Ferrocin D

Novel iron-containing peptide antibiotics, ferrocins A, B, C and D, have been isolated from the culture filtrate of Pseudomonas fluorescens YK-310. These antibiotics were purified by butanol extraction, followed by column chromatography using adsorption resin, silica gel and preparative reverse-phase HPLC. The structures of ferrocins were elucidated using spectroscopic and degradative methods. Ferrocins contain three hydroxamate moieties per ferric ion which forms an octahedral iron complex.

A Gram-negative bacterium was found to produce new iron-containing peptide antibiotics, ferrocins A, B, C and D, and the producing bacterium was characterized and identified as Pseudomonas fluorescens YK-310. These new antibiotics showed antibacterial activity against Gram-negative bacteria in vitro. Although the ferrocins showed similar antibacterial activity against both Escherichia coli and Pseudomonas aeruginosa on the standard assay media, they showed strong therapeutic effects selectively against P. aeruginosa in experimentally infected mice.