aims:
The aim of this study is to find compounds with strong antibacterial activity, low cytoxicity and development value.
background:
Drug-resistant infections kill hundreds of thousands of people around the world every year, causing huge losses to the global economy. In previous work, we found that imidazoles containing tri-methoxy- and pyridine-substituted compounds showed strong antibacterial activity.
objective:
The purpose of this work was to investigate whether compounds with aromatic heterocyclic, alkoxy, and polycyclic introduced into the central imidazole ring showed better antibacterial activity.
method:
Three series of 2-cyclopropyl-5-(5-(6-methylpyridin-2-yl)-2-substituted-1H-imidazol-4-yl)-6-phenylimidazo[2,1-b][1,3,4]thiadiazoles (13a-e, 14a-d, and 15a-f) were synthesized and evaluated their antibacterial activity. The structures were confirmed by their 1H NMR, 13C NMR and HRMS spectra. All the synthesized compounds were screened against Gram-positive strains, Gram-negative strains, and multidrug-resistant strains.
result:
Of them, more than half of all compounds showed moderate or strong antibacterial activity. Among them, compound 13e (MIC = 1-4 µg/mL) showed the strongest activity against Gram-positive and drug-resistant bacteria, and showed high selectivity against Gram-negative bacteria. The compound showed no cytotoxic effect against HepG2 cells even at 100 μM concentration, and had no hemolysis at 20 μM concentration as the positive control compound gatifloxacin.
conclusion:
These results indicate that compound 13e has drug-like properties and is valuable for further study as potential antibacterial agents.
other:
No