The Influence of Amino Acid Ligands and Vitamin C on the Reduction Potential of Fe(III): Polarographie and Electron Spin Resonance Investigations

Berthold Kiefer, Helmut Sapper, Wolfgang Lohmann
1984 Zeitschrift für Naturforschung C - A Journal of Biosciences  
The pH dependence of Fe(III)-amino acid complexes has been studied polarographically and by means of ESR spectroscopy. It could be shown that, at least, two complexes exist: one with a low molecular weight, ESR detectable at acid pH. and one with a high molecular w eight at alkaline pH, ESR non detectable. The half wave potential of Fe (III) is lowered by amino acid ligands. The redox interaction of the Fe(III)-amino acid complexes with vitamin C results in a decrease of the ascorbyl radical
more » ... ascorbyl radical concentration. Ascorbic acid also forms a complex with Fe(III) as in­dicated by a polarographic half wave potential near -0.55 V vs. S.C.E. at pH 7.
doi:10.1515/znc-1984-1-217 fatcat:dt65f3ovurh47l2ujye5sqjxfm