Characterization of Mn(II) and Mn(III) binding capability of natural siderophores desferrioxamine B and desferricoprogen as well as model hydroxamic acids

► Hydroxamates show well defined Mn(II) binding ability. ► Relaxivity values of the Mn(II)-siderophore complexes are interesting. ► In hydroxamate complexes the air oxidation of Mn(II) to Mn(III) starts pH >7.5. ► Decomposition of Mn(III)-siderophore complexes does not occur in the pH-range 7.5-10. ► Redox and thermodynamic stability of Mn(III) complexes of DFB and DFC are different.