Comparative solution equilibrium study of the interactions of copper (II), iron(II) and zinc(II) with triapine (3-Aminopyridine-2-carbaldehyde thiosemicarbazone) and related ligands

Author(s)
Eva Anna Enyedy, Nóra Veronika Nagy, Eva Zsigo, Christian Kowol, Vladimir Arion, Bernhard Keppler, Tamas Kiss
Abstract

The interactions of CuII, ZnII and FeII with Triapine (3-amino-pyridine-2-carbaldehyde thiosemicarbazone), which is currently undergoing phase II clinical trials as a chemotherapeutic antitumour agent, were investigated in a water/DMSO mixture. The proton-dissociation constants of the ligands, the stability constants and the coordination modes of the metal complexes formed were determined by pH-potentiometric, UV/Vis spectrophotometric, EPR, 1H NMR spectroscopic and ESI-MS methods. Two N-terminally dimethylated derivatives of Triapine were also studied. Mono- and bis-ligand complexes in different protonation states were identified. Furthermore, the formation of the dinuclear species [Cu2L 3]+ was confirmed for all ligands by EPR spectroscopy and ESIMS measurements. The results showed that the N-terminally dimethylated ligands are much more potent chelators than Triapine for the divalent metal ions studied. All three ligands formed the least stable complexes with Zn II, whereas the FeII complexes were somewhat more stable than the corresponding CuII species.

Organisation(s)
Department of Inorganic Chemistry
External organisation(s)
University of Szeged, Hungarian Academy of Sciences
Journal
European Journal of Inorganic Chemistry
Volume
11
Pages
1717-1728
No. of pages
12
ISSN
1434-1948
DOI
https://doi.org/10.1002/ejic.200901174
Publication date
2010
Peer reviewed
Yes
Austrian Fields of Science 2012
104003 Inorganic chemistry
Portal url
https://ucrisportal.univie.ac.at/en/publications/17675326-9e3a-4e43-9055-f68b23912a56