Adsorption Of Three Bioactive Ingredient From Natural Plant On ZSM-5 Molecular Sieve

Natural products have been regarded as important resources for discovering new drugs due to their rich chemical structural diversity and good drug-like properties.In this paper,three important plants of natural products: Eucommia ulmoides,Toddalia asiatica and Phellodendron are taken as research materials,chlorogenic acid,chelerythrine and berberine,which are important active components,are taken as research objects,ZSM-5 molecular sieve is taken as research adsorption carrier,the separation and purification of three active components from three plant extract by ZSM-5 molecular sieve are studied respectively.And the adsorption capacity and mechanism is proved respectively,which provides theoretical basis for the application of molecular sieve in the separation and purification field of plant active components.1.In this part,chlorogenic acid,chelerythrine and berberine were used as adsorbates and ZSM-5 molecular sieve was used as adsorbent,the optimal adsorption and elution capacity were studied.Batch adsorption experiments revealed that the optimum pH value of molecular sieve for the three active components was 5,6 and 8 respectively and solidliquid ratio was 2:20(g: mL),the amount of absorbed chlorogenic acid,chelerythrine and berberine reached 2.075,1.251 and 9.896 mg/g respectively.The optimal elution conditions of chlorogenic acid are as follows: the eluent pH=6,the concertration of eluent is 40%,the volume is 40 mL,under these conditions,the elution rate was 73.80%,and the purity of chlorogenic acid increased from 14.36% to 42.60%.The optimal analytical pH for chelerythrine and berberine are 2,analytical solution volume percent are 80%,and the elution rate of chelerythrine and berberine are 99.97%,98.73% respectively.The purity of chelerythrine was increased from 5.40% to 20.60%,the berberine increased from 31.40% to 73.10%,showing a good purification results.2.The results of kinetics models showed that the adsorption of chlorogenic acid,chelerythrine and berberine by ZSM-5 molecular sieve all fitted well with the pseudo second-order dynamics model,which means that chemisorption plays a major role in the adsorption process.And there existed three regions of the diffusion of chlorogenic acid,chelerythrine and berberine into the molecular sieve depicted from the plot of intraparticle diffusion model,which meant it contained the effects of intraparticle diffusion,external diffusion and boundary diffusion.The surface diffusion stage having the highest rate in the three stages which preliminarily indicates the main role of surface diffusion.3.The parameters of isothermal adsorption model showed that the adsorption of chlorogenic acid by molecular sieve was in accordance with Freundlich model,which indicated that the adsorption process of chlorogenic acid took place on a heterogeneous surface corresponding to a multilayer adsorption mechanism.While the adsorption of chelerythrine and berberine by molecular sieve conforms to Langmuir model,indicating the formation of mono-molecular layer adsorption during adsorption process.Thermodynamic data demonstrate that the adsorption process of chlorogenic acid is an endothermic and entropy increase process in nature,and chelerythrine and berberine are exothermic and entropy reduction process in nature.After repeated recycling for 15 times,the adsorption capacity of chlorogenic acid by molecular sieve is equivalent to 90.92% of the initial adsorption amount,and the chelerythrine is equivalent to 87.76% of the initial adsorption amount,the berberine is equivalent to 91.57% of the initial adsorption amount,which indicates that the ZSM-5 molecular sieve has good reuse performance.