Anticancer Gold N‐Heterocyclic Carbene Complexes: A Comparative in vitro and ex vivo Study

A series of organometallic Au(I) N-heterocyclic carbene (NHC) complexes was synthesized and characterized on anticancer activity in four human cancer cell lines. The compounds' toxicity in healthy tissue was determined using precision cut kidney slices (PCKS) as a tool to determine the potential selectivity of the Au complexes ex vivo. All evaluated compounds presented cytotoxic activity towards the cancer cells in the nano- or low micromolar range. The mixed Au(I) NHC complex - (ter-butylethynyl)-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 towards the design of mixed NHC-alkynyl gold complexes for cancer therapy.