Paclitaxel

Paclitaxel was isolated from the bark of pacific yew (Taxus brevifolia). The precursor of the drug paclitaxel can be synthesized easily from the extract of the leaves of the European yew (Taxus baccata). Most parts of the tree are toxic, except the bright red aril surrounding the seed. Paclitaxel is now used to treat a number of types of cancer. Paclitaxel's mechanism of action involves interference with the normal breakdown of microtubules during cell division.

Three panels. Centre large panel shows electron microscopy image of two cells attached to each other. Bottom left shows panel of bush branch with red small berries with black centres. Upper right panel shows chemical structure of paclitaxel.

Fig. 1. Taxus baccata tree and Paclitaxel structure