Robert Holton announces total synthesis of taxol, an important cancer drug, 1994. Taxol is used to treat breast cancer, lung cancer, ovarian cancer and AIDS-related Kaposi's sarcoma.
One of the problems with using natural products as drugs is that they are often found only in small amounts. Paclitaxel, the generic name for the blockbuster anticancer drug Taxol, is no exception.
Paclitaxel was originally isolated from the bark of the rare Pacific yew tree. However, that method–in addition to destroying the tree–was unable to produce the quantities of the drug necessary to treat the hundreds of thousands of cancer patients who might benefit from it.
Enter Robert A. Holton, chemistry professor at Florida State University. Holton has spent much of the past 20 years working on developing a synthetic pathway to paclitaxel as well as producing and evaluating analogs.
The break that liberated Bristol-Myers Squibb (BMS), which holds the patent on Taxol, from the Pacific yew came in 1989 when Holton patented a semisynthetic process for the production of Taxol. Building on this, Holton patented an improved process–known as the metal alkoxide process–in 1992. In this process, the starting material, 10-deacetylbaccatin III, is found in the needles of the common English yew as well as a species of yew tree found in India, Holton says.
BMS signed a license agreement with FSU in 1990, giving the company the right to use the process. The Food & Drug Administration approved the semisynthesized drug for marketing in 1994.
Excerpted with permission, Chemical & Engineering News
Copyright © 2003 American Chemical Society