Studies On Chemical Modification Anticoagulant Function In Vitro Of Tea Polysaccharide

The human health is seriously threatened with thrombus embolism disease.People have paid more and more attention to the increase of this kind of disease induced by coagulant factor.Anticoagulation and anti-thrombus has been set as one of the criteria for heart and brain vein disease by National Board of Sanitation.At present,anticoagulant medicine used for clinic treatment is mostly heparin and coumarin,which has some side-effects, such as causing platelet disease and so on.So it is essential to develop new type of medicine or functional food.Tea not only has nutrition,but also has pharmacological effects,and tea polysaccharide is one of the important effective components in tea.Tea polysaccharide has hypoglycemic,hypolipidemic,anticoagulant,anti-thrombosis,anti-oxidation,enhanced immunity,reducing blood pressure,slowed heart rate,increased coronary blood flow and anti-anoxia,and other pharmacological effects.Our country is rich in tea resources,which is distributed in broad region,and making tea polysaccharide has very broad developing prospect.Combined with anticoagulant activity test and using Oolong tea as the material, this research extracts,separates and purifies anticoagulant activity polysaccharide components with DEAE-52 cellulose column from the tea leaves,accessing to the four components of tea polysaccharide(TPSâ… ,TPSâ…¡,TPSâ…¢and TPSâ…£).The molecular structure of TPSâ…¡was transformated by sulfation,acetylation and carboxymethylation modification respectively,and then to analysis the anticoagulant activity changes and infrared spectral characteristics between tea polysaccharide and chemical modificated tea polysaccharide.The results showed that:1.Tea polysaccharide has anticoagulant function in tea.Tea polysaccharide can prolong activated partial thromboplastin time(APTT) of human plasma significantly,but has no effects on prothrombin time(PT) and thrombin time(TT).The anticoagulant component in tea polysaccharide works by affecting intrinsic pathway of coagulation cascade.In experimental area,the higher concentration of tea polysaccharide,the stronger anticoagulant activity.2.The anticoagulant activity of tea polysaccharide strengthened by deprotein,but the activity reduced by decolorization.Four polysaccharide components were separated by DEAE-52 cellulose column,the componentâ…¡occupied 57.36%of total tea polysaccharides and it was relatively high on anticoagulant activity. 3.The anticoagulant function of tea polysaccharides componentâ…¡was further enhanced by modification.The proportion between chemical modification reagents and polysaccharides,and modificating reaction time influenced on the modification degree of molecular structure of tea polysaccharides,and changed the anticoagulant activity accordingly.4.Infrared spectral analysis showed that sulfation,acetylation and carboxymethylation groups have been combined into ester with the tea polysaccharides by chemicalmodification.