Insights into Antimalarial Activity of N-Phenyl- Substituted Cinnamanilides

peer reviewedDue to the urgent need of innovation in the antimalarial therapeutic arsenal, a series of thirty-seven ring-substituted N-arylcinnamanilides prepared by microwave-assisted synthesis were subjected to primary screening against the chloroquine-sensitive strain of P. falciparum 3D7/MRA-102. The lipophilicity of all compounds was experimentally determined as the logarithm of the capacity factor k, and these data were subsequently used in the discussion of structure-activity relationships. Among the screened compounds, fourteen derivatives exhibited IC50 from 0.58 to 31 μM, whereas (2E)-N-(4-bromo- 2-chlorophenyl)-3-phenylprop-2-enamide (24) was the most effective agent (IC50 = 0.58 μM). In addi- tion, (2E)-N-[2,6-dibromo-4-(trifluoromethyl)- phenyl]-3-phenylprop-2-enamide (36), (2E)-N-[4-nitro-3- (trifluoromethyl)phenyl]-3-phenylprop- 2-enamide (18), (2E)-N-(2-bromo-5-fluorophenyl)-3-phenylprop- 2-enamide (23), and (2E)-3-phenyl-N-(3,4,5-trichlorophenyl)prop-2-enamide (33) demonstrated efficacy in the IC50 range from 2.0 to 4.3 μM, comparable to the clinically used standard chloroquine. The results of a cell viability screening performed using THP1-BlueTM NF-κB cells showed that none of these highly active compounds displayed any significant cytotoxic effect up to 20 μM, which makes them promising Plasmodium selective substances for further investigations

Towards Arginase Inhibition: Hybrid SAR Protocol for Property Mapping of Chlorinated N-arylcinnamamides

peer reviewedA series of seventeen 4-chlorocinnamanilides and seventeen 3,4-dichlorocinnamanilides were characterized for their antiplasmodial activity. In vitro screening on a chloroquine-sensitive strain of Plasmodium falciparum 3D7/MRA-102 highlighted that 23 compounds possessed IC50 < 30 µM. Typically, 3,4-dichlorocinnamanilides showed a broader range of activity compared to 4-chlorocinnamanilides. (2E)-N-[3,5-bis(trifluoromethyl)phenyl]-3-(3,4-dichlorophenyl)prop-2-en-amide with IC50 = 1.6 µM was the most effective agent, while the other eight most active derivatives showed IC50 in the range from 1.8 to 4.6 µM. A good correlation between the experimental logk and the estimated clogP was recorded for the whole ensemble of the lipophilicity generators. Moreover, the SAR-mediated similarity assessment of the novel (di)chlorinated N-arylcinnamamides was conducted using the collaborative (hybrid) ligand-based and structure-related protocols. In consequence, an ‘averaged’ selection-driven interaction pattern was produced based in namely ‘pseudo–consensus’ 3D pharmacophore mapping. The molecular docking approach was engaged for the most potent antiplasmodial agents in order to gain an insight into the arginase-inhibitor binding mode. The docking study revealed that (di)chlorinated aromatic (C-phenyl) rings are oriented towards the binuclear manganese cluster in the energetically favorable poses of the chloroquine and the most potent arginase inhibitors. Additionally, the water-mediated hydrogen bonds were formed via carbonyl function present in the new N-arylcinnamamides and the fluorine substituent (alone or in trifluoromethyl group) of N-phenyl ring seems to play a key role in forming the halogen bonds

Biological activities and ADMET-related properties of novel set of cinnamanilides

A series of nineteen novel ring-substituted N-arylcinnamanilides was synthesized and characterized. All investigated compounds were tested against Staphylococcus aureus as the reference strain, two clinical isolates of methicillin-resistant S. aureus (MRSA), and Mycobacterium tuberculosis. (2E)-N-[3-Fluoro-4-(trifluoromethyl)phenyl]-3-phenylprop-2-enamide showed even better activity (minimum inhibitory concentration (MIC) 25.9 and 12.9 M) againstMRSAisolates than the commonly used ampicillin (MIC 45.8 M). The screening of the cell viability was performed using THP1-Blue NF- B cells and, except for (2E)-N-(4-bromo-3-chlorophenyl)-3-phenylprop-2-enamide (IC50 6.5 M), none of the discussed compounds showed any significant cytotoxic e ect up to 20 M. Moreover, all compounds were tested for their anti-inflammatory potential; several compounds attenuated the lipopolysaccharide-induced NF- B activation and were more potent than the parental cinnamic acid. The lipophilicity values were specified experimentally as well. In addition, in silico approximation of the lipophilicity values was performed employing a set of free/commercial clogP estimators, corrected afterwards by the corresponding pKa calculated at physiological pH and subsequently cross-compared with the experimental parameters. The similarity-driven property space evaluation of structural analogs was carried out using the principal component analysis, Tanimoto metrics, and Kohonen mapping

Preparation and Photosynthesis-Inhibiting Activity of Novel Dihalogenated 3-Hydroxynaphthalene-2-carboxanilides

In this study, a series of nine 3-hydroxynaphthalene-2-carboxanilides, disubstituted on the anilide ring by fluorine, chlorine and bromine in various positions, was prepared by microwave-assisted synthesis and characterized. The compounds were tested for their activity related to the inhibition of photosynthetic electron transport (PET) in spinach (Spinacia oleracea L.) chloroplasts. The PET-inhibiting activity of the compounds was within a wide range, but rather moderate; the highest activity within the series of the compounds was observed for N-(3,5-difluorophenyl)-3-hydroxynaphthalene-2-carboxamide (IC50 = 9.8 µM). The compounds were found to inhibit PET in photosystem II

Preparation and Hydro-Lipophilic Properties of Monosubstituted <i>N</i>-Aryl-4-hydroxyquinoline-3-carboxanilides

A series of twenty-two monosubstituted N-aryl-4-hydroxyquinoline-3-carboxanilides designed as dual anti-invasive agents was prepared and characterized. Lipophilicity significantly affects biological activities of compounds and ADME properties; therefore, the lipo-hydrophilic properties of these 4-hydroxyquinoline-3-carboxanilides were investigated. All the derivatives were analyzed using reversed-phase high-performance liquid chromatography. The procedure was carried out under isocratic conditions with methanol as the organic modifier in the mobile phase using an end-capped non-polar C18 stationary reversed-phase column. In this study, correlations between the logarithm of the capacity factor k and log P/Clog P values calculated using various methods are discussed, as well as the relationships between lipophilicity and chemical structure of the studied compounds

Preparation and Hydro-Lipophilic Properties of Monosubstituted N-Aryl-4-hydroxyquinoline-3-carboxanilides

A series of twenty-two monosubstituted N-aryl-4-hydroxyquinoline-3-carboxanilides designed as dual anti-invasive agents was prepared and characterized. Lipophilicity significantly affects biological activities of compounds and ADME properties; therefore, the lipo-hydrophilic properties of these 4-hydroxyquinoline-3-carboxanilides were investigated. All the derivatives were analyzed using reversed-phase high-performance liquid chromatography. The procedure was carried out under isocratic conditions with methanol as the organic modifier in the mobile phase using an end-capped non-polar C18 stationary reversed-phase column. In this study, correlations between the logarithm of the capacity factor k and log P/Clog P values calculated using various methods are discussed, as well as the relationships between lipophilicity and chemical structure of the studied compounds

Preparation and Hydro-Lipophilic Properties of Selected Novel Chlorinated and Brominated N-Arylcinnamamides

A series of six di- and tri-halogenated N-arylcinnamanilides designed as anti-inflammatory and antimicrobial agents was prepared and characterized. Since it is known that lipophilicity significantly influences the biological activity of compounds, the hydro-lipophilic properties of these di- and tri-substituted N-arylcinnamanilides were investigated in the study. All the discussed derivatives of cinnamic acid were analyzed using the reversed-phase high performance liquid chromatography method to measure lipophilicity. The procedure was performed under isocratic conditions with methanol as an organic modifier in the mobile phase using an end-capped non-polar C18 stationary reversed-phase column. In the present study, the correlations between the logarithm of the capacity factor k and log P/Clog P values calculated in various ways as well as the relationships between the lipophilicity and the chemical structure of the studied compounds are discussed

Antistaphylococcal Activities and ADME-Related Properties of Chlorinated Arylcarbamoylnaphthalenylcarbamates

Pattern 1-hydroxy-N-(2,4,5-trichlorophenyl)-2-naphthamide and the thirteen original carbamates derived from it were prepared and characterized. All the compounds were tested against Staphylococcus aureus ATCC 29213 as a reference and quality control strain and in addition against three clinical isolates of methicillin-resistant S. aureus (MRSA). Moreover, the compounds were evaluated against Enterococcus faecalis ATCC 29212, and preliminary in vitro cytotoxicity of the compounds was assessed using the human monocytic leukemia cell line (THP-1). The lipophilicity of the prepared compounds was experimentally determined and correlated with biological activity. While pattern anilide had no antibacterial activity, the prepared carbamates demonstrated high antistaphylococcal activity comparable to the used standards (ampicillin and ciprofloxacin), which unfortunately were ineffective against E. feacalis. 2-[(2,4,5-Trichlorophenyl)carba- moyl]naphthalen-1-yl ethylcarbamate (2) and 2-[(2,4,5-trichlorophenyl)carbamoyl]naphthalen-1-yl butylcarbamate (4) expressed the nanomolar minimum inhibitory concentrations (MICs 0.018&ndash;0.064 &mu;M) against S. aureus and at least two other MRSA isolates. Microbicidal effects based on the minimum bactericidal concentrations (MBCs) against all the tested staphylococci were found for nine carbamates, while 2-[(2,4,5-trichlorophenyl)carbamoyl]naphthalen-1-yl heptylcarbamate (7) and 2-[(2,4,5-trichlorophenyl)carbamoyl]naphthalen-1-yl (4-phenylbutyl)carbamate (14) demonstrated MBCs in the range of 0.124&ndash;0.461 &mu;M. The selectivity index (SI) for most investigated carbamates was &gt;20 and for some derivatives even &gt;100. The performed tests did not show an effect on the damage to the bacterial membrane, while the compounds were able to inhibit the respiratory chain of S. aureus