Antimicrobial Activity of Quinoline-Based Hydroxyimidazolium Hybrids.

Eight quinoline-based hydroxyimidazolium hybrids were prepared and evaluated in vitro against a panel of clinically important fungal and bacterial pathogens, including mycobacteria. Hybrid compounds showed remarkable antifungal activity against with a minimum inhibitory concentration (MIC) value of 15.6 µg/mL. Against other opportunistic fungi such as spp. and spp., these hybrids showed MIC values of 62.5 µg/mL. Regarding their antibacterial activity, all the synthetic hybrids demonstrated little inhibition of Gram-negative bacteria (MIC ≥50 µg/mL), however, hybrid displayed >50% inhibition against at 20 µg/mL and full inhibition at 50 µg/mL. Moreover, this hybrid was shown to be a potent anti-staphylococcal molecule, with a MIC value of 2 µg/mL (5 µM). In addition, hybrid also demonstrated inhibition of at 20 µg/mL (47 µM). Hybrids and were the most potent against H37Rv with MIC values of 20 and 10 µg/mL (46 and 24 µM), respectively. The hybrid demonstrated high selectivity in killing and H37Rv in comparison with mammalian cells (SI >20), and thus it can be considered a hit molecule for mechanism of action studies and the exploration of related chemical space.