Three new coinage metal carbene complexes of silver and gold were synthesized from a thiamine inspired proligand. The compounds were characterized by HRMS, NMR spectroscopy (1H, 19F, 31P and 13C), FT-IR and elemental analysis. The coordination environment around the metal centers was correlated to the diffusion coefficients obtained from DOSY-NMR experiments and was in agreement with the nuclearity observed in the solid-state by single crystal X-ray crystallography. The silver and gold carbene compounds were subjected to MIC studies against a panel of pathogenic bacteria, including multidrug resistant strains, with the gold carbene derivative showing the most potent antimicrobial activity against Gram-positive methicillin resistant Staphylococcus aureus (MRSA).
Keywords: antibiotic resistance; antimicrobial; carbene; gold; silver; thiamine.