Accelerated Solvent Extraction of Paclitaxel and Related Compounds from the Bark of Taxus cuspidata

Accelerated solvent extraction (ASE) of paclitaxel and related compounds from Taxus cuspidata (Japanese yew) bark has been investigated under various conditions. In ASE, pressure is applied to the sample extraction cell to maintain the heated solvent in a liquid state during the extraction. This method 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-deacetylbaccatin III produced amounts of these compounds that were higher than those from ordinary solvent extraction at room temperature. The conditions providing the highest recovery of paclitaxel were as follows: solvent, MeOH-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 chlorinated solvents and can reduce solvent consumption because of its strong dissolving power. Moreover, with water alone, the recovery of paclitaxel and related compounds using ASE is much higher than with other extraction methods.