Structure-activity relationship (SAR) study and design strategies of nitrogen-containing heterocyclic moieties for their anticancer activities

Secosteroid - 1,3,4-oxadiazole hybrids: Synthesis and evaluation of their activity against hormone-dependent breast cancer cells

This study focused on the synthesis of secosteroids with good antiproliferative properties against hormone-dependent breast cancer. A straightforward and efficient method for synthesizing secosteroid - 1,3,4-oxadiazole hybrids was developed starting from 13α-hydroxy-3-methoxy-13,17-secoestra-1,3,5(10)-trien-17-oic acid hydrazide. The cyclization of hydrazide moiety with CS2 into 1,3,4-oxadiazole-2(3H)-thione fragment followed by sulfur alkylation resulted in the formation of various secosteroid - 2-mercapto-1,3,4-oxadiazole hybrids. These novel compounds were evaluated for their antiproliferative activity against the hormone-dependent human breast cancer cell line MCF-7. Among the synthesized hybrids, compounds 3i, 3o, and 3q displayed notable antiproliferative effects, with IC50 values ranging from 6.5 to 8.9 µM, comparable to the reference drug cisplatin. Furthermore, compound 3i showed minimal toxicity toward non-cancerous hFB-hTERT fibroblasts, indicating high selectivity. Compounds 3o and 3q exhibited antiestrogenic activity. Additionally, their effects on PARP and Bcl-2 suggest a pro-apoptotic mechanism of action. These findings highlight the potential of secosteroidal hybrids as promising candidates for the development of new anti-breast cancer agents targeting ERα and apoptosis pathways.

Synthesis and characterization of novel N-(2-(pyrazin-2-yl-oxy)ethyl)-4-(trifluoromethoxy)benzamide scaffolds, and biological evaluation and molecular docking studies

A new series of biologically potent N-(2-(6-substituted-1H-pyrazin-2-yloxy)ethyl)-4-(trifluoromethoxy)benzamide scaffolds was synthesized, and their structures were confirmed by 1H NMR, 13C NMR, and mass spectrometry. All the synthesized molecules were tested against antibacterial activity against various pathogenic microorganisms and exhibited remarkable activity. Compounds 12a and 13a exhibited good antibacterial activity against pathogenic cell lines, Staphylococcus aureus and Escherichia coli. Additionally, synthesized molecules 12a and 13a were screened for anticancer activity against the A549 (lung cancer) cell line. These compounds displayed excellent anticancer activity with IC50 values of 19 + 0.50 μM, 17 ± 0.5 μM, A549 (lung cancer). Molecular docking studies results were well supported by strong intercalative interactions of the synthesized compounds with target proteins.

Design, synthesis, molecular docking and molecular dynamics studies of some 3-methoxy flavone derivatives as an anti-breast cancer agent

OBJECTIVE

The present study aimed to synthesize flavone hybrids with 3-methoxy substitution and an N-heterocyclic ring at the 4' position of the flavone B ring and test their effectiveness against cancer.

METHOD

Molecular docking of 3-methoxy flavone was studied on ER-α and EGFR. By cyclizing chalcones, various flavonol derivatives were synthesized and 3-methoxy flavones were produced by flavonol methylation. 3-methoxy flavone derivatives substituted with various heterocyclic rings like morpholine, piperidine, N-methyl piperazine, pyrrolidine, triazole, imidazole, and benzimidazole were synthesized. 1HNMR, 13CNMR, IR, and mass spectra verified all compound's structures. 3-methoxy flavone derivatives evaluated for their anticancer potential by MTT assay and SRB assay on breast cancer (MCF-7 and MDA-MB-231). The molecular dynamics simulation was also studied for active compounds on the human estrogen receptor alpha and epidermal growth factor receptor.

RESULTS

3-methoxy flavone derivatives were successfully synthesized and evaluated by spectroscopic studies. The MTT assay on MCF-7 cell lines revealed significant cytotoxic activity of compounds Ciii and Civ by expressing IC50 values of 13.08 ± 1.80 and 20.3 ± 1.47 µg/ml, respectively. The SRB assay on MDA-MB-231 showed a potent response by compounds Cii, Cv & Cvi with IC50 values of 5.54 ± 1.57, 5.44 ± 1.66 and 8.06 ± 1.83 µg/ml, respectively. Overall results showed the effective substitution of 3-methoxy flavone was N-methyl piperazine and piperidine in all cell lines, while triazole substitution was effective in MDA-MB-231 cells. Molecular dynamics study proved the stability of synthesized compounds' ligands-protein complexes. The structure-activity relationship of flavone derivatives suggests the electron donating group increases the anticancer activity of derivatives in MDA-MB-231, while the same is not reflected in MCF-7 cell lines.

CONCLUSION

This study provides a foundation for designing flavone derivatives with N-heterocyclic ring incorporation as anticancer medicines.

Discovery and biological evaluation of hederagenin derivatives as non-substrate inhibitors of P-glycoprotein-mediated multidrug resistance

Multidrug Resistance (MDR) is an essential cause of failure of tumor chemotherapy, and P-glycoprotein (P-gp) overexpression is one of the major causes of MDR in tumor cells. Hederagenin (HRG) derivatives showed significant inhibitory effects in P-gp-mediated tumor MDR. Herein, we designed and synthesized 30 HRG derivatives and evaluated these compounds' tumor MDR reversal ability. For the first time, we identified a potential P-gp non-substrate inhibitor of the HRG derivatives 15, which binds to non-substrate active sites in transmembrane structural domains (TMDs) with high binding affinity. Subsequent assays confirmed that 15 exerted significant tumor MDR reversal activity by binding to P-gp and inhibiting P-gp function rather than affecting its expression. It could not be pumped out of the cell by P-gp. In addition, 15 inhibited Rhodamine123 efflux, rendered the KBV cells sensitive to paclitaxel (Ptx), blocked the cells in the G2/M phase, and induced apoptosis. Notably, 15 increased Ptx sensitivity in vivo, significantly inhibited the growth of KBV cell-derived xenograft tumors in nude mice, with a tumor suppression rate as high as 63.71 %.

New Amidino-Substituted Benzimidazole Derivatives as Human Dipeptidyl Peptidase III Inhibitors: Synthesis, In Vitro Evaluation, QSAR, and Molecular Docking Studies

Dipeptidyl peptidase III (DPP III) is a zinc-dependent enzyme that hydrolyses biologically active peptides by cleaving dipeptides from their amino terminus. While the fundamental role of this metallopeptidase remains incompletely understood, human DPP III (hDPP III) has been linked to several pathophysiological processes relevant to drug development. In this study, thirty-six amidino-substituted benzimidazole derivatives, including seven newly synthesized compounds, were examined for their activity against hDPP III by combining in vitro tests, in silico quantitative structure-activity relationship (QSAR) modelling, and molecular docking approaches. The experiments demonstrate that all compounds display inhibitory activity at a 30 µM concentration. A biochemical assay revealed that 2,2'-bithiophene, 4-trifluoromethylphenyl, 4-(N,N-diethylamino)phenyl, and 2,3,4-trihydroxyphenyl as substituents at position 2 of the benzimidazole core enhance inhibitor potency. Additionally, the type of substituent at positions 5(6) of the benzimidazole core influences enzyme inhibition, with effectiveness ranked as follows: 2-imidazolinyl > unsubstituted amidine > 2-tetrahydropyrimidine. A multiple linear regression QSAR model for hDPP III inhibition was developed using four Dragon descriptors (Rww, Mats3e, BELe4, and nCs), which can explain 82% of the inhibitory activity. Docking analysis of the semi-closed form of hDPP III in a complex with the most potent compounds indicates the structural features of the benzimidazole derivatives important for the binding at the hDPP III active site.

Design, synthesis, biological evaluation, and mechanism of action of new pyrazines as anticancer agents in vitro and in vivo

Cancer is the second leading cause of mortality worldwide. The development of innovative antitumor pharmaceuticals is urgently needed to alter this circumstance. N-heterocycles, pyrazines for example are prevalent pharmacophores in the architecture of anticancer medicines. This research involved the design and synthesis of seventy-seven new pyrazine derivatives, followed by an evaluation of their anticancer activity in vitro and in vivo. Several new pyrazines exhibiting remarkable antiproliferative activity and selectivity were identified. The links between structure and function were analyzed, and the mechanisms of action were examined. Our mechanistic investigations indicated that these chemicals triggered mitochondria-associated apoptosis in cancer cells. Moreover, they suppressed the phosphorylation of STAT3, concomitant with the down-regulation of BcL-2, BcL-XL, c-Myc, XIAP, GLI1, TAZ, MCL1, JAK1, JAK2 and up-regulation of Bax, p21. Furthermore, the lead compounds B-11 and C-27 demonstrated significant anticancer activity in vivo in the SKOV3 xenograft nude mouse model. Our research establishes a basis for the identification of pyrazines as JAK/STAT3 inhibition based anticancer lead compounds.

Chiral Magnesium(II)-Catalyzed Asymmetric Hydroalkylation of Imine-Containing Vinylazaarenes through Conjugate Addition

The synthesis of chiral azaarenes is of great importance for pharmaceutical development. A direct and versatile approach to obtaining such compounds is the functionalization of imine-containing 2-vinylazaarenes. We have developed a chiral N,N'-dioxide/Mg(II) Lewis acid catalytic system to control nucleophilic β-cyclic or acyclic ketone amides/esters and overcome strong background reaction, enabling highly efficient enantioselective hydroalkylation of imine-containing 2-vinylazaarenes via conjugate addition. As a result, a library of chiral azaarenes bearing an all-carbon quaternary stereocenter can be obtained in high yields with good to excellent ee values. DFT calculations indicate assistances of azaarenes in hydrogen transfer, and the CH-π interaction between the substrate and the ligand's amide group in the enantioselective differentiation.

The Acidity of Weak NH Acids: Expanding the pK a Scale in Acetonitrile

Nitrogen heterocycles and aromatic amines are well-known and widely used compounds that are usually not seen as acids, although in organic solvents like acetonitrile (MeCN) or dimethyl sulfoxide (DMSO) their acidic properties can be observed. In this work, the acidities (pK a values) of 37 such weak NH acids were determined in acetonitrile and presented together with computational gas-phase acidities and literature pK a values in DMSO. In the course of the work the weakest acids range (from pK a 29 upward) of the MeCN acidity scale has been revised and expanded to around 33.5 by adding 31 compounds in that specific region and the span of experimental pK a values in MeCN is now more than 30 orders of magnitude. The relations between the structure and acidity of a selection of the studied compounds have been investigated in MeCN and DMSO. The measured pK a values in MeCN and the gathered pK a values in DMSO were used for a correlation analysis between the two solvents and for assessing the quality of pK a conversion equations. A number of pK a values have been predicted in MeCN from pK a values in DMSO via the correlation analysis and pK a conversion equations.

Isatin-modified Calixarene derivatives: A comprehensive study on synthesis, enzyme inhibition, antioxidant, antimicrobial, and Antiproliferative activities

In this article, a series of calix[4]arenes derivatized with isatin derivatives at the phenolic-O position were synthesized as potential theranostic molecules for antitumor therapy. The cytotoxic mechanism of action of the synthesized compounds was determined by Alamar Blue assay and flow cytometry using MCF-7, MDA-MB-231, DLD1, HeLa and A549 human cancer cell lines and their ability to penetrate into PNT1A healthy epithelial cells. To detect DNA damage, the Comet test was applied after the synthesized compounds interacted with the cells. As a result, it was found that treated cells had abnormal tail nuclei and damaged DNA structures compared with untreated cells. Within the scope of enzyme inhibition experiments, studies were carried out on aromatase and COX-2 enzymes and it was determined that the compounds in the series showed inhibitory activity at varying rates. Especially compounds CLX-A3, CLX-A4, CLX-B3 and CLX-B5 attract attention with their enzyme inhibitor potential. Also, the antioxidant activities of the compounds whose synthesis was completed were also investigated and it was observed that the examined derivatives also had antioxidant activity potential. As a result of the antibacterial and antifungal test performed with broth microdilution, it was observed that the compounds had significant antibacterial and antifungal activity. The lowest MIC values were recorded as 0.006 mg/ml against Sarcina lutea and 0.048 against Candida albicans. In addition, the compound CLX-B3was observed to be effective against all strains including, Klebsiella pneumoniae and Salmonella enteritidis (Gram-negative pathogenic bacteria).

Direct Access to CF3-Containing 4H-1,3-Oxazines and 2-Aminopyrimidines Via a [4 + 2] Annulation Using In Situ Generated Carbodiimide Anions

The carbodiimide anions which were generated in situ from N-cyano-N-aryl-p-toluenesulfonamides (NCTS) in the presence of the base participated in annulations that remain less reported to date. Herein, we have developed for the first time an efficient and environmentally friendly [4 + 2] annulation reaction of CF3-substituted hetero-1,3-dienes with NCTS for the efficient synthesis of CF3-substituted 4H-1,3-oxazines and 2-aminopyrimidines under transition-metal-free conditions. The methodology demonstrates the advantages of readily available substrates, simple operation, good functional group tolerance, and broad substrate scope, providing a promising route to the synthesis of structurally diverse CF3-substituted scaffolds. The products followed by simple transformations provide a facile route to TAS2R14 agonist analogues.

Synthesis strategies and anti-parasitic evaluation of novel compounds for chagas disease: Advancing drug discovery through structure-activity relationships

This study presents a comprehensive exploration of the synthesis of novel compounds targeting Chagas Disease (CD) caused by Trypanosoma cruzi. It is a global health threat with over 6-7 million infections worldwide. Addressing challenges in current treatments, the investigation explores diverse compound classes, including thiazoles, thiazolidinone, imidazole, pyrazole, 1,6-diphenyl-1H-pyrazolo[3,4-b] pyridine, pyrrole, naphthoquinone, neolignan, benzeneacyl hydrazones, and chalcones-based compounds. Highlighting compounds with superior trypanocidal activity compared to standard drugs. The study elucidates structure-activity relationships, emphasizing the impact of substituents, fluorine presence, and substitution patterns. Noteworthy findings include neolignan derivatives demonstrating efficacy against intracellular amastigotes and free-moving trypomastigotes, with unsaturated side chains. Benzeneacylhydrazones and chalcones, as novel classes, showed varied efficacy, with certain compounds surpassing benznidazole. A novel series of triketone compounds exhibited strong anti-parasitic activity, outperforming standard drugs. Docking study revealed that the halogen and methoxy substituted phenyl ring, thiazole, thiazolidine-4-one, quinoline, isoindoline-1,3-dione, pyrrole heterocyclic motifs can play the key role in the designing of effective inhibitors of T. cruzi. Mutually, these insights placed the foundation for the development of innovative and effective treatments for CD, addressing the urgent need for improved therapeutic options.

New thiadiazolopyrimidine-ornamented pyrazolones as prospective anticancer candidates via suppressing VEGFR-2/PI3K/Akt signaling pathway: Synthesis, characterization, in-silico, and in-vitro studies

New thiadiazolopyrimidine-ornamented pyrazolones (4a-8b) have been synthesized by a cyclocondensation reaction of 3a, b with different active methylene compounds. The structure of our products was confirmed via different physical and spectroscopic data. We assessed all newly thiadiazolopyrimidine-ornamented pyrazolones' potential to inhibit angiogenesis, metastasis, and cancer growth by utilizing in-silico investigations focused on the VEGFR-2 signaling pathway and elucidate their pharmacokinetic features using ADMET. Based on our results, compound 8b was chosen for in vitro evaluation since it had the highest binding energy of -10.252 kcal/mol using molecular docking. Compound 8b significantly damaged the T47D (IC50 = 33.01 ± 2.2 μM) cells, without any toxic effect on normal cells in comparison to chemotheraputic FDA approved drug cisplatin (Cis) (IC50 = 3.163 ± 1.7 μM). Additionally, compound 8b significantly suppressed the VEGFR-2 receptor protein that triggers the inhibition of PI3K/Akt genes which causes mitochondrial membrane malfunction resulting in Bax overexpression and Bcl-2 downregulation levels. Besides, compound 8b showed a notable decrease in the levels of nitric oxide (NO) production levels and arrested the cell cycle in the G0/G1 stage. These outcomes demonstrated that compound 8b adhered to Lipinski's rules and may serve as a potential candidate for future breast cancer treatments via obstructing the VEGFR-2/PI3K/Akt signaling pathway, which in turn prevents metastasis, angiogenesis, and proliferation.

In Vitro and In Silico Assessment of Antileishmanial Potential of Novel Tri- and Penta-Valent Antimony Complexes With Phenolic Ligands

Leishmaniasis, caused by protozoan parasites of the genus Leishmania, affects nearly 12 million people annually worldwide, and has limited, highly toxic therapeutic options. This study reports the synthesis, in vitro and in silico evaluations of four novel antimony complexes (3a-3d) as potent and safe antileishmanial agents. The complexes were synthesized using Sb-salts with different phenolic ligands and characterized by elemental analysis, FT-IR and NMR spectroscopic techniques. Structural parameters were further evaluated via DFT studies. The antileishmanial activity of these complexes (3a-3d) was assessed in vitro against promastigote and axenic amastigote forms of Leishmania tropica, showing promising potential as antileishmanial agents. Complex 3a and 3c were particularly active, with IC50 values of 10.8 ± 2.1 and 11.0 ± 2.0 μmol/L against promastigotes, and 20.14 ± 6.11 and 27.72 ± 0.13 μmol/L against amastigotes, respectively. Molecular docking analysis against receptor protein (PDB ID: 8FI6) from genus Leishmania revealed high binding conformations of synthesized molecules within the active cavity of the target protein. With the lowest Ki value of 1.25 and a pattern of hydrophobic π-interactions and strong conventional hydrogen bonds, complex 3d demonstrated excellent binding affinities within the active pocket. Notably, these complexes exhibited low cytotoxicity, compared to the standard antileishmanial drugs, TA (potassium antimonyl tartrate) and AmB (Amphotericin B), with hemolysis rates of < 12% for all complexes. Our findings suggest that these complexes (3a-3d) are promising candidates for the development of new, safer antileishmanial therapies, combining potent activity against L. tropica with significantly lower cytotoxicity compared to existing treatments.

Investigation of the anticancer activity of modified 4-hydroxyquinolone analogues: in vitro and in silico studies

A set of nitrogen-based heterocycles derived from the quinoline ring as well as cyclohexanedione and dimedone cores were subjected to in vitro anticancer activity evaluation against four different cancerous cell lines namely; HCT116, A549, PC3, and MCF-7 respectively to colon, lung, prostate, and breast cancers. Compound 3g presented promising results exhibiting the best IC50 values among the investigated compounds for the four tested cell lines. In vitro results were supported with in silico studies including molecular docking simulation in order to learn more about the binding mode of the studied derivatives with relevant drug targets in cancer treatment, namely; anaplastic lymphoma kinase and cyclin-dependent kinase 2. Compound 3g showing the best in vitro results exhibited the most promising docking scores among the studied compounds. Moreover, molecular dynamics simulation was performed to the best ligand studying its stability inside the selected enzymes. Furthermore, a DFT study was performed to investigate the structural composition, electron density, and reactivity of tested compounds to identify the most important parts of the derivatives and elaborate a structure-activity relationship.

Effect of Glycoconjugation on Cytotoxicity and Selectivity of 8-Aminoquinoline Derivatives Compared to 8-Hydroxyquinoline

Numerous emerging chemotherapeutic agents incorporate N-heterocyclic fragments in their structures, with the quinoline skeleton being particularly significant. Our recent works have focused on glycoconjugates of 8-hydroxyquinoline (8-HQ), which demonstrated enhanced bioavailability and solubility compared to their parent compounds, although they fell short in selectivity. In this study, our objective was to improve the selectivity of glycoconjugates by replacing the oxygen atom with nitrogen by substituting the 8-HQ moiety with 8-aminoquinoline (8-AQ). The 8-AQ derivatives were functionalized through the amino group and linked to sugar derivatives (D-glucose or D-galactose) that were modified with an azide, alkylazide, or propargyl group at the anomeric position by copper(I)-catalyzed 1,3-dipolar azido-alkyne cycloaddition (CuAAC). The resulting glycoconjugates, as well as their potential metabolites, were evaluated for their ability to inhibit the proliferation of cancer cell lines (including HCT 116 and MCF-7) and a healthy cell line (NHDF-Neo). Two of the synthesized glycoconjugates (17 and 18) demonstrated higher cytotoxicity than their oxygen-containing counterparts and showed improved selectivity for cancer cells, thus enhancing their anticancer potential. Furthermore, it was found that glycoconjugates exhibited greater cytotoxicity in comparison to their potential metabolites.

The Facile Solid-Phase Synthesis of Thiazolo-Pyrimidinone Derivatives

A thiazolo-pyrimidinone derivative library was developed through a facile solid-phase synthesis method. For the reaction, the thiazolo[4,5-d]pyrimidin-7(6H)-one structure was synthesized through efficient Thorpe-Ziegler and cyclization reactions. The thiazolo[4,5-d]pyrimidin-7(6H)-one derivative library with a diversity of three had a total of four synthesis steps and 57 compounds. In addition, the yield per synthesis step was 65-97%, which was very high. The developed synthesis method and compounds will be used to find compounds with biological activity through the thiazole derivative structure-activity relationship.

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

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

Synthesis of Novel Benzothiazole-Profen Hybrid Amides as Potential NSAID Candidates

Herein, we report the synthesis of a series of new compounds by combining 2-aminobenzothiazole with various profens. The compounds were characterized using techniques such as 1H- and 13C-NMR, FT-IR spectrometry, and high-resolution mass spectrometry (HRMS), with detailed HRMS analysis conducted for each molecule. Their biological activities were tested in vitro, revealing significant anti-inflammatory and antioxidant effects, comparable to those of standard reference compounds. Lipophilicity was experimentally determined through partition coefficient (RM) measurements. To understand their binding affinity, molecular docking studies were perfsormed to analyze interactions with human serum albumin (HSA). The stability of these predicted complexes was further evaluated through molecular dynamics simulations. The results highlight the compounds' promising biological activity and strong affinity for HSA. The new hybrid molecule between 2-ABT and ketoprofen 3b demonstrates significant promise based on the experimental data and is further supported by in silico calculations. Compound 3b exhibits the best hydrogen peroxide scavenging activity among the tested compounds, with an IC50 of 60.24 μg/mL. Furthermore, 3b also displays superior anti-inflammatory activity, with an IC50 of 54.64 μg/mL, making it more effective than the standard ibuprofen (76.05 μg/mL).

Room-temperature synthesis of Fe3O4@MOF-5 magnetic hybrid as an efficient catalyst for the one-pot green synthesis of tetrahydropyridines

In recent two decades, considerable efforts have been devoted to the room-temperature green syntheses of metal-organic frameworks (MOFs) to reduce energy consumption and increase safety. It could improve some properties (e.g., catalysis, gas adsorption) and facilitate the utilities of sensitive compounds. Herein, the magnetic hybrid catalyst (Fe3O4@MOF-5) was synthesized through a mixing procedure at room temperature and confirmed by various techniques. The SEM images exhibit cubic crystals that were uniformly coated by the Fe3O4 cores. Then, the catalytic ability of Fe3O4@MOF-5 was studied in the green synthesis of tetrahydropyridines via a domino multi-component reaction, which led to the desired products with high yield. Magnetic solid properties make it easily separated from the reaction medium, so the proposed catalyst can be reused five times while maintaining the catalytic activity over 80%.

Nitrogen-containing heterocyclic drug products approved by the FDA in 2023: Synthesis and biological activity

This article profiles 13 newly approved nitrogen-containing heterocyclic drugs by the U.S. Food and Drug Administration (FDA) in 2023. These drugs target a variety of therapeutic areas including proteinuria in patients with IgA nephropathy, migraine in adults, Rett syndrome, PI3Kδ syndrome, vasomotor symptoms, alopecia areata, acute myeloid leukemia, postpartum depression, myelofibrosis, and various cancer and tumor types. The molecular structures of these approved drugs feature common aromatic heterocyclic compounds such as pyrrole, imidazole, pyrazole, isoxazole, pyridine, and pyrimidine, as well as aliphatic heterocyclic compounds like caprolactam, piperazine, and piperidine. Some compounds also contain multiple heteroatoms like 1,2,4-thiadiazole and 1,2,4-triazole. The article provides a comprehensive overview of the bioactivity spectrum, medicinal chemistry discovery, and synthetic methods for each compound.

Photochemical Metal-Free synthesis and biological Assessment of isocryptolepine analogues targeting estrogen receptor Alpha in breast cancer cells

The aim of this study was to develop a new series of isocryptolepines and evaluate their antiproliferative and antiestrogenic activities on cancer cells. A series of isocryptolepine derivatives were synthesized using developed one-pot photochemical, metal-free protocol, employing readily available 2-arylindoles as starting compounds. The resulting isocryptolepines demonstrated (sub)micromolar inhibitory activity against selected breast cancer cell lines. The IC50 values ​​of lead compound 3c against hormone-dependent breast cancer types (MCF7 and T47D) were 0.3 μM and 0.12 μM, respectively, and significantly greater than 3 μM against estrogen receptor α (ERα)-deficient cell lines, MDA-MB-231 and HCC1954, respectively. To assess the antiestrogenic potency of compound 3c, MCF7 cells were transfected with a plasmid containing a luciferase reporter gene under the control of an estrogen-responsive element (ERE), creating the MCF7/ERE-LUC cell subline. In these cells, luciferase activity was induced by the natural ERα ligand, 17β-estradiol (E2). Compound 3c inhibited luciferase activity by 50 % at a concentration of 0.12 μM, highlighting its potent inhibitory effect on ERα. Molecular modeling further indicated that compound 3c could directly bind to ERα. Compound 3c induced apoptosis, as evidenced by PARP cleavage and downregulation of p-Bcl-2 and Bcl-2, and demonstrated synergistic effects in combination with the chemotherapeutic agent 5-fluorouracil. Compound 3c also showed selectivity towards hormone-dependent breast cancer cells, likely targeting ERα - a key driver in this cancer subtype. In summary, we report the development of a first-in-class antiestrogenic isocryptolepine with notable pro-apoptotic efficacy.

An outlook of docking analysis and structure-activity relationship of pyrimidine-based analogues as EGFR inhibitors against non-small cell lung cancer (NSCLC)

Almost 80% of lung cancer diagnoses each year correspond to non-small cell lung cancer (NSCLC). The percentage of NSCLC with EGFR overexpression ranges from 40% to 89%, with squamous tumors showing the greatest rates (89%) and adenocarcinomas showing the lowest rates (41%). Therefore, in NSCLC therapy, blocking the EGFR-driven pathway by inhibiting the intracellular tyrosine kinase domain of EGFR has exhibited significant improvement. In this view, several small molecules particularly pyrimidine/fused pyrimidine scaffolds were intended for molecular hybridization to develop EGFR-TK inhibitors. However, the associated limitation such as resistance and genetic mutation along with adverse effects, constrained the long-term treatment and effectiveness of such medication. Therefore, in recent years, pyrimidine derivatives were uncovered as potential EGFR TKIs. The present review summarised the research progress of EGFR TKIs to dazed structure-activity relationship, biological evaluation, and comparative docking studies of pyrimidine compounds. We have added the comparative docking analysis followed by the molecular simulation study against the four different PDBs of EGFR to strengthen the already existing research. Docking analysis unfolded that compound 14 resulted as noticeable with all different PDB and managed to interact with some of the crucial amino acid residues. From a future perspective, researchers must develop a more selective inhibitor, that can selectively target the mutation. Our review will support medicinal chemists in the direction of the development of novel pyrimidine-based EGFR TKIs.Communicated by Ramaswamy H. Sarma.

In-silico design, pharmacophore-based screening, and molecular docking studies reveal that benzimidazole-1,2,3-triazole hybrids as novel EGFR inhibitors targeting lung cancer

Lung cancer is a complex and heterogeneous disease, which has been associated with various molecular alterations, including the overexpression and mutations of the epidermal growth factor receptor (EGFR). In this study, designed a library of 1843 benzimidazole-1,2,3-triazole hybrids and carried out pharmacophore-based screening to identify potential EGFR inhibitors. The 164 compounds were further evaluated using molecular docking and molecular dynamics simulations to understand the binding interactions between the compounds and the receptor. In-si-lico ADME and toxicity studies were also conducted to assess the drug-likeness and safety of the identified compounds. The results of this study indicate that benzimidazole-1,2,3-triazole hybrids BENZI-0660, BENZI-0125, BENZI-0279, BENZI-0415, BENZI-0437, and BENZI-1110 exhibit dock scores of -9.7, -9.6, -9.6, -9.6, -9.6, -9.6 while referencing molecule -7.9 kcal/mol for EGFR (PDB ID: 4HJO), respectively. The molecular docking and molecular dynamics simulations revealed that the identified compounds formed stable interactions with the active site of EGFR, indicating their potential as inhibitors. The in-silico ADME and toxicity studies showed that the compounds had favorable drug-likeness properties and low toxicity, further supporting their potential as therapeutic agents. Finally, performed DFT studies on the best-selected ligands to gain further insights into their electronic properties. The findings of this study provide important insights into the potential of benzimidazole-1,2,3-triazole hybrids as promising EGFR inhibitors for the treatment of lung cancer. This research opens up a new avenue for the discovery and development of potent and selective EGFR inhibitors for the treatment of lung cancer.Communicated by Ramaswamy H. Sarma.

Modulation of the tumor microenvironment in non-muscle-invasive bladder cancer by OncoTherad® (MRB-CFI-1) nanoimmunotherapy: effects on tumor-associated macrophages, tumor-infiltrating lymphocytes, and monoamine oxidases

Non-muscle-invasive bladder cancer (NMIBC) presents management challenges due to its high recurrence rate and a complex tumor microenvironment (TME). This study investigated the effects of OncoTherad® (MRB-CFI1) nanoimmunotherapy on the TME of BCG-unresponsive NMIBC, focusing on alterations in monoamine oxidases (MAO-A and MAO-B) and immune markers: CD163, FOXP3, CD8, and CX3CR1. A comparative analysis of immunoreactivities was made before and after OncoTherad® treatment and an immune score (IS) was established to evaluate the correlation between immunological changes and clinical outcomes. Forty bladder biopsies of twenty patients were divided into 2 groups (n = 20/group): 1 (pre-treatment biopsies); and 2 (post-treatment biopsies). Our results showed stable MAO-A levels but a significant (p < 0.05) decrease in MAO-B immunoreactivity after treatment, suggesting OncoTherad®'s efficacy in targeting the tumor-promoting and immunosuppressive functions of MAO-B. Significant (p < 0.05) reductions in CD163 and FOXP3 immunoreactivities were seen in post-treatment biopsies, indicating a decreased presence of M2 macrophages and Tregs. Corroborating with these results, we observed reductions in tumor histological grading, focality and size, factors that collectively enhanced recurrence-free survival (RFS) and pathological complete response (PCR). Moreover, elevated IFN-γ immunoreactivities in treated biopsies correlated with increased counts of CD8+ T cells and higher CX3CR1 expression, underscoring OncoTherad®'s enhancement of cytotoxic T cell functionality and overall antitumor immunity. The IS revealed improvements in immune responses post-treatment, with higher scores associated with better RFS and PCR outcomes. These findings validate OncoTherad®'s capability to modify the bladder cancer microenvironment favorably, promoting effective immune surveillance and response.

Novel benzothiazole/benzothiazole thiazolidine-2,4-dione derivatives as potential FOXM1 inhibitors: In silico, synthesis, and in vitro studies

The oncogenic transcription factor FOXM1 overexpressed in breast and other solid cancers, is a key driver of tumor growth and progression through complex interactions, making it an attractive molecular target for the development of targeted therapies. Despite the availability of small-molecule inhibitors, their limited specificity, potency, and efficacy hinder clinical translation. To identify effective FOXM1 inhibitors, we synthesized novel benzothiazole derivatives (KC10-KC13) and benzothiazole hybrids with thiazolidine-2,4-dione (KC21-KC36). These compounds were evaluated for FOXM1 inhibition. Molecular docking and molecular dynamics simulation analysis revealed their binding patterns and affinities for the FOXM1-DNA binding domain. The interactions with key amino acids such as Asn283, His287, and Arg286, crucial for FOXM1 inhibition, have been determined with the synthesized compounds. Additionally, the molecular modeling study indicated that KC12, KC21, and KC30 aligned structurally and interacted similarly to the reference compound FDI-6. In vitro studies with the MDA-MB-231 breast cancer cell line demonstrated that KC12, KC21, and KC30 significantly inhibited FOXM1, showing greater potency than FDI-6, with IC50 values of 6.13, 10.77, and 12.86 µM, respectively, versus 20.79 µM for FDI-6. Our findings suggest that KC12, KC21, and KC30 exhibit strong activity as FOXM1 inhibitors and may be suitable for in vivo animal studies.

Ir-Catalyzed Asymmetric Hydrogenation of N-Fused Heteroarenes with High Nitrogen Density: An Access to Chiral 2,5-Disubstituted 5,6-Dihydropyrrolo[1,2-a][1,2,4]triazolo[5,1-c]pyrazines

A highly enantioselective Ir-catalyzed asymmetric hydrogenation of 2,5-disubstituted pyrrolo[1,2-a][1,2,4]triazolo[5,1-c]pyrazines containing four nitrogen atoms has been first realized. Under additive-free conditions, a variety of chiral 2,5-disubstituted 5,6-dihydropyrrolo[1,2-a][1,2,4]triazolo[5,1-c]pyrazines can be afforded in high yields (86-98%) with excellent enantioselectivities of up to 99% ee. This method provides a straightforward strategy for the efficient synthesis of chiral multinitrogen polyheterocyclic compounds.

Light-promoted stereoselective late-stage difunctionalization and anti-tumor activity of oridonin

The late-stage difunctionalization of diterpene oridonin by light-promoted direct oxyamination with various O-benzoylhydroxylamines was carried out to afford C16α-N-C17-OBz-oridonin derivatives (1-25) for the first time. Though as a radical reaction, it features high stereoselectivity to only produce C16α-N-C17-OBz-oridonins. The in vitro antiproliferative activity of these C16α-N-C17-OBz-oridonins against the human breast cancer cell lines (MCF-7) was evaluated by MTT assay, showing that most of the synthesized compounds possessed moderate anticancer activity against MCF-7 cell lines superior or similar to the parent compound oridonin. The derivative 25 with a N-methyl-N-(naphthalen-1-ylmethyl) substitution showed better cytotoxicity against MCF-7 cells (IC50 value of 11.75 μM) than oridonin (IC50 value of 17.95 μM).

One-pot synthesis of tetrahydropyrimidinecarboxamides enabling in vitro anticancer activity: a combinative study with clinically relevant brain-penetrant drugs

In this study, we describe a one-pot three-component synthesis of bioactive tetrahydopyrimidinecarboxamide derivatives employing lanthanum triflate as a catalyst. Out of the synthesized compounds, 4f had the most potent anti-cancer activity and impeded cell cycle progression effectively. Anti-cancer bioactivity was observed in 4f against liver, breast, and lung cancers as well as primary patient-derived glioblastoma cell lines. Compound 4f effectively inhibited the 3D neurosphere formation in primary patient-derived glioma stem cells. Specifically, 4f exhibited synergistic cytotoxicity with the EGFR inhibitor that is the clinical epidermal growth factor receptor inhibitor osimertinib. 4f does not exhibit anti-kinase activity and is cytostatic in nature, and further work is needed to understand the true molecular target of 4f and its derivatives. Through our current work, we establish a promising tetrahydopyrimidinecarboxamide-based lead compound with anti-cancer activity, which may exhibit potent anti-cancer activity in combination with specific clinically relevant small molecule kinase inhibitors.

The 3,3'-dimethoxy-4,4'-dihydroxy-stilbene Triazole (STT) Inhibits Liver Cancer Cell Growth by Targeting Akt/mTOR Pathway

The present study was aimed to investigate the proliferation inhibitory ability of 3,3'-dimethoxy-4,4'-dihydroxy-stilbene triazole (STT) on SNU449 and Huh7 cells. Moreover, the mechanism associated with the suppression of liver cancer cell proliferation by STT was also studied. The results revealed that STT suppresses proliferation of SNU449 and Huh7 cells to 28 and 21%, respectively treatment with 20 µM. The clonogenic survival of SNU449 and Huh7 cells was also significantly reduced after incubation with STT compared to the control cultures. In comparison to the control, STT treatment significantly decreased the invasive potential of SNU449 cells. Treatment with STT led to a prominent suppression in p62 and increase in LC3B protein expression in SNU449 cells compared to the control cells. The STT treatment dramatically decreased p-Akt and p-mTOR protein expression in SNU449 cells. Docking study revealed that STT interacts via traditional hydrogen bonding with the glutamine, phenylalanine, leucine, serine, arginine, aspartic acid, and lysine residues of Akt protein. In summary, the current study demonstrates that STT effectively suppresses the viability of SNU449 and Huh7 liver cancer cells. Moreover, STT treatment of the liver cancer cells also significantly reduces the clonogenic survival and invasive potential of SNU449 cells. Treatment of liver cancer cells with STT increases the expression of autophagic, targets anti-autophagic protein expression and down-regulates Akt/mTOR pathway to inhibit cancer growth and proliferation. Thus, STT exhibits prominent anticancer effect and needs to be investigated further as a potential candidate for the treatment of liver cancer.

Electrochemical and DFT insights into 2-amino-4-(4-hydroxy-3-methoxyphenyl)-7-methyl-4H-chromene-3-carbonitrile: an innovative strategy for antibacterial activity and corrosion protection of carbon steel

This study explored the potential of a newly synthesized derivative, 2-amino-4-(4-hydroxy-3-methoxyphenyl)-7-methyl-4H-chromene-3-carbonitrile (AHMCC), as a broad-spectrum antibacterial agent and a corrosion inhibitor for carbon steel (C.STL) in 0.5 M HCl solution. AHMCC demonstrated remarkable antibacterial efficacy against Gram-negative (Escherichia coli, Klebsiella pneumoniae) and Gram-positive (Bacillus subtilis, Staphylococcus aureus) bacteria, as evidenced by agar plate tests and cell viability assays. In the corrosion inhibition studies, AHMCC exhibited mixed-type inhibitor behavior as revealed by potentiodynamic polarization (PDP) measurements. The inhibition efficiency increased with rising AHMCC concentration, confirmed by a significant enhancement in charge transfer resistance (R ct) observed in electrochemical impedance spectroscopy (EIS) analysis. Electrochemical frequency modulation (EFM) data with obtained CF2 and CF3 values further corroborated these findings. Langmuir isotherm modeling suggested AHMCC molecules followed a monolayer adsorption pattern on the C.STL surface. UV-visible spectroscopy indicated the formation of a protective layer through chemical interaction between AHMCC and the metal surface. Atomic force microscopy (AFM) provided visual confirmation of this protective film shielding the C.STL from the corrosive environment. Additionally, theoretical calculations supported the proposed adsorption mechanism of AHMCC molecules onto the C.STL surface.

Multitarget Pharmacology of Sulfur-Nitrogen Heterocycles: Anticancer and Antioxidant Perspectives

Cancer and oxidative stress are interrelated, with reactive oxygen species (ROS) playing crucial roles in physiological processes and oncogenesis. Excessive ROS levels can induce DNA damage, leading to cancer, and disrupt antioxidant defenses, contributing to diseases like diabetes and cardiovascular disorders. Antioxidant mechanisms include enzymes and small molecules that mitigate ROS damage. However, cancer cells often exploit oxidative conditions to evade apoptosis and promote tumor growth. Antioxidant therapy has shown mixed results, with timing and cancer-type influencing outcomes. Multifunctional drugs targeting multiple pathways offer a promising approach, reducing side effects and improving efficacy. Recent research focuses on sulfur-nitrogen heterocyclic derivatives for their dual antioxidant and anticancer properties, potentially enhancing therapeutic efficacy in oncology. The newly synthesized compounds often do not demonstrate both antioxidant and anticancer properties simultaneously. Heterocyclic rings are typically combined with phenyl groups, where hydroxy substitutions enhance antioxidant activity. On the other hand, electron-withdrawing substituents, particularly at the p-position on the phenyl ring, tend to enhance anticancer activity.

Construction of 5-Fluorouracil and Gallium Corrole Conjugates for Enhanced Photodynamic Therapy

Molecular hybridization is a well-established strategy for developing new drugs. In the pursuit of promising photosensitizers (PSs) with enhanced photodynamic therapy (PDT) efficiency, a series of novel 5-fluorouracil (5FU) gallium corrole conjugates (1-Ga-4-Ga) were designed and synthesized by hybridizing a chemotherapeutic drug and PSs. Their photodynamic antitumor activity was also evaluated. The most active complex (2-Ga) possesses a low IC50 value of 0.185 μM and a phototoxic index of 541 against HepG2 cells. Additionally, the 5FU-gallium corrole conjugate (2-Ga) exhibited a synergistic increase in cytotoxicity under irradiation. Excitedly, treatment of HepG2 tumor-bearing mice with 2-Ga under irradiation could completely ablate tumors without harming normal tissues. 2-Ga-mediated PDT could disrupt mitochondrial function, cause cell cycle arrest in the sub-G1 phase, and activate the cell apoptosis pathway by upregulating the cleaved PARP expression and the Bax/Bcl-2 ratios. This work provides a useful strategy for the design of new corrole-based chemo-photodynamic therapy drugs.

An efficient and practical approach for the synthesis of indoloquinolines and indolo/pyrroloquinoxalines via a Cu-catalyzed Ugi-C/Ugi-N-arylation sequence

A Cu-catalyzed tandem transformation of Ugi adducts through CH/NH bond functionalization reactions was reported for synthesizing a broad spectrum of indolo/pyrrolo-[1,2-a]quinoxaline-6/4-carboxamide, 7H-indolo[2,3-c]quinoline-6-carboxamide, and 1-(cyclohexylamino)-14H-indolo[2,3-c][1,4]oxazino[4,3-a]quinolin-4(3H)-one derivatives in moderate to excellent yields. In this protocol the Ugi condensation of aromatic aldehydes, anilines, acids, and isocyanides leads to the formation of bis-amides in methanol at room temperature. This approach employed simple reaction conditions, including Ugi product as starting material, CuI, l-proline as a ligand, and cesium carbonate, in DMSO for 8 h. This method demonstrated efficiency in synthesizing fused-nitrogen-containing heterocycles through a convenient pathway.

Radical N2-Retention Cyclizations of Aryl Diazoniums: Access to 7/8/9-Membered Heterocycles

We report herein a modular approach to synthesizing diverse functionalized 7/8/9-membered poly-N-containing heterocycles via oxidative radical N2-retention cyclizations of allylic aryl diazonium salts using CF3SO2Na as a CF3 radical source. A range of trifluoromethylated benzotriazepines, benzotriazocines, and benzotriazonines were obtained in moderate to good yields. This transition-metal-free protocol demonstrates atom economy, safe conditions, broad functional group tolerance, and availability of readily accessible reagents.

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).

Oxidative Control of Photoinduced Cascade Electrocyclizations in Aromatic Azido Imines to Access Complex Fused Imidazoles or Pyrazoles

Photoinduced cascade of two 6π-electron six- and five-center electrocyclizations in aromatic azido imines is oxidatively controlled to yield complex fused benzimidazoles or indazoles. Formation of benzimidazoles occurs via an unprecedented carbon-to-nitrogen o-iminoaryl 1,2-shift.

Nickel-catalyzed acylation of vinylpyridine with alkylzincs under 1 atm CO

A nickel-catalyzed acylation of vinylpyridines with CO at atmospheric pressure is reported, allowing for an expedient approach to synthesize β-acyl pyridine derivatives with high regio- and chemoselectivity. The electron-withdrawing property of pyridine plays pivotal roles in activating the alkenyl group, thereby facilitating this carbonylative process. In addition to vinylpyridines, other alkenylheterocycles such as thiazole and quinoline were also suitable for this method.

Minisci-Type Dehydrogenative Coupling of N-Heteroaromatic Rings with Inert C(sp3)-H Enabled by a Visible-Light-Catalyzed Intermolecular Hydrogen Atom Transfer Process

The Minisci-type dehydrogenative coupling of N-heteroaromatic rings with inert C-H or Si-H partners via visible-light-catalyzed hydrogen atom transfer has been reported. This methodology allows the coupling reactions to be carried out in water as a solvent under air atmospheric conditions with visible-light illumination. A wide range of inert C-H and Si-H partners could be directly coupled with various N-aromatic heterocycles to deliver products in good to excellent yields.

Design, synthesis, and mechanistic insight of novel imidazolones as potential EGFR inhibitors and apoptosis inducers

As regards to the structural analysis and optimization of diverse potential EGFR inhibitors, two series of imidazolyl-2-cyanoprop-2-enimidothioates and ethyl imidazolylthiomethylacrylates were designed and constructed as potential EGFR suppressors. The cytotoxic effect of the prepared derivatives was assessed toward hepatic, breast, and prostate cancerous cells (Hep-G2, MCF-7, and PC-3). Three derivatives 3d, 3e, and 3f presented potent antiproliferative activity and selectivity against the examined tumor cells showing IC50 values at low micromolar levels. Hence, successive biological assays were applied to determine the probable mechanism of action of the new compounds. They exhibited significant EGFR suppression with an IC50 range of 0.137-0.507 µM. The most effective EGFR inhibitor 3f arrested the MCF-7 cell cycle at the S phase by inducing the apoptotic pathway that was confirmed via increasing the expression of Caspases 8, 9, and Bax, which are associated with Bcl-2 decline. Additionally, molecular docking displayed a distinctive interaction between 3f and EGFR binding pocket. Overall, this work introduces some novel imidazolyl-2-cyanoprop-2-enimidothioates and ethyl imidazolylthiomethylacrylates as potential cytotoxic and EGFR inhibitors that deserve further research in tumor therapy.

Design, synthesis and biological evaluation of 1,2,3-triazole benzothiazole derivatives as tubulin polymerization inhibitors with potent anti-esophageal cancer activities

In this work, we utilized the molecular hybridization strategy to design and synthesize novel 1,2,3-triazole benzothiazole derivatives K1-26. The antiproliferative activities against MGC-803, Kyse30 and HCT-116 cells were explored, and their structure-activity relationship were preliminarily conducted and summarized. Among them, compound K18, exhibited the strongest proliferation inhibitory activity, with esophageal cancer cells Kyse30 and EC-109 being the most sensitive to its effects (IC50 values were 0.042 and 0.038 μM, respectively). Compound K18 effectively inhibited tubulin polymerization (IC50 = 0.446 μM), thereby hindering tubulin polymerize into filamentous microtubules in Kyse30 and EC-109 cells. Additionally, compound K18 induced the degradation of oncogenic protein YAP via the UPS pathway. Based on these dual molecular-level effects, compound K18 could induce G2/M phase arrest and cell apoptosis in Kyse30 and EC-109 cells, as well as regulate the expression levels of cell cycle and apoptosis-related proteins. In summary, our findings highlight a novel 1,2,3-triazole benzothiazole derivative K18, which possesses significant potential for treating esophageal cancers.

Recent drug design strategies and identification of key heterocyclic scaffolds for promising anticancer targets

Cancer, a noncommunicable disease, is the leading cause of mortality worldwide and is anticipated to rise by 75% in the next two decades, reaching approximately 25 million cases. Traditional cancer treatments, such as radiotherapy and surgery, have shown limited success in reducing cancer incidence. As a result, the focus of cancer chemotherapy has switched to the development of novel small molecule antitumor agents as an alternate strategy for combating and managing cancer rates. Heterocyclic compounds are such agents that bind to specific residues in target proteins, inhibiting their function and potentially providing cancer treatment. This review focuses on privileged heterocyclic pharmacophores with potent activity against carbonic anhydrases and kinases, which are important anticancer targets. Evaluation of ongoing pre-clinical and clinical research of heterocyclic compounds with potential therapeutic value against a variety of malignancies as well as the provision of a concise summary of the role of heterocyclic scaffolds in various chemotherapy protocols have also been discussed. The main objective of the article is to highlight key heterocyclic scaffolds involved in recent anticancer drug design that demands further attention from the drug development community to find more effective and safer targeted small-molecule anticancer agents.

FDA-approved heterocyclic molecules for cancer treatment: Synthesis, dosage, mechanism of action and their adverse effect

As the incorporation of heterocycles increases the physical characteristics and biological activity of pharmacological molecules, heterocyclic scaffolds are commonly discovered as common cores in a wide spectrum of biologically active drugs. In the contemporary context, many heterocycles have arisen, playing vital roles in diverse pharmaceutical compounds that benefit humanity. Over 85 % of FDA-approved medication molecules contain heterocycles, and most importantly, numerous heterocyclic medicinal molecules indicate potential benefits against a range: of malignancies. The unique flexibility and dynamic core scaffold of these compounds have aided anticancer research. These medications are used to treat cancer patients by targeting particular genes, enzymes, and receptors. Aside from the drugs that are now on the market, numerous forms are being researched for their potential anti-cancer activity. Here in this review, we classified some molecules and biologically active heterocycles containing anticancer medicinal moieties approved by the FDA between 2019 and 2021 based on their use in various forms of cancer. We will focus on those that are suitable for cancer treatment, as well as the essential biochemical mechanisms of action, biological targets, synthetic methods, and inherent limiting considerations in their use.

Visible Light-Enhanced [3 + 2] Cycloaddition of N,N-Disubstituted Hydrazines with Organo-Cyanamides: Access to Polysubstituted 1,2,4-Triazol-3-amines

Visible light-enhanced [3 + 2] cycloaddition of N,N-disubstituted hydrazines with N-cyano-N-aryl-p-toluenesulfonamides is an efficient reaction pathway to polysubstituted 1,2,4-triazol-3-amines. The reaction is performed under mild conditions without the addition of any transition metals. This strategy involves a C(sp3)-H bond activation, a cyano cycloaddition, and the formation of two new C═N bonds. The protocol shows the advantages of good functional group tolerance and broad substrate scope. The late-stage modification experiments provide practical applications in the field of organic synthesis and medicinal chemistry.

Recent Advances in Pyrazole-based Protein Kinase Inhibitors as Emerging Therapeutic Targets

BACKGROUND

Pyrazole-scaffold protein kinase inhibitors (PKIs) have emerged as promising therapeutic agents for the treatment of various diseases, such as cancer, inflammatory disorders, and neurological diseases. This review article provides an overview of the pharmacological properties of pyrazole-scaffold PKIs, including their mechanism of action, selectivity, potency, and toxicity. The article also summarizes the recent developments in the design and synthesis of pyrazole-scaffold PKIs, highlighting the structural features and modifications that contribute to their pharmacological activity. In addition, the article discusses the preclinical and clinical studies of pyrazole-scaffold PKIs, including their efficacy, safety, and pharmacokinetic properties.

METHODS

A comprehensive search has been conducted on several online patent databases, including the United States Patent and Trademark Office (USPTO), the European Patent Office (EPO), and the World Intellectual Property Organization (WIPO). The search was conducted using pyrazole as the keyword. The search was limited to patents filed between 2015 and 2022. Patents were included if they involved articles in the fields of protein kinase inhibitors, and included literature on some pyrazoles and their pharmacological activities.

RESULTS

Data were extracted from each included patent on the following variables: patent title, patent number, inventors, assignee, filing date, publication date, patent type, and field of invention. Data were extracted from each patent using a standardized form to ensure consistency and accuracy.

CONCLUSION

The design and pharmacological evaluation of organic compounds containing pyrazole structure as biologically active substances have been done, and the key structures from the pharmacological data obtained as protein kinase inhibitors have been addressed in detail. The review concludes with a discussion on the current challenges and future directions for the development of pyrazole-scaffold PKIs as therapeutic agents. Overall, this review article provides a comprehensive summary of the pharmacological properties of pyrazole-scaffold PKIs, which will be of interest to researchers and clinicians in the field of drug discovery and development.

In situ click chemistry-based discovery of 1,2,3-triazole-derived diarylpyrimidines as novel HIV-1 NNRTIs by exploiting the tolerant region I in binding pocket

HIV-1 reverse transcriptase (RT) is considered as one of the most significant targets for the anti-HIV-1 drug design due to their determined mechanism and well-decoded crystal structure. As a part of our continuous efforts towards the development of potent HIV-1 non-nucleoside reverse transcriptase inhibitors (NNRTIs) by exploiting the tolerant region I of NNRTIs binding pocket (NNIBP), the miniaturized parallel synthesis via CuAAC click chemistry reaction followed by in situ biological screening have been performed in this work. The in situ enzyme inhibition screening results showed that 14 compounds exhibited higher or equivalent inhibitory activity compared to the lead K-5a2 and ETR. Anti-HIV-1 activity results indicated that C1N51 displayed the most potent activity (EC50 = 0.01-0.26 μM) against wild-type and a panel of NNRTIs-resistant strains. Moreover, the molecular simulation demonstrated that the newly introduced triazole ring could develop new hydrogen bonds with Lys103 and Pro236, which explained the feasibility of introducing triazole in the tolerant region I of the RT binding pocket.

Synthesis of novel 5-[3-(4-chlorophenyl)-substituted-1,3-dimethylpyrimidine-2,4,6(1H,3H,5H)-trione derivatives as potential anti-diabetic and anticancer agents

In this work, we developed a series of novel 5-[3-(4-chlorophenyl)-substituted-1,3-dimethylpyrimidine-2,4,6(1H,3H,5H)-trione derivatives 4(a-e) via a one-pot multicomponent reaction. The structures of the compounds were confirmed using analytical and spectroscopic techniques. Also, the synthesized compounds were screened for their anti-diabetic activity, cytotoxicity and in silico studies. The activity results suggested that the compound 4e exhibited least IC50 values of 0.055 ± 0.002 µM, 0.050 ± 0.002 µM and 0.009 ± 0.001 µM for α-amylase, α-glucosidase and cytotoxicity respectively. Further, in silico molecular docking results revealed that all the obtained compounds effectively interacted with exo-β-D-glucosaminidase and P38 MAP kinase proteins with good binding energies. In that, 4e compound established the least binding energy of -9.6 and -9.1 kcal/mol, respectively. Moreover, our synthesized compounds were subjected to ADME studies, which suggested that all the synthesized compounds obeyed all five rules with good bioavailability and were suitable as drug leads against anti-diabetic and anticancer treatment.

TFE-Facilitated Synthesis of Tetrahydropyridino[2,3-d]pyrimidine via Cascade [1,5]-Hydride Transfer/Cyclization

An efficient fluorinated alcohol-driven cascade [1,5]-hydride transfer/cyclization between o-amino pyridyl aldehydes and primary amines has been developed. This unique transformation enabled an array of tetrahydropyridino[2,3-d]pyrimidine construction. Furthermore, the encouraging antifungal activity of Thanatephorus cucumeris was demonstrated by this tetrahydropyridino[2,3-d]pyrimidine core structure.

Synthesis and Antiproliferative Activity of 2,6-Disubstituted Imidazo[4,5-b]pyridines Prepared by Suzuki Cross Coupling

A series of novel 2,6-diphenyl substituted imidazo[4,5-b]pyridines was designed and synthesized using optimized Suzuki cross coupling to evaluate their biological activity in vitro. The conditions of the Suzuki coupling were evaluated and optimized using a model reaction. To study the influence of the substituents on the biological activity, we prepared N-unsubstituted and N-methyl substituted imidazo[4,5-b]pyridines with different substituents at the para position on the phenyl ring placed at position 6 on the heterocyclic scaffold. Antiproliferative activity was determined on diverse human cancer cell lines, and the selectivity of compounds with promising antiproliferative activity was determined on normal peripheral blood mononuclear cells (PBMC). Pronounced antiproliferative activity was observed for p-hydroxy substituted derivatives 13 and 19, both displaying strong activity against most of the tested cell lines (IC50 1.45-4.25 μM). The unsubstituted N-methyl derivative 19 proved to be the most active derivative. There was a dose-dependent accumulation of G2/M arrested cells in several cancer cell lines after exposure to compound 19, implying a cell cycle-phase-specific mechanism of action. Additionally, the novel series of derivatives was evaluated for antiviral activity against a broad panel of viruses, yet the majority of tested compounds did not show antiviral activity.

1,2,3-Triazolo[4,5-b]aminoquinolines: Design, synthesis, structure, acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activity, and molecular docking of novel modified tacrines

An efficient [4 + 2] cyclization protocol to synthesize a series of twelve examples of 1,2,3-triazolo[4,5-b]aminoquinolines (5) as novel structurally modified tacrines was obtained by reacting readily accessible precursors (i.e., 3-alky(aryl)-5-amino-1,2,3-triazole-4-carbonitriles (3)) and selected cycloalkanones (4) of five-, six-, and seven-membered rings. We evaluated the AChE and BChE inhibitory activity of the novel modified tacrines 5, and the compound derivatives from cyclohexanone (4b) showed the best AChE and BChE inhibitory activities. Specifically, 1,2,3-triazolo[4,5-b]aminoquinolines 5bb obtained from 3-methyl-carbonitrile (3b) showed the highest AChE (IC50 = 12.01 μM), while 5ib from 3-sulfonamido-carbonitrile (3i) was the most significant inhibitor for BChE (IC50 = 1.78 μM). In general, the inhibitory potency of compound 5 was weaker than the pure tacrine reference, and our findings may help to design and develop novel anticholinesterase drugs based on modified tacrines.