Vanadium(IV/V) complexes of Triapine and related thiosemicarbazones: Synthesis, solution equilibrium and bioactivity

Author(s)
Christian R. Kowol, Nora V. Nagy, Tamas Jakusch, Alexander Roller, Petra Heffeter, Bernhard K. Keppler, Eva A. Enyedy
Abstract

The stoichiometry and thermodynamic stability of vanadium(IV/V) complexes of Triapine and two related α(N)-heterocyclic thiosemicarbazones (TSCs) with potential antitumor activity have been determined by pH-potentiometry, EPR and

51V NMR spectroscopy in 30% (w/w) dimethyl sulfoxide/water solvent mixtures. In all cases, mono-ligand complexes in different protonation states were identified. Dimethylation of the terminal amino group resulted in the formation of vanadium(IV/V) complexes with considerably higher stability. Three of the most stable complexes were also synthesized in solid state and comprehensively characterized. The biological evaluation of the synthesized vanadium complexes in comparison to the metal-free ligands in different human cancer cell lines revealed only minimal influence of the metal ion. Thus, in addition the coordination ability of salicylaldehyde thiosemicarbazone (STSC) to vanadium(IV/V) ions was investigated. The exchange of the pyridine nitrogen of the α(N)-heterocyclic TSCs to a phenolate oxygen in STSC significantly increased the stability of the complexes in solution. Finally, this also resulted in increased cytotoxicity activity of a vanadium(V) complex of STSC compared to the metal-free ligand.

Organisation(s)
Department of Inorganic Chemistry, Core Facility Crystal Structure Analysis
External organisation(s)
Hungarian Academy of Sciences, University of Szeged, Medizinische Universität Wien
Journal
Journal of Inorganic Biochemistry
Volume
152
Pages
62-73
No. of pages
12
ISSN
0162-0134
DOI
https://doi.org/10.1016/j.jinorgbio.2015.08.023
Publication date
11-2015
Peer reviewed
Yes
Austrian Fields of Science 2012
104003 Inorganic chemistry, 106002 Biochemistry
Keywords
ASJC Scopus subject areas
Biochemistry, Inorganic Chemistry
Sustainable Development Goals
SDG 3 - Good Health and Well-being
Portal url
https://ucrisportal.univie.ac.at/en/publications/58483b3c-a5ab-4dd6-8596-348564a6abc5