One‐pot synthesis of novel ( E )‐3‐(3, 8a‐dihydro‐2 H ‐oxazolo[3,2‐a]pyridin‐2‐ylidene)chroman‐2‐one derivatives

Fragment-based design and synthesis of coumarin-based thiazoles as dual c-MET/STAT-3 inhibitors for potential antitumor agents

c-MET and STAT-3 are significant targets for cancer treatments. Here, we describe a class of very effective dual STAT-3 and c-MET inhibitors with coumarin-based thiazoles (3a-o) as its scaffold. Spectroscopic evidence (NMR, HRMS, and HPLC) validated the structural discoveries of the new compounds. The cytotoxic activity of these compounds was also tested against a panel of cancer cells in accordance with US-NCI guidelines. Compound 3g proved to be active at 10 µM, thus it was automatically scheduled to be tested at five doses. Towards SNB-75 (CNS cancer cell line), compound 3g showed notable in vitro anti-cancer activity with GI50 = 1.43 μM. For the molecular targets, compound 3g displayed potent activity towards STAT-3 and c-MET having IC50 of 4.7 µM and 12.67, respectively, compared to Cabozantinib (IC50 = 15 nM of c-MET) and STAT-3-IN-3 (IC50 = 2.1 µM of STAT-3). Moreover, compound 3g significantly induced apoptosis in SNB-75 cells, causing a 3.04-fold increase in apoptotic cell death (treated cells exhibited 11.53 % overall apoptosis, against 3.04 % in reference cells) and a 3.58-fold increase in necrosis. Moreover, it arrests cells at the G2 phase. Dual inhibition of c-MET and STAT-3 protein kinase was further validated using RT-PCR. The target compound's binding mechanism was determined by the application of molecular docking.

Discovery and Mechanistic Studies of Dual-Target Hits for Carbonic Anhydrase IX and VEGFR-2 as Potential Agents for Solid Tumors: X-ray, In Vitro, In Vivo, and In Silico Investigations of Coumarin-Based Thiazoles

A dual-targeting approach is predicted to yield better cancer therapy outcomes. Consequently, a series of coumarin-based thiazoles (5a-h, 6, and 7a-e) were designed and constructed as potential carbonic anhydrase (CA) and VEGFR-2 suppressors. The inhibitory actions of the target compounds were assessed against CA isoforms IX and VEGFR-2. The assay results showed that coumarin-based thiazoles 5a, 5d, and 5e can effectively inhibit both targets. 5a, 5d, and 5e cytotoxic effects were tested on pancreatic, breast, and prostate cancer cells (PANC1, MCF7, and PC3). Further mechanistic investigation disclosed the ability of 5e to interrupt the PANC1 cell progression in the S stage by triggering the apoptotic cascade, as seen by increased levels of caspases 3, 9, and BAX, alongside the Bcl-2 decline. Moreover, the in vivo efficacy of compound 5e as an antitumor agent was evaluated. Also, molecular docking and dynamics displayed distinctive interactions between 5e and CA IX and VEGFR-2 binding pockets.

Novel 2-substituted-quinoxaline analogs with potential antiproliferative activity against breast cancer: insights into cell cycle arrest, topoisomerase II, and EGFR activity

Breast cancer is a global health concern, with increasing disease burden and disparities in access to healthcare. Late diagnosis and limited treatment options in underserved areas contribute to poor outcomes. In response to this challenge, we developed a novel family of 2-substituted-quinoxaline analogues, combining coumarin and quinoxaline scaffolds known for their anticancer properties. Through a versatile synthetic approach, we designed, synthesized, and characterized a set of 2-substituted quinoxaline derivatives. The antiproliferative activity of the synthesized compounds was assessed toward the MCF-7 breast cancer cells. Our investigations showed that the synthesized compounds exhibit considerable antiproliferative activity toward MCF-7 cells. Notably, compound 3b, among examined compounds, displayed a superior inhibitory effect (IC50 = 1.85 ± 0.11 μM) toward the growth of MCF-7 cells compared to the conventional anticancer drug staurosporine (IC50 = 6.77 ± 0.41 μM) and showed minimal impact on normal cells (MCF-10A cell lines, IC50 = 33.7 ± 2.04 μM). Mechanistic studies revealed that compound 3b induced cell cycle arrest at the G1 transition and triggered apoptosis in MCF-7 cells, as evidenced by increasing the percentage of cells arrested in the G2/M and pre-G1 phases utilizing flow cytometric analysis and Annexin V-FITC/PI analysis. Moreover, compound 3b was found to substantially suppress topoisomerase enzyme activity in MCF-7 cells. Molecular modeling studies further supported the potential of compound 3b as a therapeutic candidate by demonstrating significant binding affinity to the active sites of both topoisomerase II and EGFR proteins. Taken together, the presented 2-substituted-quinoxaline analogues, especially compound 3b, show promise as potential candidates for the development of effective anti-breast cancer drugs.

3-(Bromoacetyl)coumarins: unraveling their synthesis, chemistry, and applications

This review emphasizes recent developments in synthetic routes of 3-(bromoacetyl)coumarin derivatives. Also, chemical reactions of 3-(bromoacetyl)coumarins as versatile building blocks in the preparation of critical polyfunctionalized heterocyclic systems and other industrially significant scaffolds are described. Recent advances of 3-(bromoacetyl)coumarins as attractive starting points towards a wide scale of five and six-membered heterocyclic systems such as thiophenes, imidazoles, pyrazoles, thiazoles, triazoles, pyrans, pyridines, thiadiazins as well as fused heterocyclic systems have been reported. Additionally, this review covers a wide range of analytical chemistry, fluorescent sensors, and biological applications of these moieties, covering the literature till May 2021.

One-Pot Solvent-and Catalyst-Free Synthesis of Some New Heteroarylaminonaphthoquinones from Lawsone

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A clean and efficient one-pot protocol for the synthesis of a series of new 2-hydroxy-3-((3-aryl)(heteroarylamino)methyl)naphthalene-1,4-dione derivatives has been developed by the three-component reaction of 2-hydroxynaphthalene-1,4-dione, aromatic aldehydes and heterocyclic amines at 90 oC under solvent and catalyst-free conditions. The procedure avoids the use of toxic solvents, tedious work-up, catalyst and purification of the products by chromatographic methods. Simple operation, short reaction times, generating the desired compounds in high to excellent yields and an environmentally benign method are advantages of this protocol.