Biomimetic semisynthesis of arglabin from parthenolide.

The semisynthesis of arglabin, an anticancer drug in clinical application, is developed from abundant natural product parthenolide via three steps. Each step in this sequence is highly stereoselective, and the substrate-dependent stereoselectivity in the epoxidation step can be explained by computational calculations. The success of chemical semisynthesis of arglabin suggests that the biosynthesis of arglabin might proceed in a similar pathway.