Adsorption And Desorption Study Of Alkaloids From Sophora Flavescens Ait. And Separation Of Oxymatrine

In this paper, the adsorption and desorption characteristic of alkaloids of Sophora flavescens Ait. on H103macroporous resin was studied, including adsorption isotherm curve,adsorption kinetics, dynamic adsorption desorption process and so on. Besides, macroporous resin column chromatography was used to separate oxymatrine from the alkaloids of Sophora flavescens Ait. that were extracted by solvent extraction. The effects of parameters on the separation process were mainly investigated.First of all, the analysis and detection methods of alkaloids were researched. Considering there were matrine and oxymatrine standard sample in our laboratory, the detection methods should comply with the principles of rapid, sensitive and accurate, At last, the program of qualitative and quantitative analysis of alkaloids was proposed by acid-base titration, TLC, HPLC and GC-MS. The content of alkaloids that were extracted by solvent extraction was analyzed by acid-base titration. In the adsorption and desorption study of alkaloids, the TLC was used to the detection of separation samples for qualitative and semi-quantitative analysis. In the separation of oxymatrine from Sophora flavescens Ait., the collected fractions were analyzed by HPLC, accurate quantification of oxymatrine was obtained by GC-MS analysis for characteristic sample.Secondly, solvent extraction was used to obtain alkaloids from Sophora flavescens Ait.. The yield of alkaloids was0.803%by acid-base titration, We found the components in alkaloids were complex and there were some impurities except alkaloids by HPLC analysis, the retention time of matrine was10.099min and the peak area percentage was5.06%, the retention time of oxymatrine was14.953min and the peak area percentage was21.08%. Besides, the material whose retention time was near12.6min and had strong adsorption peak was oxysophorcarpine by review of the literature, its peak area percentage was5.56%.Thirdly, the adsorption and desorption characteristic of alkaloids of Sophora flavescens Ait. on macroporous resin was researched. The H103macroporous resin which displayed the best adsorption capacity among nine kinds of resins was selected out; its adsorption ratio was85.86%. The adsorption isotherm curve and adsorption kinetic behaviour of alkaloids with H103macroporous resin were systematically studied, results showed that the adsorption isotherm could be described by Freundlich isotherm equation; According to dynamics adsorption curve, the balance time was100minutes, Adsorption kinetic law could be expressed by Pseudo-second-order. The dynamic adsorption and desorption capability of alkaloids on H103resin-packed column was investigated, the results showed that the optimized dynamic process was the resin column was eluted by30%C2H5OH-25%NH4OH (115:1, v/v) and80%C2H5OH, the oxymatrine was eluted firstly with recovery yield85.3%, then matrine was eluted with recovery yield90.1%, these two alkaloids could be separated effectively.Finally, oxymatrine was separated from alkaloids by means of H103macroporous resin column chromatography.30%C2H5OH-25%NH4OH (115:1, v/v) was determined as the mobile phase in the column chromatography process. The samples obtained under different conditions were analyzed by HPLC, by comparing the analysis results, the optimum chromatography conditions were concluded as follows: the H103resins were packed with ethanol, height-diameter ratio of H103resin-packed chromatogram column was33:1, the elution program was30%C2H5OH-25%NH4OH (115:1, v/v) at flow rate of2.0mL/min. In order to further determine accurate purity of oxymatrine, the sample was analyzed by GC-MS. The results demonstrated that the peak area percentage of oxymatrine was91.53%with recovery yield of78.19%.