Supercritical fluid extraction of paclitaxel and baccatin III from needles of Taxus cuspidata

Abstract

Paclitaxel and baccatin III are extracted from the ground needles of the yew tree Taxus cuspidata using supercritical carbon dioxide with and without the addition of several cosolvents, The pressure and temperature ranges tested were from 100 to 300 bar and from 305 to 343 K, respectively, and the cosolvents were ethylacetate, methanol, dichloromethane, and ethylether. To diminish a variety of waxy and nonpolar compounds the ground needles are treated with n-hexane before the extraction. The highest selectivity of paclitaxel and baccatin III in the extracts during the first four hours of SFE was about 0.262 and 0.644 mass %, respectively. Supercritical fluid extraction using carbon dioxide with and without cosolvents was found to be more selective than the conventional organic solvent extraction.