Discovery of novel urea-diarylpyrazole hybrids as dual COX-2/sEH inhibitors with improved anti-inflammatory activity and highly reduced cardiovascular risks

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.

Review of the recent advances of pyrazole derivatives as selective COX-2 inhibitors for treating inflammation

Pyrazole heterocycle is regarded as an extremely significant agent for the therapy of inflammation. Celecoxib, lonazolac, deracoxib, and phenylbutazone are examples of commercially approved pyrazole drugs with COX-2 inhibitory potential for curing inflammation. There have been recently many reviews for the biological significance of pyrazole derivatives. This review talks about pyrazole derivatives with anti-inflammatory activity and also sheds the light on the recent updates on pyrazole research with an emphasis on some synthetic pathways utilized to construct this privileged scaffold and structure activity relationship that accounts for the anti-inflammatory activity in an attempt to pave the opportunity for medicinal chemists to develop novel anti-inflammatory agents with better COX-2 selectivity.

Sulfonamide-Pyrazole derivatives as next-generation Cyclooxygenase-2 enzyme inhibitors: From molecular design to in vivo efficacy

The current research focuses on the design and synthesis of celecoxib analogues incorporating sulphonamide and pyrazole moieties (4, 5, 6a-e, and 7a-f) with the aim of achieving a broad range of COX-2 selectivity in vitro. Among these, compounds 6b-d, 7a, 7e, and 7d exhibited potent inhibition, with IC50 values ranging between 0.05 and 0.08 μM, and were selected for in vivo evaluation using the formalin-induced paw edema model. To further assess the safety profile of compound 6d, a histopathological examination of paw tissue was conducted alongside routine blood analyses evaluating key liver and kidney function parameters, including creatinine, urea, AST, and ALT levels. The results indicated normal profiles, comparable to reference drugs celecoxib and indomethacin. Additionally, compound 6d was evaluated for its effect on inflammatory biomarkers using ELISA assays. Markedly, 6d elicited a remarkable reduction in TNF-α (71.43 %) and PGE2 (77.11 %) levels, surpassing the effects of both celecoxib and indomethacin, confirming its potent anti-inflammatory properties. In terms of analgesic activity, Importantly, cardiac toxicity assessment revealed no adverse effects associated with compound 6d. Finally, compound 6d underwent in silico analysis, including molecular docking and molecular dynamics simulations, which confirmed its selective interaction with the COX-2 active site and favorable free insertion into the selectivity side pocket.

Discovery of glycosidated glycyrrhetinic acid derivatives: Natural product-based soluble epoxide hydrolase inhibitors

There are few reports on soluble epoxide hydrolase (sEH) structure-activity relationship studies using natural product-based scaffolds. In this study, we discovered that C-30 urea derivatives of glycyrrhetinic acid such as 33, rather than C-20/C-3 urea derivatives, possess in vitro sEH inhibitory capabilities. Furthermore, we explored the impact of stereoconfigurations at C-3 and C-18 positions, and glycosidic bonds at the 3-OH on the compound's activity. Consequently, a glycoside of 33, specifically 49Cα containing alpha-oriented mannose, exhibited promising in vivo efficacy in alleviating carrageenan-induced paw edema and acetic acid-induced writhing. Meanwhile, 49Cα demonstrated potential in mitigating acute pancreatitis by modulating the ratios of anti-inflammatory epoxyeicosatrienoic acids (EETs) to pro-inflammatory dihydroxyeicosatrienoic acids (DHETs). The co-crystal structure of sEH in complex with 49Cα revealed that the N-tetrahydropyranylmethylene urea hydrogen bonded with the residues within the sEH tunnel, contrasting with the mannose component that extended beyond the tunnel's confines. Our findings highlight 49Cα (coded LQ-38) as a promising candidate for anti-inflammatory and analgesic effects, and pave the way for the future rational design of triterpenoid-based sEH inhibitors.

Novel anti-inflammatory agents featuring phenoxy acetic acid moiety as a pharmacophore for selective COX-2 inhibitors: Synthesis, biological evaluation, histopathological examination and molecular modeling investigation

Inflammation management presents a critical challenge in modern medicine, with nonsteroidal anti-inflammatory drugs (NSAIDs) being a widely used therapeutic option. However, their efficacy is often accompanied by significant gastrointestinal adverse effects, necessitating the exploration of safer alternatives, particularly through the investigation of cyclooxygenase-2 (COX-2) inhibitors. This study endeavors to address this imperative through the synthesis and evaluation of pyrazoline-phenoxyacetic acid derivatives. Among the synthesized compounds, 6a and 6c emerged as promising candidates, demonstrating potent COX-2 inhibition with IC50 values of 0.03 µM for both and selectivity index = 365.4 and 196.9, respectively. Furthermore, these compounds exhibited efficacy in mitigating formalin-induced edema in male Wistar rats, accompanied by favorable safety profiles upon histological examination of vital organs. Comprehensive safety assessments, including evaluation of creatinine, AST, and ALT enzymatic as well as troponin T and creatine kinase-MB levels, further reinforce the promising attributes of the synthetic candidates. Molecular docking studies endorsed by molecular dynamic simulations corroborate the biological findings, elucidating significant protein-ligand interactions at COX-2 active sites indicative of therapeutic potential.

Synergistic integration of deep learning with protein docking in cardiovascular disease treatment strategies

This research delves into the exploration of the potential of tocopherol-based nanoemulsion as a therapeutic agent for cardiovascular diseases (CVD) through an in-depth molecular docking analysis. The study focuses on elucidating the molecular interactions between tocopherol and seven key proteins (1O8a, 4YAY, 4DLI, 1HW9, 2YCW, 1BO9 and 1CX2) that play pivotal roles in CVD development. Through rigorous in silico docking investigations, assessment was conducted on the binding affinities, inhibitory potentials and interaction patterns of tocopherol with these target proteins. The findings revealed significant interactions, particularly with 4YAY, displaying a robust binding energy of -6.39 kcal/mol and a promising Ki value of 20.84 μM. Notable interactions were also observed with 1HW9, 4DLI, 2YCW and 1CX2, further indicating tocopherol's potential therapeutic relevance. In contrast, no interaction was observed with 1BO9. Furthermore, an examination of the common residues of 4YAY bound to tocopherol was carried out, highlighting key intermolecular hydrophobic bonds that contribute to the interaction's stability. Tocopherol complies with pharmacokinetics (Lipinski's and Veber's) rules for oral bioavailability and proves safety non-toxic and non-carcinogenic. Thus, deep learning-based protein language models ESM1-b and ProtT5 were leveraged for input encodings to predict interaction sites between the 4YAY protein and tocopherol. Hence, highly accurate predictions of these critical protein-ligand interactions were achieved. This study not only advances the understanding of these interactions but also highlights deep learning's immense potential in molecular biology and drug discovery. It underscores tocopherol's promise as a cardiovascular disease management candidate, shedding light on its molecular interactions and compatibility with biomolecule-like characteristics.

GC/MS and 2D NMR-based approach to evaluate the chemical profile of hydroalcoholic extract from Agaricus blazei Murill and its anti-inflammatory effect on human neutrophils

ETHNOPHARMACOLOGICAL RELEVANCE

Agaricus blazei Murill (AbM) is one of the main mushrooms used for medicinal purposes. The use of AbM in the preparation of teas is widespread mainly in Asian countries, while in Brazil it is used as a functional food to combat inflammatory diseases and cancer.

AIM OF THE STUDY

The main focus of this study was the characterization of the chemical profile of the hydroalcoholic extract of Agaricus blazei Murill (AbE), as well as the evaluation of its cytotoxic and anti-inflammatory potential using human neutrophils.

MATERIALS AND METHODS

The extract was prepared by dynamic maceration using a mixture of ethanol and water (70/30, v v-1) as solvent. The chemical profile characterization was carried out by 2D NMR and GC-MS techniques. The cytotoxicity of AbE was evaluated through studies of hemolytic potential, cell viability and membrane integrity. The anti-inflammatory activity was analyzed by a PMA-induced neutrophil degranulation assay.

RESULTS

Chemical analysis of AbE revealed the presence of 28 metabolites in its composition, with mannitol as the major compound. AbE at 1-200 μg mL-1 and mannitol at 4-160 μg mL-1, showed low hemolytic and cytotoxic potential against human red blood cells and neutrophils. Furthermore, both were able to significantly reduce the release of myeloperoxidase.

CONCLUSIONS

These results indicate that AbE is a promising natural product to be incorporated into pharmaceutical dosage forms intended for the adjuvant treatment of inflammatory diseases.

Dual-target inhibitors based on COX-2: a review from medicinal chemistry perspectives

Inhibitors of COX-2 constitute a class of anti-inflammatory analgesics, showing potential against certain types of cancer. However, such inhibitors are associated with cardiovascular toxicity. Moreover, although single-target molecules possess specificity for particular targets, they often lead to poor safety, low efficacy and drug resistance due to compensatory mechanisms. A new generation of dual-target drugs that simultaneously inhibit COX-2 and another target is showing strong potential to treat cancer or reduce adverse cardiac effects. The present perspective focuses on the structure and functions of COX-2, and its role as a therapeutic target. It also explores the current state and future possibilities for dual-target strategies from a medicinal chemistry perspective.

Development and Assessment of 1,5-Diarylpyrazole/Oxime Hybrids Targeting EGFR and JNK-2 as Antiproliferative Agents: A Comprehensive Study through Synthesis, Molecular Docking, and Evaluation

New 1,5-diarylpyrazole oxime hybrid derivatives (scaffolds A and B) were designed, synthesized, and then their purity was verified using a variety of spectroscopic methods. A panel of five cancer cell lines known to express EGFR and JNK-2, including human colorectal adenocarcinoma cell line DLD-1, human cervical cancer cell line Hela, human leukemia cell line K562, human pancreatic cell line SUIT-2, and human hepatocellular carcinoma cell line HepG2, were used to biologically evaluate for their in vitro cytotoxicity for all the synthesized compounds 7a-j, 8a-j, 9a-c, and 10a-c. The oxime containing compounds 8a-j and 10a-c were more active as antiproliferative agents than their non-oxime congeners 7a-j and 9a-c. Compounds 8d, 8g, 8i, and 10c inhibited EGFR with IC50 values ranging from 8 to 21 µM when compared with sorafenib. Compound 8i inhibited JNK-2 as effectively as sorafenib, with an IC50 of 1.0 µM. Furthermore, compound 8g showed cell cycle arrest at the G2/M phase in the cell cycle analysis of the Hela cell line, whereas compound 8i showed combined S phase and G2 phase arrest. According to docking studies, oxime hybrid compounds 8d, 8g, 8i, and 10c exhibited binding free energies ranging from -12.98 to 32.30 kcal/mol at the EGFR binding site whereas compounds 8d and 8i had binding free energies ranging from -9.16 to -12.00 kcal/mol at the JNK-2 binding site.

Immunomodulation—a general review of the current state-of-the-art and new therapeutic strategies for targeting the immune system

In recent years, there has been a tremendous development of biotechnological, pharmacological, and medical techniques which can be implemented in the functional modulation of the immune system components. Immunomodulation has attracted much attention because it offers direct applications in both basic research and clinical therapy. Modulation of a non-adequate, amplified immune response enables to attenuate the clinical course of a disease and restore homeostasis. The potential targets to modulate immunity are as multiple as the components of the immune system, thus creating various possibilities for intervention. However, immunomodulation faces new challenges to design safer and more efficacious therapeutic compounds. This review offers a cross-sectional picture of the currently used and newest pharmacological interventions, genomic editing, and tools for regenerative medicine involving immunomodulation. We reviewed currently available experimental and clinical evidence to prove the efficiency, safety, and feasibility of immunomodulation in vitro and in vivo. We also reviewed the advantages and limitations of the described techniques. Despite its limitations, immunomodulation is considered as therapy itself or as an adjunct with promising results and developing potential.

Potential effect of novel thiadiazole derivatives against radiation induced inflammation with low cardiovascular risk in rats

The aim of the present study is to explore new selective anti-inflammatory compounds with low cardiovascular risk. Twelve thiadiazole derivatives incorporating different amino acid moieties were newly synthesized (4–15) as potential anti-inflammatory agents with low cardiovascular risks through dual COX-2/MPO inhibition. Compounds were initially screened for their anti-inflammatory effect by assay of COX-2, the most potent (4–6, 8) were further tested for COX-1 inhibition, myeloperoxidase MPO activity as well as total nitric oxide content NO in heart of irradiated rats. Cardiac toxicity potential was evaluated by assay of creatine kinase-MB (CK-MB), troponin-I (Tn-I) and lactate dehydrogenase (LDH). Celcoxcib was used as reference drug. S-(5-((4-Methoxybenzylidene)amino)-2,3-dihydro-1,3,4-thiadiazol-2-yl)2-amino propanethioate (5) was the most potent anti-inflammatory with the least cardiotoxicity effect. It exhibited IC50 0.09 µM on COX-2 inhibition with very low activity on COX-1. Troponin I was elevated by 11% using compound 5 in non-irradiated rats. Moreover, compound (5) showed 73% reduction in MPO level. Results were supported by molecular docking into the active sites of COX-2 and MPO enzymes to have more insights about the possible dual inhibition of compound 5 of both enzymes.

Novel quinoline-based derivatives: A new class of PDE4B inhibitors for adjuvant-induced arthritis

A total of 31 quinoline-based derivatives were designed and synthesized to develop novel anti-inflammatory drugs. After the toxicity of synthetic compounds to RAW264.7 cells were evaluated in vitro, their anti-inflammatory activity was assessed by inhibiting lipopolysaccharide (LPS)-induced NO production levels in the RAW264.7 cells. Among the derivatives, compound f4 had the best anti-inflammatory activity, which could reduce the production of pro-inflammatory cytokines NO, IL-1β, and TNF-α with corresponding IC₅₀ values of 20.40 ± 0.94, 18.98 ± 0.21 and 23.48 ± 0.46 μM. Western blot showed that f4 could inhibit the expression of LPS-induced inflammatory mediators iNOS and COX-2. Molecular docking showed that f4 could also enter the PDE4B receptor binding pocket, and the cellular thermal shift assay method indicated that the PDE4B protein bound to f4 had increased stability. Meanwhile, the inhibitory effect of this compound on the PDE4B enzyme (IC₅₀ = 0.94 ± 0.36 μM) was comparable to that of the positive drug rolipram (IC₅₀ = 1.04 ± 0.28 μM). Finally, in vivo studies showed that f4 could improve the degree of foot swelling and knee joint pathology in adjuvant-induced arthritic rats and decrease the levels of serum inflammatory factors TNF-α and IL-1β in a dose-dependent manner. Therefore, the development and design of quinoline-based derivatives for anti-inflammatory applications could be considered opportunities and challenges.

Non-steroidal anti-inflammatory drugs: recent advances in the use of synthetic COX-2 inhibitors

Cyclooxygenase (COX) enzymes comprise COX-1 and COX-2 isoforms and are responsible for prostaglandin production. Prostaglandins have critical roles in the inflammation pathway and must be controlled by administration of selective nonsteroidal anti-inflammatory drugs (NSAIDs). Selective COX-2 inhibitors have been among the most used NSAIDs during the ongoing coronavirus 2019 pandemic because they reduce pain and protect against inflammation-related diseases. In this framework, the mechanism of action of both COX isoforms (particularly COX-2) as inflammation mediators must be reviewed. Moreover, proinflammatory cytokines such as tumor necrosis factor-α and interleukin (IL)-6, IL-1β, and IL-8 must be highlighted due to their major participation in upregulation of the inflammatory reaction. Structural and functional analyses of selective COX-2 inhibitors within the active-site cavity of COXs could enable introduction of lead structures with higher selectivity and potency against inflammation with fewer adverse effects. This review focuses on the biological activity of recently discovered synthetic COX-2, dual COX-2/lipoxygenase, and COX-2/soluble epoxide hydrolase hybrid inhibitors based primarily on the active motifs of related US Food and Drug Administration-approved drugs. These new agents could provide several advantages with regard to anti-inflammatory activity, gastrointestinal protection, and a safer profile compared with those of the NSAIDs celecoxib, valdecoxib, and rofecoxib.

Recent advances in the development of active hybrid molecules in the treatment of cardiovascular diseases

Multifactorial nature of the underlying pathophysiology of chronic disorders hinders in the effective treatment and management of many complex diseases. The conventional targeted therapies have limited applications due to highly complicated disease etiology. Cardiovascular diseases (CVDs) are the group of disorders of the heart and blood vessels. Currently, there is limited knowledge on the underlying cellular and molecular mechanisms of many of the CVDs due to their complex pathophysiology and co-morbidities. Their management with conventional medications results in failure due to adverse drug reactions and clinical specificity of solo-targeting drug therapy. Therefore, it is critical to introduce an alternative strategy to treat multi-factorial diseases. In the past few years, discovery and use of multi-targeted drug therapy with hybrid molecules have shown promising results with minimal side effects, and thus considered a most effective approach. In this review article, prominent hybrid molecules combining with different active moieties are reported to synergistically and simultaneously block different pathways involved in CVDs. Here, we provide a critical evaluation and discussion on their pharmacology with mechanistic insights and the structure activity relationship. The timely information provided in this article reveals the recent trends of molecular hybridization to the scientific community interested in CVDs and help them in designing the next generation of multi-targeting drug therapeutics.

Further exploration of the structure-activity relationship of dual soluble epoxide hydrolase/fatty acid amide hydrolase inhibitors

Fatty acid amide hydrolase (FAAH) is a membrane protein that hydrolyzes endocannabinoids, and its inhibition produces analgesic and anti-inflammatory effects. The soluble epoxide hydrolase (sEH) hydrolyzes epoxyeicosatrienoic acids (EETs) to dihydroxyeicosatetraenoic acids. EETs have anti-inflammatory and inflammation resolving properties, thus inhibition of sEH consequently reduces inflammation. Concurrent inhibition of both enzymes may represent a novel approach in the treatment of chronic pain. Drugs with multiple targets can provide a superior therapeutic effect and a decrease in side effects compared to ligands with single targets. Previously, microwave-assisted methodologies were employed to synthesize libraries of benzothiazole analogs from which high affinity dual inhibitors (e.g. 3, sEH IC₅₀ = 9.6 nM; FAAH IC₅₀ = 7 nM) were identified. Here, our structure-activity relationship studies revealed that the 4-phenylthiazole moiety is well tolerated by both enzymes, producing excellent inhibition potencies in the low nanomolar range (e.g. 6o, sEH IC₅₀ = 2.5 nM; FAAH IC₅₀ = 9.8 nM). Docking experiments show that the new class of dual inhibitors bind within the catalytic sites of both enzymes. Prediction of several pharmacokinetic/pharmacodynamic properties suggest that these new dual inhibitors are good candidates for further in vivo evaluation. Finally, dual inhibitor 3 was tested in the Formalin Test, a rat model of acute inflammatory pain. The data indicate that 3 produces antinociception against the inflammatory phase of the Formalin Test in vivo and is metabolically stable following intraperitoneal administration in male rats. Further, antinociception produced by 3 is comparable to that of ketoprofen, a traditional nonsteroidal anti-inflammatory drug. The results presented here will help toward the long-term goal of developing novel non-opioid therapeutics for pain management.

Small molecule compounds with good anti-inflammatory activity reported in the literature from 01/2009 to 05/2021: a review

Inflammation and disease are closely related. Inflammation can induce various diseases, and diseases can promote inflammatory response, and two possibly induces each other in a bidirectional loop. Inflammation is usually treated using synthetic anti-inflammatory drugs which are associated with several adverse effects hence are not safe for long-term use. Therefore, there is need for anti-inflammatory drugs which are not only effective but also safe. Several researchers have devoted to the research and development of effective anti-inflammatory drugs with little or no side effects. In this review, we studied some small molecules with reported anti-inflammatory activities and hence potential sources of anti-inflammatory agents. The information was retrieved from relevant studies published between January 2019 and May, 2021 for review. This review study was aimed to provide relevant information towards the design and development of effective and safe anti-inflammation agents.

Design, synthesis and mechanistic study of novel diarylpyrazole derivatives as anti-inflammatory agents with reduced cardiovascular side effects

Novel diarylpyrazole (5a-d, 6a-e, 12, 13, 14, 15a-c and 11a-g) derivatives were designed, synthesized and evaluated for their dual COX-2/sEH inhibitory activities via recombinant enzyme assays to explore their anti-inflammatory activities and cardiovascular safety profiles. Comprehensively, the structures of the synthesized compounds were established via spectral and elemental analyses, followed by the assessment of both their in vitro COX inhibitory and in vivo anti-inflammatory activities. The most active compounds as COX inhibitors were further evaluated for their in vitro 5-LOX and sEH inhibitory activities, alongside with their in vivo analgesic and ulcerogenic effects. Compounds 6d and 11f showed excellent inhibitory activities against both COX-2 and sEH (COX-2 IC₅₀ = 0.043 and 0.048 µM; sEH IC₅₀ = 83.58 and 83.52 μM, respectively). Moreover, the compounds demonstrated promising results as anti-inflammatory and analgesic agents with considerable ED₅₀ values and gastric safety profiles. Remarkably, the most active COX inhibitors 6d and 11f possessed improved cardiovascular safety profiles, if compared to celecoxib, as shown by the laboratory evaluation of both essential cardiac biochemical parameters (troponin-1, prostacyclin, tumor necrosis factor-α, lactate dehydrogenase, reduced glutathione and creatine kinase-M) and histopathological studies. On the other hand, docking simulations confirmed that the newly synthesized compounds displayed sufficient structural features required for binding to the target COX-2 and sEH enzymes. Also, in silico ADME studies prediction and drug-like properties of the compounds revealed favorable oral bioavailability results. Collectively, the present work could be featured as a promising future approach towards novel selective COX-2 inhibitors with declined cardiovascular risks.

Novel 1,5-diaryl pyrazole-3-carboxamides as selective COX-2/sEH inhibitors with analgesic, anti-inflammatory, and lower cardiotoxicity effects

COX-2 selective drugs have been withdrawn from the market due to cardiovascular side effects, just a few years after their discovery. As a result, a new series of 1,5-diaryl pyrazole carboxamides 19-31 was synthesized as selective COX-2/sEH inhibitors with analgesic, anti-inflammatory, and lower cardiotoxic properties. The target compounds were synthesized and tested in vitro against COX-1, COX-2, and sEH enzymes. Compounds 20, 22 and 29 exhibited the most substantial COX-2 inhibitory activity (IC₅₀ values: 0.82-1.12 µM) and had SIs of 13, 18, and 16, respectively, (c.f. celecoxib; SI = 8). Moreover, compounds 20, 22, and 29 were the most potent dual COX-2/sEH inhibitors, with IC₅₀ values of 0.95, 0.80, and 0.85 nM against sEH, respectively, and were more potent than the standard AUDA (IC₅₀ = 1.2 nM). Furthermore, in vivo studies revealed that these compounds were the most active as analgesic/anti-inflammatory derivatives with a good cardioprotective profile against cardiac biomarkers and inflammatory cytokines. Finally, the most active dual inhibitors were docked inside COX-2/sEH active sites to explain their binding modes.

Structure-based design, synthesis, and biological evaluation of novel piperine-resveratrol hybrids as antiproliferative agents targeting SIRT-2

A series of novel piperine–resveratrol hybrids 5a–h was designed, synthesized, and structurally elucidated by IR, and ¹H, ¹³C, and ¹⁹F NMR. Antiproliferative activities of 5a–h were evaluated by NCI against sixty cancer cell lines. Compound 5b, possessing resveratrol pharmacophoric phenolic moieties, showed a complete cell death against leukemia HL-60 (TB) and Breast cancer MDA-MB-468 with growth inhibition percentage of −0.49 and −2.83, respectively. In addition, 5b recorded significant activity against the other cancer cell lines with growth inhibition percentage between 80 to 95. New 5a–h hybrids were evaluated for their inhibitory activities against Sirt-1 and Sirt-2 as molecular targets for their antiproliferative action. Results showed that compounds 5a–h were more potent inhibitors of Sirt-2 than Sirt-1 at 5 μm and 50 μm. Compound 5b showed the strongest inhibition of Sirt-2 (78 ± 3% and 26 ± 3% inhibition at 50 μM and 5 μM, respectively). Investigation of intermolecular interaction via Hirschfeld surface analysis indicates that these close contacts are mainly ascribed to the O–H⋯O hydrogen bonding. To get insights into the Sirt-2 inhibitory mechanism, a docking study was performed where 5b was found to fit nicely inside both extended C-pocket and selectivity pocket and could compete with the substrate acyl-Lys. Another possible binding pattern showed that 5b could act by partial occlusion of the NAD⁺ C-pocket. Collectively, these findings would contribute significantly to better understanding the Sirt-2 inhibitory mechanism in order to develop a new generation of refined and selective Sirt-2 inhibitors.

A series of novel piperine–resveratrol hybrids 5a–h was designed, synthesized, and structurally elucidated by IR, and ¹H, ¹³C, and ¹⁹F NMR.

Design, synthesis and mechanistic study of new 1,2,4-triazole derivatives as antimicrobial agents

Novel 5-amino-1,2,4-triazole derivatives and their cyclized 1,2,4-triazolo[1,5-a]pyrimidine analogues were designed, synthesized and evaluated for their antimicrobial activities. They were tested against five bacterial strains (Methicillin Resistant S. aureus (MRSA), E. coli, K. pneumoniae, A. baumannii and P. aeruginosa) using ciprofloxacin as a positive control and against two fungal strains (C. albicans and C. neoformans) using fluconazole and amphotericin B as positive controls. Compounds 9, 13a and 13b showed high to moderate antifungal activities against candida albicans (MIC values = 4-32 µg/ml), with considerable safety profiles; where no cytotoxicity against human embryonic kidney or red blood cells were detected at concentrations up to 32 µg/mL. Furthermore, compound 9 showed significant inhibitory activity against lansterol 14α-demethylase (IC₅₀ = 0.27 µM), compared to the reference drug fluconazole (IC₅₀ = 0.25 µM). Molecular docking of compound 9 into the active site of the cytochrome P450 enzyme revealed comparable binding modes and docking scores to those of fluconazole. Finally, in silico ADME studies prediction and drug-like properties of these compounds revealed favorable oral bioavailability results.

Small Molecule Soluble Epoxide Hydrolase Inhibitors in Multitarget and Combination Therapies for Inflammation and Cancer

The enzyme soluble epoxide hydrolase (sEH) plays a central role in metabolism of bioactive lipid signaling molecules. The substrate-specific hydrolase activity of sEH converts epoxyeicosatrienoic acids (EETs) to less bioactive dihydroxyeicosatrienoic acids. EETs exhibit anti-inflammatory, analgesic, antihypertensive, cardio-protective and organ-protective properties. Accordingly, sEH inhibition is a promising therapeutic strategy for addressing a variety of diseases. In this review, we describe small molecule architectures that have been commonly deployed as sEH inhibitors with respect to angiogenesis, inflammation and cancer. We juxtapose commonly used synthetic scaffolds and natural products within the paradigm of a multitarget approach for addressing inflammation and inflammation induced carcinogenesis. Structural insights from the inhibitor complexes and novel strategies for development of sEH-based multitarget inhibitors are also presented. While sEH inhibition is likely to suppress inflammation-induced carcinogenesis, it can also lead to enhanced angiogenesis via increased EET concentrations. In this regard, sEH inhibitors in combination chemotherapy are described. Urea and amide-based architectures feature prominently across multitarget inhibition and combination chemotherapy applications of sEH inhibitors.