Taxol from Plant Cell Fermentation

FIGURE 5.3 One of the most potent chemotherapeutic agents used in cancer, Taxol is semisynthesized from 10-DAB. 10-DAB is isolated from the needles of the English yew or is produced by a plant cell fermentation process. 

Plants have also provided a key source of potential cancer treatments. A well-known example is paclitaxel (Taxol ), isolated from the bark of the Pacific yew tree, which has become a blockbuster drug and analogues have also been approved for use that demonstrate improved efficacy (Fig. 1.4) [6]. Taxol also provides an excellent example to illustrate the challenges that remain in total synthesis. Numerous examples of the total synthesis of Taxol have been reported [7-13]. However, the overall yield and the number of steps required means it is not economically viable to synthesise the quantities required for its medicinal application. It is therefore obtained industrially via a semi-synthetic route starting from 10-deacetylbaccatin HI, a biosynthetic precursor, which can be isolated, in much larger quantities than Taxol itself, from the leaves of a different species of yew tree. More recently however, a plant cell fermentation approach has been developed for the industrial production of Taxol. 

The antitumor compound taxol was initially isolated in the 1950s from the bark of the Pacific yew, but yields were low, and extraction on the scale needed would have been environmentally damaging. A semisynthetic route was devised from the needles of the European yew (which could be harvested sustainably as the trees were not killed). Almost all modern production involves plant cell fermentation technology. 

Plant cell culture might be classified as fermentation or production from a biological or vegetable source. It is used for Taxol production (see above) and, by the Japanese, to produce shikonin, a red pigment with anti-inflammatory properties. 

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