Supercritical fluid extraction and bioassay identification of prodrug substances from natural resources

For arbitrarily chosen thirty types of natural resources which have been widely used in oriental traditional herb medicine, supercritical CO₂ extraction (SFE) and organic liquid solvent extraction (LSE) withn-hexane, chloroform and methanol were carried out to extract pharmaceutical substances. To evaluate relative advantages and shortcomings between the SFE and LSE, five types of bioactivity assays as well as gas- and thin layer-chromatographic analysis were performed for all the extracts obtained by the two extraction methods. Types of bioassays performed included cytotoxicity, bleb forming, DNA binding, oxygen free radical scavenger and Xanthine oxidase inhibitor tests. To evaluate economic viability of the SFE over the traditional LSE, extractability of prodrug substances was evaluated as the functions of extraction temperature and pressure. SFE was proven to be a feasible alternative over LSE. Also, the optimum SFE conditions which provided maximum extraction and cytotoxicity for each selected sample were presented.