Anticancer gold N-Heterocyclic carbene complexes: a comparative in vitro and ex vivo study

A series of organometallic AuIN-heterocyclic carbene (NHC) complexes was synthesized and characterized for anticancer activity in four human cancer cell lines. The compounds’ toxici-ty in healthy tissue was determined using precision-cut kidney slices (PCKS) as a tool to determine the potential selectivity of thegold complexes ex vivo. All evaluated compounds present-ed cytotoxic activity toward the cancer cells in the nano-or low micromolar range. The mixed AuINHC complex, (tert-buty-lethynyl)-1,3-bis-(2,6-diisopropylphenyl)imidazol-2-ylidene gold(I), bearing an alkynyl moiety as ancillary ligand, showed high cytotoxicity in cancer cells in vitro, while being barely toxic in healthy rat kidney tissues. The obtained results open new perspectives toward the design of mixed NHC–alkynyl gold complexes for cancertherapy.