Separation of Alkaloids from Sophora alopecuroides L. by Adsorption Using Macroporous Resins

Abstract

A macroporous adsorption resin, DF01 (cross-linked polystyrene, particle size 0.3–1.0 mm, specific area 400–420 m² g^–1), was selected from twelve kinds of resins and used to adsorb alkaloids from Sophora alopecuroides L. The adsorption capacity of DF01 on total alkaloids was as high as 17 mg cm^–3 at pH 10.0 and the NaCl concentration of 1.0 mol L^–1. Alkaloids were desorbed by ethanol/water (80:20, v/v) of pH 3.0 and 96% of the adsorbed alkaloids were eluted. The alkaloid monomers were separated by gradient elution with ethanol/water solutions of different volume ratios at reduced pressure. The major alkaloid monomers were obtained with a purity of over 90%.