Recent developments on gold N-heterocyclic carbene complexes as antibacterial tool compounds and potential antibiotics

Gold complexes with N-heterocyclic carbene (NHC) ligands have been intensively studied as new anticancer agents, while other biomedical and therapeutic applications have been less frequently explored. In this review the antibacterial properties of gold NHC complexes are summarised. In particular monocarbene complexes of the type (NHC)Au(Ⅰ)Cl have demonstrated considerable antibacterial activity with preference for Gram-positive bacteria. The inhibition of bacterial thioredoxin reductase, biofilm eradication and membrane damage have been experimentally confirmed for several examples and unwanted toxicity against eukaryotic cells could be reduced by bioconjugation or formation of hybrid agents with antibiotics. In summary, gold NHC complexes represent a new type of antibacterial agent with promising potential for antibiotic drug development.