Extraction of lignans from the seed of Schisandra chinensis by supercritical fluid extraction and subsequent separation by supercritical fluid simulated moving bed

• Lignans in Schisandra chinensis were successfully extracted by SFE technique.
• The effects of temperature, pressure and cosolvent were thoroughly discussed.
• The extraction kinetics were obtained by fitting the results with Sovova's model.
• Simulated moving bed with SCCO2 as desorbent was further applied for purification.
• Schisandrol A/B and schisandrin A/B could be individually separated and purified.

In this study, the lignans in the seed of Schisandra chinensis were extracted by supercritical fluid extraction (SFE), and the lignans in the obtained seed oil were subsequently separated by simulated moving bed (SMB) chromatography with supercritical fluid as the desorbent (SF-SMB). Four lignans: Schisandrol A, Schisandrol B, Schisandrin A and Schisandrin B, in the seed oil are monitored to study the extraction and separation. Effects of the extraction temperature (40–60 °C), pressure (20–35 MPa) and the content of ethanol as a cosolvent (0–10.8 wt%) on the yield of seed oil were investigated. Sovova's equation was applied to fit the experimental results to investigate the extraction kinetics. A three-section SMB with six packed columns configured as 2/2/2 was employed to separate the lignans in the seed oil. Preparative silica gel was selected as the adsorbent, and 2-propanol was used as the cosolvent for supercritical carbon dioxide at 40 °C and 13.6 MPa. The separation of lignans by the SF-SMB was conducted by creating a slight concentration gradient of 2-propanol (14.8–15.5%) along the six packed columns. The experimental results showed that Schisandrol A with 42.9 wt% and Schisandrin B with 4.34 wt% can be individually separated from the seed oil, and the separation of Schisandrol A and B and Schisandrin A and B was successfully achieved. This study demonstrates that the extraction and separation of bioactive ingredients from herbs can be finished by solely using the supercritical fluid related technologies.

Figure optionsDownload as PowerPoint slide