Abstract: Fused azepines and their derivatives, especially benzodiazepines and benzotriazepines, are well-known drug discovery templates, primarily for the treatment of neurological conditions. Recently, fused azepines have emerged as promising scaffolds for anticancer drug discovery due to their diverse mechanisms of action, including inhibition of kinases (e.g., cyclin-dependent kinases), histone deacetylases, tubulin, PARP enzymes, and DNA intercalation, leading to cell cycle arrest and induction of apoptosis. Despite their therapeutic potential, the translation of these compounds into clinical oncology remains limited, with only a few approved molecules, such as the pyrrolobenzodiazepine dimer-based antibody-drug conjugate, loncastuximab tesirine. This review consolidates recent advances in the synthesis and pharmacological evaluation of 1,3-, 1,4-, and 1,5- benzodiazepines and benzotriazepine derivatives, with a specific focus on anticancer activity. Various synthetic strategies, ranging from classical cyclization reactions to multicomponent, catalytic, and green chemistry approaches, are critically summarized. The review also highlights the biological activities of these derivatives, elucidating their mechanisms and discussing structure-activity relationship (SAR) studies class-wise to identify key pharmacophoric features that contribute to potency, selectivity, and synergistic potential with established chemotherapeutics. The integration of synthetic methodologies, mechanistic insights, and SAR findings is anticipated to guide rational design, structural optimization, and computational exploration, ultimately accelerating the development of novel fused azepine derivatives as anticancer agents with improved efficacy and translational potential.

In this study, we report the Pictet-Spengler enabled synthesis of a series of eighteen carboxamide-substituted imidazo[1,2-a]quinoxaline derivatives (JRC-1-JRC-18) targeting epidermal growth factor receptor (EGFR) and tubulin. Compounds JRC-2 and JRC-6 exhibited potent antiproliferative effects against MCF-7 breast cancer cells, with IC50 values of 4.59 ± 0.23 µM and 4.01 ± 0.14 µM, respectively, outperforming erlotinib (IC50 = 9.39 ± 0.16 µM). In enzymatic assays, JRC-2 and JRC-6 inhibited wild-type EGFR with IC50 values of 294.45 nM and 383.90 nM, respectively. Notably, JRC-6 displayed microtubule-stabilising activity comparable to that of paclitaxel and induced ROS generation, mitochondrial membrane depolarisation, and G2/M phase cell cycle arrest. Molecular docking and molecular dynamics simulations confirmed stable binding of compounds at the EGFR ATP-binding site and the tubulin taxol-binding site.

A green, catalyst-free synthesis of seventeen new 2,9-disubstituted purine-6-carboxamides (5 and 6) designed as EGFR inhibitors in high yields (85-93%) was accomplished. DFT analysis revealed the formation of an energetically favorable oxazolidine transition state with a lower activation barrier compared to alternative pathways, supporting the experimentally observed selectivity. In vitro anticancer activity against A549 lung cancer cells demonstrated dose-dependent growth inhibition, with IC₅₀ values ranging from 4.35 to 22.1 μM, and compound 6E emerged as the most potent derivative. It exhibited superior activity compared to the reference drug erlotinib, with a cellular IC₅₀ of 4.35 μM vs 11.83 μM and an EGFR enzymatic IC₅₀ of 105.96 nM vs 218.47 nM, indicating approximately 2-fold enhanced potency. Flow cytometric analysis demonstrated that compound 6E significantly reduced p-PI3K levels, comparably to erlotinib, indicating effective suppression of EGFR-AKT downstream signaling at the cellular level. Mechanistic investigations demonstrated that 6E increased ROS generation, induced mitochondrial depolarisation, and promoted apoptotic cell death. Further, molecular docking and MD simulations of the 6E-EGFR complex highlighted key amino acid interactions, corroborating the observed in vitro EGFR inhibition.

A series of new N-3-substituted quinazolinones targeting epidermal growth factor receptor (EGFR) was designed and synthesized for anticancer evaluation. All the target compounds (4a-4j) were synthesized using a two-step method with high yields and evaluated via an initial anticancer screening in lung (A549), prostate (PC-3), and breast (MCF-7) cancer cell lines. Subsequently, full dose-response (IC50) determination was performed only in the most responsive cell line, MCF-7. Compounds 4c, 4e, 4f, 4h, 4i and 4j showed promising anticancer activities against MCF-7 cells, with lower IC50 values (IC50 = 5.65 μM to 7.51 μM) than erlotinib (IC50 = 10.50 μM). The EGFR inhibitory activity of these compounds was then assessed, and 4h (IC50 = 86.9 nM) and 4i (IC50 = 154.35 nM) exhibited greater activity than erlotinib (IC50 = 197.94 nM). mRNA expression analysis reveals that MCF7 cells treated with compound 4h exhibit significantly decreased EGFR expression compared to the untreated cancer cells. In silico molecular modelling studies also indicated that the 4i-EGFR complex was less stable than the 4h-EGFR complex throughout the simulation time. Furthermore, the disruption of cellular redox homeostasis, as evidenced by reduced ROS generation, mitochondrial membrane depolarization, and the induction of apoptosis in treated cells, suggests a possible secondary anticancer mechanism.

We herein report the design, Pictet-Spengler reaction-mediated synthesis, and neuroprotective evaluation of new 10,11-dihydro-5H-benzo[e]imidazo[1,2-a][1,4]diazepines without (7a) or with iminic anchor (8a-8f), along with representative 5H-benzo[e]imidazo[1,2-a][1,4]diazepines (oxidized compounds; 7ao and 8co), and some nonrigid benzodiazepine analogues (4, 5a-5c, and 6a-6c). Compounds 8b, 8c, and 8e did not show any neurotoxic effects in the Neuro2a and SHSY-5Y cell lines up to 10 μM concentration and increased the number of neurite-bearing cells and neurite length, suggesting the protective abilities of compounds. In pentylenetetrazole (PTZ)-treated cells, 8b, 8c, and 8e exerted neuroprotective effects by increasing cell viability and reducing ROS levels. Notably, 8b at 10 μM reduced ROS formation more than diazepam and other compounds. Further, protein expression studies indicated that compounds at 10 μM concentration upregulated the GABAAα1 expression compared to PTZ alone-treated cells. The binding analysis at the GABAA site, using molecular docking and MD simulations, suggested a neuroprotective effect of these compounds via GABAA targeting. In vivo, compound 8b demonstrated a dose-dependent anticonvulsant effect in the PTZ-induced kindling mouse model, significantly delaying seizure onset while reducing the seizure duration, frequency, and severity with efficacy comparable to that of diazepam.

This study reports the synthesis and biological evaluation of pyrazole-fused quinolines (2a1-2a5) as potential anticancer agents targeting human DNA topoisomerases. Owing to their intrinsic fluorescence, the synthesized compounds were also explored for live-cell imaging applications. The synthetic strategy involved a multistep sequence comprising Claisen-Schmidt condensation, cyclocondensation, oxidation, reduction, and final ring annulation. In vitro biological evaluation identified compounds 2a4, 2a1 and 2a5 as the most active derivatives against MDA-MB-231 breast cancer cells, with IC₅₀ values of 6.91 ± 0.21, 8.55 ± 0.18 and 9.59 ± 0.47 μM, respectively. Enzymatic topoisomerase inhibition studies suggested that the synthesized series exhibits dual Topo I/II inhibitory potential, with compound 2a4 showing the most favorable inhibition profile and the highest antiproliferative activity against MDA-MB-231 cells. Further biological investigation indicated that compound 2a4 increased intracellular reactive oxygen species (ROS) levels and induced G2/M phase cell-cycle arrest. Computational analyses, including molecular docking and molecular dynamics simulations, suggested stable ligand-enzyme interactions, while MM-GBSA calculations provided comparative insights into the binding trends. In silico ADME prediction suggested that compound 2a4 possesses favorable drug-like characteristics, including acceptable oral absorption and limited blood-brain barrier permeability. Confocal microscopy revealed the intrinsic fluorescence of compound 2a1 and supported its fluorescence-based cellular imaging applications. Overall, compounds 2a4 and 2a1 represent promising in vitro leads for further investigation as topoisomerase-targeting anticancer scaffolds with fluorescence imaging capability.

Prostate and breast cancers are the major concerns among cancer patients. This study represents the development of new carbazoles as anticancer agents by interfering with topoisomerases II (topoII). Fifteen rationally designed carbazoles (4a-4o) were initially synthesized and screened for anticancer activities against different cancer cell lines. The promising hit compound 4f was further optimized by modifying the carbazole scaffold at positions 1, 3, 4, and 9, which led to the synthesis of its derivatives 5a-5j, 6a-6d and 7a-7d. Interestingly, 5a (IC50 = 8.47 ± 0.29 μM) and 6a (IC50 = 5.35 ± 0.30 μM) showed selective and improved anticancer activities than 4f (IC50 = 10.20 ± 0.44 μM and 8.564 ± 0.55 μM) in MCF-7 and PC-3 cells, respectively. Both compounds increased the ROS generation, depolarized the mitochondrial membrane, induced apoptosis via increased relative Bax/Bcl2 ratio, and arrested the cell cycle at G2/M phase. The selective human topoII inhibition further supported their anticancer mechanism. The in silico molecular docking and MD simulation studies aided their binding analysis in topoII and claimed them as potential topoII inhibitors.

Alkaloids, compounds found in plants with significant potential for medicine, are the subject of this comprehensive review. The review explores the connection between specific triggers, elicitors, and the production of alkaloids in plants. It examines different elicitors and their mechanism of action that influence the production of secondary metabolites in plants, focusing mainly on alkaloid production. The review method incorporated searching various search engines using keywords such as "Secondary metabolite production, Alkaloidal elicitation, elicitors, Biotic elicitors, Abiotic elicitors, Alkaloids medicinal importance." The search period covered approximately over two decades. The review considers only studies focusing on alkaloidal production, excluding those examining other secondary metabolite elicitation. For better understanding, the review also looks at the origin of these elicitors and categorizes them into biotic, abiotic, and genetic elicitors. Biotic elicitors are further classified into bacterial, fungal, algal, and yeast. Abiotic elicitors include chemical elicitors (such as heavy metals, mineral salts, and nanoparticles), physical elicitors (including light stress, drought stress, salinity, and osmotic stress), hormonal elicitors, and miscellaneous types. Genetic elicitors encompass gene editing and gene silencing techniques. Plants that are a rich source of alkaloids grow in various environments, emphasizing the need to know the exact conditions for different plant species. The review shows how plants successfully produce alkaloids under specific conditions. The review sets the stage for future research and new methods to make more alkaloids efficiently and sustainably. The insights gained from this thorough analysis will significantly aid the pharmaceutical industry in finding better ways to produce some important alkaloid compounds. (c) 2024 SAAB. Published by Elsevier B.V. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

Triple-negative breast cancer (TNBC) is an aggressive tumor among breast cancer subtypes with much lower overall survival at metastasis compared to other subtypes and with limited treatment options due to a lack of targeted therapies. This has led to the investigation of molecular targets to advance the development of novel therapeutic agents aimed at treating TNBC patients. Recent studies have led us to believe that glucocorticoid receptor (GR) expression may be predictive of decreased survival and increased risk of metastasis in TNBC tumors. Thus, a detailed understanding of GR signaling in TNBC may help understand the role of GR in TNBC proliferation as well as its role as a potential biomarker and therapeutic target. Recent research findings indicate that GR-induced gene regulations may provide an important platform for the development of GR-based therapeutic targets in TNBC. Emerging data from laboratories indicate that targeting GR has the potential to inhibit cancer cell proliferation and reduce tumor growth in TNBC. Therefore, future research focused on underlying molecular mechanisms of GR action in TNBC could lead to a new effective treatment option for TNBC patients, which is urgently needed.

This study presents the rational pharmacophore design, synthesis, and biological evaluation of new chromene-chalcone hybrids (CCHs) with dual mechanisms involving pyruvate kinase M2 (PKM2) inhibition and microtubule stabilization for their potential as anticancer agents. The synthetic route involved the formation of a chromene aldehyde 29 via an oxa-Michael addition followed by intramolecular cyclization, which subsequently underwent Claisen Schmidt condensation to afford the final chalcone derivatives. Among the synthesized compounds (30a-30o), 30o emerged as the most promising candidate, exhibiting potent anticancer activity through dual targeting of PKM2 and the microtubule network. Compound 30o demonstrated a significant antiproliferative effect against MCF-7 breast cancer cells, with an IC₅₀ value of 10.2 ± 0.07 μM, and showed PKM2 enzymatic inhibition with an IC₅₀ of 0.363 ± 0.12 μM, as confirmed through enzymatic assays and protein expression. Cell cycle analysis revealed 30o induced G2/M phase arrest and microtubule-stabilizing activity. Furthermore, molecular modeling studies revealed its binding mode and strong interactions within the PKM2 active site and taxol binding site of tubulin, supporting the experimental findings. ADMET profiling predicted favorable pharmacokinetic and drug-likeness properties, highlighting its potential as a lead compound. Together, these findings underscored compound 30o as a dual-acting anticancer agent, simultaneously targeting cancer metabolism and cytoskeletal integrity, and offered a promising scaffold for further development in breast cancer therapeutics.

The multifactorial nature of cancer requires treatment that involves simultaneous targeting of associated overexpressed proteins and cell signaling pathways, possibly leading to synergistic effects. Herein, we present a systematic study that involves the simultaneous inhibition of human topoisomerases (hTopos) and histone deacetylases (HDACs) by multitargeted quinoline-bridged hydroxamic acid derivatives. These compounds were rationally designed considering pharmacophoric features and catalytic sites of the cross-talk proteins, synthesized, and assessed for their anticancer potential. Our findings revealed that the compound 5c significantly produced anticancer effects in vitro and in vivo by reducing the tumor growth and its size in the A549 cell-induced lung cancer xenograft model through multiple mechanisms, primarily by multi-inhibition of hTopoI/II and HDACs, especially HDAC1 via atypical binding. The present paper discusses detailed mechanistic biological investigations, structure-activity effects supported by computational docking studies, and DMPK studies and provides future scope for lead optimization and modification.

Steroid receptors (SRs) play an important role in many physiological processes. including endocrine cancers. Dysregulation of SR functions has been implicated in breast-, prostate-, and endometrial- cancers. In recent years, how selective receptor modulators (SRMs) control SR-coregulators interactions has opened a unique window for novel SR-based targeted therapies. The current design of SRMs is primarily based on their modulation of coregulatory protein motif interactions with ligand binding domain/AF2 and thereby regulating the expression of target genes. These approaches overlook N-terminal domain/AF1 activity. A major obstacle to not targeting AF1 is due to its intrinsically disordered (ID) conformation, which until recently have rather been unattractive drug targets. Targeting ID proteins by small molecules to block protein-protein interactions is a rapidly evolving field. Based on our previous work, we hypothesize that TATA Box-binding Protein (TBP) binding/folding-induced AF1 conformation facilitates AF1’s interaction with specific coactivators and subsequent AF1-medaited SR’s transcriptional activity. Inhibiting/blocking coactivator-mediated SR activity that blocks AF1-TBP binding will provide a novel therapeutic strategy for the treatment of endocrine cancers. In the study, first we tested whether the flanking sequences around AF1 affect glucocorticoid receptor (GR) activity due, in part, to disorder-order conformational transition in ID AF1 that can facilitate its interaction with critical coregulatory proteins such as TBP and steroid receptor coactivator-1 (SRC-1). Using complementary biophysical techniques, we found that placing AF1 immediately upstream from the DNA binding domain (DBD) results into acquisition of a relatively ordered conformation in AF1. Further analyses revealed that removing amino acid sequences prior to AF1 or removal of amino acids between AF1 and DBD differentially regulates AF1-mediated GR activity. We also, screened and identified a small peptide molecule (P3) that blocks AF1-TBP binding. The results from this study may provide additional SR selectivity needed to target cell-tissue specific gene regulations in current endocrine-based therapies. Shagufta H Khan and Raj Kumar. Intrinsically disordered AF1 domain of steroid receptors as a novel potential target for endocrine cancers [abstract]. In: Proceedings of Frontiers in Cancer Science 2024; 2024 Nov 13-15; Singapore. Philadelphia (PA): AACR; Cancer Res 2025;85(15_Suppl):Abstract nr P62.

A novel series of bakuchiol tethered triazole compounds was synthesized by reaction of azido bakuchiol with different substituted alkynes. The anticancer activity of all synthesized compounds was evaluated against A549 (lung), MCF-7, and MDA-MB-231 (breast) human tumor cells. Cytotoxicity screening showed that several compounds displayed notable cytotoxic effects against tumor cells compared to the parent molecule bakuchiol. The prominent effects were produced by compounds 16 and 17 with IC50 values of 8.9 µM and 8.2 µM against the MCF-7 and A-549 cells, respectively.