A Brief History of Taxol

One of the most significant compounds in the fight against cancer was discovered in the bark, and at low levels in the needles, of the relatively rare Pacific Yew. In the 1970s, the National Cancer Institute tested plants in a number of collections, including an extract from the Pacific Yew collected by the U.S. Department of Agriculture in 1962. They discovered paclitaxel, which -- as Taxol (tm) -- has become one of the most effective drugs against breast and ovarian cancers. Since harvesting the bark kills the tree and still doesnít provide enough Taxol for the tens of thousands of women with breast and ovarian cancer, scientists looked for simpler structures and worked to synthesize the compound.

In 1990, Robert A. Holton, professor of chemistry at Florida State University, who had worked with David G.I. Kingston at Virginia Tech, developed the chemistry to synthesize a form of Taxol (10-deacetyl baccatin III) from the needles of the English Yew. "Baccatin is 10 times easier to isolate than paclitaxel," explains Kingston, "and since it comes from the needles, it can be a renewable source." The English Yew is also common in Europe and the United States. Holtonís procedure for synthesis is now being used by Bristol-Myers Squibb to convert baccatin into Taxol.

Improved analogs of Taxol are still needed to overcome difficulties in administration of the drug and cancerís ability to mutate and resist the drug. Kingston has devoted much of his career to understanding the chemical structure of Taxol to discover what part of the compound is the enemy of cancer and how it acts on the cancer cell. Supported by the National Cancer Institute and Bristol-Myers Squibb, he has created analogs with various enhancements, such as a Taxol that is soluble in water so that it is more easily administered.