Pharmaceutical industry paclitaxel

The transfer of basic research to a commercially valuable process is always a satisfying achievement for chemists in the pharmaceutical industry, and we have discussed some examples in Chaps. 4, 7 and 13. However, the project in which paclitaxel was made available to cancer patients in sufficient quantities and at an acceptable price was a truly heroic endeavour, initiated by scientists from various disciplines and finally completed by s)mthetic chemists. It would be equally satisfying if this example promotes enthusiasm among S3mthetic chemists to join collaborative, high quality science projects and, at the same time, to deliver effective pharmaceutical products to the community at large. 

Among the worldwide total of 30000 known natural products, about 80% stems from plant resources. The number of known chemical structures of plant secondary metabolites is four times the number of known microbial secondary metabolites. Plant secondary metabolites are widely used as valuable medicines (such as paclitaxel, vinblastine, camptothecin, ginsenosides, and artemisinin), food additives, flavors, spices (such as rose oil, vanillin), pigments (such as Sin red and anthocyanins), cosmetics (such as aloe polysaccharides), and bio-pesticides (such as pyrethrins). Currently, a quarter of all prescribed pharmaceuticals compounds in industrialized countries are directly or indirectly derived from plants, or via semi-synthesis. Furthermore, 11% of the 252 drugs considered as basic and essential by the WHO are exclusively derived from plants. According to their biosynthetic pathways, secondary metabolites are usually classified into three large molecule families phenolics, terpenes, and steroids. Some known plant-derived pharmaceuticals are shown in Table 6.1. 

Paclitaxel (Taxol, NSC-125973), obtained from Taxus species, is a diterpene with intense antitumoral activity because of its tmique mode of action on the microtubular cell system. It is one of the most successful anticancer drugs developed in the past 50 years. Due to several difficulties associated with obtaining Taxol and related taxoids firom plants growing in nature, plant cell cultures are considered to be the most favorable and environmentally sustainable approach for its production of at an industrial level. Some pharmaceutical companies, such as the... 

---