Preparative enrichment and separation of isofraxidin from Acanthopanax senticosus with HPD100C macroporous resin

Isofraxidin is known as the major pharmacological component in Acanthopanax senticosus. In the present study, in order to screen a suitable resin for the preparative separation and purification of isofraxidin, the adsorption and desorption properties of 26 widely used commercial macroporous resins were evaluated. The preliminary research results indicated that HPD100C and HPD300 have better properties. By comparing static adsorption kinetics of HPD100C and HPD300, HPD100C was selected as the most suitable resin. Langmuir and Freundlich isotherms models were used to describe the interaction between solutes and resins at 25, 30, 35°C, respectively, and the equilibrium experimental data fit better to the Langmuir isotherms. Dynamic adsorption and desorption tests have been carried out to optimize the process parameters. The optimal conditions were as follows: For adsorption, the concentration of isofraxidin in sample solution: 0.0436 mg/ml, processing volume: 24 BV, flow rate: 2 BV/h, temperature: 25°C; for desorption, ethanol–water solution: 60:40 (v/v), eluent volume: 4 BV, flow rate: 3 BV/h. Under the conditions aforementioned, the content of isofraxidin increased 23.92-fold and its recovery was 93.79 ± 0.44%. In conclusion, HPD100C demonstrated the best ability for separatingisofraxidin among the 26 tested resins.   Key words: Acanthopanax senticosus, macroporous resin, separation, isofraxidin.