Antibacterial and Anti-Influenza Activities of N-Heterocyclic Carbene–Gold Complexes

Background/Objectives: Infectious diseases represent a serious threat due to rising antimicrobial resistance, particularly among multidrug-resistant bacteria and influenza viruses. Metal-based complexes, such as N-heterocyclic carbene–gold (NHC–gold) complexes, show promising therapeutic potential due to their ability to inhibit various pathogens. Methods: Eight NHC–gold complexes were synthesized and tested for antibacterial activity against Escherichia coli, Enterococcus faecalis, Staphylococcus aureus, and for anti-influenza activity in lung and bronchial epithelial cells infected with influenza virus A/H1N1. Antibacterial activity was assessed through the determination of the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC), while the viral load was quantified using qRT-PCR. Results: Complexes 3, 4, and 6 showed significant antibacterial activity at concentrations of 10–20 µg/mL. Additionally, these complexes significantly reduced viral load, with complexes 3 and 4 markedly inhibiting replication. Conclusions: These findings support the potential use of NHC–gold complexes in combined antimicrobial and antiviral therapies, representing an attractive option for fighting resistant infections.