Studies On The Separation And Purification Of Flavonoids With Macroporous Adsorption Resins

Flavonoids are a class of polyphenolic compounds which are very important and widely distributed. And studies have shown that they have a wide range of pharmacological activity, such as antioxidant, anti-tumor, antivirus, and so on. The separation and purification of flavonoids with macroporous adsorption resins is a new technology which is developed in past several decades. Because of its good adsorption performance, high selectivity, low cost and easy regeneration, it has greater advantages compared to other purification methods.The separation and purification of flavonoids with macroporous resins is mostly implemented in a certain kind of natural plant, so the resulting date are only suitable for this kind of natural plant. The riddling of resins is also blind, and the accuracy and convenience for quantitative analysis of flavonoids are not enough. Therefore, for better separation and purification of natural plant flavonoids, this article made a preliminary study on the separation and purification of flavonoids with macroporous adsorption resins.Five flavone compounds (rutin, naringin, myricetrin, puerarin, neohesperidin dihydrochalcone) had been screened out as model compounds according to the difference of structure, existing state and glycosyl number, and26resins had been selected according to the different properties; adsorption kinetics and isotherms of five model compounds in26resins had been studied, which led to some results. Double-glycoside model compound had much greater adsorption capacity than single-glycoside one, while the adsorption rate was far less than single-glycoside model compound; the lower the polarity of resin, the greater surface area, and the smaller pore size, then the greater the amount of resin adsorption. In adopted three kinetic models, Pseudo second-order rate model fit best, the calculated value and experimental value of adsorption capacity were very close. The results of Langmuir and Freundlich isotherm equation for data fitting were both acceptable, and the flavonoids C-glycoside might be favor in monolayer adsorption tendency. The adsorption isotherm of five flavone compound in three resins at different temperatures were determined, and it had been found that the adsorption process was exothermic and spontaneous, the distribution of adsorption site on resins might be uneven. Macroporous resins easily absorbed flavonoids, and flavonoids were also easy to desorb from resins. The desorption rate of model compounds was mostly more than90%with70%ethanol as desorption solution.The dynamic adsorption of five model compounds in HPD300resin had been studied, and found that the larger the structure of model compounds, the more polar groups, then more difficult to penetrate. Neohesperidin dihydrochalcone and naringin were strongest adsorption components, their dynamic adsorption capacity was also largest, which were consistent with the regularities of the static adsorption.