A series of nine 2,3-disubstituted-quinazolin-4(3H)-one derived Schiff bases and their three Cu(II) complexes was prepared and tested for their antimicrobial activities against reference strains Staphylococcus aureus ATCC 29213 and Enterococcus faecalis ATCC 29212 and resistant clinical isolates of methicillin-resistant S. aureus (MRSA) and vancomycin-resistant E. faecalis (VRE). All the substances were tested in vitro against Mycobacterium tuberculosis H37Ra ATCC 25177, M. kansasii DSM 44162 and M. smegmatis ATCC 700084. While anti-enterococcal and antimycobacterial activities were insignificant, 3-[(E)-(2-hydroxy-5-nitrobenzylidene)amino]-2-(2-hydroxy-5-nitrophenyl)-2,3-dihydroquinazolin-4(1H)-one (SB3) and its Cu(II) complex (SB3-Cu) demonstrated bacteriostatic antistaphylococcal activity. In addition, both compounds, as well as the other two prepared complexes, showed antibiofilm activity, which resulted in a reduction of biofilm formation and eradication of mature S. aureus biofilm by 80% even at concentrations lower than the values of their minimum inhibitory concentrations. In addition, the compounds were tested for their cytotoxic effect on the human monocytic leukemia cell line THP-1. The antileukemic efficiency was improved by the preparation of Cu(II) complexes from the corresponding non-chelated Schiff base ligands.

• Keywords
• Antibacterial activity, Antibiofilm effect, Cu(II) complexes, Cytotoxicity, Quinazolinones, Schiff bases,
• Publication type
• Journal Article MeSH

Due 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 addition, (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-Blue™ 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.

• Keywords
• Plasmodium, antiplasmodial activity, cinnamanilides, structure-activity relationships,
• MeSH
• Folic Acid Antagonists * MeSH
• Antimalarials * pharmacology   MeSH
• Chloroquine pharmacology   MeSH
• Humans MeSH
• Malaria, Falciparum * MeSH
• Structure-Activity Relationship MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Folic Acid Antagonists * MeSH
• Antimalarials * MeSH
• Chloroquine MeSH

A set of twenty-four 3-hydroxynaphthalene-2-carboxanilides, disubstituted on the anilide ring by combinations of methoxy/methyl/fluoro/chloro/bromo and ditrifluoromethyl groups at different positions, was prepared. The compounds were tested for their ability to inhibit photosynthetic electron transport (PET) in spinach (Spinacia oleracea L.) chloroplasts. N-(3,5-Difluorophenyl)-, N-(3,5-dimethylphenyl)-, N-(2,5-difluorophenyl)- and N-(2,5-dimethylphenyl)-3-hydroxynaphthalene-2-carboxamides showed the highest PET-inhibiting activity (IC50 ~ 10 µM) within the series. These compounds were able to inhibit PET in photosystem II. It has been found that PET-inhibiting activity strongly depends on the position of the individual substituents on the anilide ring and on the lipophilicity of the compounds. The electron-withdrawing properties of the substituents contribute towards the PET activity of these compounds.

• Keywords
• PET inhibition, hydroxynaphthalene-carboxamides, spinach chloroplasts, structure-activity relationships,
• MeSH
• Chloroplasts drug effects   metabolism   MeSH
• Photosynthesis drug effects   MeSH
• Photosystem II Protein Complex antagonists & inhibitors   metabolism   MeSH
• Herbicides chemistry   metabolism   MeSH
• Naphthalenes chemistry   metabolism   MeSH
• Spinacia oleracea drug effects   metabolism   MeSH
• Electron Transport drug effects   MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Photosystem II Protein Complex MeSH
• Herbicides MeSH
• Naphthalenes MeSH

A series of twenty-two novel N-(disubstituted-phenyl)-3-hydroxynaphthalene- 2-carboxamide derivatives was synthesized and characterized as potential antimicrobial agents. N-[3,5-bis(trifluoromethyl)phenyl]- and N-[2-chloro-5-(trifluoromethyl)phenyl]-3-hydroxy- naphthalene-2-carboxamide showed submicromolar (MICs 0.16-0.68 µM) activity against methicillin-resistant Staphylococcus aureus isolates. N-[3,5-bis(trifluoromethyl)phenyl]- and N-[4-bromo-3-(trifluoromethyl)phenyl]-3-hydroxynaphthalene-2-carboxamide revealed activity against M. tuberculosis (both MICs 10 µM) comparable with that of rifampicin. Synergistic activity was observed for the combinations of ciprofloxacin with N-[4-bromo-3-(trifluoromethyl)phenyl]- and N-(4-bromo-3-fluorophenyl)-3-hydroxynaphthalene-2-carboxamides against MRSA SA 630 isolate. The similarity-related property space assessment for the congeneric series of structurally related carboxamide derivatives was performed using the principal component analysis. Interestingly, different distribution of mono-halogenated carboxamide derivatives with the -CF3 substituent is accompanied by the increased activity profile. A symmetric matrix of Tanimoto coefficients indicated the structural dissimilarities of dichloro- and dimetoxy-substituted isomers from the remaining ones. Moreover, the quantitative sampling of similarity-related activity landscape provided a subtle picture of favorable and disallowed structural modifications that are valid for determining activity cliffs. Finally, the advanced method of neural network quantitative SAR was engaged to illustrate the key 3D steric/electronic/lipophilic features of the ligand-site composition by the systematic probing of the functional group.

• Keywords
• CoMSA, IVE-PLS, MIC, MTT assay, antistaphylococcal activity, antitubercular activity, hydroxynaphthalenecarboxamides, lipophilicity, similarity-activity landscape index,
• MeSH
• Anti-Infective Agents chemical synthesis   MeSH
• Methicillin-Resistant Staphylococcus aureus * MeSH
• Microbial Sensitivity Tests MeSH
• Mycobacterium tuberculosis * MeSH
• Naphthalenes chemistry   MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Anti-Infective Agents MeSH
• Naphthalenes MeSH
• naphthalene-2-carboxamide MeSH Browser

A series of twenty-six methoxylated and methylated N-aryl-1-hydroxynaphthalene- 2-carboxanilides was prepared and characterized as potential anti-invasive agents. The molecular structure of N-(2,5-dimethylphenyl)-1-hydroxynaphthalene-2-carboxamide as a model compound was determined by single-crystal X-ray diffraction. All the analysed compounds were tested against the reference strain Staphylococcus aureus and three clinical isolates of methicillin-resistant S. aureus as well as against Mycobacterium tuberculosis and M. kansasii. In addition, the inhibitory profile of photosynthetic electron transport in spinach (Spinacia oleracea L.) chloroplasts was specified. In vitro cytotoxicity of the most effective compounds was tested on the human monocytic leukaemia THP-1 cell line. The activities of N-(3,5-dimethylphenyl)-, N-(3-fluoro-5-methoxy-phenyl)- and N-(3,5-dimethoxyphenyl)-1-hydroxynaphthalene-2-carbox- amide were comparable with or even better than the commonly used standards ampicillin and isoniazid. All promising compounds did not show any cytotoxic effect at the concentration >30 µM. Moreover, an in silico evaluation of clogP features was performed for the entire set of the carboxamides using a range of software lipophilicity predictors, and cross-comparison with the experimentally determined lipophilicity (log k), in consensus lipophilicity estimation, was conducted as well. Principal component analysis was employed to illustrate noticeable variations with respect to the molecular lipophilicity (theoretical/experimental) and rule-of-five violations. Additionally, ligand-oriented studies for the assessment of the three-dimensional quantitative structure-activity relationship profile were carried out with the comparative molecular surface analysis to determine electron and/or steric factors that potentially contribute to the biological activities of the investigated compounds.

• Keywords
• 3D-QSAR, CoMSA, MTT assay, PET inhibition, X-Ray structure, antimycobacterial activity, antistaphylococcal activity, cytotoxicity, hydroxynaphthalenecarboxamides, lipophilicity,
• MeSH
• Ampicillin pharmacology   MeSH
• Principal Component Analysis MeSH
• Anilides chemical synthesis   chemistry   pharmacology   MeSH
• Anti-Bacterial Agents chemical synthesis   chemistry   pharmacology   MeSH
• Chloroplasts drug effects   physiology   MeSH
• Photosynthesis drug effects   MeSH
• Isoniazid pharmacology   MeSH
• Humans MeSH
• Methicillin-Resistant Staphylococcus aureus drug effects   growth & development   MeSH
• Methylation MeSH
• Microbial Sensitivity Tests MeSH
• Mycobacterium kansasii drug effects   growth & development   MeSH
• Mycobacterium tuberculosis drug effects   growth & development   MeSH
• Naphthols chemical synthesis   chemistry   pharmacology   MeSH
• Spinacia oleracea chemistry   drug effects   metabolism   MeSH
• THP-1 Cells MeSH
• Electron Transport drug effects   MeSH
• Structure-Activity Relationship MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Comparative Study MeSH
• Names of Substances
• Ampicillin MeSH
• Anilides MeSH
• Anti-Bacterial Agents MeSH
• Isoniazid MeSH
• Naphthols MeSH

A series of 116 small-molecule 1-hydroxynaphthalene-2-carboxanilides was designed based on the fragment-based approach and was synthesized according to the microwave-assisted protocol. The biological activity of all of the compounds was tested on human colon carcinoma cell lines including a deleted TP53 tumor suppressor gene. The mechanism of activity was studied according to the p53 status in the cell. Several compounds revealed a good to excellent activity that was similar to or better than the standard anticancer drugs. Some of these appeared to be more active against the p53 null cells than their wild-type counterparts. Intercalating the properties of these compounds could be responsible for their mechanism of action.

• MeSH
• Apoptosis drug effects   MeSH
• DNA metabolism   MeSH
• Doxorubicin pharmacology   MeSH
• HCT116 Cells MeSH
• Intercalating Agents pharmacology   MeSH
• Small Molecule Libraries chemistry   pharmacology   MeSH
• Humans MeSH
• Models, Molecular MeSH
• Tumor Suppressor Protein p53 metabolism   MeSH
• Naphthols chemical synthesis   chemistry   pharmacology   MeSH
• Cell Proliferation drug effects   MeSH
• Antineoplastic Agents chemical synthesis   chemistry   pharmacology   MeSH
• Drug Design * MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• 1-naphthol MeSH Browser
• calf thymus DNA MeSH Browser
• DNA MeSH
• Doxorubicin MeSH
• Intercalating Agents MeSH
• Small Molecule Libraries MeSH
• Tumor Suppressor Protein p53 MeSH
• Naphthols MeSH
• Antineoplastic Agents MeSH

: A series of sixteen ring-substituted N-arylcinnamamides was prepared and characterized. Primary in vitro screening of all the synthesized compounds was performed against Staphylococcus aureus, three methicillin-resistant S. aureus strains, Mycobacterium tuberculosis H37Ra, Fusarium avenaceum, and Bipolaris sorokiniana. Several of the tested compounds showed antistaphylococcal, antitubercular, and antifungal activities comparable with or higher than those of ampicillin, isoniazid, and benomyl. (2E)-N-[3,5-bis(trifluoromethyl)phenyl]-3-phenylprop-2-enamide and (2E)-3-phenyl-N-[3-(trifluoromethyl)phenyl]prop-2-enamide showed the highest activities (MICs = 22.27 and 27.47 µM, respectively) against all four staphylococcal strains and against M.tuberculosis. These compounds showed an activity against biofilm formation of S.aureus ATCC 29213 in concentrations close to MICs and an ability to increase the activity of clinically used antibiotics with different mechanisms of action (vancomycin, ciprofloxacin, and tetracycline). In time-kill studies, a decrease of CFU/mL of >99% after 8 h from the beginning of incubation was observed. (2E)-N-(3,5-Dichlorophenyl)- and (2E)-N-(3,4-dichlorophenyl)-3-phenylprop-2-enamide had a MIC = 27.38 µM against M. tuberculosis, while a significant decrease (22.65%) of mycobacterial cell metabolism determined by the MTT assay was observed for the 3,5-dichlorophenyl derivative. (2E)-N-(3-Fluorophenyl)- and (2E)-N-(3-methylphenyl)-3-phenylprop-2-enamide exhibited MICs = 16.58 and 33.71 µM, respectively, against B. sorokiniana. The screening of the cytotoxicity of the most effective antimicrobial compounds was performed using THP-1 cells, and these chosen compounds did not shown any significant lethal effect. The compounds were also evaluated for their activity related to the inhibition of photosynthetic electron transport (PET) in spinach (Spinacia oleracea L.) chloroplasts. (2E)-N-(3,5-dichlorophenyl)-3-phenylprop-2-enamide (IC50 = 5.1 µM) was the most active PET inhibitor. Compounds with fungicide potency did not show any in vivo toxicity against Nicotiana tabacum var. Samsun. The structure⁻activity relationships are discussed.

• Keywords
• MTT assay, PET inhibition, antifungal activity, antistaphylococcal activity, antitubercular activity, biofilm, cinnamamides, structure–activity relationship, time-kill assay, toxicity,
• MeSH
• Anti-Bacterial Agents chemical synthesis   chemistry   pharmacology   MeSH
• Antifungal Agents chemical synthesis   chemistry   pharmacology   MeSH
• Antitubercular Agents chemical synthesis   chemistry   pharmacology   MeSH
• Biofilms drug effects   MeSH
• Cinnamates chemical synthesis   chemistry   pharmacology   MeSH
• Fusarium drug effects   MeSH
• Humans MeSH
• Methicillin-Resistant Staphylococcus aureus drug effects   physiology   MeSH
• Microbial Sensitivity Tests MeSH
• Mycobacterium tuberculosis drug effects   physiology   MeSH
• Plant Diseases microbiology   MeSH
• Plants microbiology   MeSH
• Staphylococcal Infections drug therapy   MeSH
• Staphylococcus aureus drug effects   physiology   MeSH
• Chemistry Techniques, Synthetic MeSH
• Tuberculosis drug therapy   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Anti-Bacterial Agents MeSH
• Antifungal Agents MeSH
• Antitubercular Agents MeSH
• cinnamamide MeSH Browser
• Cinnamates MeSH

The evaluation of the lipophilic characteristics of biologically active agents is indispensable for the rational design of ADMET-tailored structure⁻activity models. N-Alkoxy-3-hydroxynaphthalene-2-carboxanilides, N-alkoxy-1-hydroxynaphthalene-2-carboxanilides, and N-alkoxy-2-hydroxynaphthalene-1-carboxanilides were recently reported as a series of compounds with antimycobacterial, antibacterial, and herbicidal activity. As it was found that the lipophilicity of these biologically active agents determines their activity, the hydro-lipophilic properties of all three series were investigated in this study. All 57 anilides were analyzed using the reversed-phase high-performance liquid chromatography method for the measurement of 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, a range of software lipophilicity predictors for the estimation of clogP values of a set of N-alkoxyphenylhydroxynaphthalenecarboxamides was employed and subsequently cross-compared with experimental parameters. Thus, the empirical values of lipophilicity (logk) and the distributive parameters (π) were compared with the corresponding in silico characteristics that were calculated using alternative methods for deducing the lipophilic features. To scrutinize (dis)similarities between the derivatives, a PCA procedure was applied to visualize the major differences in the performance of molecules with respect to their lipophilic profile, molecular weight, and violations of Lipinski’s Rule of Five.

• Keywords
• hydroxynaphthalenecarboxamides, lipophilicity determinations, structure-lipophilicity relationships,
• MeSH
• Anilides chemistry   MeSH
• Chromatography, Reverse-Phase MeSH
• Hydrophobic and Hydrophilic Interactions MeSH
• Molecular Structure MeSH
• Naphthalenes chemistry   MeSH
• Structure-Activity Relationship MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Anilides MeSH
• Naphthalenes MeSH

Series of seventeen new multihalogenated 1-hydroxynaphthalene-2-carboxanilides was prepared and characterized. All the compounds were tested for their activity related to the inhibition of photosynthetic electron transport (PET) in spinach (Spinacia oleracea L.) chloroplasts. 1-Hydroxy-N-phenylnaphthalene-2-carboxamides substituted in the anilide part by 3,5-dichloro-, 4-bromo-3-chloro-, 2,5-dibromo- and 3,4,5-trichloro atoms were the most potent PET inhibitors (IC50 = 5.2, 6.7, 7.6 and 8.0 µM, respectively). The inhibitory activity of these compounds depends on the position and the type of halogen substituents, i.e., on lipophilicity and electronic properties of individual substituents of the anilide part of the molecule. Interactions of the studied compounds with chlorophyll a and aromatic amino acids present in pigment-protein complexes mainly in PS II were documented by fluorescence spectroscopy. The section between P680 and plastoquinone QB in the PET chain occurring on the acceptor side of PS II can be suggested as the site of action of the compounds. The structure-activity relationships are discussed.

• Keywords
• hydroxynaphthalene-carboxamides, photosynthetic electron transport (PET) inhibition, spinach chloroplasts, structure-activity relationships,
• MeSH
• Chloroplasts drug effects   metabolism   MeSH
• Photosynthesis drug effects   MeSH
• Photosystem II Protein Complex metabolism   MeSH
• Inhibitory Concentration 50 MeSH
• Naphthols * chemical synthesis   chemistry   pharmacology   MeSH
• Spinacia oleracea drug effects   metabolism   MeSH
• Electron Transport drug effects   MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Photosystem II Protein Complex MeSH
• Naphthols * MeSH