Fine-Tuning the Activation Mode of an 1,3-Indandione-Based Ruthenium(II)-Cymene Half-Sandwich Complex by Variation of Its Leaving Group.
Fine-tuning of the properties of a recently reported 1,3-indandione-based organoruthenium complex is attempted to optimize the stability under physiological conditions. Previous work has shown its capacity of inhibiting topoisomerase IIα; however, fast aquation leads to undesired reactions and ligand cleavage in the blood stream before the tumor tissue is reached. Exchange of the chlorido ligand for six different N-donor ligands resulted in new analogs that were stable at pH 7.4 and 8.5. Only a lowered pH level, as encountered in the extracellular space of the tumor tissue, was capable of aquating the complexes. The 50% inhibitory concentration (IC50) values in three human cancer cell lines differed only slightly, and their dependence on the utilized leaving group was smaller than what would be expected from their differences in cellular accumulation, but in accordance with the very minor variation revealed in measurements of the complexes' lipophilicity.
['Mokesch|Stephan|S|', 'Schwarz|Daniela|D|', 'Hejl|Michaela|M|', 'Klose|Matthias H M|MHM|0000-0002-7601-8333', 'Roller|Alexander|A|', 'Jakupec|Michael A|MA|0000-0001-7945-1426', 'Kandioller|Wolfgang|W|0000-0002-5630-712X', 'Keppler|Bernhard K|BK|']
D045744:Cell Line, Tumor D056831:Coordination Complexes D000081007:Cymenes D004354:Drug Screening Assays, Antitumor D006801:Humans D020128:Inhibitory Concentration 50 D015394:Molecular Structure D012428:Ruthenium
half-sandwich complexes anticancer drugs leaving group variation ruthenium(II)–arene complexes