Efficient extraction of paclitaxel and related taxoids from leaf tissue ofTaxus using a potable solvent system

Leaves of Taxus x media and Taxus brevifolia were examined for their potent ial use as a source of paclitaxel and related taxoids. Various solvent syst ems were compared for their efficacy in the extraction of paclitaxel, as we ll as the extraction of contaminating residue. A method of extraction has b een 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 ex traction, and preventing degradation of the taxoids during the drying proce ss. Using these methods, paclitaxel constituted 0.01 to 0.02% of the dry we ight of the leaf tissue from Taxus x media, and 0.04% from dried leaves of Taxus brevifolia.