Efficient Extraction of Paclitaxel and Related Taxoids From Leaf Tissue of Taxus Using a Potable Solvent System

Leaves of Taxus x media and Taxus brevifolia were examined for their potential use as a source of paclitaxel and related taxoids. Various solvent systems were compared for their efficacy in the extraction of paclitaxel, as well as the extraction of contaminating residue. A method of extraction has been developed that enriches paclitaxel by over 500-fold using only potable solvents in combination with solid phase extraction, thus avoiding the use of chlorinated hydrocarbon solvent systems. This solvent system can be used on fresh leaf material, eliminating the need for drying material before extraction, and preventing degradation of the taxoids during the drying process. Using these methods, paclitaxel constituted 0.01 to 0.02% of the dry weight of the leaf tissue from Taxus x media, and 0.04% from dried leaves of Taxus brevifolia.