Triazole derivatives and their anti-tubercular activity

Antitubercular evaluation of dihydropyridine-triazole conjugates: design, synthesis, in vitro screening, SAR and in silico ADME predictions

This study investigates the potential of click chemistry for the development of novel anti-tuberculosis agents. A targeted library of 1,4-dihydropyridine-1,2,3-triazole conjugates was synthesized and evaluated for their in vitro activity against Mycobacterium tuberculosis H37Ra using the resazurin microtiter assay (REMA). Among the synthesized derivatives, compounds J10, J11, J14, J22 and J23 demonstrated significant antimycobacterial activity. These compounds exhibited low MIC values ranging from 6.24 to 6.64 μg mL-1, highlighting their promising potential as lead compounds for further developing novel tuberculosis therapeutics. In addition to the promising in vitro activity, structure-activity relationship (SAR) analysis revealed that electron-withdrawing groups on the aryl-substituted ring of the dihydropyridines (J10-J24), a triazole with an unsubstituted aryl ring or with electron-donating groups (methyl or methoxy), and a geminal dimethyl group are essential structural features for the observed antitubercular activity. Furthermore, in silico ADME (absorption, distribution, metabolism, and excretion) parameters and pharmacokinetic studies supported the potential of these conjugates for oral bioavailability. These findings collectively highlight the 1,4-dihydropyridine-1,2,3-triazole scaffold as a promising platform for developing novel orally active anti-tuberculosis drugs.

Identification of 2-(N-aryl-1,2,3-triazol-4-yl) quinoline derivatives as antitubercular agents endowed with InhA inhibitory activity

The spread of drug-resistant tuberculosis strains has become a significant economic burden globally. To tackle this challenge, there is a need to develop new drugs that target specific mycobacterial enzymes. Among these enzymes, InhA, which is crucial for the survival of Mycobacterium tuberculosis, is a key target for drug development. Herein, 24 compounds were synthesized by merging 4-carboxyquinoline with triazole motifs. These molecules were then tested for their effectiveness against different strains of tuberculosis, including M. bovis BCG, M. tuberculosis, and M. abscessus. Additionally, their ability to inhibit the InhA enzyme was also evaluated. Several molecules showed potential as inhibitors of M. tuberculosis. Compound 5n displayed the highest efficacy with a MIC value of 12.5 μg/mL. Compounds 5g, 5i, and 5n exhibited inhibitory effects on InhA. Notably, 5n showed significant activity compared to the reference drug Isoniazid. Molecular docking analysis revealed interactions between these molecules and their target enzyme. Additionally, the molecular dynamic simulations confirmed the stability of the complexes formed by quinoline-triazole conjugate 5n with the InhA. Finally, 5n underwent in silico analysis to predict its ADME characteristics. These findings provide promising insights for developing novel small compounds that are safe and effective for the global fight against tuberculosis.

Design, Synthesis and Antibacterial Assessment of Active (4-Arylazo-3-Methyl-2-Thienyl) 4-Antipyrine Ketones

The chemicals formed from antipyrines are flexible organic building blocks that are employed in the development of pharmaceuticals. By diazotizing (4-arylazo-3-hydroxy-2-thienyl) 4-antipyrine ketones 1a, 1b and 1c and (4-arylazo-3-methyl-2-thienyl) 4-antipyrine ketones (2a, 2b and 2c) further replaced with six other coupling components, a broad spectrum of hybrid molecules have been created. Mass spectra, NMR, FTIR, and elemental analyses have all been used to confirm the structures of the synthesised compounds. The antimicrobial screening was investigated by agar well diffusion and diluting the broth technique against both Gram-negative and positive-tested bacterial strains. (3-methyl-5-(phenylamino)-4-(4-tolylazo)-2-thienyl) 4-antipyrine ketone (2a) was found to be superior to Ciprofloxacin against test strains: Acinetobacter sp (34.33±1.15 mm), Listeria monocytogenes (29.33±1.15 mm) and Streptococcus sp. (19.33±1.15 mm). Also, good to moderate activities were expressed as minimum inhibitory concentration (MIC) and minimum bacterial concentration (MBC) which were recorded at 9±1 to 59.67±4.51 μg/mL and 16±4 to >512 μg/mL, respectively, using compounds 2a, 2b, and 2c. MBC/MIC ratio showed, that only, 2a and 2b have a bactericidal effect but other antipyrines with bacteriostatic strength. To conclude, it was suggested that the use of these novel synthesized (4-arylazo-3-methyl-2-thienyl) 4-antipyrine ketone derivatives molecules as a new chemical class of antimicrobial agents to perform new drug discovery in pharmaceutical preparations and medicinal research.

Design, synthesis and antimicrobial activity of novel quinoline derivatives: an in silico and in vitro study

A series of new quinoline derivatives has been designed, synthesized and evaluated as antibacterial and antifungal agents functioning as peptide deformylase enzyme (PDF) inhibitors and fungal cell wall disruptors on the basis of computational and experimental methods. The molecular docking and ADMET assessment aided in the synthesis of quinoline derivatives starting from 6-amino-4-methyl-1H-quinoline-2-one substituted with different types of sulfonyl/benzoyl/propargyl moieties. These newly synthesized compounds were evaluated for their in vitro antibacterial and antifungal activity. Antibacterial screening of all compounds showed excellent MIC value (MIC, 50 - 3.12 µg/mL) against bacterial strains, viz. Bacillus cerus, Staphylococcus, Pseudomonas and Escherichia coli. Compounds 2 and 6 showed better activity. Fractional inhibitory concentration (FIC) values of compounds were lowered by 1/2 to 1/128 of the original MIC values when a combinatorial screening with reference drugs was performed. Further, antifungal screening against fungal strains, viz. A. flavus, A. niger, F. oxysporum and C. albicans also showed that all compounds were potentially active and compound 6 being the most potent. Further, the cytotoxicity experiments revealed that compound 6 was the least toxic molecule. The molecular dynamics (MD) simulation investigations elucidated the conformational stability of compound 6-PDF complex with flexible binding pocket residues. The highest number of stable hydrogen bonds with the PDF residues during the entire simulation time illustrated strong binding affinity of compound 6 with PDF.Communicated by Ramaswamy H. Sarma.

Synthesis, Biological Properties, and Molecular Docking Study of Novel 1,2,3-Triazole-8-quinolinol Hybrids

A new series of 1,2,3-triazole-8-quinolinol hybrids were synthesized in good yields using monosubstituted acetonitriles and 5-azidomethyl-8-quinolinol as the starting reagents via a one-step protocol. The structures of 1,2,3-triazole-8-quinolinol hybrids were characterized by nuclear magnetic resonance (1H and 13C NMR) spectroscopy and elemental analysis. Antibacterial activity in vitro of all the synthesized hybrids was investigated against Escherichia coli (E. coli), Xanthomonas fragariae (X. fragariae), Staphylococcus aureus (S. aureus), and Bacillus subtilis (B. subtilis) applying the methods of disk diffusion and minimal inhibition concentration (MIC). Hybrid 7 exhibited excellent antibacterial capacity, with an MIC value of 10 μg/mL against S. aureus and 20 μg/mL against B. subtilis, E. coli, and X. fragariae, which were comparable to those that of the standard antibiotic nitroxoline. A structure-activity relationship (SAR) study of 1,2,3-triazole-8-quinolinol hybrids showed that introducing electron-donating substituents in the 1,2,3-triazole ring at the 4-position is important for activity. Quantum chemical calculations have been undertaken to employ the Gaussian software in the B3LYP, HF, and M062X basis sets using 3-21g, 6-31g, and SDD levels to further explain linkages within the antibacterial findings. Furthermore, molecular docking investigations were also conducted to investigate the binding affinities as well as the interactions of some hybrids with the target proteins. An absorption, distribution, metabolism, excretion, and toxicity (ADME/T) investigation was carried out to scrutinize the viability of employing the 1,2,3-triazole-8-quinolinol hybrids as medicines.

A survey of isatin hybrids and their biological properties

The emergence of diverse infections worldwide, which is a serious global threat to human existence, necessitates the urgent development of novel therapeutic candidates that can combat these diseases with efficacy. Molecular hybridization has been established as an efficient technique in designing bioactive molecules capable of fighting infections. Isatin, a core nucleus of an array of compounds with diverse biological properties can be modified at different positions leading to the creation of novel drug targets, is an active area of medicinal chemistry. This review containing published articles from 2005 to 2022 highlights isatin hybrids which have been synthesized and reported in the literature alongside a discussion on their biological properties. The enriched structure-activity relationship studies discussed provides insights for the rational design of novel isatin hybrids with tailored biological properties as effective therapeutic candidates inspired by nature.

Design, synthesis and molecular docking study of novel triazole-quinazolinone hybrids as antimalarial and antitubercular agents

In a quest to discover new antimalarial and antitubercular drugs, we have designed and synthesized a series of novel triazole-quinazolinone hybrids. The in vitro screening of the triazole-quinazolinone hybrid entities against the plasmodium species P. falciparum offered potent antimalarial molecules 6c, 6d, 6f, 6g, 6j & 6k owing comparable activity to the reference drugs. Furthermore, the target compounds were evaluated in vitro against Mycobacterium tuberculosis (MTB) H37Rv strain. Among the screened compounds, 6c, 6d and 6l were found to be the most active molecules with a MIC values of 19.57-40.68 μM. The cytotoxicity of the most active compounds was studied against RAW 264.7 cell line by MTT assay and no toxicity was observed. The computational study including drug likeness and ADMET profiling, DFT, and molecular docking study was done to explore the features of target molecules. The compounds 6a, 6g, and 6k exhibited highest binding affinity of -10.3 kcal/mol with docked molecular targets from M. tuberculosis. Molecular docking study indicates that all the molecules are binding to the falcipain 2 protease (PDB: 6SSZ) of the P. falciparum. Our findings indicated that these new triazole-quinazolinone hybrids may be considered hit molecules for further optimization studies.

Furan Dearomatization: A Route to Diverse Fluoroalkyl/Aryl Triazoles

The 5-fluoroalkyl-1,2,3-triazoles, serving as a pivotal element in medicinal chemistry, hold substantial research significance. In this work, we developed a furan dearomatization reaction for the synthesis of various 5-fluoroalkyl-1,2,3-triazoles, which contains -CF3, -CF2H, -CF2CF3, -CF2CF2CF3, -CF2CO2Et, and -C6F5. This methodology relies on the intermolecular [3 + 2] cycloaddition/furan ring-opening triggered by α-fluoroalkyl furfuryl cation with azides to stereoselectively synthesize a series of (E)-fluoroalkyl enone triazoles. The reaction proceeds without metal participation, exhibits excellent substrate tolerance, and has excellent synthetic utility.

1,2,3-Triazole Hybrids Containing Isatins and Phenolic Moieties: Regioselective Synthesis and Molecular Docking Studies

The synthesis of hybrid molecules is one of the current strategies of drug discovery for the development of new lead compounds. The 1,2,3-triazole moiety represents an important building block in Medicinal Chemistry, extensively present in recent years. In this paper, we presented the design and the synthesis of new 1,2,3-triazole hybrids, containing both an isatine and a phenolic core. Firstly, the non-commercial azide and the alkyne synthons were prepared by different isatines and phenolic acids, respectively. Then, the highly regioselective synthesis of 1,4-disubstituted triazoles was obtained in excellent yields by a click chemistry approach, catalyzed by Cu(I). Finally, a molecular docking study was performed on the hybrid library, finding four different therapeutic targets. Among them, the most promising results were obtained on 5-lipoxygenase, an enzyme involved in the inflammatory processes.

1,2,3-triazole and chiral Schiff base hybrids as potential anticancer agents: DFT, molecular docking and ADME studies

A series of novel 1,2,3-triazole and chiral Schiff base hybrids 2-6 were synthesized by Schiff base condensation reaction from pre-prepared parent component of the hybrids (1,2,3-triazole 1) and series of primary chiral amines and their chemical structure were confirmed using NMR and FTIR spectroscopies, and CHN elemental analysis. Compounds 1-6 were evaluated for their anticancer activity against two cancer PC3 (prostate) and A375 (skin) and MRC-5 (healthy) cell lines by Almar Blue assay method. The compounds exhibited significant cytotoxicity against the tested cancer cell lines. Among the tested compounds 3 and 6 showed very good activity for the inhibition of the cancer cell lines and low toxicity for the healthy cell lines. All the compounds exhibited high binding affinity for Androgen receptor modulators (PDB ID: 5t8e) and Human MIA (PDB ID: 1i1j) inhibitors compared to the reference anticancer drug (cisplatin). Structure activity relationships (SARs) of the tested compounds is in good agreement with DFT and molecular docking studies. The compounds exhibited desirable physicochemical properties for drug likeness.

Application of Functionalized Zn-Based Metal-Organic Frameworks (Zn-MOFs) with CuO in Heterocycle Synthesis via Azide-Alkyne Cycloaddition

The main goal of this article is to discuss the expansion of click chemistry. A new catalyst composed of CuO nanoparticles embedded in Zn-MOF with the ligand 2,4,6-tris(4-carboxyphenoxy)-1,3,5-triazine (H3L) is presented. The incorporation of CuO nanoparticles into the Zn-MOF structure led to desirable morphology and catalytic properties. The designed catalyst was evaluated for its catalytic role in the multicomponent reaction and copper-catalyzed azide-alkyne cycloaddition (CuAAC) for preparation of triazole rings with 80-91% yield. The catalyst demonstrated an appealing architecture and exhibited robustness, high efficiency, and environmental friendliness. Characterization of the catalyst was performed using various techniques, including Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopes (TEM), high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), energy-dispersive X-ray spectroscopy (EDX), elemental mapping, and X-ray diffraction (XRD). The results suggest that this novel catalyst has the potential to be a valuable tool in the development of new synthetic approaches for a wide range of applications.

Design, synthesis, and molecular modeling studies of novel 2-quinolone-1,2,3-triazole-α-aminophosphonates hybrids as dual antiviral and antibacterial agents

With the aim to identify new antiviral agents with antibacterial properties, a series of 2-quinolone-1,2,3-triazole derivatives bearing α-aminophosphonates was synthesized and characterized by 1H NMR, 13C NMR, 31P NMR, single crystal XRD and HRMS analyses. These compounds were examined against five RNA viruses (YFV, ZIKV, CHIKV, EV71 and HRV) from three distinct families (Picornaviridae, Togaviridae and Flaviviridae) and four bacterial strains (S. aureus, E. feacalis, E. coli and P. aeruginosa). The α-aminophosphonates 4f, 4i, 4j, 4k, 4p and 4q recorded low IC50 values of 6.8-10.91 μM, along with elevated selectivity indices ranging from 2 to more than 3, particularly against YFV, CHIKV and HRV-B14. Besides, the synthesized compounds were generally more sensitive toward Gram-positive bacteria, with the majority of them displaying significant potency against E. feacalis. Specifically, an excellent anti-enterococcus activity was obtained by compound 4q with MIC and MBC values of 0.03 μmol/mL, which were 8.7 and 10 times greater than those of the reference drugs ampicillin and rifampicin, respectively. Also, compounds 4f, 4p and 4q showed potent anti-staphylococcal activity with MIC values varying between 0.11 and 0.13 μmol/mL, compared to 0.27 μmol/mL for ampicillin. The results from DFT and molecular docking simulations were in agreement with the biological assays, proving the binding capability of hybrids 4f, 4i, 4j, 4k, 4p and 4q with viral and bacterial target enzymes through hydrogen bonds and other non-covalent interactions. The in silico ADME/Tox prediction revealed that these molecules possess moderate to good drug-likeness and pharmacokinetic properties, with a minimal chance of causing liver toxicity or carcinogenic effects.

Hybrid silica nanoparticles functionalized with pyrazolone-tethered organosilane: Synthesis and application for Sn (II) ion sensing in tap water

Pyrazolone tethered triazole functionalized organosilane and their hybrid silica nanoparticles (HSNPs) have been synthesised for the selective detection of Sn(II) using spectrophotometric techniques. The prepared compounds are characterized by FT-IR, NMR (1H and 13C), XRD, mass spectrometry and FE-SEM spectral analyses. The synthesized hybrid silica nanoparticles gave improved detection limit of 4.3 × 10-8 M and stoichiometry of complex between analyte and probe was found to be 1:1. The association constant calculated for organosilane and their HSNPs came out to be 9.54 × 104 M-1 and 7.47 × 104 M-1 while the presence of other ions showed no interference in the sensing behaviour. The results of the use of this sensing system in tap water facilitate its applicability in real samples with the recovery % more than 98.

Synthesis and antibacterial activity of FST and its effects on inflammatory response and intestinal barrier function in mice infected with Escherichia coli O78

Pathogenic Escherichia coli (E. coli) can cause intestinal diseases in humans and livestock, damage the intestinal barrier, increase systemic inflammation, and seriously threaten human health and the development of animal husbandry. In this study, we designed and synthesized a novel conjugate florfenicol sulfathiazole (FST) based on drug combination principles, and investigated its antibacterial activity in vitro and its protective effect on inflammatory response and intestinal barrier function in E. coli O78-infected mice in vivo. The results showed that FST had superior antibacterial properties and minimal cytotoxicity compared with its prodrugs as florfenicol and sulfathiazole. FST protected mice from lethal E. coli infection, reduced clinical signs of inflammation, reduced weight loss, alleviated intestinal structural damage. FST decreased the expression of inflammatory cytokines IL-1β, IL-6, TNF-α, and increased the expression of claudin-1, Occludin, and ZO-1 in the jejunum, improved the intestinal barrier function, and promoted the absorption of nutrients. FST also inhibited the expression of TLR4, MyD88, p-p65, and p-p38 in the jejunum. The study may lay the foundation for the development of FST as new drugs for intestinal inflammation and injury in enteric pathogen infection.

Design, synthesis, evaluation and optimization of novel azole analogues as potent antifungal agents

In order to develop antifungal drugs, a series of novel azole analogues were designed and synthesized based on our previous work. Most of the target compounds had broad-spectrum antifungal activity, which showed excellent to moderate inhibitory activity against the tested strains, except A. fum 0504656. Among these, compounds B3, B7, B8, B11, B12 and E9 showed excellent activity against C. alb Y0109 and C. alb SC5314 (with the MIC80: 0.0156 ug/mL). In addition, compound B3 showed the best inhibitory activity against fluconazole-resistant strains C. alb 901 and C. alb 904, and had low toxicity against NIH/3T3 cells at the effective MIC range against fungi. Structure-activity relationship and docking studies of the derivatives suggest that the presence of the 2-fluoro-4-hydroxyphenyl and 1,2,3-triazole group enhance the antifungal activity of the compounds, which may be related to the interaction of the key groups with the amino acids surrounding the target enzyme.

Benzimidazole and piperidine containing novel 1,2,3-triazole hybrids as anti-infective agents: Design, synthesis, in silico and in vitro antimicrobial efficacy

Cu alkyne-azide cycloaddition was used to easily synthesize a library of novel heterocycles containing benzimidazole and piperidine based 1,2,3-triazole(7a-7l) derivatives. The synthesized analogs were characterized by various spectroscopic techniques like FTIR, 1 H nuclear magnetic resonance (NMR), 13 C NMR, and mass spectrometry. All these novel bioactive compounds (7a-7l) were evaluated for in vitro antibacterial and antifungal efficacy. Compound 7k exhibited appreciable potent activity against Escherichia coli strain. Compounds 7a, 7b, 7f, and 7i showed excellent potent activity against all bacterial strains. Compound 7b, 7c, 7d, and 7g derivatives showed excellent effects when tested in vitro for antifungal activity against various fungal strains. Additionally, a molecular docking investigation revealed that compound 7k has the ability to bind to the active site of the E. coli DNA gyrase subunit protein and form hydrogen bonds with significant amino acid residues Asp73 and Asp49 in the active sites. In a 100 ns molecular dynamics simulation, the E. coli DNA gyrase protein's steady capacity to bind compound 7k was shown by the low measured root mean square deviation, which was an indication of the complex's conformational stability.

Design, synthesis and antitubercular assessment of 1, 2, 3-triazole incorporated thiazolylcarboxylate derivatives

A library of 1, 2, 3-triazole incorporated thiazolylcarboxylate derivatives (7a-q) and (8a-j) were synthesized and evaluated for their in-vitro antitubercular activity against Mycobacterium tuberculosis H37Rv. The two compounds 7h and 8h have displayed excellent antitubercular activity with MIC values of 3.12 and 1.56 µg/mL respectively (MIC values of standard drugs; Ciprofloxacin 1.56 μg/mL & Ethambutol 3.12 μg/mL). Whereas, the four compounds 7i, 7n, 7p and 8i displayed noticeable antitubercular activity with a MIC value of 6.25 µg/mL. The active compounds of the series were further studied for their cytotoxicity against RAW264.7 cell line using MTT assay. Furthermore, to study the probable mechanism of antitubercular action, physicochemical property profiling, DFT calculation and molecular docking study were executed on mycobacterial cell wall target Decaprenylphosphoryl-β-d-ribose 2'-epimerase 1 (DprE1). Among all the compounds, 7h (-10 kcal/mol) and 8h (-10.1 kcal/mol) exerted the highest negative binding affinity against the targeted DprE1 (PDB: 4NCR) protein.

On the Question of Zwitterionic Intermediates in the [3+2] Cycloaddition Reactions between Aryl Azides and Ethyl Propiolate

The molecular mechanism of the [3+2] cycloaddition reactions between aryl azides and ethyl propiolate was evaluated in the framework of the Molecular Electron Density Theory. It was found that independently of the nature of the substituent within the azide molecule, the cycloaddition process is realized via a polar but single-step mechanism. All attempts of localization as postulated earlier by Abu-Orabi and coworkers' zwitterionic intermediates were not successful. At the same time, the formation of zwitterions with an "extended" conformation is possible on parallel reaction paths. The ELF analysis shows that the studied cycloaddition reaction leading to the 1,4-triazole proceeds by a two-stage one-step mechanism. It also revealed that both zwitterions are created by the donation of the nitrogen atom's nonbonding electron densities to carbon atoms of ethyl propiolate.

In situ click chemistry-based discovery of 1,2,3-triazole-derived diarylpyrimidines as novel HIV-1 NNRTIs by exploiting the tolerant region I in binding pocket

HIV-1 reverse transcriptase (RT) is considered as one of the most significant targets for the anti-HIV-1 drug design due to their determined mechanism and well-decoded crystal structure. As a part of our continuous efforts towards the development of potent HIV-1 non-nucleoside reverse transcriptase inhibitors (NNRTIs) by exploiting the tolerant region I of NNRTIs binding pocket (NNIBP), the miniaturized parallel synthesis via CuAAC click chemistry reaction followed by in situ biological screening have been performed in this work. The in situ enzyme inhibition screening results showed that 14 compounds exhibited higher or equivalent inhibitory activity compared to the lead K-5a2 and ETR. Anti-HIV-1 activity results indicated that C1N51 displayed the most potent activity (EC50 = 0.01-0.26 μM) against wild-type and a panel of NNRTIs-resistant strains. Moreover, the molecular simulation demonstrated that the newly introduced triazole ring could develop new hydrogen bonds with Lys103 and Pro236, which explained the feasibility of introducing triazole in the tolerant region I of the RT binding pocket.

Novel Cu(ii) acidic deep eutectic solvent as an efficient and green multifunctional catalytic solvent system in base-free conditions to synthesize 1,4-disubstituted 1,2,3-triazoles

A novel green Cu(ii)-acidic deep eutectic solvent (Cu(ii)-ADES) bearing copper salt, choline chloride, and gallic acid ([ChCl]4[2GA-Cu(ii)]) was synthesized and thoroughly specified by physicochemical approaches such as FT-IR, EDX, XRD, Mapping, ICP, and UV-Vis analyses and physicochemical properties. After the detection of authentic data, the central composite design (CCD) was utilized to accomplish the pertaining tests and develop the optimum condition, and, in the following, [ChCl]4[2GA-Cu(ii)] was applied as a green multifunctional catalytic solvent system in reducing agent-free and base-free condition for the three-component click reaction from sodium azide, alkyl, allyl, ester, and benzyl halide, and terminal alkyne made from amines and caprolactam as a cyclic amide to furnish a successful new library of 1,4-disubstituted 1,2,3-triazoles with a yield of up to 98%. The Cu(ii)-ADES is stable and can comfortably be recovered and reused without a considerable decline in its acting for seven cycles. This triazole synthesizing methodology is distinguished via its atom economy, operational facility, short reaction times, diverse substrate scope, and high performance for large-scale synthesis of the desired products including: -CN and -NO2 as efficient functional groups.

Synthesis, characterization, in vitro antimycobacterial and cytotoxicity evaluation, DFT calculations, molecular docking and ADME studies of new isomeric benzimidazole-1,2,3-triazole-quinoline hybrid mixtures

New benzimidazole-1,2,3-triazole-quinoline hybrids and their intermediates, differing in substitutions at the C-2 and/or C6 positions of the benzimidazole ring, were successfully synthesized in 55---80 % yields, with the C6-substituted ones forming as inseparable tautomeric mixtures. The synthesized compounds were fully characterised by FT-IR, 1D- and 2D-NMR, and HRMS. In-depth NMR analysis and DFT molecular calculations showed that the tautomeric mixtures formed in a ratio of almost 1:1 ratio (cis and trans), except for 5 g, where the ratio is 1:2. In vitro antimycobacterial activity evaluation against the H37Rv strain of Mycobacterial tuberculosis was undertaken on all synthesized compounds, and a selected number were further screened for their cytotoxicity on TZM-bl cell lines. Hybrid compounds showed excellent MIC90 activities ranging from 1.07 to 8.66 μM and were all more efficacious than the first-line reference drug, ethambutol (MIC90 = 9.54 μM). In particular, hybrid compounds 5b (MIC90 = 1.54 μM, CC50 = 58.89 μM and % cell viability = 14.07), 5d (MIC90 = 2.08 μM, CC50 = 0.27 μM, and % cell viability = 149.50 %) and 5 g (MIC90 = 1.49 μM, CC50 = 4.62 μM and % cell viability = 44.03) were the most promising. Significantly, 5b and 5 g were over six times more efficacious than ethambutol but exhibited cytotoxicity towards TZM-bl cell-lines compared to 5d, which was over four times more active than ethambutol. The physical combination (mimicking combination therapy) of individual pharmacophoric components making up 5 g were less active, indicating the synergistic effect of hybridization. In addition, more than 60 % of all the synthesized hybrids showed better activity than their respective pharmacophoric components. In silico ADME studies of the hybrids revealed favourable physico-chemical properties, while molecular modeling studies suggested binding interactions with Val 61, Gly 62, Glu 65, Ala 66, and Phe 69 amino acid in a reported similar manner to bedaquiline, an approved quinoline-based anti-TB drug.

Synthesis of glycyrrhizin analogues as HMGB1 inhibitors and their activity against sepsis in acute kidney injury

Glycyrrhizin (GL) is one of the antagonists of highly conserved nuclear protein (HMGB1). The researches have shown that the glycosyl of GL is an important pharmacophore for GL binding to HMGB1, and it is the determinant factor for mechanism of action. To get the HMGB1 inhibitors with higher activity and good pharmacokinetic properties, two classes of GL analogues containing C-N glycoside bond were synthesized, and their anti-inflammatory, anti-oxidative stress and anti-septic kidney injury were evaluated. The results are as follows. First, in the anti-inflammatory assay, all the compounds inhibited NO release in some degree; among them, compound 6 displayed the strongest NO inhibitory effect with IC50 value of 15.9 μM, and compound 15 with IC50 of 20.2 μM. The two compounds not only decreased IL-1β and TNF-α levels in RAW264.7 cells and HK-2 cells, but also downregulated the levels of NLRP3, P-NF-κB p65 and HMGB1 in activated HK-2 cells in a dose-dependent manner. Second, in the renal protection assay with H2O2-stimulated HK-2 cell line, they reduced MDA level and increased SOD in HK-2 cells; additionally, they also inhibited the HK-2 cell apoptosis and downregulated the Caspase-1 p20 level. Third, in the in vivo activity tests of the septic mouse, they also showed good activities just like in vitro, decreasing the IL-1β, TNF-α, MDA, blood creatinine (Scr) and urea nitrogen (BUN) in serum, and increasing SOD levels in a dose-dependent manner. The immunoblotting results showed the two compounds downregulated the levels of HMGB1, P-NF-κB p65, NLRP3 and Caspase-1 p20 protein. All in all, the two compounds improved the renal injury of septic mice, and alleviated the tube wall structure damage and renal tubular dilation in kidney, which further proved by H&E staining. This suggests the two compounds have septic acute kidney injury activity, and they will be potential therapeutic drugs for septic acute kidney injury.

Sulfadiazine analogs: anti-Toxoplasma in vitro study of sulfonamide triazoles

Toxoplasmosis is an infection that prevails all over the world and is caused by the obligate intracellular protozoan parasite Toxoplasma gondii (T. gondii). Promising novel compounds for the treatment of T. gondii are introduced in the current investigation. In order to test their in vitro potency against T. gondii tachyzoites, six 1,2,3-triazoles-based sulfonamide scaffolds with terminal NH2 or OH group were prepared and investigated as sulfadiazine equivalents. When compared to sulfadiazine, which served as a positive control, hybrid molecules showed much more anti-Toxoplasma activity. The results showed that the IC50 of the examined compounds 3(a-f) were recoded as 0.07492 μM, 0.07455 μM, 0.0392 μM, 0.03124 μM, 0.0533 μM, and 0.01835 μM, respectively, while the sulfadiazine exhibited 0.1852 μM. The studied 1,2,3-triazole-sulfadrug molecular conjugates 3(a-f) revealed selectivity index of 10.4, 8.9, 25.4, 21, 8.3, and 29; respectively. The current study focused on the newly synthesized amino derivatives 3(d-f), as they contain the more potent amino groups which are recognized to be essential elements and promote better biological activity. Extracellular tachyzoites underwent striking morphological alterations after 2 h of treatment as seen by scanning electron microscopy (SEM). Additionally, the intracellular tachyzoite exposed to the newly synthesized amino derivatives 3(d-f) for a 24-h period of treatment revealed damaged and altered morphology by transmission electron microscopic (TEM) indicating cytopathic effects. Moreover, compound 3f underwent the most pronounced changes, indicating that it had the strongest activity against T. gondii.

Antimicrobial, antibiofilm, docking, DFT and molecular dynamics studies on click-derived isatin-thiosemicarbazone-1,2,3-triazoles

In an effort to develop new antimicrobial and antibiofilm agents, we have designed and synthesized a novel class of isatin-thiosemicarbazone-1,2,3-triazoles through the CuAAC approach. All the synthesized hybrids were characterized by several spectral techniques such as FTIR, 1H NMR, 13C NMR, 2D NMR and HRMS. All the derivatives were evaluated for their antimicrobial and antibiofilm efficacy towards various microbial species. Triazole hybrid 8d exhibited the highest efficacy towards E. coli (MIC = 0.0067 µmol/mL) and S. aureus (MIC = 0.0067 µmol/mL), whereas, compounds 8b, 8c, 8d, 8e, 9a and terminal alkyne (10) significantly inhibited biofilm formation against S. aureus, B. subtilis and E. coli. To find out the structure-activity relationship and binding interactions of synthesized hybrids with enzymes 1KZN and 5TZ1, molecular docking for all the synthesized hybrids was carried out. DFT calculations for all hybrids and the molecular dynamics studies for compounds 9e and 9f were also performed to support the biological behavior of these hybrids.Communicated by Ramaswamy H. Sarma.

Design, synthesis, molecular docking and DFT studies on novel melatonin and isatin based azole derivatives

In order to address the pressing demand for newer broad-spectrum antifungal medicines with enhanced activity, computer modelling was utilised to rationally develop newer antifungal azole-based drugs. Based on the drug and active sites of the Lanosterol 14 alpha-Demethylases (LAD) of the prominent fungal pathogen Candida albicans interaction, Novel triazole-linked melatonin and isatin derivatives 7a-d and 8a-d were synthesised using bioisosterism. Besides the experimental synthesis and subsequent characterization, the present study focused on obtaining optimised geometries, frequency calculations, and TD-DFT studies of the synthesised molecules. We also performed molecular docking studies to explore the inhibitory ability of the synthesised compounds against the active sites of the Lanosterol 14 alpha-Demethylases (LAD) of the prominent fungal pathogen Candida albicans. The binding interactions resulted in positive findings, demonstrating the involvement of the synthesised compounds in the suppression of fungal growth. Comparative analysis of the binding potential of the synthesised molecules and commercially available drug fluconazole revealed a remarkable note: the docking scores for the designed drugs 7b, 7c, and 8c are much greater than those of the fluconazole molecule. The in silico study of the designed series of drug molecules serves as an important guideline for further exploration in the quest for potent antifungal agents.

Synthesis and pharmacological evaluation of 1,3-diaryl substituted pyrazole based (thio)urea derivatives as potent antimicrobial agents against multi-drug resistant Staphylococcus aureus and Mycobacterium tuberculosis

The urgent development of newer alternatives has been deemed a panacea for tackling emerging antimicrobial resistance effectively. Herein, we report the design, synthesis, and biological evaluation of 1,3-diaryl substituted pyrazole-based urea and thiourea derivatives as antimicrobial agents. Preliminary screening results revealed that compound 7a (3,4-dichlorophenyl derivative) exhibited potent activity against S. aureus (MIC = 0.25 μg mL-1) and compound 7j (2,4-difluorophenyl derivative) against Mycobacterium tuberculosis (MIC = 1 μg mL-1). Compounds 7a and 7j were non-toxic to Vero cells with a favorable selectivity index of 40 and 200, respectively, and demonstrated good microsomal stability. Compound 7a exhibited equipotent activity (MIC = 0.25 μg mL-1) against various multidrug-resistant strains of S. aureus, which include various strains of MRSA and VRSA, and elicited bacteriostatic properties. In an enzymatic assay, 7a effectively inhibited DNA gyrase supercoiling activity at a concentration of 8 times MIC. Further, molecular modeling studies suggested that compound 7a binds at the active site of DNA gyrase with good affinity.

Click derived organosilane assembled with nano platform for the detection of Cu2+ ions: Biological evaluation and molecular docking approach

Metal ions have active roles in biochemical, industrial, and environmental processes. The design and development of new rapid sensing materials with advanced reasonable, compelling, and convenient, techniques are urgent. Here in this work, we design and develop sensor with the facile amalgamation of the pyrene-based organosilane (5) through a click silylation approach silicon composite for selective detection of Cu²⁺ ions. Physicochemical and keen methods are employed to perceive the resultant hybrid nanoparticles (H-NPs), and these nanocomposites similarly displayed a strong affection for Cu²⁺ ions. In addition, the identification restrictions while utilizing 5 and H-NP's towards Cu²⁺ found in this study are far lower than the WHO rules for drinking water. Further, organosilane (5) shows good antibacterial and antioxidant activity. The antibacterial effects of triazole-based organosilane (5), are evaluated with a molecular docking study with Escherichia coli (IJZQ) was conducted. The selected ligand was revealed to have a reasonable docking score with a binding energy of -8.40 kcal mol^-1.

[1,2,4]triazolo[3,4-b][1,3,4]thiadiazole derivatives as new therapeutic candidates against urease positive microorganisms: design, synthesis, pharmacological evaluations, and in silico studies

Regarding the important role of the urease enzyme as a virulence factor in urease-positive microorganisms in this study, new series of [1,2,4]triazolo[3,4-b][1,3,4]thiadiazole derivatives were designed and synthesized. All compounds evaluated against urease enzyme exhibiting IC50 values of 0.87 ± 0.09 to 8.32 ± 1.21 µM as compared with thiourea as the positive control (IC50 = 22.54 ± 2.34 µM). The kinetic evaluations of 6a as the most potent derivative recorded a competitive type of inhibition. Molecular dynamic simulations of the 6a derivative were also conducted, showing that 6a occupied the active site with closed state. Antimicrobial activities of all derivatives were performed, and 6f (R = 3-Cl), 6g (R = 4-Cl), and 6h (R = 3,4-diCl) analogs demonstrated significant antifungal activities with MIC values of 1, 2, and 0.5 µg/mL compared with fluconazole with MIC = 2 µg/mL. Synthesized analogs also exhibited potent urease inhibitory activities against C. neoformans (IC50 = 83.7-118.7 µg/mL) and P. mirabilis (IC50 = 74.5-113.7 µg/mL), confirming their urease inhibitory potential. The results demonstrated that the designed scaffold could be considered a suitable pharmacophore to develop potent urease inhibitors.

One-Pot Synthesis of Isoxazole-Fused Tricyclic Quinazoline Alkaloid Derivatives via Intramolecular Cycloaddition of Propargyl-Substituted Methyl Azaarenes under Metal-Free Conditions

A practical method was developed for the convenient synthesis of isoxazole-fused tricyclic quinazoline alkaloids. This procedure accesses diverse isoxazole-fused tricyclic quinazoline alkaloids and their derivatives via intramolecular cycloaddition of methyl azaarenes with tert-butyl nitrite (TBN). In this method, TBN acts as the radical initiator and the source of N-O. Moreover, this protocol forms new C-N, C-C, and C-O bonds via sequence nitration and annulation in a one-pot process with broad substrate scope and functionalization of natural products.

Rejuvenating the [1, 2, 3]-triazolo [1,5-a]quinoxalin-4(5H)-one scaffold: Synthesis and derivatization in a sustainable guise and preliminary antimicrobial evaluation

The [1,2,3]-triazolo [1,5-a] quinoxalin-4(5H)-one scaffold and its analogues triazole-fused heterocyclic compounds are relevant structural templates in both natural and synthetic biologically active compounds. However, their medicinal chemistry applications are often limited due to the lack of synthetic protocols combining straightforward generation of the central core while also allowing extensive decoration activity for drug discovery purposes. Herein, we report a “refreshed” synthesis of the [1,2,3]-triazolo [1,5-a]quinoxalin-4(5H)-one core, encompassing the use of eco-compatible catalysts and reaction conditions. We have also performed a sustainable and extensive derivatization campaign at both the endocyclic amide nitrogen and the ester functionality, comprehensively exploring the reaction scope and overcoming some of the previously reported difficulties in introducing functional groups on this structural template. Finally, we unveiled a preliminary biological investigation for the newly generated chemical entities. Our assessment of the compounds on different bacterial species (two S. aureus strains, three P. aeruginosa strains, K. pneumonia), and two fungal C. albicans strains, as well as the evaluation of their activity on S. epidermidis biofilm formation, foster further optimization for the retrieved hit compounds 9, 14, and 20.

New tetrahydropyrimidine-1,2,3-triazole clubbed compounds: Antitubercular activity and Thymidine Monophosphate Kinase (TMPKmt) inhibition

Two series of new tetrahydropyrimidine (THPM)-1,2,3-triazole clubbed compounds were designed, synthesized and screened for their antitubercular (anti-TB) activity against M. tuberculosis H₃₇Rv strain using microplate alamar blue assay (MABA). The most active compounds 5c, 5d, 5e and 5f were further examined for their cytotoxicity against the growth of RAW 264.7 mouse macrophage cells using MTT assay. The four compounds showed safety profiles better than or comparable to that of ethambutol (EMB). These compounds were evaluated for their inhibition activity against mycobacterium tuberculosis thymidine monophosphate kinase (TMPKmt). Compounds 5c and 5e were the most potent exhibiting comparable inhibition activity to that of the natural substrate deoxythymidine monophosphate (dTMP). An in silico study was performed including docking of the most active compounds 5c and 5e into the TMPKmt (PDB: ID 1G3U) binding pocket in addition to prediction of their physicochemical and pharmacokinetic properties to explore the overall activity of these anti-TB candidates. Compounds 5c and 5e are promising anti-TB agents and TMPKmt inhibitors with acceptable oral bioavailability, physicochemical and pharmacokinetic properties.

An Overview of 1,2,3-triazole-Containing Hybrids and Their Potential Anticholinesterase Activities

Acetylcholine (ACh) neurotransmitter of the cholinergic system in the brain is involved in learning, memory, stress responses, and cognitive functioning. It is hydrolyzed into choline and acetic acid by two key cholinesterase enzymes, viz., acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE). A loss or degeneration of cholinergic neurons that leads to a reduction in ACh levels is considered a significant contributing factor in the development of neurodegenerative diseases (NDs) such as Alzheimer's disease (AD). Numerous studies have shown that cholinesterase inhibitors can raise the level of ACh and, therefore, enhance people's quality of life, and, at the very least, it can temporarily lessen the symptoms of NDs. 1,2,3-triazole, a five-membered heterocyclic ring, is a privileged moiety, that is, a central scaffold, and is capable of interacting with a variety of receptors and enzymes to exhibit a broad range of important biological activities. Recently, it has been clubbed with other pharmacophoric fragments/molecules in hope of obtaining potent and selective AChE and/or BuChE inhibitors. The present updated review succinctly summarizes the different synthetic strategies used to synthesize the 1,2,3-triazole moiety. It also highlights the anticholinesterase potential of various 1,2,3-triazole di/trihybrids reported in the past seven years (2015-2022), including a rationale for hybridization and with an emphasis on their structural features for the development and optimization of cholinesterase inhibitors to treat NDs.

Synthesis and in vitro antileishmanial activity of alkylene-linked nitrofurantoin-triazole hybrids

Leishmaniasis is a vector-borne parasitic disease that mostly affects populations in tropical and sub-tropical countries. There is currently no protective anti-leishmanial vaccine and only a paucity of clinical drugs is available to treat this disease albeit their toxicity. Leishmaniasis is curable but its eradication and elimination have been hampered by the emergence of multidrug resistant strains of the causative pathogens. This heightens the necessity for new and effective antileishmanial drugs. In search for such agents, nitrofurantoin, a clinical antibiotic, was appended to triazole scaffold through alkylene linkers of various length, and the resulting hybrids were evaluated for in vitro antileishmanial efficacy against Leishmania (L.) parasite of two strains. The hybrid 13, harboring a n-pentylene linker was uncovered as a leishmanicidal hit with micromolar activity against antimonial-resistant L. donovani, the causative of deadly visceral Leishmaniasis.

Synthesis and Pharmacological Evaluation of Novel Triazole-Pyrimidine Hybrids as Potential Neuroprotective and Anti-neuroinflammatory Agents

OBJECTIVE

Neuroprotection is a precise target for the treatment of neurodegenerative diseases, ischemic stroke, and traumatic brain injury. Pyrimidine and its derivatives have been proven to use antiviral, anticancer, antioxidant, and antimicrobial activity prompting us to study the neuroprotection and anti-inflammatory activity of the triazole-pyrimidine hybrid on human microglia and neuronal cell model.

METHODS

A series of novel triazole-pyrimidine-based compounds were designed, synthesized and characterized by mass spectra, 1HNMR, 13CNMR, and a single X-Ray diffraction analysis. Further, the neuroprotective, anti-neuroinflammatory activity was evaluated by cell viability assay (MTT), Elisa, qRT-PCR, western blotting, and molecular docking.

RESULTS

The molecular results revealed that triazole-pyrimidine hybrid compounds have promising neuroprotective and anti-inflammatory properties. Among the 14 synthesized compounds, ZA3-ZA5, ZB2-ZB6, and intermediate S5 showed significant anti-neuroinflammatory properties through inhibition of nitric oxide (NO) and tumor necrosis factor-α (TNF-α) production in LPS-stimulated human microglia cells. From 14 compounds, six (ZA2 to ZA6 and intermediate S5) exhibited promising neuroprotective activity by reduced expression of the endoplasmic reticulum (ER) chaperone, BIP, and apoptosis marker cleaved caspase-3 in human neuronal cells. Also, a molecular docking study showed that lead compounds have favorable interaction with active residues of ATF4 and NF-kB proteins.

CONCLUSION

The possible mechanism of action was observed through the inhibition of ER stress, apoptosis, and the NF-kB inflammatory pathway. Thus, our study strongly indicates that the novel scaffolds of triazole-pyrimidine-based compounds can potentially be developed as neuroprotective and anti-neuroinflammatory agents.

Photoredox catalysis leading to triazolo-quinoxalinones at room temperature: selectivity of the rate determining step

The interest in the fusion product of quinoxalinone skeletons and 1,2,3-triazole units has greatly increased in recent years since they are known to be agonists of G-protein-coupled Niacin receptor 109A and inhibitors of the benzodiazepine and adenosine receptors. Here, we unveil the mechanism for the photoredox catalyzed synthesis of those scaffolds by means of DFT calculations. The calculations indicate that the rate determining step of this transformation is the attack of the in situ generated radical intermediate on the CN bond of the quinoxalinone species to form a new C-C bond. Predictive chemistry here reveals that the energy difference is so subtle, and gives the recipe of which substituents, sterically and electronically, can fit to perform the reaction at room temperature.

A minireview of 1,2,3-triazole hybrids with O-heterocycles as leads in medicinal chemistry

Over the past few decades, the dynamic progress in the synthesis and screening of heterocyclic compounds against various targets has made a significant contribution in the field of medicinal chemistry. Among the wide array of heterocyclic compounds, triazole moiety has attracted the attention of researchers owing to its vast therapeutic potential and easy preparation via copper and ruthenium-catalyzed azide-alkyne cycloaddition reactions. Triazole skeletons are found as major structural components in a different class of drugs possessing diverse pharmacological profiles including anti-cancer, anti-bacterial, anti-fungal, anti-viral, anti-oxidant, anti-inflammatory, anti-diabetic, anti-tubercular, and anti-depressant among various others. Furthermore, in the past few years, a significantly large number of triazole hybrids were synthesized with various heterocyclic moieties in order to gain the added advantage of the improved pharmacological profile, overcoming the multiple drug resistance and reduced toxicity from molecular hybridization. Among these synthesized triazole hybrids, many compounds are available commercially and used for treating different infections/disorders like tazobactam and cefatrizine as potent anti-bacterial agents while isavuconazole and ravuconazole as anti-fungal activities to name a few. In this review, we will summarize the biological activities of various 1,2,3-triazole hybrids with copious oxygen-containing heterocycles as lead compounds in medicinal chemistry. This review will be very helpful for researchers working in the field of molecular modeling, drug design and development, and medicinal chemistry.

Silver-Catalyzed Cascade Cyclization of Amino-NH-1,2,3-Triazoles with 2-Alkynylbenzaldehydes: An Access to Pentacyclic Fused Triazoles

An operationally simple Ag(I)-catalyzed approach for the synthesis of isoquinoline and quinazoline fused 1,2,3-triazoles was developed by a condensation and amination cyclization cascade of amino-NH-1,2,3-triazoles with 2-alkynylbenzaldehydes involving three new C-N bond formations in one manipulation, in which the group of -NH of the triazole ring serves as a nucleophile to form the quinazoline skeleton. The efficient protocol can be applied to a variety of substrates containing a range of functional groups, delivering novel pentacyclic fused 1,2,3-triazoles in good-to-excellent yields.

The 1,2,3-triazole 'all-in-one' ring system in drug discovery: a good bioisostere, a good pharmacophore, a good linker, and a versatile synthetic tool

INTRODUCTION

The 1,2,3-triazole ring occupies an important space in medicinal chemistry due to its unique structural properties, synthetic versatility and pharmacological potential making it a critical scaffold. Since it is readily available through click chemistry for creating compound collections against various diseases, it has become an emerging area of interest for medicinal chemists.

AREAS COVERED

This review article addresses the unique properties of the1,2,3-triazole nucleus as an intriguing ring system in drug discovery while focusing on the most recent medicinal chemistry strategies exploited for the design and development of 1,2,3-triazole analogs as inhibitors of various biological targets.

EXPERT OPINION

Evidently, the 1,2,3-triazole ring with unique structural features has enormous potential in drug design against various diseases as a pharmacophore, a bioisoster or a structural platform. The most recent evidence indicates that it may be more emerging in drug molecules in near future along with an increasing understanding of its prominent roles in drug structures. The synthetic feasibility and versatility of triazole chemistry make it certainly ideal for creating compound libraries for more constructive structure-activity relationship studies. However, more comparative and target-specific studies are needed to gain a deeper understanding of the roles of the 1,2,3-triazole ring in molecular recognition.[Figure: see text].

Synthesis methods of 1,2,3-/1,2,4-triazoles: A review

Triazole, comprising three nitrogen atoms and two carbon atoms, is divided into two isomers 1,2,3-triazole and 1,2,4-triazole. Compounds containing a triazole are one of the significant heterocycles that exhibit broad biological activities, such as antimicrobial, analgesic, anti-inflammatory, anticonvulsant, antineoplastic, antimalarial, antiviral, antiproliferative, and anticancer activities. A great quantity of drugs with a triazole structure has been developed and proved, for example, ketoconazole and fluconazole. Given the importance of the triazole scaffold, its synthesis has attracted much attention. This review summarizes the synthetic methods of triazole compounds from various nitrogen sources in the past 20 years.

Quinoline-derivatives as privileged scaffolds for medicinal and pharmaceutical chemists: A comprehensive review

The quinoline scaffolds are privileged for their numerous biological activities in the pharmaceutical field. This moiety constitutes a well-known space in several marketed preparations. The quinoline scaffolds gained attention in modern days being an important chemical moiety in the identification, designing, and synthesis of novel potent derivatives. The current review is developed to shine the light on critical and significant insights on the quinoline derivatives possessing diverse biological activities such as analgesic, anti-inflammatory, antialzheimer, anti-convulsant, anti-oxidant, antimicrobial, anti-cancer activities and so on. A detailed summary of quinoline ring from its origin to the recent advancements regarding its synthesis, green chemistry approaches, patented methods, and its marketed drugs is presented in the review. We attempted to review the literature compiling the critical information that has potential to encourage fellow researchers and scientists for the design and development of quinoline scaffold based active molecules that have improved therapeutic performance along with profound pharmacological properties.