Pupa Chitosan Amino Acid Derivatives Preparation And Anticoagulation Study

Chitosan is the second largest part of natural resources. The study show that chitosan extracted from silkworm chrysalis has high degree of deacetylation, consistent with requirements of pharmaceutical chitosan production. Chitosan is easily modified for the production of polysaccharide matrix objects which is used for anticoagulant.This article describes the physical and chemical properties of chitosan and its application to blood coagulation research progress.And pointed out its still exist industrialization problems. For the development of new anticoagulants to find a breakthrough point.This study is divided into two parts:the first part is preparation of chitosan from silkworm materials, preparation of chitosan glycine derivatives, and characterization of molecular structure determination of molecular weight, degree of substitution, calcium chelating ability. The second part study of the anticoagulant activity of the chitosan derivatives, initially revealed the mechanism of its anticoagulant and its relationship of structure-activity.The results show that:1. Silkworm can be using up to produced deacetylation degree of chitosan to 96.38%, the reaction time has direct impact on deacetylation degree, extend the response time can increase the deacetylation degree of chitosan. Reaction time was controlled at 12,14,16 hours, can be respectively receive degree of 87.99%,92.51%,96.38%of deacetylation.2. Produce chitosan derivatives of glycine by using chemical synthesis method. Analysis of its structure by infrared spectroscopy and nuclear magnetic resonance, the resault was confirmed that etherification occurred in the C6-OH of chitosan, carboxyl group activity derivatives was introduced in the molecule, and the degree of substitution are 0.8. Chitosan derivatives have chelating properties, derivatives can be chelated 161.5-184.1 mg of calcium carbonate per gram of chitosan derivatives.3.Chitosan derivatives of silkworm have anticoagulant activity. Concentration differences has significant influence on anticoagulation (CT, APTT, PT, TT):with the increasing of the derivatives concentration its anticoagulant activity enhanced. Testing Performance that Chitosan derivatives have the bility to chelation calcium, it can reduce Ca2+levels of the blood, prolong the coagulation time. Chitosan derivatives affect many areas of blood clotting, longer the value of APTT, PT, TT.which is affect exogenous, endogenous coagulation of blood, thrombin also affects on blood coagulation enzyme or inhibit the aggregation of fibrin.4. Study by relationship of structure-activity, found that chitosan derivatives on the carboxyl group on C6 have the lone pair of electrons, which forming coordination bonds with metal ions. The amino of C2 and synergies with C6 calcium calciumions together, used to play an anti-clotting effect.