Process research of macroporous resin chromotography for separation of N-(p-coumaroyl)serotonin and N-feruloylserotonin from Chinese safflower seed extracts

N-(p-Coumaroyl)serotonin (CS) and N-feruloylserotonin (FS) are two bioactive serotonin derivatives in safflower (Carthamus tinctorius L.) seeds with many biological effects. In the present study, the sorption and desorption characteristics of six widely used macroporous resins, coded D312, 860021, DM131, HZ801, AB-8 and XDA-1, respectively, is critically evaluated and compared for enrichment and preparative separation of CS and FS. Static adsorption and desorption experiments on these resins showed that XDA-1 had the best adsorption and desorption equilibrium for CS and FS, and its adsorption equilibrium fits the best to the Langmuir isotherm. Dynamic adsorption and desorption experiments on XDA-1 resin packed column were conducted to establish the optimum parameters as: CS and FS concentration in sample solution 0.346 and 0.276 mg/mL, respectively, sample size 5-bed volumes (BV), sample flow rate 2 mL/min, temperature 25 °C (for adsorption); eluent 80% ethanol, 11 BV, flow rate 1 mL/min (for desorption). After one run of adsorption and desorption, the contents of CS and FS were increased from 2.01%, 1.67% to 24.1% and 22.4%, and the recoveries were 77.2% and 68.5%, respectively. The chromatographic process optimized in the present work is a promising basis for large scale preparation of CS and FS upon further scaling up tests.