Paclitaxel plants routes in bacteria
U.S. and Singaporean researchers have engineered strains of Escherichia coli that produce two precursors of the cancer drug Taxol paclitaxel at up to 100-fold higher yields than previously attained in microorganisms.1 The results suggest that complete synthesis of paclitaxel in bacteria is feasible and provide a shortcut that could help generate new bioactive analogs derived from the precursors taxadiene and taxadien-5a-ol.
Paclitaxel was isolated from the Pacific yew tree (Taxus brevifolia) and is now produced via chemical reaction sequences consisting of 35 or more steps that result in overall paclitaxel yields of less than 1%. There is a shorter reaction sequence that starts with 10-deacetylbaccatin III, a paclitaxel precursor isolated from the European yew tree (T. baccata), but that reaction depends on a plant source for starting material.
The inefficiency of both approaches has driven a continuing search