Voltammetric investigation of iron(III) complexes with siderophore chrysobactin in aqueous solution

Voltammetric investigations of iron(III)-chrysobactin complexes in aqueous solution at static mercury electrode, were performed. With c(Fe) = (0.5-30) x 10(-7) mol dm(-3) and C-cb = (0.5-100) x 10(-7) mol dm(-3) in pH range 6.7-10, reduction peaks with E-p -0.64 to -0.74V ((1) under bar) and E-p -0.50 to -0.62V ((2) under bar) vs. Ag/AgCl, were registered. These reduction processes were time dependent as well as solution composition (c(Fe), c(Cb) and pH). Complexes are adsorbed at the mercury drop surface. Presumed stoichiometry of the detected complexes was (FeCb3)-Cb-III ((1) under bar) and (FeCb2)-Cb-III(OH)(x) ((2) under bar). Their formation/dissociation processes were described. These investigations are of biological importance as well, since provide an insight into possible reduction mechanism in the bacterial cells that use chrysobactin to acquire the iron. (C) 2011 Elsevier Ltd. All rights reserved.