Coordination Chemistry of Microbial Iron Transport Compounds. 24. Characterization of Coprogen and Ferricrocin, Two Ferric Hydroxamate Siderophores

Article abstract of DOI:10.1021/ja00342a027

The physical and thermodynamic properties of corpogen and ferricrocin, two hydroxamate siderophores produced by the fungus Neurospora crassa, have been examined.Formation constants determined by ethylenediaminetetraacetic acid (EDTA) competition reactions yielded the values logK^* = 4.6 and 3.3 and logβ₁₁₀ ca. 30.2 and 30.4, respectively, where K^* = (³)/(3+>) and β₁₁₀ = /(3+>3->), showing that these siderophores possess affinities for ferric ion similar to other hydroxamate ligands.Redox potentials of -447 and -412 mV vs.NHE, respectively, were found.Circular dichroism measurements have demonstrated that coprogen adopts primarily a Δ absolute configuration about the iron, whereas ferricrocin exists as the Λ isomer.