Synthesis of new thiazolo-celecoxib analogues as dual cyclooxygenase-2/15-lipoxygenase inhibitors: Determination of regio-specific different pyrazole cyclization by 2D NMR

Synthesis and Biological Evaluation of 1-(4-(Methylsulfonyl)Phenyl)-5-Phenyl-1H-Pyrazole-4-Carboxamides as Epidermal Growth Factor Receptor-Targeting Anticancer Agents

We reported the synthesis of novel pyrazole amide derivatives. The newly synthesized compounds are exhibiting in vitro anti-cancer efficacy against MCF-7 and A-549 human cancer cell lines. The compounds, 6m, 6o, and 6p have greater activity against A-549 cell lines with reference to 5-Fluorouracil. Similarly, in vitro, epidermal growth factor receptor results revealed that compounds 6p (50% inhibitory concentration [IC50] = 0.79 ± 0.04 µM) and 6m (IC50 = 0.86 ± 0.06 µM) have shown improved activity in comparison to the standard Erlotinib (IC50 = 0.41 ± 0.03 µM). This article systematically examines the docking studies of lead compounds 6i, 6m, 6o, and 6p, finally found compound 6o showing better binding properties (-10.85 kcal) among all.

Innovative Pyrazole Hybrids: A New Era in Drug Discovery and Synthesis

Heterocyclic compounds that include nitrogen and their derivatives have long been regarded as excellent sources of medicinal substances. Pyrazole is a compound with two nitrogen atoms and an aromatic structure. It has several uses and intricate stereochemistry arranged in a five-membered ring. The knowledge of different pyrazole derivatives and their range of physiological and pharmacological actions has grown significantly in recent years. The scientific community has recently increasingly focused on exploring the chemistry of various pyrazole hybrids due to their enhanced biological activities. This review investigates the chemistry of these diverse pyrazole hybrids, emphasizing their synthesis and their antidiabetic, antibacterial, anticancer, antimicrobial, antioxidant, and anti-inflammatory activities. Articles published from 2014 onward with an emphasis on the last 5 years are included in this review. This review is anticipated to be useful for future investigations and innovative concepts in the pursuit of designs for creating more promising hybrids of pyrazoles.

Insight into the therapeutic potential of pyrazole-thiazole hybrids: A comprehensive review

Several pyrazole-thiazole hybrids featuring two potentially bioactive pharmacophores with or without linker have been synthesized using the molecular hybridization approach as target structures by medicinal chemists to modulate multiple drug targets simultaneously. The presented review aims to provide an overview of the diversified and wide array of pharmacological activities of these hybrids bestowing anticancer, antifungal, antibacterial, analgesic, anti-inflammatory, antioxidant, antitubercular, antiviral, antiparasitic, and miscellaneous activities. The structure-activity relationships and potential mechanism of action are also reviewed to shed light on the development of more effective and biotargeted candidates. This review focuses on the latest research advances in the biological profile of pyrazole-thiazole hybrids reported from 2015 to the present, providing medicinal researchers with a comprehensive platform to rationally design and develop more promising pyrazole-thiazole hybrids.

Discovery of new thymol-3,4-disubstituted thiazole hybrids as dual COX-2/5-LOX inhibitors with in vivo proof

New thymol-3,4-disubstitutedthiazole hybrids were synthesised as dual COX-2/5-LOX inhibitors. Compounds 6b, 6d, 6e, and 6f displayed in vitro inhibitory activity against COX-2 (IC50= 0.037, 0.042, 0.046, and 0.039 µM) nearly equal to celecoxib (IC50= 0.045 µM). 6b, 6d, and 6f showed SI (379, 341, and 374, respectively) higher than that of celecoxib (327). 6a-l elicited in vitro 5-LOX inhibitory activity higher than quercetin. 6a-f, 6i-l, 7a, and 7c possessed in vivo inhibition of formalin induced paw edoema higher than celecoxib. 6a, 6b, 6f, 6h-l, and 7b showed gastrointestinal safety profile as celecoxib and diclofenac sodium in the population of fasted rats. Induced fit docking and molecular dynamics simulation predicted good fitting of 6b and 6f without changing the packing and globularity of the apo protein. In conclusion, 6b and 6f achieved the target goal as multitarget inhibitors of inflammation.

Discovery of novel thiazole derivatives containing pyrazole scaffold as PPAR-γ Agonists, α-Glucosidase, α-Amylase and COX-2 inhibitors; Design, synthesis and in silico study

A novel series of thiazole derivatives with pyrazole scaffold 16a-l as hybrid rosiglitazone/celecoxib analogs was designed, synthesized and tested for its PPAR-γ activation, α-glucosidase, α-amylase and COX-2 inhibitory activities. Regarding the anti-diabetic activity, all compounds were assessed in vitro against PPAR-γ activation, α-glucosidase and α-amylase inhibition in addition to in vivo hypoglycemic activity (one day and 15 days studies). Compounds 16b, 16c, 16e and 16 k showed good PPAR-γ activation (activation % ≈ 72-79 %) compared to that of the reference drug rosiglitazone (74 %). In addition, the same derivatives 16b, 16c, 16e and 16 k showed the highest inhibitory activities against α-glucosidase (IC50 = 0.158, 0.314, 0.305, 0.128 μM, respectively) and against α-amylase (IC50 = 32.46, 23.21, 7.74, 35.85 μM, respectively) compared to the reference drug acarbose (IC50 = 0.161 and 31.46 μM for α-glucosidase and α-amylase, respectively). The most active derivatives 16b, 16c, 16e and 16 k also revealed good in vivo hypoglycemic effect comparable to that of rosiglitazone. In addition, compounds 16b and 16c had the best COX-2 selectivity index (S.I. = 18.7, 31.7, respectively) compared to celecoxib (S.I. = 10.3). In vivo anti-inflammatory activity of the target derivatives 16b, 16c, 16e and 16 k supported the results of in vitro screening as the derivatives 16b and 16c (ED50 = 8.2 and 24 mg/kg, respectively) were more potent than celecoxib (ED50 = 30 mg/kg). In silico docking, ADME, toxicity, and molecular dynamic studies were carried out to explain the interactions of the most active anti-diabetic and anti-inflammatory compounds 16b, 16c, 16e and 16 k with the target enzymes in addition to their physiochemical parameters.

Experimental investigation and molecular simulations of quinone related compounds as COX/LOX inhibitors

Quinone-containing compounds have risen as promising anti-inflammatory targets; however, very little research has been directed to investigate their potentials. Accordingly, the current study aimed to design and synthesize group of quinones bearing different substituents to investigate the effect of these functionalities on the anti-inflammatory activities of this important scaffold. The choice of these substituents was carefully done, varying from a directly attached heterocyclic ring to different aromatic moieties linked through a nitrogen spacer. Both in vitro and in vivo anti-inflammatory activities of the synthesized compounds were assessed relative to the positive standards: celecoxib and indomethacin. The in vitro enzymatic and transcription inhibitory actions of all the synthesized compounds were tested against cyclooxygenase-2 (COX-2), cyclooxygenase-1 (COX-1), and 5-lipoxygenase (LOX) and the in vivo gene expression of Interleukin-1, interleukin 10, and Tumor Necrosis Factor-α (TNF-α) were determined. The IC50 against COX-1 and COX-2 enzymes obtained by the immunoassay test revealed promising activities of sixteen compounds with selectivity indices higher than 100-fold COX-2 selectivity. Out of those, four compounds revealed selectivity indices comparable to celecoxib as a reference drug. Furthermore, all the tested compounds inhibited LOX with an IC50 in the range of 1.59-3.11 µM superior to that of the reference drug used; zileuton (IC50 = 3.50 µM). Consequently, these results highlight the promising LOX inhibitory activity of the tested compounds. The obtained in vivo paw edema results showed high inhibitory percentage for the compounds 9a, 9b, and 11a with the significant lower TNF-α relative mRNA expression for compounds 5a, 5d, 9a, 9b, 12d, and 12e. Finally, in silico docking of the most active compounds (5b, 5d, 9a, 9b) against COX2 enzymes presented an acceptable justification of the obtained in vitro inhibitory activities. As a conclusion, Compounds 5b, 5d, 9a, 9b, and 11b showed promising results and thus deserves further investigation.

Discovery of new 2-(3-(naphthalen-2-yl)-4,5-dihydro-1H-pyrazol-1-yl)thiazole derivatives with potential analgesic and anti-inflammatory activities: In vitro, in vivo and in silico investigations

Joining the global demand for the discovery of potent NSAIDs with minimized ulcerogenic effect, new pyrazole clubbed thiazole derivatives 5a-o were designed and synthesized. The new derivatives were initially evaluated for their analgesic activity. Eight compounds 5a, 5c, 5d, 5e, 5f, 5h, 5m, and 5o showed higher activity than Indomethacin (potency = 105-130 % vs. 100 %). Subsequently, they were picked for further evaluation of their anti-inflammatory activity, ulcerogenic liability as well as toxicological studies. Derivatives 5h and 5m showed a potential % edema inhibition after 3 h (79.39 % and 72.12 %, respectively), with a promising safety profile and low ulcer indices (3.80 and 3.20, respectively). The two compounds 5h and 5m were subjected to in vitro COX-1 and COX-2 inhibition assay. The candidate 5h showed nearly equipotent COX-1 inhibition (IC50 = 38.76 nM) compared to the non-selective reference drug Indomethacin (IC50 = 35.72 nM). Compound 5m expressed significant inhibitory activities and a higher COX-2 selectivity index (IC50 = 87.74 nM, SI = 2.05) in comparison with Indomethacin (SI = 0.52), with less selectivity than Celecoxib (SI = 8.31). Simulation docking studies were carried out to gain insights into the binding interaction of compounds 5h and 5m in the vicinity of COX-1 and COX-2 enzymes that illustrated the importance of pyrazole clubbed thiazole core in hydrogen bonding interactions. The thiazole motif of compounds 5h and 5m exhibited a well orientation toward COX-1 Arg120 key residue by hydrogen bonding interactions. Compound 5h revealed an additional arene-cation interaction with Arg120 that could rationalize its superior COX-1 inhibitory activity. Compounds 5h and 5m overlaid the co-crystallized ligand Celecoxib I differently in the active site of COX-2. Compound 5m showed an enhanced accommodation with binding energy of - 6.13 vs. - 1.70 kcal/mol of compounds 5h. The naphthalene ring of compound 5m adopted the Celecoxib I benzene sulfonamide region that is stabilized by hydrogen-arene interactions with the hydrophobic sidechains of the key residues Ser339 and Phe504. Further, the core structure of compound 5m, pyrazole clubbed thiazole, revealed deeper hydrophobic interactions with Ala513, Leu517 and Val509 residues. Finally, a sensitive and accurate UPLC-MS/MS method was developed for the simultaneous estimation of some selected promising pyrazole derivatives in rat plasma. Accordingly, compounds 5h and 5m were suggested to be promising potent analgesic and anti-inflammatory agents with improved safety profiles and a novel COX isozyme modulation activity.

Dual COX-2 and 15-LOX inhibition study of novel 4-arylidine-2-mercapto-1-phenyl-1H-imidazolidin-5(4H)-ones: Design, synthesis, docking, and anti-inflammatory activity

Novel arylidene-5(4H)-imidazolone derivatives 4a-r were designed and evaluated as multidrug-directed ligands, that is, inflammatory, proinflammatory mediators, and reactive oxygen species (ROS) inhibitors. All of the tested compounds showed cyclooxygenase (COX)-1 inhibitory effect more than celecoxib and less than indomethacin and also demonstrated an improved inhibitory activity against 15-lipoxygenase (15-LOX). Compounds 4f, 4l, and 4p exhibited COX-2 selectivity comparable to that of celecoxib, while 4k was the most selective COX-2 inhibitor. Interestingly, the screened results showed that compound 4k exhibited a superior inhibition effect against 15-LOX and was found to be the most selective COX-2 inhibitor over celecoxib, whereas compound 4f showed promising COX-2 and 15-LOX inhibitory activities besides its inhibitory effect against ROS production and its lowering effect of both tumor necrosis factor-α and interleukin-6 levels by ∼80%. Moreover, compound 4f attenuated the lipopolysaccharide-mediated increase in NF-κB activation in RAW 264.7 macrophages. The preferred binding affinity of these molecules was confirmed by docking studies. We conclude that arylidene-5(4H)-imidazolone scaffolds provide promising hits for developing new synthons with anti-inflammatory and antioxidant activities.

Pyrazole-based and N,N-diethylcarbamate functionalized some novel aurone analogs: Design, synthesis, cytotoxic evaluation, docking and SAR studies, against AGS cancer cell line

The present study involves the design, synthesis, and biological evaluation of a series of thirty-three, pyrazole-based and N,N-diethylcarbamate functionalized, novel aurone analogs, against AGS cancer cell line. These novel aurone analogs are obtained from the reaction of pyrazole-based 6-hydroxyaurones with diethyl carbamoyl chloride using mild basic reagent. The cytotoxic activities of these compounds were evaluated against a human gastric adenocarcinoma cell line (AGS) and disclosed some potential outcomes as several analogs were found to have cytotoxicity better than the reference drugs Oxaliplatin and Leucovorin. The structure-activity relationship (SAR) study further unveiled the critical role of replacing the hydroxyl group in ring A with a carbamoyl group for cytotoxic activity. Among these aurone analogs, 8e and 8f, with IC50 values of 6.5 ± 0.024 μM and 6.6 ± 0.035 μM, respectively, are identified as the most active compounds. Molecular docking studies were conducted against HER2, a human epidermal growth factor involved in gastric and ovarian cancer, to investigate the binding interactions between the compounds and the protein HER2, where7e and 8e exhibited maximum interactions.

Dual COX-2/15-LOX inhibitors: A new avenue in the prevention of cancer

Dual cyclooxygenase 2/15-lipoxygenase inhibitors constitute a valuable alternative to classical non-steroidal anti-inflammatory drugs (NSAIDs) and selective COX-2 (cyclooxygenase-2) inhibitors for the treatment of inflammatory diseases, as well as preventing the cancer. Indeed, these latter present diverse side effects, which are reduced or absent in dual-acting agents. In this review, COX-2 and 15-LOX (15-lipoxygenase) pathways are first described in order to highlight the therapeutic interest of designing such compounds. Various structural families of dual inhibitors are illustrated. This study discloses various structural families of dual 15-LOX/COX-2 inhibitors, thus pave the way to design potentially-active anticancer agents with balanced dual inhibition of these enzymes.

Methanesulfonamide derivatives as gastric safe anti-inflammatory agents: Design, synthesis, selective COX-2 inhibitory activity, histopathological and histochemical studies

Novel chalcone 3a-c, pyrazoline 4a-i and pyridine 5a-c, 6a&b derivatives bearing methanesulfonamide moiety were synthesized. Their construction was confirmed using spectral data and elemental analysis. The stereo-chemical configuration for compounds 3a-c was predicted by MM2 property and 1H NMR spectra. All the prepared compounds were screened for their in vitro COX-1/COX-2 inhibitory activities and in vivo anti-inflammatory activity. The most active anti-inflammatory derivatives, 4f-4i, after 3, 5 & 7 h were further subjected to histopathological and histochemical studies showing safe effect on gastric mucosa, especially 4h derivative. To explore the mechanism of action of COX-2 inhibitory compounds 4f and 6b with the highest S.I. values, they were docked inside COX-2 active site. Physicochemical properties for 4f-i and 6b derivatives were predicted and compared to the reference drug celecoxib. They showed good oral bio-availability specially pyrazoline derivative 4f and pyridine containing compound 6b.

Fragment merging approach for the design of thiazole/thiazolidine clubbed pyrazoline derivatives as anti-inflammatory agents: Synthesis, biopharmacological evaluation and molecular modeling studies

Fragment merging approach was applied for the design of thiazole/thiazolidinone clubbed pyrazoline derivatives 5a-e, 6a-c, 7 and 10a-d as dual COX-2 and 5-LOX inhibitors. Compounds 5a, 6a, and 6b were the most potent and COX-2 selective inhibitors (IC50= 0.03-0.06 μM, SI = 282.7-472.9) with high activity against 5-LOX (IC50 = 4.36-4.86 μM), while compounds 5b and 10a were active and selective 5-LOX inhibitors with IC50 = 2.43 and 1.58 μM, respectively. In vivo assay and histopathological examination for most active candidate 6a revealed significant decrease in inflammation with higher safety profile in comparison to standard drugs. Compound 6a exhibited the same orientation and binding interactions as the reference COX-2 and 5-LOX inhibitors (celecoxib and quercetin, respectively). Consequently, compound 6a has been identified as a potential lead for further optimization and the development of safe and effective anti-inflammatory drugs.

Design, Synthesis and Anticancer Evaluation of New 1-allyl-4-oxo-6-(3,4,5- trimethoxyphenyl)-1,4-dihydropyrimidine-5-carbonitrile Bearing Pyrazole Moieties

AIM

pyrimidine and pyrazole have various biological and pharmaceutical applications such as antibacterial, antifungal, antileishmanial, anti-inflammatory, antitumor, and anti-cancer.

INTRODUCTION

In this search, the goal is to prepare pyrimidine-pyrazoles and study their anticancer activity.

METHODS

1-allyl-4-oxo-6-(3,4,5-trimethoxyphenyl)-1,4-dihydropyrimidine-5-carbonitrile bearing pyrazoles (4,6-8) have been synthesized. Firstly, the reaction of 1-allyl-2-(methylthio)-4-oxo-6- (3,4,5-trimethoxyphenyl)-1,4-dihydropyrimidine-5-carbonitrile (1) with chalcones 2a-b produced the intermediates 3a-b. The latter was reacted with hydrazine hydrate to give the targets 4a-b. On the other hand, hydrazinolysis of compound 1 yielded the hydrazino derivative 5 which upon reaction with chalcones 2c-i or 1,3-bicarbonyl compounds afforded the compounds 6-8. Finally, the new compounds were characterized by spectral data (IR, 1H NMR, 13C NMR) and elemental analysis. Moreover, they were evaluated for Panc-1, MCF-7, HT-29, A-549, and HPDE cell lines as anticancer activity.

RESULTS

All the tested compounds 3,4,6-8 showed IC50 values > 50 μg/mL against the HPDE cell line. Compounds 6a and 6e exhibited potent anticancer activity where the IC50 values in the range of 1.7- 1.9, 1.4-182, 1.75-1.8, and 1.5-1.9 μg/mL against Panc-1, MCF-7, HT-29, and A-549 cell lines.

CONCLUSION

New pyrimidine-pyrazole derivatives were simply synthesized, in addition, some of them showed potential anticancer activity.

One-Pot Synthesis of Novel Hydrazono 1,3-Thiazolidin-4-One Derivatives: Molecular Modelling, ADMET And Biological Evaluation of Anti-HIV And Anti-Tubercular Agents

BACKGROUND

The necessity for newer anti-HIV and anti-tubercular medications has arisen as a result of the prevalence of opportunistic infections caused by HIV (human immunodeficiency virus).

OBJECTIVE

A series of ten new hydrazono 1,3-thiazolidin-4-one derivatives were synthesized in one-pot and evaluated for anti-HIV and anti-tubercular activities. Molecular Docking was perormed with HIV-1 reverse transcriptase protein (PDB ID: 1REV) and Mycobacterium Tuberculosis (M. tuberculosis) H37Rv protein (PDB ID: 2YES) receptors along with drug-likeness and ADMET properties.

METHODS

One-pot synthesis of hydrazono 1,3-thiazolidin-4-one derivatives was carried out by ketones, thiosemicarbazide and ethylchloroacetate with the catalyst of anhydrous sodium acetate. All the synthesized compounds were characterized, and evaluated for their in-vitro anti-HIV and also evaluated for their in-vitro anti-tubercular activity against M. tuberculosis H37Rv. In-silico predicted physicochemical parameters were done by MedChem DesignerTM software version 5.5 and ADMET parameters by pkCSM online tool. Furthermore, molecular docking was performed with pyrx 0.8 by autodock vina software.

RESULTS

All the synthesized compounds were characterized and evaluated for their in-vitro anti-HIV activity for inhibition of syncytia formation, which shows KTE1 with EC5¬0 47.95 µM and Selectivity Index (SI) of >4.17 and for inhibition of p24 antigen production EC5¬0 was found to be 80.02 µM and SI of >2.49. The compounds were also evaluated for their in-vitro anti-tubercular activity against M. tuberculosis H37Rv, in which KTE1 MIC values of 12.5µg/ml with SI of >4.0 and cytotoxicity against Vero cell lines. In-silico predicted physicochemical parameters for synthesized compounds which were found to be drug-like. Furthermore, docking has shown a good dock score and binding energy with anti-HIV and anti-tubercular receptors.

CONCLUSION

From the novel synthesized molecules none of the molecule is as effective as standards for anti-HIV and anti-tubercular drugs and hence can be further explored for its potential activities. Furthermore, derivatization was made to achieve more potent compounds for anti-HIV and anti-tubercular drugs.

Recent development on COX-2 inhibitors as promising anti-inflammatory agents: The past 10 years

Cyclooxygenases play a vital role in inflammation and are responsible for the production of prostaglandins. Two cyclooxygenases are described, the constitutive cyclooxygenase-1 and the inducible cyclooxygenase-2, for which the target inhibitors are the non-steroidal anti-inflammatory drugs (NSAIDs). Prostaglandins are a class of lipid compounds that mediate acute and chronic inflammation. NSAIDs are the most frequent choices for treatment of inflammation. Nevertheless, currently used anti-inflammatory drugs have become associated with a variety of adverse effects which lead to diminished output even market withdrawal. Recently, more studies have been carried out on searching novel selective COX-2 inhibitors with safety profiles. In this review, we highlight the various structural classes of organic and natural scaffolds with efficient COX-2 inhibitory activity reported during 2011–2021. It will be valuable for pharmaceutical scientists to read up on the current chemicals to pave the way for subsequent research.

Pharmacological report of recently designed multifunctional coumarin and coumarin-heterocycle derivatives

Coumarin is a naturally available molecule and has been identified as a potent pharmacophore due to its pharmacological activity. Because of this, coumarin has been exploited synthetically to prepare a wide range of derivatives. In fact, most coumarin derivatives have been found to be less toxic, which is the most essential property for a drug molecule. Such molecules are being prepared for therapeutic use as broad-spectrum pharmacological agents. Microbial diseases including viral diseases have become very common and are responsible for many deaths worldwide. In particular, microbial drug resistance is a problem that needs to be tackled in an effective manner. Also, for Alzheimer's disease, which affects most elderly persons, no efficient chemotherapy exists. In addition, although diabetes, a metabolic syndrome, can be treated with many drugs, there is no complete cure. Thus, more potent antidiabetic agents are required for the management of diabetes. Likewise, for the treatment of a wide range of ailments caused by microbes, genetic factors, or lifestyle-related factors, an efficient drug regimen is needed. In view of this, coumarin derivatives are designed and evaluated. Here, coumarin derivatives that have been reported recently are compiled, classified and evaluated critically. This study briefly takes the structure-activity relationship into consideration and suggests the next suitable step. With a focus on the most potent molecules, the pharmacological activity of the evaluated molecules is described.

The Importance of Rhodanine Scaffold in Medicinal Chemistry: A Comprehensive Overview

After the clinical use of epalrestat that contains a rhodanine ring, in type II diabetes mellitus and diabetic complications, rhodanin-based compounds have become an important class of heterocyclic in the field of medicinal chemistry. Various modifications to the rhodanine ring have led to a broad spectrum of biological activity of these compounds. Synthesis of rhodanine derivatives, depended on advenced throughput scanning hits, frequently causes potent and selective modulators of targeted enzymes or receptors, which apply their pharmacological activities through different mechanisms of action. Rhodanine-based compounds will likely stay a privileged scaffold in drug discovery because of different probability of chemical modifications of the rhodanine ring. We have, therefore reviewed their biological activities and structure activity relationship.

Challenging inflammatory process at molecular, cellular and in vivo levels via some new pyrazolyl thiazolones

The work reported herein describes the synthesis of a new series of anti-inflammatory pyrazolyl thiazolones. In addition to COX-2/15-LOX inhibition, these hybrids exerted their anti-inflammatory actions through novel mechanisms. The most active compounds possessed COX-2 inhibitory activities comparable to celecoxib (IC₅₀ values of 0.09-0.14 µM) with significant 15-LOX inhibitory activities (IC₅₀s 1.96 to 3.52 µM). Upon investigation of their in vivo anti-inflammatory activities and ulcerogenic profiles, these compounds showed activity patterns equivalent or more superior to diclofenac and/or celecoxib. Intriguingly, the most active compounds were more effective than diclofenac in suppressing monocyte-to-macrophage differentiation and inflammatory cytokine production by activated macrophages, as well as their ability to induce macrophage apoptosis. The latter finding potentially adds a new dimension to the previously reported anti-inflammatory mechanisms of similar compounds. These compounds were effectively docked into COX-2 and 15-LOX active sites. Also, in silico predictions confirmed the appropriateness of these compounds as drug-like candidates.

Optimization of pyrazole-based compounds with 1,2,4-triazole-3-thiol moiety as selective COX-2 inhibitors cardioprotective drug candidates: Design, synthesis, cyclooxygenase inhibition, anti-inflammatory, ulcerogenicity, cardiovascular evaluation, and molecular modeling studies

The cardiovascular side effects associated with COX-2 selective drugs were the worst for coxibs leading to their withdrawal from the market a few years after their discovery. Therefore, the design of new series of pyrazole (4a,b 5a,b, 7a,b, 9a,b, 10a-h, and 11a-f) substituted with a triazole moiety as selective COX-2 inhibitors with cardioprotective effect was aimed in this paper. The target compounds were prepared and evaluated in-vitro against COX-1 and COX-2 enzymes. Compound 5-(5-Methyl-1-phenyl-1H-pyrazol-4-yl)-4H-1,2,4-triazole-3-thiol (7a) showed the highest selectivity towards COX-2 enzyme (S.I. = 27.56) and was the most active anti-inflammatory agent. Interestingly, its cardiovascular profile showed the cardiac biomarkers (ALP, AST, CK-MB, and LDH), as well as inflammatory cytokines named (TNF-α and IL-6) nearly similar to the control. Besides, a histopathological study of the heart muscle and the stomach was also included. The results confirmed that compound 7a has a more favorable cardio profile than celecoxib. Moreover, docking simulation for the most selective compounds 4b, 7a, 10e, 11c, and 11e inside COX-2 active site was performed to explain their binding mode. Finally, an ADME study was applied and proved the promising activity of the new compounds as a new oral anti-inflammatory agent. In conclusion, the newly developed compound 7a represents a potential selective COX-2 NSAID candidate with minimum cardiovascular risks.

The Emerging Role of COX-2, 15-LOX and PPARγ in Metabolic Diseases and Cancer: An Introduction to Novel Multi-target Directed Ligands (MTDLs)

Emerging evidence supports an intertwining framework for the involvement of different inflammatory pathways in a common pathological background for a number of disorders. Of importance are pathways involving arachidonic acid metabolism by cyclooxygenase-2 (COX-2) and 15-lipoxygenase (15-LOX). Both enzyme activities and their products are implicated in a range of pathophysiological processes encompassing metabolic impairment leading to adipose inflammation and the subsequent vascular and neurological disorders, in addition to various pro- and antitumorigenic effects. A further layer of complexity is encountered by the disparate, and often reciprocal, modulatory effect COX-2 and 15-LOX activities and metabolites exert on each other or on other cellular targets, the most prominent of which is peroxisome proliferator-activated receptor gamma (PPARγ). Thus, effective therapeutic intervention with such multifaceted disorders requires the simultaneous modulation of more than one target. Here, we describe the role of COX-2, 15-LOX, and PPARγ in cancer and complications of metabolic disorders, highlight the value of designing multi-target directed ligands (MTDLs) modifying their activity, and summarizing the available literature regarding the rationale and feasibility of design and synthesis of these ligands together with their known biological effects. We speculate on the potential impact of MTDLs in these disorders as well as emphasize the need for structured future effort to translate these early results facilitating the adoption of these, and similar, molecules in clinical research.

Design, synthesis and molecular docking of new pyrazole-thiazolidinones as potent anti-inflammatory and analgesic agents with TNF-α inhibitory activity

A new set of derivatives bearing pyrazole-methylenehydrazono-thiazolidinone scaffold 4-23 was designed, synthesized and confirmed by different spectroscopic means and elemental analyses. In-vivo anti-inflammatory and ulcerogenic evaluation was performed for all the newly synthesized derivatives using indomethacin, celecoxib and diclofenac as standard drugs. The compounds 5, 10, 15, 17, 21, 22 appeared to be the most promising candidates producing rapid onset and long duration of anti-inflammatory activity as well as promising GIT safety profile. Furthermore, analgesic evaluation revealed that the compounds 5, 10, 15 and 22 produced potent and long acting analgesia accompanied with significant inhibition of the inflammatory cytokine TNF-α level in comparison with the standard drugs. Molecular docking study of the latter derivatives was also carried out to rationalize their binding affinities and their modes of interactions with the active site of TNF-α.

An Overview of the Synthesis and Antimicrobial, Antiprotozoal, and Antitumor Activity of Thiazole and Bisthiazole Derivatives

Thiazole, a five-membered heteroaromatic ring, is an important scaffold of a large number of synthetic compounds. Its diverse pharmacological activity is reflected in many clinically approved thiazole-containing molecules, with an extensive range of biological activities, such as antibacterial, antifungal, antiviral, antihelmintic, antitumor, and anti-inflammatory effects. Due to its significance in the field of medicinal chemistry, numerous biologically active thiazole and bisthiazole derivatives have been reported in the scientific literature. The current review provides an overview of different methods for the synthesis of thiazole and bisthiazole derivatives and describes various compounds bearing a thiazole and bisthiazole moiety possessing antibacterial, antifungal, antiprotozoal, and antitumor activity, encouraging further research on the discovery of thiazole-containing drugs.

Novel 1,3,5-triazine-based pyrazole derivatives as potential antitumor agents and EFGR kinase inhibitors: synthesis, cytotoxicity, DNA binding, molecular docking and DFT studies

The development of new 1,3,5-triazine-based pyrazole derivatives as effective anticancer agents.

New indomethacin analogs as selective COX-2 inhibitors: Synthesis, COX-1/2 inhibitory activity, anti-inflammatory, ulcerogenicity, histopathological, and docking studies

New indomethacin analogs 4a-g, 5, 6, 8a, and 8b were synthesized to overcome the nonselectivity and ulcer liability of indomethacin. All newly synthesized compounds were more potent against cyclooxygenase 2 (COX-2; IC₅₀ value range: 0.09-0.4 μМ) as compared with celecoxib (IC₅₀  = 0.89 μМ). Compounds 4a, 4b, 4d, 5, and 6 showed the highest COX-2 selectivity index (SI range = 4.07-6.33) as compared with indomethacin (SI = 1.14) and celecoxib (SI = 3.52). Additionally, 4a, 4b, 4d, 5, and 7 showed good anti-inflammatory activity with edema inhibition (79.36-88.8%), relative to celecoxib (78.96%) and indomethacin (90.43%), after 5 h. Also, ulcerogenic effects and histopathological examination were assessed for the most potent analogs, 4b, 4d, 5, and 6, to determine their safety. The results can shed light on indomethacin analog 5 as a remarkable anti-inflammatory lead compound with a good safety profile (ulcer index = 10.62) close to the nonulcerogenic drug celecoxib (ulcer index = 10.53) and better than indomethacin (ulcer index = 18.50). Docking studies were performed in the COX-2 active site for the most active compounds, to test their selectivity and to confirm their mechanism of action.

Synthesis of novel halogenated triarylpyrazoles as selective COX-2 inhibitors: Anti-inflammatory activity, histopatholgical profile and in-silico studies

A novel series of halogenated triarylpyrazoles 12a-l was designed and synthesized. All target compounds showed good in vitro COX-2 inhibitory activity (IC₅₀ = 0.043-0.17 µM) over COX-1 (IC₅₀ = 7.8 - 15.4 µM) relative to celecoxib (COX-1/IC₅₀ = 9.87, COX-2/IC₅₀ = 0.055), with acceptable selectivity index values (SI = 50.6-253.1). Also, they displayed moderate to potent in vivo anti-inflammatory activity (% edema inhibition = 16.9-87.9) comparable to celecoxib (% edema inhibition = 46.6-72.1) as standard drug. Three fluorinated pyrazoles 12a, 12g and 12j, exhibited superior anti-inflammatory activity at all time intervals (% edema inhibition = 42.1-87.9) with better gastric profile (UI = 1.25-2.5) than the traditional NSAID; indomethacin (UI = 14) and were close to the selective COX-2 inhibitor; celecoxib (UI = 1.75). In-silico docking and ADME studies of 12a, 12g and 12j supported the obtained biological data and pointed out their potential use for the development of bio-available, safe and potent anti-inflammatory drugs.

New pyrazole derivatives possessing amino/methanesulphonyl pharmacophore with good gastric safety profile: Design, synthesis, cyclooxygenase inhibition, anti-inflammatory activity and histopathological studies

New series of pyrazole derivatives Va-c, VIa-c, VIIa-f, and VIII possessing amino/methanesulphonyl moiety as COX-2 pharmacophore were designed and synthesized. All compounds were evaluated for both in vitro COX inhibition and in vivo anti-inflammatory activities and all of them were more potent against COX-2 than COX-1 isozyme and showed good in vivo anti-inflammatory activity. Compounds Va, VIa, VIc and VIIa-c showed good COX-2 SI (246.8-353.8) in comparison with the COX-2 selective drug; celecoxib (326.7). Also, they showed good anti-inflammatory activity with edema inhibition (51-86 and 83-96%) relative to celecoxib (60.6 and 82.8%) after 3 and 5 h respectively. Additionally, these potent derivatives Va, VIa, VIc and VIIa-c were significantly less ulcerogenic (ulcer indexes = 0.7-2.0) than indomethacin (ulcer index = 21.3) and were of acceptable ulcerogenicity when compared with the non-ulcerogenic reference drug celecoxib (ulcer index = 1.3). The obtained ulcerogenic liability data revealed the gastric safety of these derivatives which was confirmed by the histopathological studies. Docking study was performed for all synthesized derivatives to explain their interaction with COX-2 receptor active site.

Synthesis and biological evaluations of novel isoxazoles and furoxan derivative as anti-inflammatory agents

Novel isoxazoles (10, 12a&b, 15a-c) and the furoxan derivative (14) have been prepared as new safe anti-inflammatory agents from the hydroximoyl 9. All compounds were evaluated for COX-1\COX-2 and most of them showed promising selectivity. The furoxan derivative 14 gave 59% inhibitory activity using carrageenan induced paw rat edema model. Ulcer index experiment and histo-pathological study of stomach samples were also included. Also the proposed binding mode of certain newly synthesized compounds with COX-2 isoform was briefly discussed.

A novel synthesis, X-ray analysis and computational studies of (Z)-ethyl 2-((Z)-5-((dimethylamino)methylene)- 4-oxo-3-phenylthiazolidin-2-ylidene)acetate as a potential anticancer agent

Background

4-Thiazolidinone ring is reported to have almost all types of biological activities. Also, it present in many marketed drugs.

Results

Ethyl acetoacetate reacted with phenyl isothiocyanate and ethyl chloroacetate in presence of K₂CO₃ and DMF to afford the thiazolidinone derivative 5. Thiazolidinone 5 reacted with dimethylformamide-dimethylacetal to afford (Z)-ethyl 2-((Z)-5-((dimethylamino) methylene)-4-oxo-3-phenylthiazolidin-2-ylidene)acetate (6). The structure of thiazolidinone 6 was elucidated from its spectral analysis and X-ray crystallography and was optimized using B3LYP/6-31G(d,p) method. The geometric parameters and NMR spectra were discussed both experimentally and theoretically. Also, the natural charges at the different atomic sites were predicted. The synthesized compounds had moderate cytotoxic activity.

Conclusions

An unexpected synthesis of (Z)-ethyl 2-((Z)-5-((dimethylamino)methylene)-4-oxo-3-phenylthiazolidin-2-ylidene)acetate via deacetylation mechanism. The structure was established using X-ray and spectral analysis. The geometric parameters, and NMR spectra were discussed. The synthesized compounds showed moderate anticancer activity.

Synthesis and biological evaluation of purine-pyrazole hybrids incorporating thiazole, thiazolidinone or rhodanine moiety as 15-LOX inhibitors endowed with anticancer and antioxidant potential

Novel purine-pyrazole hybrids combining thiazoles, thiazolidinones and rhodanines, were designed and tested as 15-LOX inhibitors, potential anticancer and antioxidant agents. All tested compounds were found to be potent 15-LOX inhibitors with IC₅₀ ranging from 1.76 to 6.12 µM. The prepared compounds were evaluated in vitro against five cancer cell lines: A549 (lung), Caco-2 (colon), PC3 (prostate), MCF-7 (breast) and HepG-2 (liver). Compounds 7b and 8b displayed broad spectrum anticancer activity against the five tested cell lines (IC₅₀ = 18.5-95.39 µM). While, compound 7h demonstrated moderate anticancer activity against lung A549 and colon Caco-2 cell lines. Antioxidant screening revealed that six compounds (5a, 5b, 6b, 7b, 7h and 8b) with IC₅₀ ranging from 0.93 to 14.43 µg/ml were found to be more potent scavengers of 2,2- diphenyl-1-picrylhydrazyl (DPPH) than the reference ascorbic acid with IC₅₀ value of 15.34 µg/ml. Compounds 7b, 7h and 8b, when evaluated for their antioxidant activity, where found to be potent DPPH scavengers. Moreover, compound 7b displayed twice the potency of ascorbic acid as NO scavenger. Docking study was performed to elucidate the possible binding mode of the most active compounds with the active site of 15-LOX enzyme. Collectively, the purine-pyrazole hybrids having thiazoline or thizolidinone moieties (7b, 7h and 8b) constitute a promising scaffold in designing more potent 15-LOX inhibitors with anticancer and antioxidant potential.

Synthesis, anti-inflammatory screening, molecular docking, and COX-1,2/-5-LOX inhibition profile of some novel quinoline derivatives

New quinoline compounds comprising pyrazole scaffold through different amide linkages were synthesized. The synthesized compounds were evaluated for their anti-inflammatory activity. Eight compounds (5c, 11b,c, 12c, 14a,b, 20a and 21a) were found to exhibit promising anti-inflammatory profiles in acute and sub-acute inflammatory models. They were screened for their ulcerogenic activity and none of them showed significant ulcerogenic activity comparable to the reference drug celecoxib and are well tolerated by experimental animals with high safety margin (ALD50 > 0.3 g/kg). Compounds 5c, 11b,c, 12c, 14a,b, 20a and 21a showed significant in vitro LOX inhibitory activity higher than that of zileuton. In vitro COX-1/COX-2 inhibition study revealed that compounds 12c, 14a,b and 20a showed higher selectivity towards COX-2 than COX-1. Among the tested compounds, 12c, 14a and 14b showed the highest inhibitory activity against COX-2 with an IC50 values of 0.1, 0.11 and 0.11 μM respectively. The docking experiments attempted to postulate the binding mode for the most active compounds in the binding site of COX-2 enzymes and confirmed the high selectivity binding towards COX-2 enzyme over COX-1.

Synthesis, biological evaluation and docking study of 1,3,4-thiadiazole-thiazolidinone hybrids as anti-inflammatory agents with dual inhibition of COX-2 and 15-LOX

Selective inhibition of both cyclooxygenase-2 (COX-2) and 15-lipooxygenase (15-LOX) may provide good strategy for alleviation of inflammatory disorders while minimizing side effects associated with current anti-inflammatory drugs. The present study describes the synthesis, full characterization and biological evaluation of a series of thiadiazole-thiazolidinone hybrids bearing 5-alk/arylidene as dual inhibitors of these enzymes. Our design was based on merging pharmacophores that exhibit portent anti-inflammatory activities in one molecular frame. 5-(4-hydroxyphenyl)-1,3,4-thiadiazol-2-amine (3) was efficiently synthesized, chloroacetylated and cyclized to give the key 4-thiazolidinone (5). Knovenagel condensation of 5 with different aldehydes afforded the final compounds 6a-m, 7, 8 and 9. These compounds were subjected to in vitro COX-1/COX-2, 15-LOX inhibition assays. Compounds (6a, 6f, 6i, 6l, 6m and 9) with promising potency (IC₅₀ = 70-100 nM) and selectivity index (SI = 220-55) were further tested for in vivo anti-inflammatory activity and effect on gastric mucosa. The most promising compound (6l) inhibits COX-2 enzyme at a nanomolar concentration (IC₅₀ = 70 nM, SI = 220) with simultaneous inhibition of 15-LOX (IC₅₀ = 11 µM). These results are comparable to the potency and selectivity of the standard drugs of both enzymes; celecoxib (COX-2 IC₅₀ = 49 nM, SI = 308) and zileuton (15-LOX IC₅₀ = 15 µM) in one construct. Interestingly three compounds (6a, 6l and 9) exhibited equivalent to or even higher than that of celecoxib in vivo anti-inflammatory activity at 3 h interval with good GIT safety profile. Molecular docking study conferred binding sites of these compounds on COX-2 and 15-LOX. Such type of compounds would represent valuable leads for further investigation and derivatization.

Thiazoles and Thiazolidinones as COX/LOX Inhibitors

Inflammation is a natural process that is connected to various conditions and disorders such as arthritis, psoriasis, cancer, infections, asthma, etc. Based on the fact that cyclooxygenase isoenzymes (COX-1, COX-2) are responsible for the production of prostaglandins that play an important role in inflammation, traditional treatment approaches include administration of non-steroidal anti-inflammatory drugs (NSAIDs), which act as selective or non-selective COX inhibitors. Almost all of them present a number of unwanted, often serious, side effects as a consequence of interference with the arachidonic acid cascade. In search for new drugs to avoid side effects, while maintaining high potency over inflammation, scientists turned their interest to the synthesis of dual COX/LOX inhibitors, which could provide numerous therapeutic advantages in terms of anti-inflammatory activity, improved gastric protection and safer cardiovascular profile compared to conventional NSAIDs. Τhiazole and thiazolidinone moieties can be found in numerous biologically active compounds of natural origin, as well as synthetic molecules that possess a wide range of pharmacological activities. This review focuses on the biological activity of several thiazole and thiazolidinone derivatives as COX-1/COX-2 and LOX inhibitors.

Recent development of lipoxygenase inhibitors as anti-inflammatory agents

Inflammation is favorable in most cases, because it is a kind of body defensive response to external stimuli; sometimes, inflammation is also harmful, such as attacks on the body's own tissues. It could be that inflammation is a unified process of injury and resistance to injury. Inflammation brings extreme pain to patients, showing symptoms of rubor, swelling, fever, pain and dysfunction. As the specific mechanism is not clear yet, the current anti-inflammatory agents are given priority for relieving suffering of patients. Thus it is emergent to find new anti-inflammatory agents with rapid effect. Lipoxygenase (LOX) is a kind of rate-limiting enzyme in the process of arachidonic acid metabolism into leukotriene (LT) which mediates the occurrence of inflammation. The inhibition of LOX can reduce LT, thereby producing an anti-inflammatory effect. In this review, the LOX inhibitors reported in recent years are summarized, and, in particular, their activities, structure-activity relationships and molecular docking studies are emphasized, which will provide new ideas to design novel LOX inhibitors.

Synthesis and biological evaluations of new nitric oxide-anti-inflammatory drug hybrids

Three novel series of nitroso derivatives (11-15), isoxazolopyrazoles (17a-c) and isoxazolo[3,4-d]pyridazines (18a-c) were prepared from the hydroxyimoyl chloride 10. In vitro COX1⧹2 inhibition activities were evaluated, both of 17b and 18a proved a promising inhibitory activity with IC50=1.12, 0.78μM in sequent. Carrageenan induced Paw edema, ulcer liability, nitric oxide (NO) release and histopathological study were determined. Most of the prepared compounds showed excellent activities. Reactions of 2-aminopyridine and enaminone with hydroxyimoyl chloride 10 were investigated and proved by 2D NMR. Molecular docking for most active compounds was operated giving a hint for compound-receptor interactions.

New benzothiophene derivatives as dual COX-1/2 and 5-LOX inhibitors: synthesis, biological evaluation and docking study

Aim: Simultaneous inhibition of 5-LOX/COX may enhance anti-inflammatory effects and reduce side effects. Hence, synthesis of novel dual inhibitors of 5-LOX/COX is an important strategy for treatment of inflammation. Results/methodology: The target compounds were designed to hybridize benzothiophene scaffold or its bioisostere benzofuran with various anti-inflammatory pharmacophore hetercycles through different atoms spacers. Compounds 4a, 4c, 4d, 5b, 7a, showed significant in vitro LOX inhibitory activity higher than that of meclofenamate sodium. Compounds 4b, 4e, 4f, 5a exhibited significant in vitro COX-2 inhibition higher than celecoxib and in vitro LOX inhibitory activity twice that of reference. These compounds elicited significant in vivo anti-inflammatory activities higher than celecoxib in formalin-induced paw edema test. Compound 4e exhibited gastrointestinal safety profile as celecoxib. The results were also consistent with the docking studies. Conclusion: Compound 4e could be considered as structural lead for the development of a new class of anti-inflammatory agents with better safety profile.