Design, synthesis and evaluation of piperazine clubbed 1,2,4-triazine derivatives as potent anticonvulsant agents

Benzothiazole a privileged scaffold for Cutting-Edges anticancer agents: Exploring drug design, structure-activity relationship, and docking studies

Cancer is a major societal, public health, and economic burden in the 21st century, with 9.7 million deaths in 2022 (9.96 million in 2020) and 20 million new cancer cases (19.6 million in 2020). Considering the increasing number of cancer cases and deaths, heterocyclic compounds always paved the gold mine for the development of potential anticancer drugs as these compounds have unique flexibility and dynamic cores. Benzothiazoles and their derivatives have potential anticancer properties, making them a desirable scaffold among different heterocycles. Title structures are a class of chemicals that may bind to various receptors with high affinity, particularly those engaged in oncogenic processes. The use of these compounds allows medicinal chemists to rapidly produce anticancer treatments across a large range of targets over an extended length of time. The current study presents a thorough success story of benzothiazole derivatives as anticancer agents. It discusses the current state of cancer, the profile of benzothiazole-based derivatives synthetic pathways, and its relevance as an anticancer agent on several oncogenic pathways. The structure-activity relationship was also added to offer insight into the connection of biological data with structure and the rational design of more active drugs.

Therapeutic potential of anticancer activity of nitrogen-containing heterocyclic scaffolds as Janus kinase (JAK) inhibitor: Biological activity, selectivity, and structure-activity relationship

The JAK-STAT signalling pathway is primarily involved in cytokine signalling and induces various factors namely, erythropoietin, thrombopoietin, interferons, interleukins, and granulocyte colony-stimulating factors. These factors tremendously influenced understanding human health and illness, specifically cancer. Inhibiting the JAK/STAT pathway offers enormous therapeutic promises against cancer. Many JAK inhibitors are now being studied due to their efficacy in various cancer treatments. Further, the Nitrogen-heterocyclic (N-heterocyclic) scaffold has always shown to be a powerful tool for designing and discovering synthetic compounds with diverse pharmacological characteristics. The review focuses on several FDA-approved JAK inhibitors and their systematic categorization. The medicinal chemistry perspective is highlighted and classified review on the basis of N-heterocyclic molecules. Several examples of designing strategies of N-heterocyclic rings including pyrrolo-azepine, purine, 1H-pyrazolo[3,4-d]pyrimidine, 1H-pyrrolo[2,3-b]pyridine, pyrazole, thieno[3,2-d] pyrimidine, and, pyrimidine-based derivatives and their structure-activity relationships (SAR) are discussed. Among the various N-heterocyclic-based JAK inhibitors pyrimidine-containing compound 1 exhibited excellent inhibition activity against JAK2WT and mutated-JAK2V617F with IC50 of 2.01 and 18.84 nM respectively. Amino pyrimidine-containing compound 6 and thiopheno[3,2-d]pyrimidine-containing compound 13 expressed admirable JAK3 inhibition activity with IC50 of 1.7 nM and 1.38 nM respectively. Our review will support the medicinal chemists in refining and directing the development of novel N-heterocyclic-based JAK inhibitors.

In-silico based discovery of potential Keap1 inhibitors using the strategies of pharmacophore screening, molecular docking, and MD simulation studies

Introduction

The main objective of this research is to identify potential leads for developing potent Keap1 inhibitors.

Methods

In the current research article, in-silico methods have been employed to discover potential Keap1 inhibitors. 3D-QSAR was generated using the ChemBL database of Keap1 inhibitors with IC50. The best pharmacophore was selected for the screening of three different libraries namely Asinex, MiniMaybridge, and Zinc. The molecules screened from the databases were filtered through druggability rules and molecular docking studies. The best binding molecules obtained after docking studies were subjected to physicochemical properties toxicity determination by in-silico methods. The best hits were studied for stability in the cavity of Keap1 by molecular dynamic simulations.

Results

The virtual screening of different databases was carried out separately and three leads, were obtained. These lead molecules ASINEX 508, MiniMaybridgeHTS_01719, and ZINC 0000952883 showed the best binding in the Keap1 cavity. The molecular dynamic simulations of the binding complexes of the leads support the docking analysis. The leads (ASINEX 508, MiniMaybridgeHTS_01719, and ZINC 0000952883) were stabilized in the Keap1 binding cavity throughout 100 ns simulation, with average RMSD values of 0.100, 0.114, and 0.106 nm, respectively.

Conclusion

This research proposes three lead molecules as potential Keap1 inhibitors based on high throughput screening, docking, and MD simulation studies. These hit molecules can be used for further design and development of Keap1 inhibitors. This research provides the preliminary data for discovering novel Keap1 inhibitors. It opens new avenues for medicinal chemists to explore antioxidant-stimulating molecules targeting the Keap1-Nrf2 pathway.

Salicylaldehyde-derived piperazine-functionalized hydrazone ligand-based Pt(II) complexes: inhibition of EZH2-dependent tumorigenesis in pancreatic ductal adenocarcinoma, synergism with PARP inhibitors and enhanced apoptosis

Piperazine is an important functional unit of many clinically approved drugs, including chemotherapeutic agents. In the current study, methyl piperazine was incorporated and eight salicylaldehyde-derived piperazine-functionalized hydrazone ONN-donor ligands (L) and their Pt(II) complexes (L-PtCl) were prepared. The structures of all these ligands (L1-L8) and Pt(II) complexes (C1-C8) were determined using 1H and 13C NMR, UV-vis, FT-IR and HR-ESI MS analyses, whereas the structures of C1, C5, C6, C7 and C8 were determined in the solid state using single crystal X-ray diffraction analysis. Solution state stabilities of C3, C4, C5 and C6 were determined via time-dependent UV-vis spectroscopy. All these complexes (C1-C8) were studied for their anticancer effect in pancreatic ductal adenocarcinoma cells, including BxPC3, MIAPaCa-2 and PANC1 cells. C1-C8 displayed a potential cytotoxic effect in all these cancer cells, among which C5, C6 and C8 showed the strongest inhibitory effect in comparison with standard chemotherapeutic agents, including 5-fluorouracil (5-FU), cisplatin (CP), oxaliplatin and doxorubicin (DOX). C5, C6 and C8 suppressed the growth of pancreatic cancer cells in a dose-dependent manner. Moreover, C5, C6 and C8 inhibited clonogenic potential and invasion ability and induced apoptosis in PANC1 cells. Importantly, C5, C6 and C8 synergized the anticancer effect with PARP inhibitors, including olaparib, veliparib and niraparib, in pancreatic cancer cells, thus suggesting an important role of C5, C6 and C8 in induction of apoptosis in combination with PARP inhibitors. C5 combined with PARP inhibitors induced caspase3/7 activity and suppressed ATP production. Mechanistically, C5, C6 and C8 inhibited EZH2 protein expression to suppress EZH2-dependent tumorigenesis. Overall, these results highlighted the importance of these piperazine-functionalized Pt(II) complexes as potential anticancer agents to suppress pancreatic ductal adenocarcinoma tumorigenesis by targeting the EZH2-dependent pathway.

Poly (ADP-ribose) polymerase (PARP) inhibitors as anticancer agents: An outlook on clinical progress, synthetic strategies, biological activity, and structure-activity relationship

Poly (ADP-ribose) polymerase (PARP) is considered an essential component in case of DNA (Deoxyribonucleic acid) damage, response by sensing DNA damage and engaging DNA repair proteins. Those proteins repair the damaged DNA via an aspect of posttranslational modification, known as poly (ADP-Ribosyl)ation (PARylation). Specifically, PARP inhibitors (PARPi) have shown better results when administered alone in a variety of cancer types with BRCA (Breast Cancer gene) mutation. The clinical therapeutic benefits of PARP inhibitors have been diminished by their cytotoxicity, progression of drug resistance, and limitation of indication, regardless of their tremendous clinical effectiveness. A growing number of PARP-1 inhibitors, particularly those associated with BRCA-1/2 mutations, have been identified as potential cancer treatments. Recently, several researchers have identified various promising scaffolds, which have resulted in the resuscitation of the faith in PARP inhibitors as cancer therapies. This review provided a comprehensive update on the anatomy and physiology of the PARP enzyme, the profile of FDA (Food and Drug Administration) and CFDA (China Food and Drug Administration)-approved drugs, and small-molecule inhibitors of PARP, including their synthetic routes, biological evaluation, selectivity, and structure-activity relationship.

Design and synthesis of pyrrolo[2,3-d]pyrimidine linked hybrids as α-amylase inhibitors: molecular docking, MD simulation, ADMET and antidiabetic screening

Novel pyrrolo[2,3-d]pyrimidine-based analogues were designed, synthesized, and evaluated for their ability to inhibit the α-amylase enzyme in order to treat diabetes. In vitro antidiabetic analysis demonstrated excellent antidiabetic action for compounds 5b, 6c, 7a, and 7b, with IC50 values in the 0.252-0.281 mM range. At a 200 μg/mL concentration, the exceptional percent inhibition values for compounds 5a, 5b, 5d, and 6a varied from 97.79 ± 2.86% to 85.56 ± 4.13% overperforming the standard (acarbose). Molecular docking of all compounds performed with Bacillus paralicheniformis α-amylase enzyme. The most active compounds via in vitro and non-toxic via in silico ADMET and molecular docking analysis, hybrids 6c, 7a, and 7b displayed binding affinity from - 8.2 and - 8.5 kcal/mol. Molecular dynamic simulations of most active compound 5b and 7a investigated into the active sites of the Bacillus paralicheniformis α-amylase enzyme for a 100-ns indicating the stability of hybrid-protein complex. Consistent RGyr values for the two complexes under study further suggest that the system's proteins are closely packed in the dynamic state. Synthesized analogs' in vitro biological assessments, ADMET, molecular docking, and MD modelling reveal that 5b, 6c, 7a, and 7b hybrid analogs may be employed in the development of future antidiabetic drugs.

Synthesis of Novel Triazine-Based Chalcones and 8,9-dihydro-7H-pyrimido[4,5-b][1,4]diazepines as Potential Leads in the Search of Anticancer, Antibacterial and Antifungal Agents

This study presents the synthesis of four series of novel hybrid chalcones (20,21)a-g and (23,24)a-g and six series of 1,3,5-triazine-based pyrimido[4,5-b][1,4]diazepines (28-33)a-g and the evaluation of their anticancer, antibacterial, antifungal, and cytotoxic properties. Chalcones 20b,d, 21a,b,d, 23a,d-g, 24a-g and the pyrimido[4,5-b][1,4]diazepines 29e,g, 30g, 31a,b,e-g, 33a,b,e-g exhibited outstanding anticancer activity against a panel of 60 cancer cell lines with GI50 values between 0.01 and 100 μM and LC50 values in the range of 4.09 μM to >100 μM, several of such derivatives showing higher activity than the standard drug 5-fluorouracil (5-FU). On the other hand, among the synthesized compounds, the best antibacterial properties against N. gonorrhoeae, S. aureus (ATCC 43300), and M. tuberculosis were exhibited by the pyrimido[4,5-b][1,4]diazepines (MICs: 0.25-62.5 µg/mL). The antifungal activity studies showed that triazinylamino-chalcone 29e and triazinyloxy-chalcone 31g were the most active compounds against T. rubrum and T. mentagrophytes and A. fumigatus, respectively (MICs = 62.5 μg/mL). Hemolytic activity studies and in silico toxicity analysis demonstrated that most of the compounds are safe.

Exploring new cyclohexane carboxamides based GABA agonist: Design, synthesis, biological evaluation, in silico ADME and docking studies

The new series of 5a-e, 6a-e and 7a-e derivatives were designed, synthesized and tested for their anticonvulsant activity using "gold standard methods" ScPTZ and MES model, neurotoxicity, liver enzymes and neurochemical assay. Screening of the synthesized analogues exhibited variable anticonvulsant potential especially in chemically induced seizures. Quantification study showed that compounds 6d and 6e were the most potent analogues with ED₅₀ 44.77 and 11.31 mg/kg, respectively in ScPTZ test. Compound 6e (0.031 mmol/kg) was about 2 fold more potent than phenobarbital (0.056 mmol/kg) and was 30 folds more potent than Ethosuximide (0.92 mmol/kg) as reference standard drug. Moreover, all the synthesized compounds were screened for acute neurotoxicity using the rotarod method to recognize motor impairment, whereas all compounds devoid from neurotoxicity except compound 5a, 5b, 7a and 7e. The most active compounds were examined for acute toxicity and the estimates for LD₅₀ were stated. Further neurochemical study was performed to investigate the effect of the most active compounds in ScPTZ test on GABA level in brain of the mice; a significant elevation in GABA level was obvious for compound 6d compared to control group confirming GABAergic modulating activity. Docking study was accomplished to examine the binding interaction of the newly synthesized analogues with GABA-AT enzyme. Additionally, physicochemical and pharmacokinetic parameters were predicted. The attained results indicate that the newly target compounds are considered a promising scaffolds for further development of newly anticonvulsants.

Design, synthesis of 1,2,4-triazine derivatives as antidepressant and antioxidant agents: In vitro, in vivo and in silico studies

The novel series of substituted-N-(5,6-diphenyl-1,2,4-triazin-3-yl) benzamides (R: 1-12) were designed, synthesized and evaluated for in-vitro and in-vivo antidepressant-like activity. In MAO-A inhibition assay, compound R: 5 and R: 9 displayed most potent activity with IC₅₀ = 0.12 and 0.30 µM. R: 5 and R: 9 were also evaluated for in-vivo antidepressant using FST and TST. In both models, the test samples R: 5 and R: 9 showed noteworthy antidepressant effect. R: 5 showed 46.48 % and 45.96 % reduction in immobility in FST and TST respectively at dosage of 30 mg/kg (p.o). Whereas compound R: 9 reduced the immobility time by 52.76 % and 47.14 % as compared to control in FST and TST, respectively at same dosage. Both the compounds were also tested for behavioural study using actophotometer and grip tests. None of compounds exhibited decrease in locomotor activity. Further, these compounds were subjected to in silico studies to determine their ADME properties along with binding energies and binding orientions. In ADME studies none of the compounds violated the Lipinski rule and all other parameters were also within the acceptable ranges. In docking study R: 5 (-10.7) and R: 9 (-10.4) were also displayed highest docking score. These encouraging results present the pharmacophoric features of substituted-N-(5,6-diphenyl-1,2,4-triazin-3-yl) benzamides as interesting lead for further development of new antidepressant drug molecules.