Factors affecting paclitaxel content in yew

Abstract

The anti-cancer agent paclitaxel has been the subject of intense scientific evaluation since it was first isolated from the bark of the Pacific yew [T. brevifolia] in 1971. It is currently used extensively in the treatment of ovarian, breast and non-small cell lung cancers as well as AIDS-related Kaposi's sarcoma. The success of this agent is largely due to its novel mode of action ie. promotes the polymerisation of tubulin and stabilises the resultant microtubules to disassembly. Despite continuing efforts to develop a total synthetic route or an in vitro method of production which would ultimately be more reliable, more consistent and potentially inexhaustible paclitaxel is currently produced by semi-synthesis from 10-deacetylbaccatin 111, a natural biosynthetic precursor isolated from the needles of the European yew. The problems associated with paclitaxel production include (1) the correct identification of the species in order to comply with the FDA licence and (2) the production of sufficient biomass to meet the world-wide demand for this drug.