Insights into the strong in-vitro anticancer effects for bis(triphenylphosphane)iminium compounds having perchlorate, tetrafluoridoborate and bis(chlorido)argentate anions

Three new compounds containing the bis(triphenylphosphane)iminium cation (PPN+) with ClO4−, BF4− and [AgCl2]− as counter anions have been synthesized and structurally characterized. The two derivatives with ClO4− and BF4− were found to be isostructural by single crystal X-ray diffraction. Interestingly, the three compounds show extremely potent antiproliferative effects against the human cancer cell line SKOV3. To gain insights into the possible mechanisms of biological action, several intracellular targets have been considered. Thus, DNA binding has been evaluated, as well as the effects of the compounds on the mitochondrial function. Furthermore, the compounds have been tested as possible inhibitors of the seleno-enzyme thioredoxin reductase. Salts of the bis(triphenylphosphane)iminium cation show cancer cell cytotoxicity, DNA binding, mitochondrial bioenergetic impairment and inhibition of the enzyme thioredoxin reductase. [Display omitted] •Three new compounds with the PPN cation have been prepared and structurally characterized.•The compounds show strong antiproliferative effects against the human cancer cell line SKOV3.•The DNA binding and the effects of the compounds on the mitochondrial function are studied.•The compounds were tested as possible inhibitors of thioredoxin reductase.