Figure 48.

Mechanisms of FPP cyclization catalyzed by α-bisabolol synthase (AaBOS) and the penta-substituted mutant AaBOS-M2. These reaction sequences are compared with the reactions catalyzed by the related sesquiterpene cyclase amorphadiene synthase (AaADS). Artemisinin is a well-known antimalarial drug, and its biosynthetic pathway is highlighted in gray. Numbered products are trans-α-bisabolene (1), cis-γ-bisabolene (2), cis-α-bisabolene (3), and β-bisabolene (4). Reprinted with permission from ref (225). Copyright 2013 Biochemical Society.