Design,Synthesis,Screen Of Chrysin Derivatives With Pro-and Anti-coagulant Bi-directionally Regulated Activity In Blood Plasma

Chrysin(5,7-dihydroxy flavone)is one of natural flavonoids with various important physiological function for common diseases in human.It is widely distributed in Passiflora(passionflower),medicinal herb,flowers and honey of many other plant species.It has been shown to possess several biological activities,including anticancer,antioxidant,anti-inflammatory,vasodilatory and estrogenic effects.Recently,lots of articles have been published on the pharmacological characters of chrysin and its derivative.Some chrysin derivatives with good actives have been found,which have a good clinical application foreground.However,chrysin derivative drug has not been found in the market.In this thesis chrysin and its derivatives were studied for finding chrysin derivatives with good biological activity.Firstly,taking into account of chrysin structural characteristics,it is a rigid 2-phenyl chromone with two easily oxidized phenolic hydroxyl group.So the thermostability of chrysin was studied by thermogravimetry techniques(TG).Thermal decomposing curves of chrysin in different heating speeds were obtained by TG-DTG techniques.Four thermal analysis kinetic methods(Achar,Coats-Redfern,Kissinger,and Ozawa)were used to speculate the probable mechanism of thermal decomposing reaction and the kinetic parameters.The shelflife of chrysin at room temperature(25℃)was calculated by the kinetic parameters.The result showed chrysin had excellent thermostability.It was less likely to decomposition due to chemical degradation or toxic compounds.The binding properties of chrysin with serum albumin(SA)were investigated under physiological conditions:A microcalorimetric study was carried out to monitor thermogram of the interaction between chrysin and SA.And molar reaction enthalpy,reaction order(n),the rate constant(k),the thermokinetic equation between chrysin and SA interaction were calculated based on the thermodynamic data.Circular dichroism(CD)spectroscopy was employed to explore the changes of SA secondary structure.The binding site and binding forces were explored by molecular modelling.The results of reverse screening by PharmMapper suggested that chrysin can act on approved targets which were relation with treatment disseminated intravascular coagulopathy,thromboembolism,and deep vein thrombosis.Clinical commonly used hemostatic drugs(p-aminomethyl benzoic acid(PAMBA),tranexamic acid,aminocaproic acid(EACA),Ethylenediamine Diaceturate,and adrenobazonum)have good hemostatic effect.But they should not be used in the patients who hemorrhage with disseminated intravascular coagulation,thrombophilia,and thromboembolism.So in this study,we collected the chrysin derivatives(MW<700)to build up a chrysin derivatives library for virtual screening by looking up SciFinder and Reaxys database.And then ADME-Tox and oral bioavailability of chrysin derivatives were predicted.There were 253 compounds passed drug-like soft.The 253 compounds were further screened for finding pro-and anti-coagulant bi-directionally regulated compounds by PyRx Vina.Six compounds were found by virtual screening which can act on both pro-and anti-coagulant targets.The six compounds,the derivatives of protected amino group in three hemostatic drugs PAMBA,Tranexamic acid,EACA,and anti-coagulant drug taurine were synthesized.The clotting time of plasma calcium restoration were measured by that derivatives affected.The interaction processes of many compounds with HS A were studied by isothermal titration calorimetry(ITC),CD,and molecular simulation.At last,we improved the method for measuring clotting time of plasma calcium restoration by fluorescence induction kinetics and UV kinetics methods.The improved methods were used to measure the clotting time of three hemostatic drugs PAMBA,Tranexamic acid,and EACA,which proved the improved method is of reasonable and credible.