Synthesis of the Siderophore Coelichelin and Its Utility as a Probe in the Study of Bacterial Metal Sensing and Response

A convergent total synthesis of the siderophore coelichelin is described. The synthetic route also provided access to acetyl coelichelin and other congeners of the parent siderophore. The synthetic products were evaluated for their ability to bind ferric iron and promote growth of a siderophore-deficient strain of the Gram-negative bacterium Pseudomonas aeruginosa under iron restriction conditions. The results of these studies indicate coelichelin and several derivatives serve as ferric iron delivery vehicles for P. aeruginosa.