Aqueous two-phase system for preliminary purification of lignans from fruits of Schisandra chinensis Baill

Abstract A simple aqueous two-phase systems (ATPS) was proposed for the purification of lignans from Schisandra chinensis Baill ( S. chinensis ) extracts. Taking Schisandrol A (S), Schisantherin A (ST), Deoxyschisandrin (DS), Schisandrin B (SB) and Schisandrin C (SC) as indicative mark, the partition behaviors of lignans compounds analyzed by High performance chromatography were investigated first, ATPS composed of 21% (w/w) ammonium sulfate [(NH 4 ) 2 SO 4 ] and 22% (w/w) ethanol with a K of 50.81 was chosen. Response surface methodology (RSM) based on Box-Behnken Design was further used to study the effect of temperature, pH and concentration of lignans on purification of lignans. The optimized ATPS conditions were found at pH 2.7, temperature 32.56 °C and total concentration of five lignans 259.24 μg/mL. Under these optimal conditions, the remove ratio of polysaccharide and protein reached 95.12% and 90.43%, respectively, especially the purity of the five lignans increased 5-fold from 0.98% to 4.49% with the recovery rate of 97.07%, which was well matched with the value predicted by the model. Compared with other liquid-liquid extractions, the ethanol/salt system proposed in this study was much simpler, lower in cost because of the high recovery of phase-forming components, which will provide a potential approach for large-scale production of bioactive ingredients in plants.