Supercritical fluid extraction of lignans and cinnamic acid from Schisandra chinensis

Biologically active lignans from caulomas (stems) and leaves of Schisandra chinensis were extracted with supercritical carbon dioxide at the pressures 20-27 MPa, temperatures 40, 50 and 60 degrees C, and solvent-to-feed ratio 36-43. Six major lignans were determined by means of HPLC: schizandrin, gomisin A, deoxyschizandrin, gamma-schizandrin, gomisin N and wuweizisu C. At the optimum conditions 27 MPa and 50 degrees C, the extraction yield of lignans from caulomas was 1.3% dry weight and their content in the extract was higher than 32 wt.%. At the optimum conditions for CO2 extraction from S. chinensis leaves, 27 MPa and 60 degrees C, the yield of lignans was 0.22% d.w. and the yield of (E)-cinnamic acid was 0.18% d.w. Addition of 2-4% ethanol to CO2 increased the extraction rate but not the final yield of lignans. The solubility of extracted substances in supercritical CO2 was estimated from their extraction rates. (c) 2007 Elsevier B.V. All rights reserved.