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Kratky M.,Charles University | Vinsova J.,Charles University | Stolarikova J.,Regional Institute of Public Health in Ostrava
Molecules | Year: 2012

The increasing emergence especially of drug-resistant tuberculosis has led to a strong demand for new anti-tuberculosis drugs. Eighteen salicylanilide benzoates were evaluated for their inhibition potential against Mycobacterium tuberculosis, Mycobacterium avium and two strains of Mycobacterium kansasii; minimum inhibitory concentration values ranged from 0.5 to 16 μmol/L. The most active esters underwent additional biological assays. Four benzoates inhibited effectively the growth of five multidrug-resistant strains and one extensively drug-resistant strain of M. tuberculosis at low concentrations (0.25-2 μmol/L) regardless of the resistance patterns. The highest rate of multidrug-resistant mycobacteria inhibition expressed 4-chloro-2-[4- (trifluoromethyl)-phenylcarbamoyl]phenyl benzoate (0.25-1 μmol/L). Unfortunately, the most potent esters were still considerably cytotoxic, although mostly less than their parent salicylanilides. © 2012 by the authors.

Kratky M.,Charles University | Vinsova J.,Charles University | Buchta V.,Charles University | Horvati K.,Eotvos Lorand University | And 2 more authors.
European Journal of Medicinal Chemistry | Year: 2010

Eleven halogenated (S)-2-(phenylcarbamoyl)phenyl 2-acetamido-3- phenylpropanoates (3a-3k) were designed and synthesized as potential antimicrobial agents. They were evaluated in vitro against some mycobacterial, bacterial and fungal strains. These compounds were active against drug-sensitive and atypical mycobacterial strains with general MIC values from 0.25 to 16 μmol/L. The most active compounds were (S)-4-chloro-2-(4-(trifluoromethyl) phenylcarbamoyl)phenyl 2-acetamido-3-phenylpropanoate (3i) and (S)-4-bromo-2-(4-(trifluoromethyl)phenylcarbamoyl)phenyl 2-acetamido-3- phenylpropanoate (3k) which exhibited activity against MDR and XDR-TB strains with MICs from 1 to 2 μmol/L. 3k was shown to be less cytotoxic with higher IC50. Some compounds exhibited low MICs on Gram-positive bacteria (MICs ≥ 0.98 μmol/L) and on fungi (MICs ≥ 3.9 μmol/L). © 2010 Elsevier Masson SAS. All rights reserved.

Kratky M.,Charles University | Bosze S.,Eotvos Lorand University | Baranyai Z.,Eotvos Lorand University | Szabo I.,Eotvos Lorand University | And 3 more authors.
Bioorganic and Medicinal Chemistry | Year: 2015

Based on the previously described antimicrobial activity of salicylanilide derivatives, we designed and synthesized novel 2-(phenylcarbamoyl)phenyl 4-substituted benzoates. The most active salicylanilides were selected for esterification by various 4-substituted benzoic acids. These compounds were evaluated in vitro against Mycobacterium tuberculosis, including multidrug-resistant strains, nontuberculous mycobacteria (Mycobacterium avium and Mycobacterium kansasii), and eight bacterial and fungal strains. We also investigated the cytostatic and cytotoxic actions of the esters. The minimum inhibitory concentrations (MICs) against mycobacteria ranged from 0.125 to 8 μM. Interestingly, the drug-resistant strains exhibited the highest susceptibility without any cross-resistance with established drugs. 4-Bromo-2-[4-(trifluoromethyl)phenylcarbamoyl]phenyl 4-nitrobenzoate showed the most potent inhibition with MIC values ranging from 0.25 to 2 μM. Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus, were inhibited by two derivatives with MIC values of at least 0.49 μM, whereas Gram-negative bacteria and most of the tested fungi did not display any marked susceptibility. Benzoates exhibited no cytotoxicity at concentrations up to 50 μM but most caused significant cytostasis with IC50 values lower than 10 μM. Some cytotoxicity-based selectivity indexes for drug-susceptible and drug-resistant M. tuberculosis as well as Staphylococci were higher than 100. These values indicate that some of these derivatives are promising candidates for future research. © 2014 Elsevier Ltd. All rights reserved.

Kratky M.,Charles University | Vinsova J.,Charles University | Volkova M.,Charles University | Buchta V.,Charles University | And 2 more authors.
European Journal of Medicinal Chemistry | Year: 2012

A series of novel sulfonamides containing 5-chloro-2-hydroxybenzaldehyde or 5-chloro-2-hydroxybenzoic acid scaffolds were designed, synthesized and characterized by IR, 1H NMR and 13C NMR. All ten target synthesized derivatives and starting sulfonamides were evaluated in vitro for the activity against Gram-positive and Gram-negative bacteria, fungi, Mycobacterium tuberculosis, Mycobacterium avium and Mycobacterium kansasii. The most active compound against methicillin-sensitive and methicillin-resistant Staphyloccoccus aureus was 5-chloro-N-{4-[N-(4,6-dimethylpyrimidin-2-yl) sulfamoyl]phenyl}-2-hydroxybenzamide with MIC 15.62-31.25 μmol/L. 4-Amino-N-(thiazol-2-yl)benzenesulfonamide and 4-(5-chloro-2- hydroxybenzylideneamino)-N-(thiazol-2-yl)benzenesulfonamide have shown the best activity against M. kansasii at the concentrations of 1-4 μmol/L. The efficacy against other strains was weaker and the studied derivatives exhibited almost none antifungal potency. © 2012 Elsevier Masson SAS. All rights reserved.

Kratky M.,Charles University | Vinsova J.,Charles University | Novotna E.,Charles University | Mandikova J.,Charles University | And 2 more authors.
Molecules | Year: 2013

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 μmol/L, with 4-chloro-2-[4- (trifluoromethyl)phenylcarbamoyl] phenyl 4-(trifluoromethyl)benzoate superiority. Grampositive bacteria including MRSA were inhibited with MICs ≥ 0.49 μmol/L, while Gramnegative 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. © 2013 by the authors.

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