Recent developments in synthetic chemistry and biological activities of pyrazole derivatives

In vitro and in vivo antidiabetic evaluation of new Coumarin and Chromone derivatives: Design, synthesis and molecular modeling

Diabetes mellitus is a chronic metabolic disease characterized by an imbalance in glucose homeostasis, which raises blood glucose levels. α-glucosidase enzyme hydrolyzes polysaccharides to produce glucose and since glucose is one of the primary energy sources in eukaryotes, α-glucosidase is a target for postprandial hyperglycemia regulation. The design and synthesis of new oxadiazole coumarin (5a,b and 6a,b), acryloyl chromone (10a-c) and pyrazolyl chromone (11a-c) derivatives as naturally based scaffolds are presented in this work. The new compounds were assessed as antidiabetic agents targeting α-glucosidase enzyme. With an IC50 value of 119.7 ± 4.3 μM, compound 11c demonstrated the most promising α-glucosidase inhibitory activity, superior to the standard drug acarbose (IC50 = 300.9 ± 10.9 μM). Furthermore, compared to the group of diabetic rats, the in vivo investigations demonstrated that medium and high dosages of 11c ameliorated the expression of diabetic related genes (GCK, SYT11, SNAP-25 and Ins1). According to the molecular docking results, 11c possessed the best binding energy score (-9.1 kcal/mol) within the α-glucosidase active site, outperforming the rest of the derivatives and the reference inhibitor acarbose (-8.2 kcal/mol). Lastly, an in silico molecular dynamic simulation and a pharmacokinetic study were performed on compound 11c.

Exploring green catalysis with Zn(II)-chitosan-alginate beads for pyran and pyranopyrazole synthesis

Biopolymers are natural and sustainable materials, offering numerous advantages in terms of environmental impact and abundant availability, including reduced dependency on non-renewable materials and minimized pollution associated with synthetic resources. These polymers exhibit high metal ion sorption capabilities and can be shaped into various forms. For these reasons, biopolymers like chitosan and alginate are currently under extensive study in heterogeneous catalysis. In this work, we prepared hybrid beads using a combination of chitosan microspheres, sodium alginate, and zinc ions (Zn-MCS-SA). The prepared beads were fully characterized and have demonstrated that can be used as a catalyst for the synthesis of derivatives of 4H-pyran and pyrano[2,3-c]pyrazole under greener reaction conditions. Moreover, the heterogeneous nature of the catalyst beads was proven, and good recyclability was demonstrated.

Design, Synthesis, in Silico and in Vitro Dipeptidyl Peptidase-4 Activity of Triazole-Based Heterocyclic Compounds

1,2,3-triazole-based ring connected with pyridazine, triazine, methyl pyrazole, diphenyl pyrazole, and phthalimide moieties through propylene linker has been synthesized for antidiabetic evaluation via click chemistry. The antidiabetic evaluations have been done by molecular docking studies and in-vitro tests against the dipeptidyl peptidase-4 (DPP-4) enzyme. The molecular docking studies have revealed that compounds 22, 23, 29, and 30 showed hydrogen bonds with the DPP-4 enzyme while in-vitro tests have revealed that compound 30 has (IC50 values 12.82 nM), exhibited potent activity compared to the standard drug, sitagliptin (14.8 nM). Among the heterocyclic compounds, phthalimide and pyrazole derivatives were found more potent for DPP-4 inhibitors.

Recent advances in the synthesis of anticancer pyrazole derivatives using microwave, ultrasound, and mechanochemical techniques

Pyrazole and its derivatives have attracted considerable attention in pharmaceutical and medicinal chemistry, as reflected in their presence in numerous FDA-approved drugs and clinical candidates. This review presents a comprehensive analysis of articles published between 2014 and 2024, focusing on the microwave-, ultrasound-, and mechanochemical-assisted synthesis of pyrazole derivatives with anticancer activity. It explores synthetic methodologies, anticancer efficacy, and molecular docking studies, underscoring the significance of pyrazole derivatives in drug discovery and medicinal chemistry. Notably, microwave irradiation stands out as the most widely employed technique, providing high efficiency by significantly reducing reaction times while maintaining moderate temperatures. Ultrasound irradiation serves as a valuable alternative, particularly for processes that require milder conditions, whereas mechanochemical activation, though less frequently employed, offers distinct advantages in terms of sustainability.

Antibacterial and antifungal pyrazoles based on different construction strategies

The growing prevalence of microbial infections, and antimicrobial resistance (AMR) stemming from the overuse and misuse of antibiotics, call for novel therapeutic agents, particularly ones targeting resistant microbial strains. Scientists are striving to develop innovative agents to tackle the rising microbial infections and abate the risk of AMR. Pyrazole, a five-membered heterocyclic compound belonging to the azole family, is a versatile scaffold and serves as a core structure in many drugs with antimicrobial and other therapeutic effects. In this review, we have updated pyrazole-based antibacterial and antifungal agents mainly developed between 2016 and 2024, by combining with diverse pharmacophores such as coumarin, thiazole, oxadiazole, isoxazole, indole, etc. Meanwhile, the various strategies (molecular hybridization, bioisosterism, scaffold hopping, multicomponent reactions, and catalyst-free synthesis) for integrating different functional groups with the pyrazole ring are discussed. Additionally, structure-activity relationships of these pyrazole derivatives, i.e., how structural modifications impact their selectivity and therapeutic potential against bacterial and fungal strains, are highlighted. This review provides insights into designing next-generation antimicrobials to combat AMR, and offers valuable perspectives to the scientists working on heterocyclic compounds with diverse bioactivities.

Diastereomeric pure pyrazolyl-indolyl dihydrofurans: Unveiling isomeric selectivity in antibacterial action via in vitro and in silico insights

Developing pure diastereoisomeric molecular hybrids for the selective inhibition of bacterial growth opened new avenues for combating the ever-increasing microbial resistance. Considering this, a series of diastereoisomeric pure pyrazolyl-dihydrofurans (7a-7y) were synthesized and characterized using NMR, LCMS, and X-ray crystallography. DFT based method was used to explore the configurational stability of cis over trans isomeric form. Considering 7a and 8a as representative isomeric forms with same structural framework, the difference in their bio-efficacy against bacterial and fungal strains was assessed using serial dilution method. The relatively high inhibition of bacterial growth by the cis isomeric form (7a) (MIC = 1.562 µg/mL), amoxicillin (MIC = 3.125 µg/mL) inspired us to broaden the substrate scope for synthesizing a series of pure diastereoisomeric cis forms as selective anti-bacterial agents. However, both the isomers displayed antifungal activity less than the standard drug (Fluconazole) employed in the study. All the reactions proceeded smoothly and yielded a diverse array of dihydrofuran derivatives. The developed synthetics were found to be non-cytotoxic against mouse fibroblast cells and didn't affect the seed germination of Brassica nigra seeds when treated at 1 mg/mL concentration. The experimentally determined in vitro results were further validated using in silico molecular docking and dynamics studies.

Pyrazole, Pyrazoline, and Fused Pyrazole Derivatives: New Horizons in EGFR-Targeted Anticancer Agents

Pyrazole and its derivatives remain popular heterocycles in drug research, design, and development. Several drugs include the pyrazole scaffold, such as ramifenazone, ibipinabant, antipyrine, and axitinib, etc. They have been extensively studied by the scientific community and are said to have a wide range of biological activity, especially anticancer agents targeting EGFR. Overexpression of EGFR signalling promotes tumor growth by inhibiting apoptosis. EGFR dysfunction has been described in multiple cancers, including colon, head and neck, NSCLC, colon, liver, breast, and ovarian cancer. As a result, EGFR represents a prospective target for cancer treatment. Several anti-EGFR drugs are thriving, notably dacomitinib, afatinib, erlotinib, gefitinib, and osimertinib. However, almost all currently available anti-EGFR drugs have limited therapeutic effectiveness due to a lack of selectivity as well as substantial side effects. Furthermore, aberrant EGFR signalling across numerous human malignancies/carcinomas is impeded by gene amplification, protein overexpression, mutations, or in-frame deletions, making EGFR-induced cancer treatment challenging. To overcome such, novel therapeutic anti-EGFR drugs with high efficacy and minimal toxicity are required. To battle cancer and therapeutic resistance to EGFR inhibitors, pyrazole, pyrazoline, and their derivatives have been investigated as a viable pharmacophore for the development of new drugs with better potency, lesser toxicity, and favourable pharmacokinetic characteristics. The present investigation covers the examination of progress toward anti-cancer therapies targeting EGFR via pyrazole, pyrazoline, and fused pyrazole-based compounds. The current study also represents inclusive data on pyrazole-based marketed drugs as well as therapeutic candidates undergoing preclinical and clinical development. Lastly, we have discussed recent advances in the medicinal chemistry of pyrazole-based derivatives with their anti-EGFR significance for the eradication of various cancers and provide the direction toward structure-activity relationship (SAR), including mechanistic studies.

Recent highlights in the synthesis and biological significance of pyrazole derivatives

Aza-heterocyclic scaffolds are privileged cores in the composition of their potential therapeutic profiles and versatile synthetic intermediates. Pyrazole is one of the frequently studied compounds of "azole" family and consists of nitrogen in a 1,2 linking sequence. These motifs possess a wide-spectrum of applications in the field of pharmaceuticals, agrochemicals, polymer chemistry, cosmetics, food industries and more. In addition, functionalized pyrazole derivatives are frequently used as ligands in coordination chemistry and metal-catalysed reactions. As exemplified by numerous recent reports, pyrazoles are highly promising pharmacophores with excellent therapeutic applications. Owing to their aromaticity, the ring structures have many reactive positions, where electrophilic, nucleophilic, alkylation and oxidative reactions might occur. The structural adroitness and diversity of pyrazole cores further emanated numerous fused bicyclic skeletons with various biological applications. In this review, we highlight the recent synthetic methods developed for the preparation of functionalized pyrazole derivatives (From 2017 to present). In addition, we have also covered the notable biological activities (anti-cancer, anti-inflammatory, anti-bacterial and anti-viral) of this ubiquitous core. Herein, we emphasised the synthesis of pyrazoles from variety of precursors such as, alkynes, α,β-unsaturated carbonyl compounds, diazo reagents, nitrile imines, diazonium salts, 1,3-dicarbonyl compounds and etc. Moreover, the recent synthetic methodologies focusing on the preparation of pyrazolines and pyrazolones and variously fused-pyrazoles are also included. Authors expect this review could significantly help the researchers in finding elegant novel tools to synthesize pyrazole skeletons and expand their biological evaluation.

Novel thiazole-based cyanoacrylamide derivatives: DNA cleavage, DNA/BSA binding properties and their anticancer behaviour against colon and breast cancer cells

A novel series of 2-cyano-3-(pyrazol-4-yl)-N-(thiazol-2-yl)acrylamide derivatives (3a-f) were synthesized using Knoevenagel condensation and characterized using various spectral tools. The weak nuclease activity of compounds (3a-f) against pBR322 plasmid DNA was greatly enhanced by irradiation at 365 nm. Compounds 3b and 3c, incorporating thienyl and pyridyl moieties, respectively, exhibited the utmost nuclease activity in degrading pBR322 plasmid DNA through singlet oxygen and superoxide free radicals' species. Furthermore, compounds 3b and 3c affinities towards calf thymus DNA (CT-DNA) and bovine serum albumin (BSA) were investigated using UV-Vis and fluorescence spectroscopic analysis. They revealed good binding characteristics towards CT-DNA with Kb values of 6.68 × 104 M-1 and 1.19 × 104 M-1 for 3b and 3c, respectively. In addition, compounds 3b and 3c ability to release free radicals on radiation were targeted to be used as cytotoxic compounds in vitro for colon (HCT116) and breast cancer (MDA-MB-231) cells. A significant reduction in the cell viability on illumination at 365 nm was observed, with IC50 values of 23 and 25 µM against HCT116 cells, and 30 and 9 µM against MDA-MB-231 cells for compounds 3b and 3c, respectively. In conclusion, compounds 3b and 3c exhibited remarkable DNA cleavage and cytotoxic activity on illumination at 365 nm which might be associated with free radicals' production in addition to having a good affinity for interacting with CT-DNA and BSA.

Laccase-mediated chemoselective C-4 arylation of 5-aminopyrazoles

Chemoselective arylation of 5-aminopyrazoles was performed through oxidative formation of orthoquinones from catechols catalyzed by Myceliophthora thermophila laccase (Novozym 51003), and subsequently nucleophilic attack of 5-aminopyrazole to the catechol intermediates. The C-4 arylated products were obtained under extremely mild conditions without the need for amine protection or halogenation of the substrates. From this method, 10 derivatives with moderate to good efficiency (42-94%) were prepared.

Synthesis of novel pyrazole acetals of andrographolide and isoandrographolide as potent anticancer agents

Globally, cancer is the most prevalent chronic disease-related cause of death. Although there are many anticancer drugs, some of them have adverse effects. Due to their limited side effects, natural products are preferred over synthetic drugs. Andrographolide and its derivatives are known to be potent anticancer agents. In this context, sixteen novel 3,19-(NH-3-aryl-pyrazole) acetals of andrographolide and isoandrographolide (1a-1h, 2a-2g, 2i) from 3-aryl-1-H-pyrazole-4-carboxaldehydes (a-i) were synthesized. All the synthesized compounds were characterized using 1H NMR, 13C NMR, HRMS, FT-IR, and UV-vis spectroscopy. All the compounds were evaluated against a panel of 60 different human cancer cell lines for their anticancer potential at NCI, USA. Four compounds, having promising GI50s (50% growth inhibitory activity) on all 60-cell lines were selected for further in vitro studies. Out of these four compounds, compound 1g exhibited the best IC50 (3.08 μM) against the colon cancer cell line, HCT-116. Cell cycle analysis, annexin V-FITC/PI, and ROS assays revealed that the apoptosis of HCT-116 cells induced by compound 1g could be mainly attributed to the elevated levels of intracellular ROS. Further, the structure-activity relationship revealed that the pyrazole moiety of andrographolide plays a key role in their anticancer properties. These compounds were further examined for in silico ADMET and Lipinski characteristics to assess their potential as lead compounds.

Acyl pyrazole sulfonamides as new antidiabetic agents: synthesis, glucosidase inhibition studies, and molecular docking analysis

Diabetes mellitus is a multi-systematic chronic metabolic disorder and life-threatening disease resulting from impaired glucose homeostasis. The inhibition of glucosidase, particularly α-glucosidase, could serve as an effective methodology in treating diabetes. Attributed to the catalytic function of glucosidase, the present research focuses on the synthesis of sulfonamide-based acyl pyrazoles (5a-k) followed by their in vitro and in silico screening against α-glucosidase. The envisaged structures of prepared compounds were confirmed through NMR and FTIR spectroscopy and mass spectrometry. All compounds were found to be more potent against α-glucosidase than the standard drug, acarbose (IC50 = 35.1 ± 0.14 µM), with IC50 values ranging from 1.13 to 28.27 µM. However, compound 5a displayed the highest anti-diabetic activity (IC50 = 1.13 ± 0.06 µM). Furthermore, in silico studies revealed the intermolecular interactions of most potent compounds (5a and 5b), with active site residues reflecting the importance of pyrazole and sulfonamide moieties. This interaction pattern clearly manifests various structure-activity relationships, while the docking results correspond to the IC50 values of tested compounds. Hence, recent investigation reveals the medicinal significance of sulfonamide-clubbed pyrazole derivatives as prospective therapeutic candidates for treating type 2 diabetes mellitus (T2DM).

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.

A review of poly(ADP-ribose)polymerase-1 (PARP1) role and its inhibitors bearing pyrazole or indazole core for cancer therapy

Cancer is a disease with a high mortality rate characterized by uncontrolled proliferation of abnormal cells. The hallmarks of cancer evidence the acquired cells characteristics that promote the growth of malignant tumours, including genomic instability and mutations, the ability to evade cellular death and the capacity of sustaining proliferative signalization. Poly(ADP-ribose) polymerase-1 (PARP1) is a protein that plays key roles in cellular regulation, namely in DNA damage repair and cell survival. The inhibition of PARP1 promotes cellular death in cells with homologous recombination deficiency, and therefore, the interest in PARP protein has been rising as a target for anticancer therapies. There are already some PARP1 inhibitors approved by Food and Drug Administration (FDA), such as Olaparib and Niraparib. The last compound presents in its structure an indazole core. In fact, pyrazoles and indazoles have been raising interest due to their various medicinal properties, namely, anticancer activity. Derivatives of these compounds have been studied as inhibitors of PARP1 and presented promising results. Therefore, this review aims to address the importance of PARP1 in cell regulation and its role in cancer. Moreover, it intends to report a comprehensive literature review of PARP1 inhibitors, containing the pyrazole and indazole scaffolds, published in the last fifteen years, focusing on structure-activity relationship aspects, thus providing important insights for the design of novel and more effective PARP1 inhibitors.

Investigations of new N1-substituted pyrazoles as anti-inflammatory and analgesic agents having COX inhibitory activity

Background: The search is ongoing for ideal anti-inflammatory and analgesic agents with promising potency and reasonable selectivity. Methods: New N1-substituted pyrazoles with or without an acetamide linkage were synthesized and evaluated for their anti-inflammatory and analgesic activities. COX inhibitory testing, molecular docking, molecular dynamics simulation and antiproliferative activity assessments were performed. Results: All compounds exhibited anti-inflammatory activity up to 90.40% inhibition. They also exhibited good analgesic activity with up to 100% protection. N1-benzensulfonamides 3d, 6c and 6h were preferentially selective agents toward COX-2. Compound 3d showed good cytotoxicity against MCF-7 and HTC116 cancer cell lines. Molecular modeling studies predicted the binding pattern of the most active compounds. Molecular dynamics confirmed the docking results. All compounds showed remarkable pharmacokinetic properties.

A review on metal complexes and its anti-cancer activities: Recent updates from in vivo studies

Research into cancer therapeutics has uncovered various potential medications based on metal-containing scaffolds after the discovery and clinical applications of cisplatin as an anti-cancer agent. This has resulted in many metallodrugs that can be put into medical applications. These metallodrugs have a wider variety of functions and mechanisms of action than pure organic molecules. Although platinum-based medicines are very efficient anti-cancer agents, they are often accompanied by significant side effects and toxicity and are limited by resistance. Some of the most studied and developed alternatives to platinum-based anti-cancer medications include metallodrugs based on ruthenium, gold, copper, iridium, and osmium, which showed effectiveness against many cancer cell lines. These metal-based medicines represent an exciting new category of potential cancer treatments and sparked a renewed interest in the search for effective anti-cancer therapies. Despite the widespread development of metal complexes touted as powerful and promising in vitro anti-cancer therapeutics, only a small percentage of these compounds have shown their worth in vivo models. Metallodrugs, which are more effective and less toxic than platinum-based drugs and can treat drug-resistant cancer cells, are the focus of this review. Here, we highlighted some of the most recently developed Pt, Ru, Au, Cu, Ir, and Os complexes that have shown significant in vivo antitumor properties between 2017 and 2023.

Novel pyrazoline linked acyl thiourea pharmacophores as antimicrobial, urease, amylase and α-glucosidase inhibitors: design, synthesis, SAR and molecular docking studies

In the present work, a small library of novel pyrazolinyl-acyl thiourea (5a-j) was designed and synthesized through a multistep sequence and the synthesized compounds were screened for their antifungal, antibacterial and antioxidant activities as well as urease, amylase and α-glucosidase inhibitory activities. The synthesized series (5a-o) was characterized using a combination of spectroscopic techniques, including FT-IR, 1H NMR and 13C NMR. All compounds (5a-j) were found to have significant potency against urease, α-glucosidase, α-amylase, and DPPH. The synthesized compounds were also screened for potential antibacterial and anti-fungal inhibition activities. IC50 values for all the prepared compounds for urease, α-glucosidase, amylase, and DPPH inhibition were determined and derivatives 5b and 5g were found to be the most potent urease inhibitors with IC50 values of 54.2 ± 0.32 and 43.6 ± 0.25 μM, respectively. Whilst compound 5b (IC50 = 68.3 ± 0.11 μM) is a potent α-glucosidase inhibitor, compound 5f (90.3 ± 1.08 μM) is a potent amylase inhibitor and compound 5b (103.4 ± 1.15 μM) is a potent antioxidant. The different substitutions on the phenyl ring were the basis for structure-activity relationship (SAR) study. The molecular docking study was performed for the confirmation of binding interactions.

Pyrazoline Derivatives as Promising MAO-A Targeting Antidepressants: An Update

Depression is one of the key conditions addressed by the Mental Health Gap Action Programme (mhGAP) of WHO that can lead to self-harm and suicide. Depression is associated with low levels of neurotransmitters, which eventually play a key role in the progression and development of mental illness. The nitrogen-containing heterocyclic compounds exhibit the most prominent pharmacological profile as antidepressants. Pyrazoline, a dihydro derivative of pyrazole, is a well-known five-membered heterocyclic moiety that exhibits a broad spectrum of biological activities. Many researchers have reported pyrazoline scaffold-containing molecules as potential antidepressant agents with selectivity for monoamine oxidase enzyme (MAO) isoforms. Several studies indicated a better affinity of pyrazoline-based moiety as (monoamine oxidase inhibitors) MAOIs. In this review, we have focused on the recent advancements (2019-2023) in the development of pyrazoline-containing derivatives exhibiting promising inhibition of MAO-A enzyme to treat depression. This review provides structural insights on pyrazoline-based molecules along with their SAR analysis, in silico exploration of binding interactions between pyrazoline derivatives and MAO-A enzyme, and clinical trial status of various drug molecules against depression. The in-silico exploration of potent pyrazoline derivatives at the active site of the MAOA enzyme will provide further insights into the development of new potential MAO-A inhibitors for the treatment of depression.

Synthesis, in silico modelling, and in vitro biological evaluation of substituted pyrazole derivatives as potential anti-skin cancer, anti-tyrosinase, and antioxidant agents

Twenty-five azole compounds (P1-P25) were synthesised using regioselective base-metal catalysed and microwave-assisted approaches, fully characterised by high-resolution mass spectrometry (HRMS), nuclear magnetic resonance (NMR), and infrared spectra (IR) analyses, and evaluated for anticancer, anti-tyrosinase, and anti-oxidant activities in silico and in vitro. P25 exhibited potent anticancer activity against cells of four skin cancer (SC) lines, with selectivity for melanoma (A375, SK-Mel-28) or non-melanoma (A431, SCC-12) SC cells over non-cancerous HaCaT-keratinocytes. Clonogenic, scratch-wound, and immunoblotting assay data were consistent with anti-proliferative results, expression profiling therewith implicating intrinsic and extrinsic apoptosis activation. In a mushroom tyrosinase inhibition assay, P14 was most potent among the compounds (half-maximal inhibitory concentration where 50% of cells are dead, IC50 15.9 μM), with activity greater than arbutin and kojic acid. Also, P6 exhibited noteworthy free radical-scavenging activity. Furthermore, in silico docking and absorption, distribution, metabolism, excretion, and toxicity (ADMET) simulations predicted prominent-phenotypic actives to engage diverse cancer/hyperpigmentation-related targets with relatively high affinities. Altogether, promising early-stage hits were identified - some with multiple activities - warranting further hit-to-lead optimisation chemistry with further biological evaluations, towards identifying new skin-cancer and skin-pigmentation renormalising agents.

Identification of novel pyrazole containing ɑ-glucosidase inhibitors: insight into pharmacophore, 3D-QSAR, virtual screening, and molecular dynamics study

Pharmacophore modelling, 3 D QSAR modelling, virtual screening, and molecular dynamics study, all-in-one combination were employed successfully design and develop an alpha-glucosidase inhibitor. To explain the structural prerequisites of biologically active components, 3 D-QSAR models were generated using the selected best hypothesis (AARRR) for compounds 55 included in the model C. The selection of 3 D-QSAR models showed that the Gaussian steric characteristic is crucial to alpha glucosidase's inhibitory potential. The alpha-glucosidase inhibitory potency of the compound is enhanced by other components, including Gaussian hydrophobic groups, Gaussian hydrogen bond acceptor or donor groups, Gaussian electrostatic characteristics, and a Gaussian steric feature. An identification of structure-activity relationships can be obtained from the developed 3 D-QSAR, C model, with R2 = 0.77 and SD = 0.02 for training set, and Q2 = 0.66, RMSE 0.02, and Pearson R = 0.81 for testing set, corresponding to elevated predictive ability. Additionally, docking and MM/GBSA experiments on 1146023 showed that it interacts with critical amino acids in the binding site when coupled with acarbose. Further, five compounds that display a high affinity for alpha-glucosidase were found, and these compounds may serve as potent leads for alpha-glucosidase inhibitor development. Biological activity will be tested for these compounds in the future.Communicated by Ramaswamy H. Sarma.

Heterocyclic compounds with different moieties: synthesis and evaluation of biological activities assisted with the computational study

In the present work, heterocyclic compounds containing different moieties, such as pyrazole and thiophene, were synthesized and screened for inhibitory potency against medicinal enzymes and bacterial and cancer (breast and cervical) cell lines. The synthesized compounds have exhibited inhibitory capability against the studied enzymes. Among substances, C3 compound showed AChE and BChE inhibitory potency with the lowest IC50 value of 3.72 ± 0.57 and 1.66 ± 0.22 µM, respectively, in comparison to the standard tacrine. These analogs indicated varying degrees of tyrosinase inhibitory potencies ranging from 1.12 ± 0.50 to 7.70 ± 0.88 µM, and substance C4 was more potent against the enzyme than the reference compound, kojic acid. All four compounds have IC50 values between 37.11 ± 1.56-124.8 ± 2.09 µM for α-glucosidase. It was found that compound C1 exhibited a better antiproliferative activity compared to other substances, with IC50 values at 5.068 and 6.460 µg mL-1 for MCF-7 and HeLa cells, respectively. C1 and C2 compounds had good inhibitory ability against E. faecalis with a MIC value (16 µg mL-ˡ). Molecular docking analysis showed that C3 has the lowest binding score against α-glucosidase (-8.617 kcal/mol).Communicated by Ramaswamy H. Sarma.

Inherent efficacies of pyrazole-based derivatives for cancer therapy: the interface between experiment and in silico

There has been an increasing trend in the design of novel pyrazole derivatives for desired biological applications. For a cost-effective strategy, scientists have implemented various computational drug design tools to go hand in hand with experiments for the design and discovery of potentially effective pyrazole-based therapeutics. This review highlights the milestones of pyrazole-containing inhibitors and the use of molecular modeling techniques in conjunction with experimental studies to provide a view of the binding mechanism of these compounds. The review focuses on the established targets that play a key role in cancer therapy, including proteins involved in tubulin polymerization, carbonic anhydrase and tyrosine kinase. Overall, using both experimental and computational methods in drug design represents a promising approach to cancer therapy.

Antiproliferative Activity of New Pyrazole-4-sulfonamide Derivatives: Synthesis and Biological Evaluation

Pyrazole and sulfonamide constitute an important class of drugs, with several types of pharmacological agents. Facile synthesis of two new series of 3,5-dimethyl-1H-pyrazole-4-sulfonamide and 1,3,5-trimethyl-1H-pyrazole-4-sulfonamide derivatives was designed and synthesized. These pyrazole-4-sulfonamide derivatives are characterized by Fourier transform infrared (FT-IR), ¹H NMR, ¹³C NMR, and elemental analysis, and their biological evolution data are presented. This paved way for the development of new pyrazole-4-sulfonamide derivatives. These compounds are tested for their in vitro antiproliferative activity against U937 cells by the CellTiter-Glo Luminescent cell viability assay using Mitomycin C. Cytotoxicity detection is based on the measurement of LDH activity, while these compounds did not exhibit cytotoxic activity on these cells. Half maximal inhibitory concentration (IC₅₀) was calculated by Graph Pad Prism software for each dose. Their structure-activity relationships were obtained and discussed.

The Importance of the Pyrazole Scaffold in the Design of Protein Kinases Inhibitors as Targeted Anticancer Therapies

The altered activation or overexpression of protein kinases (PKs) is a major subject of research in oncology and their inhibition using small molecules, protein kinases inhibitors (PKI) is the best available option for the cure of cancer. The pyrazole ring is extensively employed in the field of medicinal chemistry and drug development strategies, playing a vital role as a fundamental framework in the structure of various PKIs. This scaffold holds major importance and is considered a privileged structure based on its synthetic accessibility, drug-like properties, and its versatile bioisosteric replacement function. It has proven to play a key role in many PKI, such as the inhibitors of Akt, Aurora kinases, MAPK, B-raf, JAK, Bcr-Abl, c-Met, PDGFR, FGFRT, and RET. Of the 74 small molecule PKI approved by the US FDA, 8 contain a pyrazole ring: Avapritinib, Asciminib, Crizotinib, Encorafenib, Erdafitinib, Pralsetinib, Pirtobrutinib, and Ruxolitinib. The focus of this review is on the importance of the unfused pyrazole ring within the clinically tested PKI and on the additional required elements of their chemical structures. Related important pyrazole fused scaffolds like indazole, pyrrolo[1,2-b]pyrazole, pyrazolo[4,3-b]pyridine, pyrazolo[1,5-a]pyrimidine, or pyrazolo[3,4-d]pyrimidine are beyond the subject of this work.

Pyrazole and pyrazoline derivatives as antimalarial agents: A key review

Malaria poses a severe public health risk and a significant economic burden in disease-endemic countries. One of the most severe issues in malaria control is the development of drug resistance in malaria parasites. The standard treatment for malaria is artemisinin-combination therapy (ACT). Nevertheless, the Plasmodium parasite's extensive resistance to prior drugs and reduced ACT efficiency necessitates novel drug discovery. The progress in discovering novel, affordable, and effective antimalarial agents is significant in combating drug resistance, and the hybrid drug concept can be used to covalently link two or more active pharmacophores that may act on multiple targets. Pyrazole and pyrazoline derivatives are considered pharmacologically necessary active heterocyclic scaffolds that possess almost all types of pharmacological activities. This review summarized recent progress in antimalarial activities of synthesized pyrazole and pyrazoline derivatives. The studies published since 2000 are included in this systematic review. This review is anticipated to be beneficial for future study and new ideas in searching for rational development strategies for more effective pyrazole and pyrazoline derivatives as antimalarial drugs.

Heteroaromatic Diazirines Are Essential Building Blocks for Material and Medicinal Chemistry

In materials (polymer) science and medicinal chemistry, heteroaromatic derivatives play the role of the central skeleton in development of novel devices and discovery of new drugs. On the other hand, (3-trifluoromethyl)phenyldiazirine (TPD) is a crucial chemical method for understanding biological processes such as ligand-receptor, nucleic acid-protein, lipid-protein, and protein-protein interactions. In particular, use of TPD has increased in recent materials science to create novel electric and polymer devices with comparative ease and reduced costs. Therefore, a combination of heteroaromatics and (3-trifluoromethyl)diazirine is a promising option for creating better materials and elucidating the unknown mechanisms of action of bioactive heteroaromatic compounds. In this review, a comprehensive synthesis of (3-trifluoromethyl)diazirine-substituted heteroaromatics is described.

Pyrazole scaffold-based derivatives: A glimpse of α-glucosidase inhibitory activity, SAR, and route of synthesis

The α-glucosidase is a validated target to develop drugs for treating type 2 diabetes mellitus. The existing α-glucosidase inhibitors have certain shortcomings related to side effects and route of synthesis. Accordingly, it is inevitable to develop new chemical templates as α-glucosidase inhibitors. Pyrazole derivatives have a special place in medicinal chemistry because of various biological activities. Recently, pyrazole-based heterocyclic compounds have emerged as a promising scaffold to develop α-glucosidase inhibitors. This study focuses on the recently reported pyrazole-based α-glucosidase inhibitors, including their biological activity (in vivo, in vitro, and in silico), structure-activity relationship, and ways of synthesis. The literature revealed the development of several promising pyrazole-based α-glucosidase inhibitors and new synthetic routes for their preparation. The encouraging α-glucosidase inhibitory results of the pyrazole-based heterocyclic compounds make them an attractive target for further research. The authors also foresee the arrival of the pyrazole-based α-glucosidase inhibitors in clinical practice.

Novel Quinazolinone–Isoxazoline Hybrids: Synthesis, Spectroscopic Characterization, and DFT Mechanistic Study

Quinazolinone and isoxazoline systems have attracted much attention due to their interesting pharmacological properties. The association of these two pharmacophores in a single hybrid structure can boost the biological activity or bring a new one. Inspired by this new paradigm, in the present work we report the synthesis and spectroscopic characterization of new quinazolinone–isoxazoline hybrids. The target compounds were obtained via 1,3-dipolar cycloaddition reactions of arylnitriloxides and N-allylquinazolinone. The synthesized compounds were characterized using spectroscopic techniques such as IR, 1D NMR (1H and 13C), 2D NMR (COSY and HSQC), and high-resolution mass spectrometry (HRMS). The spectral data show that this reaction leads only to the 3,5-disubstituted isoxazoline regioisomer, and that the observed regiochemistry is not affected by the nature of the substituents in the phenyl ring of the dipole. In addition, a theoretical study was performed using density functional theory (DFT) to support the experimental results in regard to the regiochemistry of the studied reactions. The computational mechanistic study was in good agreement with the experimental data.

Synthesis of Novel 2,3-Dihydro-1,5-Benzothiazepines as α-Glucosidase Inhibitors: In Vitro, In Vivo, Kinetic, SAR, Molecular Docking, and QSAR Studies

In the present study, a series of 2,3-dihydro-1,5-benzothiazepine derivatives 1B-14B has been synthesized sand characterized by various spectroscopic techniques. The enzyme inhibitory activities of the target analogues were assessed using in vitro and in vivo mechanism-based assays. The tested compounds 1B-14B exhibited in vitro inhibitory potential against α-glucosidase with IC50 = 2.62 ± 0.16 to 10.11 ± 0.32 μM as compared to the standard drug acarbose (IC50 = 37.38 ± 1.37 μM). Kinetic studies of the most active derivatives 2B and 3B illustrated competitive inhibitions. Based on the α-glucosidase inhibitory effect, the compounds 2B, 3B, 6B, 7B, 12B, 13B, and 14B were chosen in vivo for further evaluation of antidiabetic activity in streptozotocin-induced diabetic Wistar rats. All these evaluated compounds demonstrated significant antidiabetic activity and were found to be nontoxic in nature. Moreover, the molecular docking study was performed to elucidate the binding interactions of most active analogues with the various sites of the α-glucosidase enzyme (PDB ID 3AJ7). Additionally, quantitative structure-activity relationship (QSAR) studies were performed based on the α-glucosidase inhibitory assay. The value of correlation coefficient (r) 0.9553 shows that there was a good correlation between the 1B-14B structures and selected properties. There is a correlation between the experimental and theoretical results. Thus, these novel compounds could serve as potential candidates to become leads for the development of new drugs provoking an anti-hyperglycemic effect.

Synthesis, spectral analysis, DFT calculations, biological potential and molecular docking studies of indole appended pyrazolo-triazine

A series of novel 5-(3,5-disubstituted-1H-indol-2-yl)-2,3-dimethyl-1-phenyl-2,6-dihydro-1H-pyrazolo[4,3-e][1,2,4]triazines (3a-l) were synthesized in single step from 3,5-disubstituted indole-2-carbohydrazide and 4-aminoantipyrine under acidic conditions with excellent yields. The various spectroscopic methods were used to prove the formation of all these products. The compounds 3a, 3b, 3e, 3f, 3i and 3j exhibited excellent antibacterial and antifungal activities with an MIC value of 3.125 µg/ml against the tested pathogens and anti-tuberculosis inhibitory potential against M. tuberculosis which is equivalent to standard drug. The antidiabetic activity of the compounds 3a and 3b showed the maximum potential as glucosidase inhibitors with IC₅₀ = 47.21 μg/ml and IC₅₀ = 48.36 μg/ml, respectively. The physicochemical characteristics like ADMET, drug-likeness and bioactivity scores for these molecules were also disclosed. To comprehend the electronic behavior of compound 3a, density functional theory estimations at the DFT/B3LYP level via 6-31G++ (d, p) have been carried out to replicate the structure and geometry. The first-order hyperpolarizability calculation was used to calculate the nonlinear visual feature of compound 3a. The charge transfer interface among the structure is elucidated by the estimated HOMO-LUMO analysis. Further, molecular docking studies were carried out for synthesized compounds with human maltase-glucoamylase (PDB: 2QMJ).

Pyrazole Scaffolds: Centrality in Anti-Inflammatory and Antiviral Drug Design

BACKGROUND

Pyrazole is a component of a diversity of bioactive heterocyclic congeners with a broad-spectrum range of biological and pharmacological uses. Designing novel pyrazole and its analogues, revealing new routes for synthesizing this nucleus, exploring various potencies of that heterocycles, and looking for possible applications of pyrazoles are all becoming more important due to their numerous potential applications.

OBJECTIVES

Pyrazole scaffolds have been proven to be successful as anti-viral and anti-inflammatory therapeutic against multiple targets like HSV-1, NNRTI, H1N1, CoX-1, and CoX-2. Due to this miscellany in the biotic area, this moiety has engrossed the consideration of many scientists to study chemistry and pharmacological profile.

RESULTS

The review encompasses pyrazole having various scaffolds with multiple biological activities and attempts have also been made to correlate their structure-activity relationship. Multiple pyrazole correspondents have been synthesized as lead molecules and performed valuation for their actions.

CONCLUSION

The incorporation of pyrazole with other pharmacophores in the molecule might lead to novel potent therapeutic agents that will further help in designing potent lead molecules.

(E)-5-(4-Methyl-benzyl-idene)-1-phenyl-4,5,6,7-tetra-hydro-1H-indazol-4-one

In the title compound, C21H18N2O, the non-aromatic six-membered ring adopts a distorted envelope conformation with one of the methyl-ene-C atoms being the flap atom. The dihedral angle between the phenyl and 4-tolyl rings is 75.3 (1)°. The 1,2-diazole ring forms dihedral angles of 41.9 (1) and 65.5 (1)° with the phenyl and 4-tolyl rings, respectively. In the crystal, stabilizing C-H⋯O, C-H⋯π and π-π inter-actions are evident. The calculated Hirshfeld surfaces highlight the prominent role of C-H⋯O inter-actions (8.6%), along with H⋯H (51.7%) and C⋯H/H⋯C (29.2%) surface contacts.

Elhagali G, A. Eyada H, S. Aboul-Magd D, Ragab A. In Vitro Antimicrobial Evaluation, Single-Point Resistance Study, and Radiosterilization of Novel Pyrazole Incorporating Thiazol-4-one/Thiophene Derivatives as Dual DNA Gyrase and DHFR Inhibitors against MDR Pathogens

A series of thiazol-4-one/thiophene-bearing pyrazole derivatives as pharmacologically attractive cores were initially synthesized using a hybridization approach. All structures were confirmed using spectra analysis techniques (IR, ¹H NMR, and ¹³C NMR). In vitro antimicrobial activities, including the minimum inhibitory concentration (MIC), minimum bactericidal/fungicidal concentration (MBC/MFC), and time-kill assay, were evaluated for the most active derivatives 4a, 5a, 7b, 10, and 13. These derivatives were significantly active against the tested pathogens, with compound 7b as the most active derivative (MIC values range from 0.22 to 0.25 μg/mL). In the MBC and MFC, the active target pyrazole derivatives showed -cidal activities toward the pathogenic isolates. Further, the inhibition of biofilm formation of Staphylococcus aureus and Staphylococcus epidermidis was also carried out. Additionally, these derivatives displayed significant antibiofilm potential with a superior % reduction in the biofilm formation compared with Ciprofloxacin. The target derivatives behaved synergistically with Ciprofloxacin and Ketoconazole, reducing their MICs. Hemolytic results revealed that these derivatives were nontoxic with a significantly low hemolytic activity (%lysis range from 3.23 to 15.22%) compared with Triton X-100 and showed noncytotoxicity activity with IC₅₀ values > 60 μM. In addition, these derivatives proved to be active DNA gyrase and DHFR inhibitors with IC₅₀ ranging between 12.27-31.64 and 0.52-2.67 μM, respectively. Furthermore, compound 7b showed bactericidal activity at different concentrations in the time-kill assay. Moreover, a gamma radiation dose of 10.0 kGy was efficient for sterilizing compound 7b and enhancing its antimicrobial activity. Finally, molecular docking simulation of the most promising derivatives exhibited good binding energy with different interactions.

An In Silico and an In Vitro Inhibition Analysis of Glycogen Phosphorylase by Flavonoids, Styrylchromones, and Pyrazoles

Glycogen phosphorylase (GP) is a key enzyme in the glycogenolysis pathway. GP inhibitors are currently under investigation as a new liver-targeted approach to managing type 2 diabetes mellitus (DM). The aim of the present study was to evaluate the inhibitory activity of a panel of 52 structurally related chromone derivatives; namely, flavonoids, 2-styrylchromones, 2-styrylchromone-related derivatives [2-(4-arylbuta-1,3-dien-1-yl)chromones], and 4- and 5-styrylpyrazoles against GP, using in silico and in vitro microanalysis screening systems. Several of the tested compounds showed a potent inhibitory effect. The structure–activity relationship study indicated that for 2-styrylchromones and 2-styrylchromone-related derivatives, the hydroxylations at the A and B rings, and in the flavonoid family, as well as the hydroxylation of the A ring, were determinants for the inhibitory activity. To support the in vitro experimental findings, molecular docking studies were performed, revealing clear hydrogen bonding patterns that favored the inhibitory effects of flavonoids, 2-styrylchromones, and 2-styrylchromone-related derivatives. Interestingly, the potency of the most active compounds increased almost four-fold when the concentration of glucose increased, presenting an IC₅₀ < 10 µM. This effect may reduce the risk of hypoglycemia, a commonly reported side effect of antidiabetic agents. This work contributes with important considerations and provides a better understanding of potential scaffolds for the study of novel GP inhibitors.