Exploring Natural Product Artifacts: The Polyketide Enterocin Warms to a Ballet of Isomers.

The polyketide enterocin is responsive to environmental stimuli, where mild heating promotes an equilibrium mixture of the isomeric acetals enterocins B and C, which subsequently undergo pseudo-chair-boat inversion to enterocin D. When exposed to aqueous base, enterocin is converted to the isomeric Michael acceptor enterocin F. These studies demonstrate that knowledge of environmental stimuli and associated artifacts is critical to understanding the chemical and ecological properties of enterocins and other classes of natural products.