Challenges in the isolation of taxanes from Taxus canadensis by fast pyrolysis

The Waterloo Fast Pyrolysis Process (WFPP) was used to determine the feasibility of extracting taxanes from needles, twigs and whole clippings of Taxus canadensis. Purification techniques developed for solvent extracts were not suitable for achieving analytic chromatographic separation of taxanes from pyrolytic lignins and other pyrolysis products as these materials are in much higher quantities in pyrolysis oil than in solvent extracts. A number of separation techniques were attempted including liquid-liquid partitioning, silica gel chromatography, adsorption and sodium phenoxide formation. Pretreatment of the feedstock by deionization was also attempted. Taxol(R) was identified in pyrolysis oils of needles and whole clippings with 20% recovery compared to solvent extraction. Other taxanes were most likely present in higher concentrations but could not be analyzed because of interference by phenolic substances. (C) 2001 Elsevier Science B.V. All rights reserved.