Supercritical fluids as the desorbent for simulated moving bed-Application to the concentration of triterpenoids from Taiwanofugus camphorata

This study employs the SFE (supercritical fluid extraction) to extract the triterpenoids from the fruiting bodies of Antrodia cinnamomea (Syn. Antrodia camphorata and Taiwanofugus camphorata) cultivated in Petri-dish, followed by applying SF-SMB (supercritical fluid-simulated moving bed) to remove impurities from the crude extract of SFE to enrich the triterpenoids. Ethanol is used as cosolvent for the SFE extraction and SMB separation. A three-section SMB with open-loop design is employed and silica gel and C18 adsorbent are used as adsorbent. Four SMB experiments were designed and conducted to study the feasibility in removing impurities from the crude extract. When silica gel is used, two experiments of SF-SMB were conducted. The first SF-SMB experiment is conducted at constant concentration of ethanol and called as iso-SF-SMB, and the second experiment is designed to create gradient of elution power along the columns of the SMB unit and named as grad-SF-SMB. If RP-18 is used, iso-SF-SMB and classical SMB with liquid as desorbent are testified. The results show that grad-SF-SMB with silica gel has the highest effectiveness on removing the impurities and iso-SF-SMB with silica gel can also be applied to remove the impurities. The iso-SF-SMB with RP-18 can also be used for removing impurities with little loss of the triterpenoids, but classical SMB with RP-18 is not suitable for removing impurities from the crude extract. This study demonstrates that grad-SF-SMB could be a useful technology for developing botanical drugs and provides greener alternative for industries. This study also found that the operation of iso-SF-SMB and grad-SF-SMB can only qualitatively predictable by the triangle theory, and the removing of impurities can mainly achieved by serial trials.