Abstract: OTPS 2-1, a main constituent of OTPS, was obtained by DEAE-52 and Sephadex G-150 column chromatography. It was found that OTPS 2-1 was a trinal compound of polysaccharide containing rich uronic acid and little protein by using methods of UV, IR, GC, HPLC and GPC-LLS. The results showed that the average molecular weight of OTPS 2-1 was 8.877×10⁴, and it was composed of Gal, Glu, Ara, Fuc and Rha with a molar ratio of 7.58:2.14:7.05:1.76:1.02. By using the technique of AMF, QELS, CD and LSCM, the three-dimensional conformation and solution behavior were studied. The results also showed that the molecule of OTPS 2-1 twisted each other, which formed short stick of 0.2-0.5 μm in diameter and 0.3-0.6 μm in length with a strong fluorescent light. The conformation could be changed by the factors of pH, ion intensity and complex compound. By using SEM, the folding and curling image under low-powered microscope, but smooth figure under high-powered microscope were also observed. Thermal analysis of OTPS 2-1 also indicated that there appeared 3 endothermic peaks and 3 exothermic peaks during heating.

Key words: Oolong tea polysaccharides, Spectrum, Morphology, Thermal analysis