Platinum(IV) Complexes Featuring Axial Michael Acceptor Ligands - Synthesis, Characterization, and Cytotoxicity

Author(s)
Nadine S. Sommerfeld, Daniel Strohhofer, Klaudia Cseh, Sarah Theiner, Michael A. Jakupec, Gunda Koellensperger, Mathea Sophia Galanski, Bernhard K. Keppler
Abstract

A series of four new (1R,2R)-cyclohexane-1,2-diamineplatinum(IV) complexes featuring axial Michael acceptor ligands on the basis of the thiol-affine maleimide moiety is presented. The complexes vary in their equatorial ligand sphere (bearing additionally one bidentate oxalate ligand or two monodentate acetate ligands) as well as in their axial Michael acceptor unit (pyrroledione, methylenedioxopyrrolidine, methyldioxodihydropyrrole). Hydrolysis, reaction behavior towards cysteine in water and phosphate buffered saline, and towards human serum albumin was monitored using HPLC,

1H NMR spectroscopy and size exclusion chromatography coupled to ICP-MS, respectively. Reaction with cysteine at pH = 7 was instant and complete within three minutes. In contrast, derivatization of the maleimide moiety resulted in decreased binding kinetics of the complex, especially within the first hour of incubation with human serum. In stability studies using analytical HPLC and

1H NMR spectroscopic measurements, we observed a concentration-dependent stability for the maleimide-containing complex 3 and the methyl derivatized compound 4. A significant increase in hydrolysis rate (up to 100 %) was found at 0.01 mm in comparison to a solution of 1 mm. In contrast, the exocyclic derivatization (5, 6) led to an overall stability in water. The antiproliferative behavior revealed IC

50 values mainly in the low micromolar range for all complexes.

Organisation(s)
Department of Inorganic Chemistry, Department of Analytical Chemistry, Mass Spectrometry Centre, NMR Centre
Journal
European Journal of Inorganic Chemistry
Volume
2017
Pages
4049-4054
No. of pages
6
ISSN
1434-1948
DOI
https://doi.org/10.1002/ejic.201700753
Publication date
09-2017
Peer reviewed
Yes
Austrian Fields of Science 2012
104003 Inorganic chemistry
Keywords
ASJC Scopus subject areas
Inorganic Chemistry
Sustainable Development Goals
SDG 3 - Good Health and Well-being
Portal url
https://ucrisportal.univie.ac.at/en/publications/954f732d-1f61-4832-8cd4-24102b76f2b4