Accelerated solvent extraction of paclitaxel and related compounds from the bark of Taxus cuspidata

Accelerated solvent extraction (ASE) of paclitaxel and related compounds fr om Taxus cuspidata (Japanese yew) bark has been investigated under various conditions. In ASE, pressure is applied to the sample extraction cell to ma intain the heated solvent in a liquid state during the extraction. This met hod is able to shorten the extraction time and to increase the recovery of target compounds. In this study, ASE of paclitaxel, baccatin III, and 10-de acetylbaccatin III produced amounts of these compounds that were higher tha n those from ordinary solvent extraction at room temperature. The condition s providing the highest recovery of paclitaxel were as follows: solvent, Me OH-H2O (90:10); temperature, 150 degrees C; and pressure, 10.13 MPa (0.128% w/w recovery based on oven-dried sample powder). ASE does not require chlo rinated solvents and can reduce solvent consumption because of its strong d issolving power. Moreover, with water alone, the recovery of paclitaxel and related compounds using ASE is much higher than with other extraction meth ods.