Total and Chemoenzymatic Synthesis of Seongsanamide E.

The total and chemoenzymatic synthesis of the depsipeptide natural product seongsanamide E, 3, is described. The synthetic C-terminal N-acetylcysteamine thioester of linear natural product 1 was macrolactonized by the excised recombinant purified seongsanamide thioesterase (Sgd-TE) domain, generating 3. Sgd-TE also effects the ring opening of 3. Chemical synthesis provided 3 through a macrolactamization strategy. This work confirms the biosynthesis of 3 and demonstrates the power of Sgd-TE as a biocatalyst.