TOUR DE PACLITAXEL: Biocatalysis for Semisynthesis

Abstract

In collaboration with the National Cancer Institute, Bristol-Myers Squibb has developed paclitaxel for treatment of various cancers; it has been approved by the Food and Drug Administration for the treatment of ovarian and metastatic breast cancer. Originally paclitaxel was isolated and purified from the bark of Pacific yew trees. This source of paclitaxel was considered to be economically and ecologically unsuitable as it required the destruction of the yew trees. This review article describes alternate methods for the production of paclitaxel, specifically, a semisynthetic approach and the application of biocatalysis in enabling the semisynthesis of paclitaxel. Three novel enzymes were discovered in our laboratory that converted the variety of taxanes to a single molecule, namely 10-deacetylbaccatin III (paclitaxel without C-13 side chain and C-10 acetate), a precursor for paclitaxel semisynthesis. These enzymes are C-13 taxolase (catalyzes the cleavage of C-13 side chain of various taxanes), C-10 deacetylase (catalyzes the cleavage of C-10 acetate of various taxanes), and C-7 xylosidase (catalyzes the cleavage of C-7 xylose from various xylosyltaxanes). Using a biocatalytic approach, paclitaxel and a variety of taxane in extracts of a variety of Taxus cultivars were converted to a 10-deacetylbaccatin III. The concentration of 10-deacetylbaccatin III was increased by 5.5- to 24-fold in the extracts treated with the enzymes, depending upon the type of Taxus cultivars used. Biocatalytic processes have also been described for the preparation of C-13 paclitaxel side chain synthons. The chemical coupling of 10-deacetylbaccatin III or baccatin III to C-13 paclitaxel side chain has been summarized to prepare paclitaxel by semisynthesis.

Microbial paclitaxel: advances and perspectives

“…3,4 An important development was the semisynthesis from natural precursors extracted from needles of yew trees (including baccatin III and 10-deacetylbaccatin III). The technique has been used since the 1990s as a renewable source of commercial paclitaxel, [5][6][7] but the process still relies on plant precursor compounds that are difficult to purify. Cell culture systems were successfully developed for large-scale paclitaxel production even though complex and specialized techniques, with long incubation times, are required.…”

Studies on trigonelline from Moringa oleifera and its in vitro regulation by feeding precursor in cell cultures

“…Biosynthetic pathway of any bioactives is regarded as the key point for industrial production of any pharmaceutical, which may lead to a drastic effect at a commercial level by use of precursor (Patel, 1998). Exogenous supply of a precursor to culture medium has been advocated to increase the yield of the desired product in cell cultures (Staba, 1985).…”

Biocatalytic Synthesis of Chiral Pharmaceutical Intermediates

“…the formation of the spindle during cell division (35)(36)(37)(38)(39). Paclitaxel inhibits the depolymerization process of microtubulin (39,40). Various types of cancers have been treated with paclitaxel and the results in treatment of ovarian cancer and metastatic breast cancer are very promising.…”