Purification of Calycosin from Astragalusme mbranceus with Macroporous Resins by Response Surface Analysis

To optimize the technical condition for purification of calycosin of Astragalus membranceus with macroporous resin, the static adsorption and desorption performance of macroporous resin of seventy types （H103, D101, AB-8, DM130, HPD-400, DM301, HPD-600） were compared for select the best type resin. The optimum process condition was obtained by single factor experiments and response surface experiment. The results showed that HPD-400 macroporous resin was the best macroporous resin for purification of calycosin of Astragalus membranceus, and the adsorption quantity of the resin was gradual decreasing with temperature increasing, and the adsorption process fitted characteristic of second-order kinetics model. The optimum process condition were as follows: The initial concentration of sample solution was 2.97 mg/mL, the volume was 60 mL with loading speed of 1.0 mL/min, the pH of sample solution was 4.9, and the volume fraction of ethanol was 79.8%, the eluent volume was 140 mL with flow rate of 1.0 mL/min. The contents of calycosin in product increased from 2.17% to 10.36%, which was about 4.8 times of that before purification. Therefore, the HPD-400 macroporous resin had good performance for separation and purification of calycosin from extracts, the purification process obtained in this study was suitable for the purification of Astragalus membranceus calycosin.