Synthesis and evaluation of a novel quinoline-triazole analogs for antitubercular properties via molecular hybridization approach

Identification of new anti-mycobacterial agents based on quinoline-isatin hybrids targeting enoyl acyl carrier protein reductase (InhA)

Tuberculosis (TB) is a global issue that poses a significant economic burden as a result of the ongoing emergence of drug-resistant strains. The urgent requirement for the development of novel antitubercular drugs can be addressed by targeting specific enzymes. One such enzyme, Mycobacterium tuberculosis (MTB) enoyl-acyl carrier protein (enoyl-ACP) reductase (InhA), plays a crucial role in the survival of the MTB bacterium. In this research study, a series of hybrid compounds combining quinolone and isatin were synthesized and assessed for their effectiveness against MTB, as well as their ability to inhibit the activity of the InhA enzyme in this bacterium. Among the compounds tested, 7a and 5g exhibited the most potent inhibitory activity against MTB, with minimum inhibitory concentration (MIC) values of 55 and 62.5 µg/mL, respectively. These compounds were further evaluated for their inhibitory effects on InhA and demonstrated significant activity compared to the reference drug Isoniazid (INH), with IC50 values of 0.35 ± 0.01 and 1.56 ± 0.06 µM, respectively. Molecular docking studies investigated the interactions between compounds 7a and 5g and the target enzyme, revealing hydrophobic contacts with important amino acid residues in the active site. To further confirm the stability of the complexes formed by 5g and 7a with the target enzyme, molecular dynamic simulations were employed, which demonstrated that both compounds 7a and 5g undergo minor structural changes and remain nearly stable throughout the simulated process, as assessed through RMSD, RMSF, and Rg values.

Investigation of new 1,2,3-triazolyl-quinolinyl-propan-2-ol derivatives as potential antimicrobial agents: in vitro and in silico approach

A new series of 1-((1-(4-substituted benzyl)-1H-1,2,3-triazol-4-yl)methoxy)-2-(2-substituted quinolin-4-yl)propan-2-ol (9a-x) have been synthesized. The newly synthesized 1,2,3-triazolyl-quinolinyl-propan-2-ol (9a-x) derivatives were screened for in vitro antimicrobial activity against M. tuberculosis H37Rv, E. coli, P. mirabilis, B. subtilis, and S. albus. Most of the compounds showed good to moderate antibacterial activity and all derivatives have shown excellent to good antitubercular activity with MIC 0.8-12.5 μg/mL. To know the plausible mode of action for antibacterial activity the docking study against DNA gyrase from M. tuberculosis and S. aureus was investigated. The compounds have shown significant docking scores in the range of -9.532 to -7.087 and -9.543 to -6.621 Kcal/mol with the DNA gyrase enzyme of S. aureus (PDB ID: 2XCT) and M. tuberculosis (PDB ID: 5BS8), respectively. Against the S. aureus and M. tuberculosis H37Rv strains, the compound 9 l showed good activity with MIC values of 62.5 and 3.33 μM. It also showed significant docking scores in both targets with -8.291 and -8.885 Kcal/mol, respectively. Molecular dynamics was studied to investigate the structural and dynamics transitions at the atomistic level in S. aureus DNA gyrase (2XCT) and M. tuberculosis DNA gyrase (5BS8). The results revealed that the residues in the active binding pockets of the S. aureus and M. tuberculosis DNA gyrase proteins that interacted with compound 9 l remained relatively consistent throughout the MD simulations and thus, reflected the conformation stability of the respective complexes. Thus, the significant antimicrobial activity of derivatives 9a-x recommended that these compounds could assist in the development of lead compounds to treat for bacterial infections.Communicated by Ramaswamy H. Sarma.

Synthesis of 12-quinoline substituted andrographolide derivatives and their preliminary evaluation as anti-aggregation drugs

Based on the structure of the natural product andrographolide, a series of novel 12-quinoline substituted derivatives 9 were designed and synthesized. In preliminary biological evaluation, these synthesized compounds showed prominent anti-platelet aggregation activities in response to thrombin and adenosine diphosphate (ADP) agonists. Among them, compound 9o (inhibition rate 55.73%, IC50 0.36 µM/L) had the highest anti-platelet aggregation activity induced by ADP. Compound 9q (inhibition rate 54.31%, IC50 0.30 µM/L) showed the highest anti-platelet aggregation activity induced by thrombin. Most of the derivatives had no significant cytotoxicity. Our research results provide a novel candidate drug structure for anti-platelet aggregation and enrich the scope of application of andrographolide derivatives.

Recent advances in functionalized quinoline scaffolds and hybrids-Exceptional pharmacophore in therapeutic medicine

Quinoline is one of the most common nitrogen-containing heterocycles owing to its fascinating pharmacological properties and synthetic value in organic and pharmaceutical chemistry. Functionalization of this moiety at different positions has allowed for varying pharmacological activities of its derivative. Several publications over the last few decades have specified various methods of synthesis. This includes classical methods of synthesizing the primary quinoline derivatives and efficient methods that reduce reaction time with increased yield employing procedures that fulfill one of the twelve green chemistry principles, "safer solvent". The metal nanoparticle-catalyzed reaction also serves as a potent and effective technique for the synthesis of quinoline with excellent atom efficiency. The primary focus of this review is to highlight the routes to synthesizing functionalized quinoline derivatives, including hybrids that have moieties with predetermined activities bound to the quinoline moiety which are of interest in synthesizing drug candidates with dual modes of action, overcoming toxicity, and resistance amongst others. This was achieved using updated literature, stating the biological activities and mechanisms through which these compounds administer relief. The ADMET studies and Structure-Activity Relationship (SAR) of novel derivatives were also highlighted to explore the drug-likeness of the quinoline-hybrids and the influence of substituent characteristics and position on the biological activity of the compounds.

Chemistry and Therapeutic Aspect of Triazole: Insight into the Structure-activity Relationship

The triazole ring is a highly significant heterocycle that occurs naturally in many commodities and is a common feature in pharmaceuticals. Recently, heterocyclic compounds and their derivatives have been getting a lot of attention in medicinal chemistry because they have a lot of pharmacological and biological potential. For example, a lot of drugs have nitrogen-containing heterocyclic moieties. The triazole ring is often used as a bio-isostere of the oxadiazole nucleus. The oxygen atom in the oxadiazole nucleus is replaced by nitrogen in the triazole analogue. This article explores the pharmacological properties of the triazole moiety, including but not limited to antibacterial, analgesic, anticonvulsant, anthelmintic, anti-inflammatory, antitubercular, antimalarial, antioxidant, antiviral, and other properties. Additionally, we discuss the diverse multi- target pharmacological activities exhibited by triazole-based compounds. Based on a literature review, it is evident that triazole-based chemicals hold significant potential for various applications.

Molecular Target Interactions of Quinoline Derivatives as Anticancer Agents: A Review

One of the leading causes of death worldwide is cancer, which poses substantial risks to both society and an individual's life. Cancer therapy is still challenging, despite developments in the field and continued research into cancer prevention. The search for novel anticancer active agents with a broader cytotoxicity range is therefore continuously ongoing. The benzene ring gets fused to a pyridine ring at two carbon atoms close to one another to form the double ring structure of the heterocyclic aromatic nitrogen molecule known as quinoline (1-azanaphthalene). Quinoline derivatives contain a wide range of pharmacological activities, including antitubercular, antifungal, antibacterial, and antimalarial properties. Quinoline derivatives have also been shown to have anticancer properties. There are many quinoline derivatives widely available as anticancer drugs that act via a variety of mechanisms on various molecular targets, such as inhibition of topoisomerase, inhibition of tyrosine kinases, inhibition of heat shock protein 90 (Hsp90), inhibition of histone deacetylases (HDACs), inhibition of cell cycle arrest and apoptosis, and inhibition of tubulin polymerization.

Synthesis and biological activity profile of novel triazole/quinoline hybrids

Based on the significant and diverse pharmacophore features of triazole ring and considering the potent antimicrobial properties of quinoline scaffold, a novel series of 1,2,3-triazole-based polyaromatic compounds containing chloroquinoline moiety were synthesized through a well-established synthetic methodology, named click chemistry. The structure of the synthetic compounds was characterized by various spectroscopic methods. The final products of triazole/quinoline hybrids and ((prop-2-yn-1-yloxy)methyl)benzene intermediates were screened for their antibacterial (Staphylococcus aureus, Escherichia coli, Shigella flexneri, and Salmonella enterica), antifungal (Candida albicans, Saccharomyces cerevisiae, and Aspergillus fumigatus), and cytotoxic activities. The best antifungal compounds exhibited minimum inhibitory concentration (MIC), in the range of 0.35-0.63 µM, against S. cerevisiae without any cytotoxic effect. These compounds can be selected as the potential candidates for treating invasive fungal infections caused by S. cerevisiae, after further investigation. Preliminary in silico ADME studies also predicted the favorable pharmacokinetic attributes of most compounds.

GANAB and N-Glycans Substrates Are Relevant in Human Physiology, Polycystic Pathology and Multiple Sclerosis: A Review

Glycans are one of the four fundamental macromolecular components of living matter, and they are highly regulated in the cell. Their functions are metabolic, structural and modulatory. In particular, ER resident N-glycans participate with the Glc3Man9GlcNAc2 highly conserved sequence, in protein folding process, where the physiological balance between glycosylation/deglycosylation on the innermost glucose residue takes place, according GANAB/UGGT concentration ratio. However, under abnormal conditions, the cell adapts to the glucose availability by adopting an aerobic or anaerobic regimen of glycolysis, or to external stimuli through internal or external recognition patterns, so it responds to pathogenic noxa with unfolded protein response (UPR). UPR can affect Multiple Sclerosis (MS) and several neurological and metabolic diseases via the BiP stress sensor, resulting in ATF6, PERK and IRE1 activation. Furthermore, the abnormal GANAB expression has been observed in MS, systemic lupus erythematous, male germinal epithelium and predisposed highly replicating cells of the kidney tubules and bile ducts. The latter is the case of Polycystic Liver Disease (PCLD) and Polycystic Kidney Disease (PCKD), where genetically induced GANAB loss affects polycystin-1 (PC1) and polycystin-2 (PC2), resulting in altered protein quality control and cyst formation phenomenon. Our topics resume the role of glycans in cell physiology, highlighting the N-glycans one, as a substrate of GANAB, which is an emerging key molecule in MS and other human pathologies.

Emerging impact of triazoles as anti-tubercular agent

Tuberculosis, a disease of poverty is a communicable infection with a reasonably high mortality rate worldwide. 10 Million new cases of TB were reported with approx 1.4 million deaths in the year 2019. Due to the growing number of drug-sensitive and drug-resistant tuberculosis cases, there is a vital need to develop new and effective candidates useful to combat this deadly disease. Despite tremendous efforts to identify a mechanism-based novel antitubercular agent, only a few have entered into clinical trials in the last six decades. In recent years, triazoles have been well explored as the most valuable scaffolds in drug discovery and development. Triazole framework possesses favorable properties like hydrogen bonding, moderate dipole moment, enhanced water solubility, and also the ability to bind effectively with biomolecular targets of M. tuberculosis and therefore this scaffold displayed excellent potency against TB. This review is an endeavor to summarize an up-to-date innovation of triazole-appended hybrids during the last 10 years having potential in vitro and in vivo antitubercular activity with structure activity relationship analysis. This review may help medicinal chemists to explore the triazole scaffolds for the rational design of potent drug candidates having better efficacy, improved selectivity and minimal toxicity so that these hybrid NCEs can effectively be explored as potential lead to fight against M. tuberculosis.

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.

1,2,3-Triazole- and Quinoline-Based Hybrids with Potent Antiplasmodial Activity

BACKGROUND

Malaria is a disease causing millions of victims every year and requires new drugs, often due to parasitic strain mutations. Thus, the search for new molecules that possess antimalarial activity is constant and extremely important. However, the potential that an antimalarial drug possesses cannot be ignored, and molecular hybridization is a good strategy to design new chemical entities.

OBJECTIVE

This review article aims to emphasize recent advances in the biological activities of new 1,2,3-triazole- and quinoline-based hybrids and their place in the development of new biologically active substances. More specifically, it intends to present the synthetic methods that have been utilized for the syntheses of hybrid 1,2,3-triazoles with quinoline nuclei.

METHOD

We have comprehensively and critically discussed all the information available in the literature regarding 1,2,3-triazole- and quinoline-based hybrids with potent antiplasmodial activity.

RESULTS

The quinoline nucleus has already been proven to lead to new chemical entities in the pharmaceutical market, such as drugs for the treatment of malaria and other diseases. The same can be said about the 1,2,3-triazole heterocycle, which has been shown to be a beneficial scaffold for the construction of new drugs with several activities. However, only a few triazoles have entered the pharmaceutical market as drugs.

CONCLUSION

Many studies have been conducted to develop new substances that may circumvent the resistance developed by the parasite that causes malaria, thereby improving the therapy currently used.

Current Pharmaceutical Aspects of Synthetic Quinoline Derivatives

Quinoline derivatives are considered broad-spectrum pharmacological compounds that exhibit a wide range of biological activities. Integration of quinoline moiety can improve its physical and chemical properties and also pharmacological behavior. Due to its wide range of pharmaceutical applications, it is a very popular compound to design new drugs for the treatment of multiple diseases like cancer, dengue fever, malaria, tuberculosis, fungal infections, AIDS, Alzheimer's disease and diabetes. In this review, our major focus is to pay attention to the biological activities of quinoline compounds in the treatment of these diseases such as anti-viral, anti-cancer, anti-malarial, antibacterial, anti-fungal, anti-tubercular and anti-diabetic.

Design, Synthesis and Anticancer Evaluation of Substituted Cinnamic Acid Bearing 2-Quinolone Hybrid Derivatives

A new series of hybrid molecules containing cinnamic acid and 2-quinolinone derivatives were designed and synthesized. Their structures were confirmed by 1H-NMR, 13C-NMR and mass analyses. All the synthesized hybrid molecules were assessed for their in vitro antiproliferative activity against more than one cancer cell lines. Compound 3-(3,5-dibromo-7,8-dihydroxy-4-methyl-2-oxoquinolin-1(2H)-ylamino)-3-phenylacrylic acid (5a) with IC50 = 1.89 μM against HCT-116 was proved to the most potent compound in this study, as compared to standard drug staurosporin. DNA flow cytometry assay of compound 5a revealed G2/M phase arrest and pre-G1 apoptosis. Annexin V-FITC showed that the percentage of early and late apoptosis was increased. The results of topoisomerase enzyme inhibition activity showed that the hybrid molecule 5a displays potent inhibitory activity compared with control.

Triazole analogues as potential pharmacological agents: a brief review

Background

A large number of studies have recently reported that, because of their significant biological and pharmacological properties, heterocyclic compounds and their derivatives have attracted a strong interest in medicinal chemistry. The triazole nucleus is one of the most important heterocycles which has a feature of natural products as well as medicinal agents. Heterocyclic nitrogen is abundantly present in most medicinal compounds. The derivatization of triazole ring is based on the phenomenon of bio-isosteres in which substituted the oxygen atom of oxadiazole nucleus with nitrogen triazole analogue.

Main text

This review focuses on recent synthetic procedure of triazole moiety, which comprises of various pharmacological activities such as antimicrobial, anticonvulsant, anti-inflammatory, analgesic, antitubercular, anthelmintic, antioxidant, antimalarial, antiviral, etc..

Conclusion

This review highlights the current status of triazole compounds as different multi-target pharmacological activities. From the literature survey, triazole is the most widely used compound in different potential activities.

Triazole-containing hybrids with anti-Mycobacterium tuberculosis potential - Part I: 1,2,3-Triazole

Tuberculosis regimens currently applied in clinical practice require months of multidrug therapy, which imposes a major challenge of patient compliance and drug resistance development. Moreover, because of the increasing emergence of hard-to-treat tuberculosis, this disease continues to be a significant threat to the human population. 1,2,3-triazole as a privileged structure has been widely used as an effective template for drug discovery, and 1,2,3-triazole-containing hybrids that can simultaneously act on dual or multiple targets in Mycobacterium tuberculosis have the potential to circumvent drug resistance, enhance efficacy, reduce side effects and improve pharmacokinetic as well as pharmacodynamic profiles. Thus, 1,2,3-triazole-containing hybrids are useful scaffolds for the development of antitubercular agents. This review aims to highlight recent advances of 1,2,3-triazole-containing hybrids with potential activity against various forms of M. tuberculosis, covering articles published between 2015 and 2020. The structure-activity relationship and the mechanism of action are also discussed to facilitate further rational design of more effective drug candidates.

Antiproliferative activity, enzymatic inhibition and apoptosis-promoting effects of benzoxazole-based hybrids on human breast cancer cells

New benzoxazole derivatives containing 1,3,4-oxadiazole, 1,2,4-triazole or triazolothiadiazine rings were synthesized and screened for their in vitro antiproliferative activities against MCF-7 and MDA-MB-231 breast cancer cell lines using MTT assay. Doxorubicin, cisplatin and 2-(4-aminophenyl)benzothiazole (CJM 126) were used as references. The most active compounds 7a, 8d, 8e and 10c were screened for their antiproliferative activities against MCF-10A normal breast cells where compounds 8e and 7a were the most selective towards MCF-7 and MDA-MB-231 cell lines, respectively compared to CJM 126. In vitro enzymatic inhibition assays of epidermal growth factor receptor (EGFR) and aromatase (ARO) enzymes were performed. Compound 7a showed inhibition of EGFR comparable to that of erlotinib while compound 8e exhibited nearly half the inhibitory activity of erlotinib towards EGFR and was more potent inhibitor of ARO than letrozole. Caspase-9 activation assay, cell cycle analysis and Annexin-V/ Propidium iodide assay performed for compounds 7a, 8d, 8e and 10c demonstrated over expression of caspase-9 protein level, pre G₁ apoptosis and high annexin V binding affinity. Therefore, these compounds are considered as potent apoptosis-promoting agents. The predicted docking studies and in silico chemo-informatic properties of compounds 7a and 8e were appropriate. Compounds 7a and 8e are promising anti-breast cancer agents exhibiting potent apoptosis-promoting properties.

Development of an efficient, one-pot, multicomponent protocol for synthesis of 8-hydroxy-4-phenyl-1,2-dihydroquinoline derivatives

A one-pot quick and efficient multicomponent reaction has been developed for the synthesis of a new series of functionalized 8-hydroxy-4-phenyl-1,2-dihydroquinoline derivatives using 30 mol% ammonium acetate in ethanol as solvent. This economical protocol run smoothly to give variety of quinoline derivatives in 55% to 98% yield from inexpensive reagents and catalyst in mild reaction conditions. Various spectroscopic techniques like FTIR, 1H NMR and 13C NMR, MALDI-TOF-MS, and EI-MS were used to study and confirm their structure.

Synthesis and antibiofilm activity of 1,2,3-triazole-pyridine hybrids against methicillin-resistant Staphylococcus aureus (MRSA)

Antibiotic-resistant bacteria are emerging at an alarming rate, posing a potential threat to human health. A series of 1,2,3-triazole-pyridine hybrids were synthesised as promising antibiofilm agents against planktonic and sessile MRSA.

Antimicrobial Screening, in Silico Studies and QSAR of Chalcone-based 1,4-disubstituted 1,2,3-triazole Hybrids

The in vitro antimicrobial properties of some chalcones (1A-1C: ) and chalcone tethred 1,4-disubstituted 1,2,3-triazoles (2A-2U: ) towards different microbial strains viz. Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa, Aspergillus niger and Candida albicans are reported. Compounds 2G: and 2U: exhibited better potency than the standard Fluconazole with MIC values of 0.0063 µmol/mL and 0.0068 µmol/mL, respectively. Furthermore, molecular docking was performed to investigate the binding modes of two potent compounds 2Q: and 2G: with E. coli topoisomerase II DNA gyrase B and C. albicans lanosterol 14α-demethylase, respectively. Based on these results, a statistically significant quantitative structure activity relationship (QSAR) model was successfully summarized for antibacterial activity against B. subtilis.

A Review on Recent Advances in Nitrogen-Containing Molecules and Their Biological Applications

The analogs of nitrogen-based heterocycles occupy an exclusive position as a valuable source of therapeutic agents in medicinal chemistry. More than 75% of drugs approved by the FDA and currently available in the market are nitrogen-containing heterocyclic moieties. In the forthcoming decade, a much greater share of new nitrogen-based pharmaceuticals is anticipated. Many new nitrogen-based heterocycles have been designed. The number of novel N-heterocyclic moieties with significant physiological properties and promising applications in medicinal chemistry is ever-growing. In this review, we consolidate the recent advances on novel nitrogen-containing heterocycles and their distinct biological activities, reported over the past one year (2019 to early 2020). This review highlights the trends in the use of nitrogen-based moieties in drug design and the development of different potent and competent candidates against various diseases.