Synthesis of novel 1,2,4-triazoles, triazolothiadiazines and triazolothiadiazoles as potential anticancer agents

Recent advances in zirconium-based catalysis and its applications in organic synthesis: a review

In recent years, transition metal-catalysed organic synthesis has received great importance. Zirconium, a second-row transition metal, has gained prominence owing to its luster and abundance, but it is more expensive than other transition metals because it is difficult to refine and process. In particular, active zirconia-based catalysts have fascinated researchers owing to their low toxicity, affordability, flexibility and excellent dispersion. This review focuses on the latest zirconium catalysts used in the manufacturing of medicinal compounds, bioactive molecules and pertinent synthesis mechanisms reported since 2020. In this review, the synthesis of various heterocycles such as imidazoles, pyrazole, pyrimidinones, quinolines, quinazolinones, pyridines, pyrroles, benzopyrans, substituted amides and triazolidine-based bioactive molecules is discussed in detail. Future research in this area is based on further understanding the scope of zirconium catalysed sustainable and approachable synthesis of biologically active compounds.

Pharmacological Evaluation of Bioisosterically Replaced and Triazole- Tethered Derivatives for Anticancer Therapy

Cancer has been the cause of the highest number of deaths in the human population despite the development and advancement in treatment therapies. The toxicity, drug resistance, and side effects of the current medicaments and therapies have left the void for more research and development. One of the possibilities to fill this void is by incorporating Triazole moieties within existing anticancer pharmacophores to develop new hybrid drugs with less toxicity and more potency. The placement of nitrogen in the triazole ring has endowed its characterization of being integrated with anticancer pharmacophores via bioisosteric replacement, click chemistry and organocatalyzed approaches. This review paper emphasizes the discussions from articles published from the early 2000s to the current 2020s about the triazole-based derivatives used in anticancer therapy, elaborating more on their chemical structures, target receptors or enzymes, mechanism of action, structure-activity relationships, different triazole-derived hybrid drugs under clinical and nonclinical trials, and recent advancements toward developing more potent and less toxic anticancer agents.

Targeting cyclin-dependent kinase 2 CDK2: Insights from molecular docking and dynamics simulation - A systematic computational approach to discover novel cancer therapeutics

Global public health is confronted with significant challenges due to the prevalence of cancer and the emergence of treatment resistance. This work focuses on the identification of cyclin-dependent kinase 2 (CDK2) through a systematic computational approach to discover novel cancer therapeutics. A ligand-based pharmacophore model was initially developed using a training set of seven potent CDK2 inhibitors. The obtained most robust model was characterized by three features: one donor (|Don|) and two acceptors (|Acc|). Screening this model against the ZINC database resulted in identifying 108 hits, which underwent further molecular docking studies. The docking results indicated binding affinity, with energy values ranging from -6.59 kcal mol⁻¹ to -7.40 kcal mol⁻¹ compared to the standard Roscovitine. The top 10 compounds (Z1-Z10) selected from the docking data were further screened for ADMET profiling, ensuring their compliance with pharmacokinetic and toxicological criteria. The top 3 compounds (Z1-Z3) chosen from the docking were subjected to Density Functional Theory (DFT) studies. They revealed significant variations in electronic properties, providing insights into the reactivity, stability, and polarity of these compounds. Molecular dynamics simulations confirmed the stability of the ligand-protein complexes, with acceptable RMSD and RMSF values. Specifically, compound Z1 demonstrated stability, around 2.4 Å, and maintained throughout the 100 ns simulation period with minimal conformational changes, stable RMSD, and consistent protein-ligand interactions.

Advances in synthesis and biological evaluation of CDK2 inhibitors for cancer therapy

One of the leading causes of mortality in the world is cancer. This disease occurs when responsible genes that regulate the cell cycle become inactive due to internal or external factors. Specifically, the G1/S and S/G2 transitions in the cell cycle are controlled by a protein called cyclin-dependent kinase 2 (CDK2). CDKs, which play a crucial role in managing the cell cycle, have been a wide area of research in cancer treatment. Over the past 11 years, significant research has been made in identifying potent, targeted, and efficient inhibitors of CDK2. In this summary, we have summarized recent developments in the synthesis and biological evaluation of CDK2 inhibitors.

Design, synthesis and anticancer activities evaluation of novel pyrazole modified catalpol derivatives

Catalpol, a natural product mainly existed in plenty of Chinese traditional medicines, is an iridoid compound with the comprehensive effects on neuroprotective, anti-inflammatory, choleretic, hypoglycemic and anticancer. However, there are some disadvantages for catalpol such as a short half-life in vivo, low druggability, stingy binding efficiency to target proteins and so on. It is necessary to make structural modification and optimization which enhance its performance on disease treatments and clinic applications. Pyrazole compounds have been reported to have excellent anticancer activities. Based on the previous research foundation of our research group on iridoids and the anticancer activities of catalpol and pyrazole, a series of pyrazole modified catalpol compounds were synthesized by principle of drug combination for serving as potential cancer inhibitors. These derivatives are characterized by ¹H NMR, ¹³C NMR and HRMS. The efficacy of anti-esophageal cancer and anti-pancreatic cancer activities were evaluated by the MTT assay on two esophageal cancer cells Eca-109 and EC-9706, and two pancreatic cancer cells PANC-1, BxPC-3 and normal pancreatic cell line HPDE6-C7, which showed that the compound 3e had strong inhibitory activity against esophageal cancer cells, this providing a theoretical basis for the discovery of catalpol-containing drugs.

Synthesis, X-ray crystal structure, Hirshfeld surface analysis and computational investigation into the potential inhibitory action of novel 6-(p-tolyl)-2-((p-tolyl)thio)methyl-7H-[1.2.4]triazolo[5,1-b][1,3,4]thiadiazine inhibits the main protease of COVID-19

In recent times, the novel coronavirus disease (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has now become a worldwide pandemic. With over 71 million confirmed cases, even though the effectiveness and side effects of the specific drugs and vaccines approved for this disease are still limited. Scientists and researchers from all across the world are working to find a vaccine and a cure for COVID-19 by using large-scale drug discovery and analysis. Heterocyclic compounds are regarded to be valuable sources for the discovery of new antiviral medications against SARS-CoV-2 because virus occurrences are still on the rise, and infectivity and mortality may also rise shortly. In this regard, we have synthesized a new triazolothiadiazine derivative. The structure was characterized by NMR spectra and confirmed by X-ray diffraction analysis. The structural geometry coordinates of the title compound are well reproduced by DFT calculations. NBO and NPA analyses have been performed to determine the interaction energies between bonding and antibonding orbital, and natural atomic charges of heavy atoms. Molecular docking suggests that the compounds may have good affinity for SAR-CoV-2 main protease, RNA-dependent RNA polymerase and nucleocapsid enzymes, particularly the main protease enzyme (binding energy of -11.9 kcal mol-1). The predicted docked pose of the compound is dynamically stable and reports a major van der Waals contribution (-62.00 kcal mol-1) to overall net energy.Communicated by Ramaswamy H. Sarma.

Design, synthesis and evaluation of novel 1,2,4-triazole derivatives as promising anticancer agents

Herein, we reported the synthesis of nineteen novel 1,2,4-triazole derivatives including 1,3-diphenyl-2-(1H-1,2,4-triazol-1-yl) propan-1-ones (7a-e), 1-(1,3-diphenylpropan-2-yl)-1H-1,2,4-triazole (8a-c) and 1,4-diphenyl-2-(1H-1,2,4-triazol-1-yl) butane-1,4-diones (10a-k). The structures of these derivatives were confirmed by spectroscopic techniques like IR, 1H-NMR, Mass spectroscopy and Elemental analysis. The cytotoxic activities of the synthesized compounds were evaluated against three human cancer cell lines including MCF-7, Hela and A549 using MTT assay. Compounds 7d, 7e, 10a and 10d showed a promising cytotoxic activity lower than 12 μM against Hela cell line. The safety of these compounds was also, evaluated on MRC-5 as a normal cell line and relieved that most of the synthesized compounds have proper selectivity against normal and cytotoxic cancerous cell lines. Finally, molecular docking studies were also, done to understand the mechanism and binding modes of these derivatives in the binding pocket of aromatase enzyme as a possible target.

Vision on Synthetic and Medicinal Facets of 1,2,4-Triazolo[3,4-b][1,3,4]thiadiazine Scaffold

The present review article strives to compile the latest synthetic approaches for the synthesis of triazolothiadiazine and its derivatives, along with their diverse pharmacological activities, viz. anticancer, antimicrobial, analgesic and anti-inflammatory, antioxidant, antiviral, enzyme inhibitors (carbonic anhydrase inhibitors, cholinesterase inhibitors, alkaline phosphatase inhibitors, anti-lipase activity, and aromatase inhibitors) and antitubercular agents. The review focuses particularly on the structure–activity relationship of biologically important 1,2,4-triazolo[3,4-b][1,3,4]thiadiazines, which have profound importance in drug design, discovery and development. In silico pharmacokinetic and molecular modeling studies have also been summarized. It is hoped that this review article will be of help to researchers engaged in the development of new biologically active entities for the rational design and development of new target-oriented 1,2,4-triazolo[3,4-b][1,3,4]thiadiazine-based drugs for the treatment of multifunctional diseases.

Design, Synthesis, and Biological Evaluation of Novel Triazolothiadiazoles Derived From NSAIDs as Anticancer Agents

BACKGROUND

Although transplantation, surgical resection, and tumor ablation are treatment options available following early diagnosis of HCC, their efficacy is restricted due to poor prognosis and high recurrence rates. Hence, small molecules with high selectivity and bioactivity are urgently required.

OBJECTIVE

This study presents the synthesis of a series of new triazolothiadiazole derivatives (1a-3j) with NSAID moieties and their cytotoxic bioactivities.

METHODS

The new synthetic derivatives (1-3; 1a-3j) and NSAIDs ibuprofen, naproxen, and flurbiprofen that commonly used in clinics were screened against human liver (Huh7), breast (MCF7), and colon (HCT116) carcinoma cell lines under in vitro conditions via NCI-sulforhodamine B assay.

RESULTS

The 4-methoxyphenyl substituted condensed derivatives 1h, 2h, and 3h were the most active compounds. Based on its high potency, compound 3h was selected for the further biological evaluation of hepatocellular carcinoma cell lines, and the mechanisms underlying cell death induced by 3h were determined. The results revealed that compound 3h induced apoptosis and cell cycle arrest in the sub G1 phase in human liver cancer cells.

CONCLUSION

These new small molecules may be used for the development of new lead compounds.

An insight on medicinal attributes of 1,2,4-triazoles

The present review aims to summarize the pharmacological profile of 1,2,4-triazole, one of the emerging privileged scaffold, as antifungal, antibacterial, anticancer, anticonvulsant, antituberculosis, antiviral, antiparasitic, analgesic and anti-inflammatory agents, etc. along with structure-activity relationship. The comprehensive compilation of work carried out in the last decade on 1,2,4-triazole nucleus will provide inevitable scope for researchers for the advancement of novel potential drug candidates having better efficacy and selectivity.

Antimicrobial, Antioxidant and Antiproliferative Activities of Novel Quinolones

The compound (2) formed by esterification of dimethyl morpholine (1) was converted to acetohydrazide (3). Subsequently Schiff bases (4 a–d) and carboxy(thio)amide derivatives (5 a–e) were synthesized. Then 1,2,4‐triazole (6 a–e), thia(oxa)zolidine (7 c,e) and thia(oxa)zol (8 c,e) derivatives were obtained by ring closure from carboxy(thio)amides. Mannich bases, which are containing quinolone were synthesized from 1,2,4‐triazoles. The structures of newly synthesized compounds were illuminated by spectroscopic methods. Their antimicrobial (MIC method), antioxidant (DPPH, FRAP, and CUPRAC methods), and anticancer activities (MTT method) were examined. Results showed that most of the compounds exhibited good antimicrobial (<0.03–31.25 μg/mL with MIC values) and antioxidant activities (IC50=0.001–0.004 with DPPH values). Also, some of the compounds have been found to have antiproliferative effects on the prostate (PC‐3), liver (Hep3B), and breast (MCF‐7) human cancer cells, and also these compounds did not have a cytotoxic effect on a normal cell.

Synthesis, ADMET Properties, and In Vitro Antimicrobial and Antibiofilm Activity of 5-Nitro-2-thiophenecarbaldehyde N-((E)-(5-Nitrothienyl)methylidene)hydrazone (KTU-286) against Staphylococcus aureus with Defined Resistance Mechanisms

The emergence of drug-resistant Staphylococcus aureus is responsible for high morbidity and mortality worldwide. New therapeutic options are needed to fight the increasing antimicrobial resistance among S. aureus in the clinical setting. We, therefore, characterized the in silico absorption, distribution, metabolism, elimination, and toxicity (ADMET) and in vitro antimicrobial activity of 5-nitro-2-thiophenecarbaldehyde N-((E)-(5-nitrothienyl)methylidene)hydrazone (KTU-286) against drug-resistant S. aureus strains with genetically defined resistance mechanisms. The antimicrobial activity of KTU-286 was determined by CLSI recommendations. The ADMET properties were estimated by using in silico modeling. The activity on biofilm integrity was examined by crystal violet assay. KTU-286 demonstrated low estimated toxicity and low skin permeability. The highest antimicrobial activity was observed among pan-susceptible (Pan-S) S. aureus (minimal inhibitory concentration (MIC) 0.5–2.0 µg/mL, IC₅₀ = 0.460 µg/mL), followed by vancomycin resistant S. aureus (VRSA) (MIC 4.0 µg/mL, IC₅₀ = 1.697 µg/mL) and methicillin-resistant S. aureus (MRSA) (MIC 1.0–16.0 µg/mL, IC₅₀ = 2.282 µg/mL). KTU-286 resulted in significant (p < 0.05) loss of S. aureus biofilm integrity in vitro. Further studies are needed for a better understanding of safety, synergistic relationship, and therapeutic potency of KTU-286.

Design, Synthesis, and Biological Evaluation of Novel 7H-[1,2,4]Triazolo[3,4-b][1,3,4]thiadiazine Inhibitors as Antitumor Agents

A series of novel anticancer hydrazinotriazolothiadiazine-based derivatives were designed based on the structure-activity relationship of the previously reported anticancer triazolothiadiazines. These derivatives were synthesized and biologically screened against full NCI-60 cancer cell lines revealing compound 5l with a potential antiproliferative effect. 5l was screened over 16 kinases to study its cytotoxic mechanism which showed to inhibit glycogen synthase kinase-3 β (GSK-3β) with IC₅₀ equal to 0.883 μM and 14-fold selectivity over CDK2. Also, 5l increased active caspase-3 levels, induced cell cycle arrest at the G2-M phase, and increased the percentage of Annexin V-fluorescein isothiocyanate-positive apoptotic cells in PC-3 prostate cancer-treated cells. Molecular docking and dynamics were performed to predict the binding mode of 5l in the GSK-3β ATP binding site. 5l can be utilized as a starting scaffold for developing potential GSK-3β inhibitors.

The different modes of chiral [1,2,3]triazolo[5,1-b][1,3,4]thiadiazines: crystal packing, conformation investigation and cellular activity

The crystal structures of four new chiral [1,2,3]triazolo[5,1-b][1,3,4]thiadiazines are described, namely, ethyl 5'-benzoyl-5'H,7'H-spiro[cyclohexane-1,6'-[1,2,3]triazolo[5,1-b][1,3,4]thiadiazine]-3'-carboxylate, C₁₉H₂₂N₄O₃S, ethyl 5'-(4-methoxybenzoyl)-5'H,7'H-spiro[cyclohexane-1,6'-[1,2,3]triazolo[5,1-b][1,3,4]thiadiazine]-3'-carboxylate, C₂₀H₂₄N₄O₄S, ethyl 6,6-dimethyl-5-(4-methylbenzoyl)-6,7-dihydro-5H-[1,2,3]triazolo[5,1-b][1,3,4]thiadiazine-3-carboxylate, C₁₇H₂₀N₄O₃S, and ethyl 5-benzoyl-6-(4-methoxyphenyl)-6,7-dihydro-5H-[1,2,3]triazolo[5,1-b][1,3,4]thiadiazine-3-carboxylate, C₂₁H₂₀N₄O₄S. The crystallographic data and cell activities of these four compounds and of the structures of three previously reported similar compounds, namely, ethyl 5'-(4-methylbenzoyl)-5'H,7'H-spiro[cyclopentane-1,6'-[1,2,3]triazolo[5,1-b][1,3,4]thiadiazine]-3'-carboxylate, C₁₉H₂₂N₄O₃S, ethyl 5'-(4-methoxybenzoyl)-5'H,7'H-spiro[cyclopentane-1,6'-[1,2,3]triazolo[5,1-b][1,3,4]thiadiazine]-3'-carboxylate, C₁₉H₂₂N₄O₄S, and ethyl 6-methyl-5-(4-methylbenzoyl)-6-phenyl-6,7-dihydro-5H-[1,2,3]triazolo[5,1-b][1,3,4]thiadiazine-3-carboxylate, C₂₂H₂₂N₄O₃S, are contrasted and compared. For both crystallization and an MTT assay, racemic mixtures of the corresponding [1,2,3]triazolo[5,1-b][1,3,4]thiadiazines were used. The main manner of molecular packing in these compounds is the organization of either enantiomeric pairs or dimers. In both cases, the formation of two three-centre hydrogen bonds can be detected resulting from intramolecular N-H...O and intermolecular N-H...O or N-H...N interactions. Molecules of different enantiomeric forms can also form chains through N-H...O hydrogen bonds or form layers between which only weak hydrophobic contacts exist. Unlike other [1,2,3]triazolo[5,1-b][1,3,4]thiadiazines, ethyl 5'-benzoyl-5'H,7'H-spiro[cyclohexane-1,6'-[1,2,3]triazolo[5,1-b][1,3,4]thiadiazine]-3'-carboxylate contains molecules of only the (R)-enantiomer; moreover, the N-H group does not participate in any significant intermolecular interactions. Molecular mechanics methods (force field OPLS3e) and the DFT B3LYP/6-31G+(d,p) method show that the compound forming enantiomeric pairs via weak N-H...N hydrogen bonds is subject to greater distortion of the geometry under the influence of the intermolecular interactions in the crystal. For intramolecular N-H...O and S...O interactions, an analysis of the noncovalent interactions (NCIs) was carried out. The cellular activities of the compounds were tested by evaluating their antiproliferative effect against two normal human cell lines and two cancer cell lines in terms of half-maximum inhibitory concentration (IC₅₀). Some derivatives have been found to be very effective in inhibiting the growth of Hela cells at nanomolar and submicromolar concentrations with minimal cytotoxicity in relation to normal cells.

Two decades of the synthesis of mono- and bis-aminomercapto[1,2,4]triazoles

4-Amino-5-mercapto[1,2,4]triazole and its 3-substituted derivatives have proven to be of biological interest and provide access to a new class of biologically active heterocyclic compounds for biomedical applications. This study will be helpful for scientific researchers interested in the chemistry of bifunctional versatile compounds as it provides a collection of all the methods for the preparation of 3-substituted-4-amino-5-mercapto[1,2,4]triazoles with aliphatic, aromatic, and heterocyclic moieties during the period from 2000 to mid-2020.

Synthesis, Characterization and Bioassay of Novel Substituted 1-(3-(1,3-Thiazol-2-yl)phenyl)-5-oxopyrrolidines

Thiazole derivatives attract the attention of scientists both in the field of organic synthesis and bioactivity research due to their high biological activity. In the present study, thiazole ring was obtained by the interaction of 1-(4-(bromoacetyl)phenyl)-5-oxopyrrolidine-3-carboxylic acid with thiocarbamide or benzenecarbothioamide, as well as tioureido acid. A series of substituted 1-(3-(1,3-thiazol-2-yl)phenyl)-5-oxopyrrolidines with pyrrolidinone, thiazole, pyrrole, 1,2,4-triazole, oxadiazole and benzimidazole heterocyclic fragments were synthesized and their antibacterial properties were evaluated against Gram-positive strains of Staphylococcus aureus, Bacillus cereus, Listeria monocytogenes and Gram-negative Pseudomonas aeruginosa, Escherichia coli and Salmonella enterica enteritidis. The vast majority of compounds exhibited between twofold and 16-fold increased antibacterial effect against the test-cultures when compared with Oxytetracycline.

Nanocrystalline ZnO: A Competent and Reusable Catalyst for the Preparation of Pharmacology Relevant Heterocycles in the Aqueous Medium

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Nanoparticle catalyzed synthesis is a green and convenient method to achieve most of the chemical transformations in water or other green solvents. Nanoparticle ensures an easy isolation process of catalyst as well as products from the reaction mixture avoiding the hectic work up procedure. Zinc oxide is a biocompatible, environmentally benign and economically viable nanocatalyst with effectivity comparable to the other metal nanocatalyst employed in several reaction strategies. This review mainly focuses on the recent applications of zinc oxide in the synthesis of biologically important heterocyclic molecules under sustainable reaction conditions.

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Application of zinc oxide in organic synthesis: Considering the achievable advantages of this nanocatalyst, presently several research groups are paying attention in anchoring zincoxide or its modified structure in several types of organic conversions e.g. multicomponent reactions, ligand-free coupling reactions, cycloaddition reaction, etc. The advantages and limitations of this nanocatalyst are also demonstrated. The present study aims to highlight the recent multifaceted applications of ZnO towards the synthesis of diverse heterocyclic motifs. Being a promising biocompatible nanoparticle, this catalyst has an important contribution in the fields of synthetic chemistry and medicinal chemistry.

Molecular docking studies, biological evaluation and synthesis of novel 3-mercapto-1,2,4-triazole derivatives

Synthesis of bioactive heterocyclic compounds having effective biological activity is an essential research area for wide-ranging applications. In this study, a conventional methodology has been developed for the synthesis of a series of new 3-mercapto-1,2,4-triazole derivatives 4a-f. The purity and structure of the synthesized molecules were confirmed by ¹H NMR, ¹³C NMR and elemental analysis. In addition, the prepared compounds were screened for their anti-proliferative activity against three human cancer cell lines including A549 (lung cancer), MCF7 (breast cancer) and SKOV3 (ovarian cancer) using MTT reduction assay. All the tested compounds demonstrated remarkable cytotoxic activity with IC₅₀ values ranging from 3.02 to 15.37 µM. The heterocyclic compound bearing 3,4,5-trimethoxy moiety was found to be the most effective among the series displaying an IC₅₀ of 3.02 µM specifically against the ovarian carcinoma cancer cell line (SKOV3). Moreover, Annexin V-FITC/propidium iodide staining assay indicated that this compound can induce apoptosis in SKOV3 cells. Furthermore, cell cycle assay showed a significant cell cycle arrest at the G2/M phase in a dose-dependent manner for this compound. The molecular docking results was showed binding modes of potent compound 4d perfectly corroborated the suggestion of binding to the colchicine site. The entire results conclude that 3-mercapto-1,2,4-triazole derivatives can be synthesized by a green method for biological and pharmacological applications. New analogs of 3-mercapto-1,2,4-triazole potential derivatives for anti-proliferative activity were synthesized. Cytotoxic activity of all synthesized compounds was evaluated against tree human cancer cell lines: lung (A549), breast (MCF7) and ovarian (SKOV3).

Synthesis of novel star-shaped molecules based on a 1,3,5-triazine core linked to different heterocyclic systems as novel hybrid molecules

The synthesis of novel star-shaped compounds based on an s-triazine core and linked to hexahydroacridinediones, pyrimido[4,5-b]quinolones, 1H-isoquinolino[2,1-a]quinolines, tetrahydro-4H-chromenes, dihydropyrano[2,3-c]pyrazoles, thiazole, or benzothiazole as new hybrid molecules through Michael and Hantzsch reactions is reported. For this purpose, 2,4,6-tris(4-formylphenoxy)benzaldehyde was used as a versatile precursor.

The synthesis of novel star-shaped compounds based on an s-triazine core and linked to different heterocycles as new hybrid molecules through Michael and Hantzsch reactions is reported.

Synthesis and evaluation of the HIF-1α inhibitory activity of 3(5)-substituted-4-(quinolin-4-yl)- and 4-(2-phenylpyridin-4-yl)pyrazoles as inhibitors of ALK5

The transcription factor hypoxia-inducible factor-1α (HIF-1α) plays an important role in apoptosis, metastasis, and proliferation and is recognized as an important potential therapeutic target for cancer. Six series of 3(5)-(6-methylpyridin-2-yl)-4-(quinolin-4-yl)pyrazoles (11a-d, 12a-d, and 18a-d) and 3(5)-(6-methylpyridin-2-yl)-4-(2-phenyl-pyridin-4-yl)pyrazoles (19a-d, 20a-d, and 21a-d) were synthesized and evaluated for activin receptor-like kinase 5 (ALK5) and HIF-1α inhibitory activity at the enzyme and cell levels. The effect of the lead compound 20d (J-1012) on HIF-1α activation in HCT116 cells was investigated. J-1012 markedly decreased the hypoxia-induced or TNF-induced accumulation of HIF-1α protein dose-dependently. Analysis revealed that J-1012 inhibited HIF-1α protein synthesis, without affecting the degradation of HIF-1α protein. Furthermore, by inhibiting the activation of HIF-1α, J-1012 suppressed the metastasis and proliferation and promoted apoptosis of HCT116 cells. These results suggest that J-1012 may be a potential therapeutic agent against human colon cancer.

Efficient synthesis of novel pyrazole-linked 1,2,4-triazolidine-3-thiones using bismuth on zirconium oxide as a recyclable catalyst in aqueous medium

The Bi₂O₃ loading on ZrO₂ as heterogeneous catalyst was established as an extremely efficient catalyst for the synthesis of a series of novel 5-(1-(2,4-dinitrophenyl)-3-substituted-phenyl-1H-pyrazol-4-yl)-1,2,4-triazolidine-3-thione derivatives (3a-o) with high yields (90-96%) by reaction of 1-(2,4-dinitrophenyl)-3-substituted-phenyl-1H-pyrazole-4-carbaldehydes and thiosemicarbazide using water as a greener solvent at 80 °C within 30-45 min. Materials with different percentages of Bi₂O₃ on ZrO₂ were prepared by simple wet impregnation method. The synthesized material has been characterized by various techniques (XRD, TEM, SEM, BET). 2.5% Bi₂O₃/ZrO₂ proved superior catalyst. The Bi₂O₃/ZrO₂ catalyst is easily recoverable and reused up to sixth run with no loss of activity. Excellent yields, short reaction time, avoidance of hazardous solvents, and no need for chromatographic purifications are the proven advantages.

Structural alterations based on naproxen scaffold: Synthesis, evaluation of antitumor activity and COX-2 inhibition, and molecular docking

A new series of non-carboxylic naproxen analogues, bearing a variety of ring systems, such as oxadiazoles 3a-c and 6a-c, cycloalkanes 4a-d, cyclic imides 5a-c, and triazoles 7-9 and 10a-c, was synthesized. In addition, in vitro antitumor activity and cyclooxygenase isozymes (COX-1/COX-2) inhibition assay of the target compounds 3-10 was studied. The results of the antitumor activity assays indicated that compounds 4b, 6c, 10b, and 10c exhibited the greatest antitumor activities against the tested cell lines MCF-7, MDA-231, HeLa, and HCT-116, with an IC₅₀ range of 4.83-14.49 μM. By comparison, the reference drugs doxorubicin, afatinib, and celecoxib yielded IC₅₀ values of 3.18-26.79, 6.20-11.40, and 22.79-42.74 μM, respectively. Furthermore, in vitro COX-1/COX-2 inhibition testing showed that the compounds 4b, 6c, 10b, and 10c exhibited effective COX-2 inhibition, with IC₅₀ values of 0.40-1.20 μM, and selectivity index (SI) values of >62.50-20.83, using celecoxib as a reference drug (IC₅₀ = 0.11 μM; COX-2 SI: >227.20). Compounds 6c and 10c, which were potent COX-2 inhibitors, were docked into the COX-2 binding site, where these compounds exhibited strong interactions.

Synthesis, biological evaluation and molecular dynamics studies of 1,2,4-triazole clubbed Mannich bases

The present work highlightsthe synthesis of a newer biologically active Mannich bases contributing 4-((4-fluorobenzylidene)amino)-5-(pyridin-4-yl)-4H-1,2,4-triazole-3-thiol and various heterocyclic amines via N-Mannich reaction by the conventional method as well as microwave heating approach as a part of an environmentally benign synthetic protocol. All the synthesized compounds were characterized by spectral analysis and were screened for in vitro antimicrobial, antitubercular and antiprotozoal activity. The compound 4k was found to be most active respectively against S. aureus (MIC 12.5 μM) and C. albicans (MIC 100 μM). The derivative 4 g displayed potency against L.mexicana and T. cruzi with IC₅₀ value 1.01 and 3.33 μM better than reference drug Miltefosina and Nifurtimox. The compound 4b displayed excellent potency against M. tuberculosis (MIC 6.25 μM) in the primary screening. The computational studies revealed for that Mannich derivative (4b) showed a high affinity toward the active site of enzyme which provides a strong platform for new structure-based design efforts. The Lipinski's parameters showed good drug-likeness properties and can be developed as an oral drug candidate.

Design, synthesis, and evaluation of novel ursolic acid derivatives as HIF-1α inhibitors with anticancer potential

Hypoxia-inducible factor-1α (HIF-1α), a key mediator in tumor metastasis and angiogenesis, is associated with poor patient prognosis and has been recognized as an important cancer drug target. In this work, four novel series of ursolic acid derivatives containing oxadiazole, triazolone, and piperazine moieties were designed, synthesized, and evaluated for anti-tumor activity as HIF-1α inhibitors. The majority of the compounds showed an excellent ability to inhibit the expression of HIF-1α. In particular, 11b inhibited HIF-1α transcriptional activity under hypoxic conditions with IC50=36.9μM. The cytotoxicity of these compounds was also assessed in human colon cancer cell HCT116 cells by the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay, and no compounds showed any appreciable cytotoxic activity (IC50>100μmol/L), which was lower than that of ursolic acid (IC50=23.8μmol/L). The mechanism of action of the representative compound 11b was also investigated.

Synthesis of thiophene and N-substituted thieno[3,2-d] pyrimidine derivatives as potent antitumor and antibacterial agents

A novel series of carbamothioylamino-benzene-sulfonamide-thiophene-carboxylates 4a-c and thieno[3,2-d]pyrimidin-2-yl-amino-benzene-sulfonamides 5a-c were synthesized in a series of synthetic steps and were used as key intermediates for the synthesis of thienotriazolopyrimidine-benzene-sulfonamide derivatives 6a-c and 7a-c. Thieno[3,2-d]pyrimidinones (8 and 9) were also prepared. Compound 9 was used as an intermediate for the synthesis of imidazole/1,2,4-triazole and tetrazine functionalized thieno[3,2-d]pyrimidine derivatives (10-12). Pyrrole derivatives/pyrrolopyrimidine/pyrrolotriazolopyrimidine functionalized thiophenes (15-19) were also synthesized. Structures of the newly synthesized compounds were established by elemental analysis and spectral data. Most of the newly synthesized compounds were evaluated for their in vitro activity against three human tumor cell lines, namely, liver cancer (HepG-2), colon cancer (HT-29) and lung cancer (NCI-H460), using doxorubicin as standard. Compounds 16 (GI50 = 0.02, 0.04 and 0.06 μmol L-1, resp.) and 19b (GI50 = 0.02, 0.03 and 0.05 μmol L-1, resp.) showed higher activity against all cell lines than doxorubicin. Most of the compounds were also screened for antibacterial activity using ciprofloxacin as standard drug. Compounds 4b and 6b, both containing benzenesulfonamide linked to N-, 10 bearing imidazole moiety, and 15 and 19b,c with a thiophene-2-carboxylic acid chain, exhibited high activity against Gram-positive and Gram-negative bacteria.