Purification Of Heparin And Preparation Of Low Molecular Weight Heparin

This thesis is mainly discussing on the purification of heparin and preparation of low molecular weight heparin.We first studied the purification of heparin by H2O2-H2O2 double oxidation process. On one hand, to solve the difficulty of moving away of the precipitation, we used centrifugal technology under low temperature. On the other hand, there were some free proteins in crude product of the heparin sodium salt. The free proteins were difficult to move by routine way in the purification of process. To move the free proteins in crude product of the heparin sodium salt, the heparin sodium salt was degraded by trypsin. To raise the potency and recovery of the heparin sodium salt, we combined the process of degradation and oxidation. Then the process of technology were established.In the oxidation process, the advanced potency of the heparin sodium salt was difficult to obtain because the configuration of the heparin sodium salt was destroyed. In order to obtain the heparin sodium salt with advanced potency and chalkiness, the product were deoxidized by sodium borohydride, factors of which were studiedThe heparin is an acidity polysaccharide. The processes of static and dynamic adsorption for heparin were studied using strong basic anion exchange resin D208. Adsorption condition and isotherms equation were determined for resin D208 by the process of static adsorption, and kinetic of which was discussed. The equilibrium temperature equation could be described with Langmuir isotherms equation. Factors of the process of adsorption were analyzed theoretically, and the process of technology is determined. Results showed the anticoagulant potency of heparin purified was 155U/mg and the recovery of heparin reached 92.1%.A method of preparation of low molecular weight heparin from crude and pure hog mucosal heparin by depolymerization with nitrous acid was studied. In the study of optimization of the experimental conditions, factors as temperature, time, concentration of nitrous acid and pH have been investigated. The depolymerized heparin having molecular weight of 4000-7000 dalton was purified with column of Sephacryl S-200 . Average molecular weight and distribution of low molecular weight heparin were determined. The structure of the low molecular weight heparin was identified with IR, 1H-NMR and 13C-NMR spectra.Experimental results showed that method of preparation of low molecular weight heparin was satisfactory. The depolymerized product has some advantages, such as lower cost, higher yields and milder experimental conditions. In the same condition, molecular weight of the depolymerized product from crude heparin is higher, but it still meets the need of pharmacopoeia. So the technology of preparation of low molecular weight heparin from crude has broader prospect.