Electron transfer in N-hydroxyurea complexes with iron(III)

• Published in: European journal of medicinal chemistry 2005, Vol.40 (1), p.51-55
• Main Authors: NIGOVIC, Biljana, KUJUNDZIC, Nikola, SANKOVIC, Kresimir
• Format: Article
• Language: English
• Subjects: Antineoplastic Agents - chemistry; Biological and medical sciences; Chemistry; Coordination compounds; Electrochemistry; Electron Spin Resonance Spectroscopy; Electron transfer; EPR; Exact sciences and technology; Hydroxyurea; Hydroxyurea - chemistry; Inorganic chemistry and origins of life; Iron - chemistry; Iron(III) complexes; Medical sciences; Miscellaneous; Oxidation-Reduction; Pharmacology. Drug treatments; Preparations and properties; Voltammetry
• ISSN: 0223-5234; 1768-3254
• DOI: 10.1016/j.ejmech.2004.09.012

Redox behaviour of the iron(III) complex with the antitumour drug hydroxyurea was studied by cyclic voltammetry. The complex underwent a one-electron reduction, followed by an irreversible chemical reaction (EC mechanism) in which a ligand was released. In addition, it was found that the hydroxyurea gave up an electron to iron(III) in solution. Differential-pulse voltammetry revealed an increase in the concentration of the generated iron(II) species. Electron paramagnetic resonance (EPR) spectroscopy studies of the oxidative degradation of hydroxyurea confirmed formation of the radical species H 2N–CO–NHO .. Electrochemical data for iron(III) complexes of hydroxyurea and its structural analogue 3-ethylhydroxyurea, which also exhibits antitumour activity, show the same mechanism involved in the electron transfer. The observed redox properties indicate that hydroxyurea may interfere with electron transfer processes in biological systems after binding to iron-containing ribonucleotide reductase.