Purification, characterization and anticoagulant activity of the polysaccharides from green tea.

The crude tea polysaccharides were extracted from the leaves of Camellia sinensis using deionized water. The tea polysaccharides (TPS) were further separated and purified by anion exchange chromatograph on DEAE sepharose CL-6B column to afford TPS-1, TPS-2, TPS-3 and TPS-4. The high performance gel permeation chromatograph analysis showed that the average molecular weight of polysaccharides (TPS-1, TPS-2 and TPS-3) were 20,760, 24,230 and 250,643, respectively. TPS-4 was 689, 113 and 4150, suggesting it was heterogeneous. Monosaccharide analysis detected fucose, glucosamine, rhamnose, arabinose, galactosamine, galactose, glucose, xylose, mannose, ribose, galacturonic acid and glucuronic acid in the four polysaccharide fractions. Anticoagulant activities in vitro tests showed TPS-4 could significantly prolong APTT and TT, but not PT. The result indicated TPS-4 in the regulation of coagulation initiated via the intrinsic pathway. With current findings TPS-4 should be explored as a natural potential anticoagulant.