Synthesis and Biological Evaluation of New 1,2,3‐Triazolyl‐Pyrazolyl‐Quinoline Derivatives as Potential Antimicrobial Agents

Design, synthesis, and anti-mycobacterial evaluation of 1,8-naphthyridine-3-carbonitrile analogues

Twenty-eight compounds, viz., 1,8-naphthyridine-3-carbonitrile (ANC and ANA) derivatives, were designed and synthesized through a molecular hybridization approach. The structures of these compounds were analyzed and confirmed using 1H NMR, 13C NMR, LCMS, and elemental analyses. The synthesized compounds were evaluated by in vitro testing for their effectiveness against tuberculosis using the MABA assay, targeting the Mycobacterium tuberculosis H37Rv strain. Their minimum inhibitory concentration (MIC) was determined, showing that the tested compounds' MIC values ranged from 6.25 to ≤50 μg mL-1. Among the derivatives studied, ANA-12 demonstrated prominent anti-tuberculosis activity with a MIC of 6.25 μg mL-1. Compounds ANC-2, ANA-1, ANA 6-8, and ANA-10 displayed moderate to good anti-tuberculosis activity with MIC values of 12.5 μg mL-1. Compounds with MIC ≤ 12.5 μg mL-1 were screened against human embryonic kidney cells to assess their potential cytotoxicity. Interestingly, these compounds showed less toxicity towards normal cells, with a selectivity index value ≥ 11. To further evaluate the binding pattern in the active site of enoyl-ACP reductase (InhA) from Mtb (PDB-4TZK), a molecular docking analysis of compound ANA-12 was performed using the glide module of Schrodinger software. The stability, confirmation, and intermolecular interactions of the cocrystal ligand and the highly active compound ANA-12 on the chosen target protein were investigated through molecular dynamics simulations lasting 100 ns. In silico predictions were utilized to assess the ADMET properties of the final compounds. A suitable single crystal was developed and analyzed for compound ANA-5 to gain a deeper understanding of the compounds' structures.

A Structure-Based Design Strategy with Pyrazole-Pyridine Derivatives Targeting TNFα as Anti-Inflammatory Agents: E-Pharmacophore, Dynamic Simulation, Synthesis and In Vitro Evaluation

Any pathogenic attack, infection, or disease can initiate inflammation. It results in significant adverse consequences like inflammatory bowel disease, rheumatoid arthritis, etc. TNFα is one of the major pro-inflammatory cytokines for the progression of inflammation-the present study designed a series of hybrid compounds consisting of the pyrazole-pyridine moiety. Virtual screening was performed utilizing the e-pharmacophore hypothesis with the co-ligand of TNFα, screening, docking, and ADMET study. Induced fit docking, DFT analysis, and molecular dynamic simulation showed that the four best molecules - Dh1- Dh4-showed crucial interaction with Tyrosine, higher dock scores, and better stability than Diclofenac. Following the synthesis of hit molecules, an in vitro albumin denaturation IC50 of Dh1 was found to be 118.01 μM. Further in-depth in vitro and in vivo analyses of these pyrazole-pyridine small compounds may serve as potential space for creating new anti-inflammatory leads.

Click chemistry beyond metal-catalyzed cycloaddition as a remarkable tool for green chemical synthesis of antifungal medications

Click chemistry is widely used for the efficient synthesis of 1,4-disubstituted-1,2,3-triazole, a well-known scaffold with widespread biological activity in the pharmaceutical sciences. In recent years, this magic ring has attracted the attention of scientists for its potential in designing and synthesizing new antifungal agents. Despite scientific and medical advances, fungal infections still account for more than 1.5 million deaths globally per year, especially in people with compromised immune function. This increasing trend is definitely related to a raise in the incidence of fungal infections and prevalence of antifungal drug resistance. In this condition, an urgent need for new alternative antifungals is undeniable. By focusing on the main aspects of reaction conditions in click chemistry, this review was conducted to classify antifungal 1,4-disubstituted-1,2,3-triazole hybrids based on their chemical structures and introduce the most effective triazole antifungal derivatives. It was notable that in all reactions studied, Cu(I) catalysts generated in situ by the reduction in Cu(II) salts or used copper(I) salts directly, as well as mixed solvents of t-BuOH/H2O and DMF/H2O had most application in the synthesis of triazole ring. The most effective antifungal activity was also observed in fluconazole analogs containing 1,2,3-triazole moiety and benzo-fused five/six-membered heterocyclic conjugates with a 1,2,3-triazole ring, even with better activity than fluconazole. The findings of structure-activity relationship and molecular docking of antifungal derivatives synthesized with copper-catalyzed azide-alkyne cycloaddition (CuAAC) could offer medicinal chemistry scientists valuable data on designing and synthesizing novel triazole antifungals with more potent biological activities in their future research.

Quinoline Hydrazide/Hydrazone Derivatives: Recent Insights on Antibacterial Activity and Mechanism of Action

Antibiotics are becoming gradually ineffective due to drug resistance, leading to greater difficulty in the treatment of infectious diseases. Therefore, the development of new chemical entities with different mechanisms of action is essential in the fight against resistant microorganisms. Various studies have shown that quinoline hydrazide/hydrazone derivatives possess several biological activities, such as antimalarial, antitubercular, anticancer, anti-inflammatory, and antimicrobial. Among these activities, the antibacterial activity of quinoline hydrazide/hydrazone derivatives is noteworthy. The synthetic flexibility of the quinoline ring has led to the development of a wide range of structurally diverse quinoline hydrazide/hydrazone derivatives, which can act at various bacterial targets such as DNA gyrase, glucosamine-6-phosphate synthase, enoyl ACP reductase, and 3-ketoacyl ACP reductase. This review emphasizes the antibacterial potential of various reported quinoline hydrazide/hydrazone derivatives based on substitution in the quinoline ring. The antibacterial activity of various metal-quinoline hydrazide/hydrazone complexes is also discussed. The aim of this review is to assemble and scrutinize the latest reports in this promising area of drug development.

Synthesis of 2-(6-substituted quinolin-4-yl)-1-alkoxypropan-2-ol as potential antimycobacterial agents

Resistance to antibiotic drugs has directed global health security to a life-threatening situation due to mycobacterial infections. In search of a new potent antimycobacterial, a series of (±) 2-(6-substituted quinolin-4-yl)-1-alkoxypropan-2-ol (8a-p) have been synthesized. The structures of the newly synthesized derivatives were characterized by spectrometric analysis. Derivatives 8a-p were evaluated for antitubercular activity against Mycobacterium tuberculosis H37Rv (ATCC 25177), antibacterial activity against Proteus mirabilis (NCIM2388), Escherichia coli (NCIM 2065), Bacillus subtilis (NCIM2063) Staphylococcus albus (NCIM 2178) and antifungal activity against Candida albicans (NCIM 3100), Aspergillus niger (ATCC 504). Thirteen 2-(6-substituted quinolin-4-yl)-1-alkoxypropan-2-ol (8a-m) derivatives reported moderate to good antitubercular activity against M. tuberculosis H37Rv with MIC 9.2-106.4 μM. Compounds 8a and 8h showed comparable activity with respect to the standard drug pyrazinamide. The active compounds screened for cytotoxicity activity against L929 mouse fibroblast cells showed no significant cytotoxic activity. Compounds 8c, 8d, 8e, 8g, 8k, and 8o displayed good activity against S. albus. Compounds 8c and 8n showed good activity against P. mirabilis and E. coli, respectively. The potential antimycobacterial activities imposed that the 2-(6-substituted quinolin-4-yl)-1-alkoxypropan-2-ol derivatives could lead to compounds that could treat tuberculosis.

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Supplementary Information

The online version contains supplementary material available at 10.1007/s11696-023-02741-3.

Design, Synthesis, and Molecular Docking Studies of Some New Quinoxaline Derivatives as EGFR Targeting Agents

The synthesis of some new quinoxaline derivatives (IVa-n) and their structure determination using 1H NMR, 13C NMR and mass spectral analysis was described herein. The in vitro anti-cancer activity of the these compounds (IVa-n) revealed that the compound1-((1-(4-bromophenyl)-1H-1,2,3-triazol-4-yl)methyl)-2-(tetrazolo[1,5-a]quinoxalin-4-yl)pyrazolidine-3,5-dione (IVd) has shown promising activity, whereas, compounds 1-((1-phenyl-1H-1,2,3-triazol-4-yl)methyl)-2-(tetrazolo[1,5-a]quinoxalin-4-yl)pyrazolidine-3,5-dione (IVa), 1-(tetrazolo[1,5-a]quinoxalin-4-yl)-2-((1-(m-tolyl)-1H-1,2,3-triazol-4-yl)methyl)pyrazolidine-3,5-dione (IVb), 1-((1-(3,5-dimethoxyphenyl)-1H-1,2,3-triazol-4-yl)methyl)-2-(tetrazolo[1,5-a]quinoxalin-4-yl)pyrazolidine-3,5-dione (IVh) and 1-((1-(4-nitrophenyl)-1H-1,2,3-triazol-4-yl)methyl)-2-(tetrazolo[1,5-a]quinoxalin-4-yl)pyrazolidine-3,5-dione (IVi) exhibited good to moderate activity against four human cancer cell lines such as HeLa, MCF-7, HEK 293T, and A549 as compared to the doxorubicin. Predominantly, the compound displayed excellent activity over HeLa, MCF-7, HEK 293T, and A549 with IC50 values of 3.20 ± 1.32, 4.19 ± 1.87, 3.59 ± 1.34, and 5.29 ± 1.34 μM, respectively. Moreover, molecular docking studies of derivatives (IVa-n) on EGFR receptor suggested that the most potent compound strongly binds to protein EGFR (pdbid:4HJO) and the energy calculations of in silico studies were also in good agreement with the obtained IC50 values.

Supplementary Information

The online version contains supplementary material available at 10.1134/S1068162022030220.

Hybridized 4-Trifluoromethyl-(1,2,3-triazol-1-yl)quinoline System: Synthesis, Photophysics, Selective DNA/HSA Bio-interactions and Molecular Docking

The synthesis, structural analysis, and evaluation of the photophysical properties of twelve novel 2-aryl(heteroaryl)-6-(4-alkyl(aryl)-1H-1,2,3-triazol-1-yl)-4-(trifluoromethyl)quinolines (6-8), where aryl(heteroaryl)=Ph, 4-Me-C₆ H₄ , 4-F-C₆ H₄ and 2- furyl; 4-alkyl(aryl)=-CH₂ OH, -(CH₂ )₅ CH₃ and Ph, are reported. Hybrid scaffolds 6-8 were synthesized at 77-95 % yields by regioselective copper-catalysed azide-alkyne cycloaddition (CuAAC) reaction of unpublished 6-azido-4-(trifluoromethyl)quinolines (2) with selected terminal alkynes (3-5). Azido intermediates 2 were obtained from the reaction of 6-amino-4-(trifluoromethyl)quinolines (1) and sodium azide at good yields (78-87 %). Compounds 6-8 were structurally fully characterized by ¹ H-, ¹³ C- and ¹⁹ F- and ¹ H-¹³ C 2D-NMR (HSQC, HMBC) spectroscopy, X-ray diffraction (SC-XRD) and HRMS analysis. Moreover, the photophysical properties, DNA- and HSA-binding experiments (bio-interactions), and molecular docking studies for compounds 6-8 were performed. These are discussed and compared with similar compounds from recent research.

Synthesis and biological activity of novel 4-aminoquinoline/1,2,3-triazole hybrids against Leishmania amazonensis

Quinoline and 1,2,3-triazoles are well-known nitrogen-based heterocycles presenting diverse pharmacological properties, although their antileishmanial activity is still poorly exploited. As an effort to contribute with studies involving these interesting chemical groups, in the present study, a series of compounds derived from 4-aminoquinoline and 1,2,3-triazole were synthetized and biological studies using L. amazonensis species were performed. The results pointed that the derivative 4, a hybrid of 4-aminoquinoline/1,2,3-triazole exhibited the best antileishmanial action, with inhibitory concentration (IC₅₀) values of ~1 µM against intramacrophage amastigotes of L. amazonensis , and being 16-fold more active to parasites than to the host cell. The mechanism of action of derivative 4 suggest a multi-target action on Leishmania parasites, since the treatment of L. amazonensis promastigotes caused mitochondrial membrane depolarization, accumulation of ROS products, plasma membrane permeabilization, increase in neutral lipids, exposure of phosphatidylserine to the cell surface, changes in the cell cycle and DNA fragmentation. The results suggest that the antileishmanial effect of this compound is primarily altering critical biochemical processes for the correct functioning of organelles and macromolecules of parasites, with consequent cell death by processes related to apoptosis-like and necrosis. No up-regulation of reactive oxygen and nitrogen intermediates was promoted by derivative 4 on L. amazonensis -infected macrophages, suggesting a mechanism of action independent from the activation of the host cell. In conclusion, data suggest that derivative 4 presents selective antileishmanial effect, which is associated with multi-target action, and can be considered for future studies for the treatment against disease.