of the complexes in vitro were also determined. The main studies and results in the paper were mentioned as follows:1.The preparation process of complexes was studied.The synthesis conditions that influenced the synthesis rate of complexes were optimized by orthogonal design, the optimum synthesis conditions were:rare earth addition is 0.06%,24h, at 70℃,pH 8.0.The contents of Ce(Ⅳ) in different complexes can be determined by the method of arsenazo(Ⅲ).We notarized the makeup of the complexes through the UV spectra and the fluorescent emission spectra.The results confirmed that the new complexes were synthesized and Ce(Ⅳ) was reacted with the hydroxyl group of polysaccharides.2.The paper compared the different degraded activities among the different complexes for phosphoester.The optimum degraded conditions were determined by single factor test,the best hydrolysis conditions were as follows:the concentration of PNPPNa2 was 3mmol/L, pH 7.0,at 40℃. The results showed that all of the complexes could degrade PNPPNa2, and the degraded activity of Ce-PLCP to PNPPNa2 was the highest among the Ce-polysaccharide complexes in given conditions. Gas chromatography was used to analyse the degradation products of organophosphorus pesticides by Ce-polysaccharide complexes.And the effects of degradation were varied because of the different molecule structures of organophosphorus pesticides.The result showed that Ce-polysaccharide complexes had the best degraded effect on chlorpyrifos. The degradation rates of Ce-HMP, Ce-GAP, Ce-TPS and Ce-PLCP were 92.19%,88.78%,96.89%,46.11% respectively.3. The antioxidant effects of different polysaccharides and Ce-polysaccharide complexes were studied in vitro by different testing systems,which included superoxide anion radieal, hydroxyl radieal, DPPH radical,β-carotene-linoleic acid oxidation system. The results showed that the four polysaccharides and Ce-polysaccharide complexes all had certain antioxidant activity.And the Ce-polysaccharides complexes showed the similar antioxidant activity with their ligands. The correlativity of their effects and the doses were positive, in a certain concentration range. In those four antioxidant system, the antioxidant activitivies of the polysaccharides and Ce-polysaccharide complexes were as follows:TPS> HMP> GAP> PLCP, Ce-TPS> Ce-HMP> Ce-GAP> Ce-PLCP.4. Antibacterial activities of these complexes were studied by the method of filter paper. The results indicated that these products had varying resistance to Escherichia coli, Staphylococcus aureus Rosenbach and Bacillus subtilis. The antibacterial activity of Ce-TPS was stronger than other complexes, and the antibacterial activity of Ce-TPS for E.coli was especially strong.But Ce-GAP didn't have any antibacterial effect.