Abstract
The development of novel antimicrobial agents represents a timely research topic. Eighteen salicylanilide 4-(trifluoromethyl)benzoates were evaluated against Mycobacterium tuberculosis, M. avium and M. kansasii, eight bacterial strains including methicillin-resistant Staphylococcus aureus (MRSA) and for the inhibition of mycobacterial isocitrate lyase.
Some compounds were further screened against drug-resistant M. tuberculosis and for their cytotoxicity. Minimum inhibitory concentrations (MICs) for all mycobacterial strains were within 0.5-32 mu mol/L, with 4-chloro-2-[4-(trifluoromethyl)phenylcarbamoyl] phenyl 4-(trifluoromethyl) benzoate superiority.
Grampositive bacteria including MRSA were inhibited with MICs >= 0.49 mu mol/L, while Gram-negative ones were much less susceptible. Salicylanilide 4-(trifluoromethyl) benzoates showed significant antibacterial properties, for many strains being comparable to standard drugs (isoniazid, benzylpenicillin) with no cross-resistance.
All esters showed mild inhibition of mycobacterial isocitrate lyase and four compounds were comparable to 3-nitropropionic acid without a direct correlation between in vitro MICs and enzyme inhibition.