Four research groups, working collaboratively, have determined the remarkable single-step mechanism by which the acyclic compound geranylgeranyl diphosphate (GGPP) is converted biosynthetically into the tricyclic core of Bristol-Myers Squibb's anticancer agent Taxol (paclitaxel). The work has implications for the development of improved processes for producing Taxol and other terpenoids biosynthesized by similar cyclization mechanisms. In the cascade reaction that leads to the tricyclic Taxol core structure, the researchers have discovered what appears to be the first intramolecular proton transfer that is not enzyme-assisted. Such proton transfers are generally believed to be assisted by enzyme active-site bases, but in Taxol biosynthesis a double bond in the substrate seems to act as a "base" by accepting the proton. The study was a collaboration by chemistry professor Heinz G. Floss of the University of Washington; chemistry professor Robert M. Coates of the University of Illinois, Urbana-Champaign; ch...