Search

Herein, we report the synthesis of four new hybrid molecules between ketoprofen or 2-(3-benzoylphenyl)propanoic acid and N-containing heterocyclic compounds, such as piperidine, pyrrolidine, 1,2,3,4-tetrahydroquinoline, and 1,2,3,4-tetrahydroisoquinoline. The obtained hybrid compounds were fully characterized using 1H- and 13C-NMR, UV-Vis, and HRMS spectra. Detailed HRMS analysis is provided for all novel hybrid molecules. The compounds were assessed for their in vitro anti-inflammatory and antioxidant activity. The lipophilicity of the hybrids was determined, both theoretically (cLogP) and experimentally (RM). The affinity of the compounds to the human serum albumin was assessed in silico by molecular docking study using two software, and the stability of the predicted complexes was evaluated by molecular dynamics study. All novel hybrids have shown very good HPSA activity, statistically close when compared to the reference—quercetin. The molecular docking confirmed the obtained in vitro results. Tetrahydroquinoline derivative 3c and tetrahydroisoquinoline derivative 3d have the highest affinity for albumin. They show stronger anti-inflammatory action than their predecessor, ketoprofen and the regularly used ibuprofen.

Considering the well-established antifungal activity of azole compounds, a new series of thiazolyl-methylen-1,3,4-oxadiazolines derivatives were designed and synthesized as lanosterol-demethylase inhibitors. The final compounds were screened for antifungal activity against the Candida albicans ATCC 90028 strain. Molecular docking studies were performed to investigate the interaction modes between the compounds and the active site of lanosterol 14a-demethylase, which is a target enzyme for anticandidal azoles. Theoretical ADME predictions were also calculated for the final compounds 5a-h.

In an effort to obtain new NSAIDs, that act as COX-2 selective inhibitors with simultaneous iNOS inhibition properties and direct antioxidant activity, we designed a series of 8 new compounds bearing the 5-thiazolyl-carbohydrazon-N-allyl-thiazoline scaffold. The synthesized compounds were physicochemically characterized by: 1H-NMR, MS and elemental analysis. An initial, in vitro, free radical scavenging assay (DPPH bleaching) test showed that most compounds are superior to standard antioxidants Trolox and BHT.

Thiazolidine-2,4‑dione represents a key heterocyclic core in medicinal chemistry because it has the ability to bind to a wide variety of protein targets and has been intensively studied for developing bioactive multitargeting agents. The N-alkylation of imides and O-alkylation of phenols are important reactions frequently used in the synthesis of biologically active compounds, like the thiazolidine-2,4‑dione derivatives. Based on literature data, by treating (Z)-5-(4-hydroxybenzylidene)-thiazolidine-2,4‑dione with alkyl halides in a 1:1 molar ratio, either O-alkylation or N-alkylation reactions can take place. Six (Z)-5-(4-hydroxybenzylidene)-thiazolidine-2,4‑dione derivatives were synthesized by alkylating (Z)-5-(4-hydroxybenzylidene)-thiazolidine-2,4‑dione with aliphatic halogenated derivatives in alkaline environment, using a 1:1 molar ratio and then were physically and spectrally analyzed. The spectral data and the results obtained from the theoretical evaluation of the parent compound's acidity support the formation of N-alkylated derivatives in the reaction conditions.

Oxidative stress has been incriminated in the physiopathology of many diseases, such as diabetes, cancer, atherosclerosis, and cardiovascular and neurodegenerative diseases. There is a great interest in developing new antioxidants that could be useful for preventing and treating conditions for which oxidative stress is suggested as the root cause. The thiazolidine-2,4-dione derivatives have been reported to possess various pharmacological activities and the phenol moiety is known as a pharmacophore in many naturally occurring and synthetic antioxidants. Twelve new phenolic derivatives of thiazolidine-2,4-dione were synthesized and physicochemically characterized. The antioxidant capacity of the synthesized compounds was assessed through several in vitro antiradical, electron transfer, and Fe2+ chelation assays. The top polyphenolic compounds 5f and 5l acted as potent antiradical and electron donors, with activity comparable to the reference antioxidants used. The ferrous ion chelation capacity of the newly synthesized compounds was modest. Several quantum descriptors were calculated in order to evaluate their influence on the antioxidant and antiradical properties of the compounds and the chemoselectivity of the radical generation reactions has been evaluated. The correlation with the energetic level of the frontier orbitals partially explained the antioxidant activity, whereas a better correlation was found while evaluating the O&ndash, H bond dissociation energy of the phenolic groups.

C. albicans is the most frequently occurring fungal pathogen, and is becoming an increasing public health problem, especially in the context of increased microbial resistance. This opportunistic pathogen is characterized by a versatility explained mainly by its ability to form complex biofilm structures that lead to enhanced virulence and antibiotic resistance. In this context, a review of the known C. albicans biofilm formation inhibitors were performed and a new N-(oxazolylmethyl)-thiazolidinedione scaffold was constructed. 16 new compounds were synthesized and characterized in order to confirm their proposed structures. A general antimicrobial screening against Gram-positive and Gram-negative bacteria, as well as fungi, was performed and revealed that the compounds do not have direct antimicrobial activity. The anti-biofilm activity evaluation confirmed the compounds act as selective inhibitors of C. albicans biofilm formation. In an effort to substantiate this biologic profile, we used in silico investigations which suggest that the compounds could act by binding, and thus obstructing the functions of, the C. albicans Als surface proteins, especially Als1, Als3, Als5 and Als6. Considering the well documented role of Als1 and Als3 in biofilm formation, our new class of compounds that target these proteins could represent a new approach in C. albicans infection prevention and management.

Background and aims. Synthesis of new potential antimicrobial agents and evaluation of their lipophilicity. Methods. Ten new thiazolyl-oxadiazoline derivatives were synthesized and their structures were validated by 1 H-NMR and mass spectrometry. The lipophilicity of the compounds was evaluated using the principal component analysis (PCA) method. The necessary data for applying this method were obtained by reverse-phase thin-layer chromatography (RP-TLC). The antimicrobial activities were tested in vitro against four bacterial strains and one fungal strain. Results. The lipophilicity varied with the structure but could not be correlated with the antimicrobial activity, since this was modest. Conclusions. We have synthesized ten new heterocyclic compounds. After their physical and chemical characterization, we determined their lipophilicity and screened their antimicrobial activity.

The chromatographic behavior of a series of thiazolyl-1,3,4-oxadiazoles with antifungal activity was studied by reverse-phase thin-layer chromatography (RP-TLC). The lipophilicity parameters derived from RP-TLC were correlated with the data derived from liquid-chromatography mass-spectrometry. Good linear relationships were observed between the chromatographic lipophilicity parameters and the theoretical lipophilicity descriptors (logP) generated by various computer software and internet modules. Principal component analysis, applied on the experimental chromatographic lipophilicity indices and the theoretically calculated logP, enabled us to obtain a lipophilicity chart for better vizualization of the similarities and differences of the investigated compounds, which were grouped by k-means clustering in two congeneric classes.

Non-steroidal anti-inflammatory drugs (NSAIDs) are commonly used therapeutic agents that exhibit frequent and sometimes severe adverse effects, including gastrointestinal ulcerations and cardiovascular disorders. In an effort to obtain safer NSAIDs, we assessed the direct cyclooxygenase (COX) inhibition activity and we investigated the potential COX binding mode of some previously reported 2-(trimethoxyphenyl)-thiazoles. The in vitro COX inhibition assays were performed against ovine COX-1 and human recombinant COX-2. Molecular docking studies were performed to explain the possible interactions between the inhibitors and both COX isoforms binding pockets. Four of the tested compounds proved to be good inhibitors of both COX isoforms, but only compound A3 showed a good COX-2 selectivity index, similar to meloxicam. The plausible binding mode of compound A3 revealed hydrogen bond interactions with binding site key residues including Arg120, Tyr355, Ser530, Met522 and Trp387, whereas hydrophobic contacts were detected with Leu352, Val349, Leu359, Phe518, Gly526, and Ala527. Computationally predicted pharmacokinetic profile revealed A3 as lead candidate. The present data prove that the investigated compounds inhibit COX and thus confirm the previously reported in vivo anti-inflammatory screening results suggesting that A3 is a suitable candidate for further development as a NSAID.

Nineteen bisthiazoles were tested in order to assess their anti-inflammatory and antioxidant properties. First, we evaluated the in vitro direct antioxidant capacity of the bisthiazoles using the DPPH radical scavenging method. Then, the anti-inflammatory effect was tested in acute rat experimental inflammation by measuring the acute phase bone marrow response, the phagocytic capacity and the serum nitro-oxidative stress status. Although none of the substances showed significant direct antioxidant potential in the DPPH assay, most of them improved serum oxidative status, when administered to rats with inflammation. Four of the bisthiazoles proved to have good anti-inflammatory properties, similar or superior to that of equal doses meloxicam.

&nbsp, In an effort to improve the antimicrobial activity of norfloxacin, a series of hybrid norfloxacin&ndash, thiazolidinedione molecules were synthesized and screened for their direct antimicrobial activity and their anti-biofilm properties. The new hybrids were intended to have a new binding mode to DNA gyrase, that will allow for a more potent antibacterial effect, and for activity against current quinolone-resistant bacterial strains. Moreover, the thiazolidinedione moiety aimed to include additional anti-pathogenicity by preventing biofilm formation. The resulting compounds showed promising direct activity against Gram-negative strains, and anti-biofilm activity against Gram-positive strains. Docking studies and ADMET were also used in order to explain the biological properties and revealed some potential advantages over the parent molecule norfloxacin.

Sortase A inhibition is a well establish strategy for decreasing bacterial virulence by affecting numerous key processes that control biofilm formation, host cell entry, evasion and suppression of the immune response and acquisition of essential nutrients. A meta-analysis of structures known to act as Sortase A inhibitors provided the starting point for identifying a new potential scaffold. Based on this template a series of new potential Sortase A inhibitors, that contain the 2-phenylthiazole moiety, were synthesized. The physicochemical characterisation confirmed the identity of the proposed structures. Antibacterial activity evaluation showed that the new compounds have a reduced activity against bacterial cell viability. However, the compounds prevent biofilm formation at very low concentrations, especially in the case of E. faecalis. Molecular docking studies performed estimate that this is most likely due to the inhibition of Sortase A. The new compounds could be used as add-on therapies together with known antibacterial agents in order to combat multidrug-resistance enterococcal infections.

Considering the promising antimicrobial activity of compounds bearing the thiazole or the oxadiazole rings in their structures, we set out to obtain new antimicrobial molecules bearing the 2-(thiazol-5-yl)-1,3,4-oxadiazole schaffold. The structures of the 8 new compounds obtained was confirmed by physicochemical characterization including: 1H-NMR, MS and elemental analysis. Antimicrobial activity was investigated against 5 Gram-positive bacterial strains, 2 Gram-negative bacterial strains and 2 fungal strains. The newly synthesized compounds showed modest antimicrobial activity.

The present paper presents the synthesis, physicochemical characterization, in vitro antimicrobial activity and the molecular docking study of a series of ten new thiazolidine-2,4-dione derivatives conjugated to para-aminobenzoic acid (PABA). The lipophilicity of the new molecules was evaluated in silico. Quantitative elemental C, H, N, S analysis and spectral data (mass spectrometry, infrared and nuclear magnetic resonance) were consistent with the expected data. The results of the antimicrobial activity screening revealed that some of the synthesized compounds had moderate to good activity against E. coli ATCC 25922, S. aureus, ATCC 6538P and C. albicans ATCC 10231.