Paclitaxel, also known as Taxol, was isolated from the bark of the Pacific Yew tree. It is approved in the UK for use against breast, lung and ovarian cancer and Kaposi's sarcoma.
However, Taxol can only be extracted in small quantities before harvesting the bark kills the tree. Scientists have, therefore, tried to find a synthetic route to Taxol and also to look for similarly active compounds in related species of tree.
Prunings from yews at the Botanic Garden are contributed for making these drugs and assisting the development of successful but cheaper and more readily available synthetic alternatives.
Docetaxel (Taxotere), a closely related analogue, is found in the European Yew, which is much more abundant. It can also be synthesised. It has anti-cancer properties and is used in the treatment of breast, prostate and other non-small-cell cancers.