Discovery of indolinone-bearing benzenesulfonamides as new dual carbonic anhydrase and VEGFR-2 inhibitors possessing anticancer and pro-apoptotic properties

Design and Discovery of New Dual Carbonic Anhydrase IX and VEGFR-2 Inhibitors Based on the Benzenesulfonamide-Bearing 4-Thiazolidinones/2,4-Thiazolidinediones Scaffold

Dual-targeting drug design has become a popular approach in investigating and developing potent anticancer agents. In this regard, carbonic anhydrase (CAIX) and vascular endothelial growth factor receptor (VEGFR-2) are emerging as highly effective targets in the battle against cancer. In the present study, two series of 4-thiazolidinones/2,4-thiazolidinediones carrying 2-methylbenzenesulfonamide derivatives were designed and synthesized as potential dual CAIX/VEGFR-2 inhibitors. All the target compounds were evaluated against CAIX enzyme compared to dorzolamide and acetazolamide, subsequently the most potent CAIX inhibitors (3a, 3b, 3o, 6d, 6g, and 6i) were selected to evaluate their inhibitory activity against VEGFR-2 using sorafenib as a reference drug. These compounds were also evaluated against MCF-7 breast cancer cells and the murine fibroblast 3T3 cell line. According to the results, 3b (CAIX IC50 = 0.035 µM, VEGFR-2 IC50 = 0.093 µM) and 6i (CAIX IC50 = 0.041 µM, VEGFR-2 IC50 = 0.048 µM) emerged the most potent compounds against CAIX and VEGFR-2. Furthermore, docking studies of selected compounds were performed with the CAIX and the tyrosine kinase domain of VEGFR-2 to comprehend the ligand-binding interactions. Physicochemical predictions were examined using in silico techniques. In conclusion, these scaffolds present promising leads and furnish promising chemical backbones for the design of potent dual CAIX and VEGFR-2 inhibitors.b.

Spiro-fused indoline-quinazoline hybrids as smart bombs against TNF-α-mediated inflammation

Inflammation is central to numerous diseases, highlighting the need for new anti-inflammatory agents. This study explores the potential of novel spirofused indoline-quinazoline hybrids (4a-p) as anti-inflammatory compounds, inspired by a spiroisatin analogue (VI) that showed modest TNF-α inhibition. We aimed to enhance activity by modifying the isatin scaffold: first, introducing N-alkylation (propyl, butyl, or isobutyl) to improve hydrophobic interactions within the TNF-α dimer active site; second, adding halogens (F, Cl, Br) at the 5-position to increase lipophilicity. Anti-inflammatory activity against TNF-α was confirmed in-vivo for all synthesized analogues, with 4b, 4e, 4k, and 4n emerging as the top candidates. Further studies on these four compounds assessed their analgesic effects, as well as their impact on PGE2, NF-κB, paw thickness, and paw weight. In-vitro analyses revealed nanomolar TNFR2-TNF-α binding inhibition for the four leads. Safety evaluations included histopathology, ulcerogenic potential, kidney and liver functions, and acute hemotoxicity. In-silico studies examined drug-likeness, pharmacokinetics, and TNF-α dimer interactions. These results suggest that the four lead compounds possess promising profiles compared to standard therapies.

Targeting Vascular Endothelial Growth Factor Receptor 2 (VEGFR-2): Latest Insights on Synthetic Strategies

Vascular endothelial growth factor receptor 2 (VEGFR-2) is a crucial mediator of angiogenesis, playing a pivotal role in both normal physiological processes and cancer progression. Tumors harness VEGFR-2 signaling to promote abnormal blood vessel growth, which is a key step in the metastasis process, making it a valuable target for anticancer drug development. While there are VEGFR-2 inhibitors approved for therapeutic use, they face challenges like drug resistance, off-target effects, and adverse side effects, limiting their effectiveness. The quest for new drug candidates with VEGFR-2 inhibitory activity often starts with the selection of key structural motifs present in molecules currently used in clinical practice, expanding the chemical space by generating novel derivatives bearing one or more of these moieties. This review provides an overview of recent advances in the development of novel VEGFR-2 inhibitors, focusing on the synthesis of new drug candidates with promising antiproliferative and VEGFR-2 inhibition activities, organizing them by relevant structural features.

Discovery of new sulfonamide-tethered 2-aryl-4-anilinoquinazolines as the first-in-class dual carbonic anhydrase and EGFR inhibitors

In today's medical field, there is a growing trend of exploiting a single small molecule to target two different molecular targets concurrently. This approach is proving to be highly effective in fighting against cancer. The 4-anilinoquinazoline scaffold, known for its potential in cancer therapy and its effectiveness as a leading class of tyrosine kinase inhibitors, was employed to develop a novel series of anilinoquinazoline-sulfonamides (AQSs) (8a-d, 9a-f, and 10a-d) as dual inhibitors of the tumor-associated carbonic anhydrases (CA) IX/XII and EGFR. 2-(3-Methoxyphenyl)quinazoline bearing p-sulfanilamide 10b elicited superior hCA IX and XII inhibition in the low nanomolar range (KIs = 38.4 and 8.9 nM, respectively). Also, 10b shined as a potent and selective EGFR inhibitor, boasting an impressive IC50 value of 51.2 ± 0.97 nM, surpassing the reference EGFR inhibitor Erlotinib (IC50 = 80 ± 2.0 nM). Compound 10b exhibited broadest-spectrum antiproliferative activity against the NCI-tumor panel with a mean GI% value of 68 %. Of special interest, 10b demonstrated potent growth inhibition (GI% ≥ 80-97 %) toward cell lines reported to express high levels of EGFR belonging to renal, colon, breast, and lung cancers. Compound 10b's molecular docking in the CA IX/XII and EGFR active sites revealed binding modes that justify its potent enzyme inhibitory effects. Additionally, molecular dynamic simulations demonstrated strong and stable interactions of 10b with the binding sites of these targets.

Unveiling the potential of isatin-grafted phenyl-1,2,3-triazole derivatives as dual VEGFR-2/STAT-3 inhibitors: Design, synthesis and biological assessments

The use of VEGFR-2 inhibitors as a stand-alone treatment has proven to be ineffective in clinical trials due to the robustness of cellular response loops that lead to treatment resistance when only targeting VEGFR-2. The over-activation of the signal transducer/activator of transcription 3 (STAT-3) is expected to significantly impact treatment failure and resistance to VEGFR-2 inhibitors. In this study, we propose the concept of combined inhibition of VEGFR-2 and STAT-3 to combat induced STAT-3-mediated resistance to VEGFR-2 inhibition therapy. To explore this, we synthesized new isatin-grafted phenyl-1,2,3-triazole derivatives "6a-n" and "9a-f". Screening on PANC1 and PC3 cancer cell lines revealed that compounds 6b, 6 k, 9c, and 9f exhibited sub-micromolar ranges. The most promising molecules, 6b, 6 k, 9c, and 9f, demonstrated the highest inhibition when tested as dual inhibitors on VEGFR-2 (with IC50 range 53-82 nM, respectively) and STAT-3 (with IC50 range 5.63-10.25 nM). In particular, triazole 9f showed the best results towards both targets. Inspired by these findings, we investigated whether 9f has the ability to trigger apoptosis in prostate cancer PC3 cells via the assessment of the expression levels of the apoptotic markers Caspase-8, Bcl-2, Bax, and Caspase-9. Treatment of the PC3 cells with compound 9f significantly inhibited the protein expression levels of VEGFR-2 and STAT-3 kinases compared to the control.

Recent advances and future directions on small molecule VEGFR inhibitors in oncological conditions

"A journey of mixed emotions" is a quote that best describes the progress chart of vascular endothelial growth factor receptor (VEGFR) inhibitors as cancer therapeutics in the last decade. Exhilarated with the Food and Drug Administration (FDA) approvals of numerous VEGFR inhibitors coupled with the annoyance of encountering the complications associated with their use, drug discovery enthusiasts are on their toes with an unswerving determination to enhance the rate of translation of VEGFR inhibitors from preclinical to clinical stage. The recently crafted armory of VEGFR inhibitors is a testament to their growing dominance over other antiangiogenic therapies for cancer treatment. This review perspicuously underscores the earnest attempts of the researchers to extract the antiproliferative potential of VEGFR inhibitors through the design of mechanistically diverse structural assemblages. Moreover, this review encompasses sections on structural/molecular properties and physiological functions of VEGFR, FDA-approved VEGFR inhibitors, and hurdles restricting the activity range/clinical applicability of VEGFR targeting antitumor agents. In addition, tactics to overcome the limitations of VEGFR inhibitors are discussed. A clear-cut viewpoint transmitted through this compilation can provide practical directions to push the cart of VEGFR inhibitors to advanced-stage clinical investigations in diverse malignancies.

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.

pH regulators and their inhibitors in tumor microenvironment

As an important characteristic of tumor, acidic tumor microenvironment (TME) is closely related to immune escape, invasion, migration and drug resistance of tumor. The acidity of the TME mainly comes from the acidic products produced by the high level of tumor metabolism, such as lactic acid and carbon dioxide. pH regulators such as monocarboxylate transporters (MCTs), carbonic anhydrase IX (CA IX), and Na+/H+ exchange 1 (NHE1) expel protons directly or indirectly from the tumor to maintain the pH balance of tumor cells and create an acidic TME. We review the functions of several pH regulators involved in the construction of acidic TME, the structure and structure-activity relationship of pH regulator inhibitors, and provide strategies for the development of small-molecule antitumor inhibitors based on these targets.

Identification of new anti-mycobacterial agents based on quinoline-isatin hybrids targeting enoyl acyl carrier protein reductase (InhA)

Tuberculosis (TB) is a global issue that poses a significant economic burden as a result of the ongoing emergence of drug-resistant strains. The urgent requirement for the development of novel antitubercular drugs can be addressed by targeting specific enzymes. One such enzyme, Mycobacterium tuberculosis (MTB) enoyl-acyl carrier protein (enoyl-ACP) reductase (InhA), plays a crucial role in the survival of the MTB bacterium. In this research study, a series of hybrid compounds combining quinolone and isatin were synthesized and assessed for their effectiveness against MTB, as well as their ability to inhibit the activity of the InhA enzyme in this bacterium. Among the compounds tested, 7a and 5g exhibited the most potent inhibitory activity against MTB, with minimum inhibitory concentration (MIC) values of 55 and 62.5 µg/mL, respectively. These compounds were further evaluated for their inhibitory effects on InhA and demonstrated significant activity compared to the reference drug Isoniazid (INH), with IC50 values of 0.35 ± 0.01 and 1.56 ± 0.06 µM, respectively. Molecular docking studies investigated the interactions between compounds 7a and 5g and the target enzyme, revealing hydrophobic contacts with important amino acid residues in the active site. To further confirm the stability of the complexes formed by 5g and 7a with the target enzyme, molecular dynamic simulations were employed, which demonstrated that both compounds 7a and 5g undergo minor structural changes and remain nearly stable throughout the simulated process, as assessed through RMSD, RMSF, and Rg values.

Identification of thienopyrimidine derivatives tethered with sulfonamide and other moieties as carbonic anhydrase inhibitors: Design, synthesis and anti-proliferative activity

Eighteen novel compounds harboring the privileged thienopyrimidine scaffold (5a-q, and 6a),were designed based on molecular hybridization strategy. These compounds were synthesized and tested for their inhibitory activity against four different carbonic anhydrase isoforms: CA I, II, IX, and XII. Microwave and conventional techniques were applied for their synthesis. Compounds 5b, 5g, 5l, and 5p showed the highest inhibition activity against the four CA isoforms. Compound 5p exhibited promising inhibitory activity against CA II, CA IX and CA XII with KI values of8.6, 13.8, and 19 nM, respectively, relative to AAZ, where KIs = 12, 25, and 5.7 nM, respectively. Also, compound 5 l showed significant activity against the tumor-associated isoform CA IX with KI = 16.1 nM. All the newly synthesized compounds were also screened for their anticancer activity against NCI 60 cancer cell lines at a 10 µM concentration. Compound 5n showed 80.38, 83.95, and 87.39 % growth inhibition against the leukemic cell lines CCRF-CEM, HL-60 (TB), and RPMI-8226, respectively. Also, 5 h showed 87.57 % growth inhibition against breast cancer cell line MDA-MB-468; and 66.58 and 60.95 % inhibitionagainst renal cancer cell lines UO-31, and ACHN, respectively. A molecular docking studywas carried out to predict binding modes of our synthesized compounds in the binding pockets of the four carbonic anhydrase isoforms, and results revealed that compounds 5b, 5g, 5l, and 5p succeeded in mimicking the binding mode of AAZ through metal coordination with Zn+2 ion and binding to the amino acids Thr199, His94, and His96 that are critical for activity.

Antineoplastic indole-containing compounds with potential VEGFR inhibitory properties

Cancer is one of the most significant health challenges worldwide. Various techniques, tools and therapeutics/materials have been developed in the last few decades for the treatment of cancer, together with great interest, funding and efforts from the scientific society. However, all the reported studies and efforts seem insufficient to combat the various types of cancer, especially the advanced ones. The overexpression of tyrosine kinases is associated with cancer proliferation and/or metastasis. VEGF, an important category of tyrosine kinases, and its receptors (VEGFR) are hyper-activated in different cancers. Accordingly, they are known as important factors in the angiogenesis of different tumors and are considered in the development of effective therapeutic approaches for controlling many types of cancer. In this case, targeted therapeutic approaches are preferable to the traditional non-selective approaches to minimize the side effects and drawbacks associated with treatment. Several indole-containing compounds have been identified as effective agents against VEGFR. Herein, we present a summary of the recent indolyl analogs reported within the last decade (2012-2023) with potential antineoplastic and VEGFR inhibitory properties. The most important drugs, natural products, synthesized potent compounds and promising hits/leads are highlighted. Indoles functionalized and conjugated with various heterocycles beside spiroindoles are also considered.

Identification of novel ureido benzothiophenes as dual VEGFR-2/EGFR anticancer agents

Presently, dual-targeting by a single small molecule stands out as a fruitful cancer-fighting strategy. Joining the global effort to fight cancer, a leading cause of death worldwide, we report in this study a novel set for benzothiophene-based aryl urea derivatives as potential anti-proliferative candidates endowed with dual VEGFR-2/EGFR inhibitory activities. The prepared ureido benzothiophenes 6a-r have been evaluated for their anticancer action on a panel of tumor cell lines, namely PanC-1, MCF-7, and HepG2 cells. Most newly synthesized benzo[b]thiophene ureas disclosed effective cytotoxic activities against the examined cancer cell lines. In particular, compound 6q, with an appended 4-trifluoromethoxy group on the terminal phenyl ring, exhibited the most significant cytotoxic activity in MCF-7 with IC50 3.86 ± 0.72 ug/mL; IC50 of 3.65 ± 0.18 ug/ml in PanC-1 cell line and an IC50 of 4.78 ± 0.06 ug/ml in HepG2. After that, derivatives that exhibited the most potent cytotoxic activities (6g, 6j, 6q, and 6r) were further evaluated as VEGFR-2 and EGFR inhibitors. Fortunately, they displayed low nanomolar IC50 values against both enzymes, where compound 6q emerged to possess superior inhibitory effects towards both EGFR and VEGFR-2 with IC50 46.6 nM and 11.3 nM simultaneously compared to the reference medications Erlotinib and Sorafenib, respectively. The docked structure of 6q within the catalytic region of VEGFR-2 and EGFR kinases was acquired and studied so that we could investigate potential binding mechanisms for the target ureido benzothiophenes. Hence, the benzothiophene-based aryl urea scaffold has great potential for advancing the development of highly effective dual inhibitors targeting both EGFR and VEGFR-2, which can serve as effective candidates for anticancer therapy.

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.

Small Schiff Base Molecules-A Possible Strategy to Combat Biofilm-Related Infections

Microorganisms participating in the development of biofilms exhibit heightened resistance to antibiotic treatment, therefore infections involving biofilms have become a problem in recent years as they are more difficult to treat. Consequently, research efforts are directed towards identifying novel molecules that not only possess antimicrobial properties but also demonstrate efficacy against biofilms. While numerous investigations have focused on antimicrobial capabilities of Schiff bases, their potential as antibiofilm agents remains largely unexplored. Thus, the objective of this article is to present a comprehensive overview of the existing scientific literature pertaining to small molecules categorized as Schiff bases with antibiofilm properties. The survey involved querying four databases (Web of Science, ScienceDirect, Scopus and Reaxys). Relevant articles published in the last 10 years were selected and categorized based on the molecular structure into two groups: classical Schiff bases and oximes and hydrazones. Despite the majority of studies indicating a moderate antibiofilm potential of Schiff bases, certain compounds exhibited a noteworthy effect, underscoring the significance of considering this type of molecular modeling when seeking to develop new molecules with antibiofilm effects.