Studies On The Synthesis And Hydrolyzation To Phosphodiester Bond Of Saccharide-REE Complexes

The rare earth elements (REE) have effects on immune-related enzyme activities, content of chlorophyll and the mineral nutrition metabolism of plants, and can improve its growth, development, physiological function, yields. REE can also restrain tumour and lung cancer,have the abilities of decreasing blood glucose and scavenging the free radicals by influencing immune activities and endocrine system of animals.However, REE cannot be efficiently untilized by the creatures under neutral conditions, because REE will form steady gel-deposit, which reduces its solubility. Rencent studies find that REE can combine with polysaccharides and form into polysaccharide-REE complexes, which can improve REE bioavailability. The complexes have efficient hydrolysis activities on the degradation of phosphodiester bond, especially to organophosphorus pesticides, while the structure of complexes and degradation mechanism of pesticides have not been reported.Several saccharide-REE complexes have been synthesized in this paper. In given conditions, the hydrolysis activities of different complexes are determined on pNPP2Na containing phosphodiester bond. The results show that hydrolysis activities of aldose-REE complexes are better than that of ketose-REE complexes, 6-C saccharide-REE complexes have higher hydrolysis activities than 5-C saccharide-REE complexes, and the hydrolysis activity of glucose-REE complex to pNPP2Na is the highest among the monsaccharide-REE complexes. Hydrolysis of polysaccharide-REE complexes to pNPP2Na shows that hydrolysis activities have correlation with content of aldose in polysaccharides. The complexes with polysaccharides mainly composed of aldose, especially 6-C saccharides, have conspicuous hydrolysis activities. Furthermore, degradation activities to phosphodiester bond are significantly related to the polymerization degree of polysaccharides, the higher the polymerization degree polysaccharide-REE...