Application of central composite designs in the supercritical fluid extraction of tropane alkaloids in plant extracts

Central composite designs were used in the study of supercritical fluid ext raction (SFE) of three tropane alkaloids : hyoscyamine and scopolamine from Datura candida x D. aurea hairy roots and cocaine from coca leaves (Erythr oxylum coca). Several SFE parameters, such as pressure, temperature, the na ture and percentage of the polar modifier were examined. The tropane alkalo id extraction yield was established as response. A comparison between the p redicted and the experimental extraction yields was established in order to assess the prediction quality of the model. Response surfaces were drawn f rom the mathematical models and enabled to determine the optimal conditions and to visualise the method robustness. The behaviour of the compounds inv estigated was discussed in relation with the selected SFE parameters.