Composition, characteristic and activity of rare earth element-bound polysaccharide from tea

The compositions and structural characteristics of rare earth elements-boun d polysaccharides from tea (REE-TPS) were studied with the methods of Induc tively Coupled Plasma Mass Spectrometry (ICP-MS), Gas Chromatography (GC) a nd Extended X-ray Absorption Fine Structure (EXAFS) spectroscopy. The resul ts show that polysaccharide from tea (TPS) was a sort of glycoprotein and c oordinated with Rare Earth Elements (REE) closely. The sugar fraction was c omposed of Rha, Ara, Xyl, Fuc, Gic, and Gal. There existed almost all natur al amino acids with Glx, Asx, and Hyp as the major parts in the protein fra ction. The REEs in REE-TPS were mainly composed of La, Ce, and Nd, especial ly, more than 75% of them was La. The coordination atom of the first coordi nation shell of La in REE-TPS was oxygen, the coordination number of which was 6, and the average distance between the atoms was 2.52 Angstrom. The se cond shell was formed from sulfur atoms, the coordination number and the av erage distance were 3 and 2.91 Angstrom, respectively. The bio-experiments show that REE-TPS could