Design, synthesis and biological evaluation of a series of novel 2-benzamide-4-(6-oxy-N-methyl-1-naphthamide)-pyridine derivatives as potent fibroblast growth factor receptor (FGFR) inhibitors

A Promising Paradigm Shift in Cancer Treatment with FGFR Inhibitors

FGFR have been demonstrated to perform a crucial role in biological processes but their overexpression has been perceived as the operator component in the occurrence and progression of different types of carcinoma. Out of all the interest around cancer, FGFR inhibitors have assembled pace over the past few years. Therefore, FGFR inhibitors are one of the main fundamental tools to reverse drug resistance, tumor growth, and angiogenesis. Currently, many FGFR inhibitors are under the development stage or have been developed. Due to great demand and hotspots, different pharmacophores were approached to access structurally diverse FGFR inhibitors. Here, we have selected to present several representative examples such as Naphthyl, Pyrimidine, Pyridazine, Indole, and Quinoline derivatives that illustrate the diversity and advances of FGFR inhibitors in medicinal chemistry. This review focuses on the SAR study of FGFR inhibitors last five years which will be a great future scope that influences the medicinal chemist to work towards more achievements in this area.

Scaffold hopping approaches for dual-target antitumor drug discovery: opportunities and challenges

INTRODUCTION

Scaffold hopping has emerged as a practical tactic to enrich the synthetic bank of small molecule antitumor agents. Specifically, it enables the chemist to refine the lead compound's pharmacodynamic, pharmacokinetic, and physiochemical properties. Scaffold hopping opens up fresh molecular territory beyond established patented chemical domains.

AREA COVERED

The authors present the scaffold hopping-based drug design strategies for dual inhibitory antitumor structural templates in this review. Minor modifications, structure rigidification and simplification (ring-closing and opening), and complete structural overhauls were the strategies employed by the medicinal chemist to generate a library of bifunctional inhibitors. In addition, the review presents an overview of the computational methods of scaffold hopping (software and programs) and organopalladium catalysis leveraged for the synthesis of templates designed via scaffold hopping.

EXPERT OPINION

The medicinal chemist has demonstrated remarkable prowess in furnishing dual inhibitory antitumor chemical architectures. Scaffold hopping-based drug design strategies have yielded a plethora of pharmacodynamically superior dual modulatory antitumor agents. An integrated approach involving computational advancements, synthetic methodology advancements, and conventional drug design strategies is required to increase the number of scaffold-hopping-assisted drug discovery campaigns.

Discovery of N-(4-((6-(3,5- Dimethoxyphenyl)-9H-purine derivatives as irreversible covalent FGFR inhibitors

Fibroblast growth factor receptor (FGFR) is an attractive target for cancer therapy, but existing FGFR inhibitors appear to hardly meet the demand for clinical application. Herein, a number of irreversible covalent FGFR inhibitors were designed and synthesized by selecting several five- and six-membered azaheterocycles as parent scaffold with different substituents to take over the hydrophobic region in the active pocket of FGFR proteins. Among the resulting target compounds, III-30 showed the most potent effect on enzyme activity inhibition and anti-proliferative activity against the tested cancer cell lines. Significantly, III-30 could inhibit the enzyme activity by achieving irreversible covalent binding with FGFR1 and FGFR4 proteins. It could also regulate FGFR-mediated signaling pathway and mitochondrial apoptotic pathway to promote cancer cell apoptosis and inhibit cancer cell invasion and metastasis. Moreover, III-30 had a good metabolic stability and showed relatively potent anti-tumor activity in the MDA-MB-231 xenograft tumor mice model.

Recent advances in nitrogen-containing heterocyclic compounds as receptor tyrosine kinase inhibitors for the treatment of cancer: Biological activity and structural activity relationship

Erratic cell proliferation is the initial symptom of cancer, which can eventually metastasize to other organs. Before cancer becomes metastatic, its spread is triggered by pro-angiogenic factors including vascular endothelial growth factor receptor (VEGFR), epidermal growth factor receptor (EGFR), Platelet-derived growth factor receptor (PDGFR), fibroblast growth factor receptor (FGFR) and Platelet Factor (PF4), all of which are part of receptor tyrosine kinase (RTK) family. Receptor tyrosine kinases (RTKs) are cell-surface proteins and aresignaling enzymes that transfer ATP-phosphate to tyrosine residue substrates. Important biological processes like proliferation, differentiation, motility, and cell-cycle regulation are all possessedby these proteins. Unusual RTK expression is typically associated with cell growth abnormalities, which is linked to tumor acquisition, angiogenesis, and cancer progression. In addition to the already available medications, numerous other heterocyclic are being studied for their potential action against a variety of cancers. In the fight against cancer, in particular, these heterocycles have been used for their dynamic core scaffold and their inherent adaptability. In this review article, we have compiled last five years research work including nitrogen containing heterocycles that have targeted RTK. Herein, the SAR and activity of various compounds containing diverse heterocyclic (pyrimidine, indole, pyridine, pyrazole, benzimidazole, and pyrrole) scaffolds are discussed, and they may prove useful in the future for designing new leads against RTKs. Our focus in this manuscript is to comprehensively review the latest research on the biological activity and structural activity relationship of nitrogen compounds as RTK inhibitors. We believe that this may be an important contribution to the field, as it can help guide future research efforts and facilitate the development of more effective cancer therapies.

Angiogenic signaling pathways and anti-angiogenic therapy for cancer

Angiogenesis, the formation of new blood vessels, is a complex and dynamic process regulated by various pro- and anti-angiogenic molecules, which plays a crucial role in tumor growth, invasion, and metastasis. With the advances in molecular and cellular biology, various biomolecules such as growth factors, chemokines, and adhesion factors involved in tumor angiogenesis has gradually been elucidated. Targeted therapeutic research based on these molecules has driven anti-angiogenic treatment to become a promising strategy in anti-tumor therapy. The most widely used anti-angiogenic agents include monoclonal antibodies and tyrosine kinase inhibitors (TKIs) targeting vascular endothelial growth factor (VEGF) pathway. However, the clinical benefit of this modality has still been limited due to several defects such as adverse events, acquired drug resistance, tumor recurrence, and lack of validated biomarkers, which impel further research on mechanisms of tumor angiogenesis, the development of multiple drugs and the combination therapy to figure out how to improve the therapeutic efficacy. Here, we broadly summarize various signaling pathways in tumor angiogenesis and discuss the development and current challenges of anti-angiogenic therapy. We also propose several new promising approaches to improve anti-angiogenic efficacy and provide a perspective for the development and research of anti-angiogenic therapy.

Design, Microwave-Assisted Synthesis, Antimicrobial and Anticancer Evaluation, and In Silico Studies of Some 2-Naphthamide Derivatives as DHFR and VEGFR-2 Inhibitors

Naphthamide is a common structural framework with diverse pharmacological activities. Ten novel 2-naphthamide derivatives have been designed, synthesized, and evaluated for their in vitro antibacterial, antifungal, and anticancer activities. The title compounds were synthesized from dimethoxybenzaldehyde derivatives through a four-step microwave-assisted synthesis process. The structures were confirmed by ¹H NMR, ¹³C NMR, and MS spectra. Compound 8b showed good antibacterial activity against Escherichia coli, Streptococcus faecalis, Salmonella enterica, MSSA, and MRSA with MIC values of 16, 16, 16, 8, and 16 μg/mL, respectively, compared to ciprofloxacin (MIC = 8-16 μg/mL). Compounds 5b (IC₅₀ = 3.59-8.38 μM) and 8b (IC₅₀ = 2.97-7.12 μM) exhibited good cytotoxic activity against C26, HepG2, and MCF7 cancer cell lines as compared to paclitaxel (IC₅₀ = 2.85-5.75 μM). Moreover, compounds 5b and 8b exhibited better anticancer activity than PTX against the C26 cell line. In particular, compound 8b showed potent in vitro VEGFR-2 inhibitory activity with the IC₅₀ value of 0.384 μM compared with sorafenib (IC₅₀ = 0.069 μM). Therefore, compound 8b is the most potent compound for anticancer activity as indicated by in vitro cell line inhibition, in silico ADMET, molecular docking, and in vitro VEGFR-2 inhibition studies.

Recent progress on vascular endothelial growth factor receptor inhibitors with dual targeting capabilities for tumor therapy

Vascular endothelial growth factor receptors (VEGFRs) are a family of receptor protein tyrosine kinases that play an important role in the regulation of tumor-induced angiogenesis. Currently, VEGFR inhibitors have been widely used in the treatment of various tumors. However, current VEGFR inhibitors are limited to a certain extent due to limited clinical efficacy and potential toxicity, which hinder their clinical application. Thus, the development of new strategies to improve the clinical outcomes and minimize the toxic effects of VEGFR inhibitors is required. Given the synergistic effect of VEGFR and other therapies in tumor development and progression, VEGFR dual-target inhibitors are becoming an attractive approach due to their favorable pharmacodynamics, low toxicity, and anti-resistant effects. This perspective provides an overview of the development of VEGFR dual-target inhibitors from multiple aspects, including rational target combinations, drug discovery strategies, structure–activity relationships and future directions.

Signaling Pathway and Small-Molecule Drug Discovery of FGFR: A Comprehensive Review

Targeted therapy is a groundbreaking innovation for cancer treatment. Among the receptor tyrosine kinases, the fibroblast growth factor receptors (FGFRs) garnered substantial attention as promising therapeutic targets due to their fundamental biological functions and frequently observed abnormality in tumors. In the past 2 decades, several generations of FGFR kinase inhibitors have been developed. This review starts by introducing the biological basis of FGF/FGFR signaling. It then gives a detailed description of different types of small-molecule FGFR inhibitors according to modes of action, followed by a systematic overview of small-molecule-based therapies of different modalities. It ends with our perspectives for the development of novel FGFR inhibitors.

The crystal structure of bis(2-oxidopyridin-1-ium-3-carboxylato-κ2 O,O′)-(phenantroline-κ2 N,N′)manganese(II) - methanol (1/3), C27H28N4O9Mn

C27H28N4O9Mn, monoclinic, P21/n (no. 14), a = 10.0269(7) Å, b = 14.1702(10) Å, c = 20.0750(14) Å, β = 100.298(1)°, V = 2806.4(3) Å3, Z = 4, R gt (F) = 0.0403, wR ref (F 2) = 0.0985, T = 296.15 K.

Crystal structure of (1,10-phenanthroline-κ2 N,N′)-bis(3-thiophenecarboxylato-κ2 O,O′)copper(II), C22H14N2O4S2Cu

C22H14N2O4S2Cu, orthorhombic, Pbcn (no. 60), a = 20.171(7) Å, b = 9.684(3) Å, c = 10.372(4) Å, V = 2025.9(12) Å3, Z = 4, R gt (F) = 0.0334, wR ref (F 2) = 0.0908, T = 273.15 K.

The crystal structure of aqua-bis(6-chloropicolinato-κ2 N,O)copper(II), C12H8Cl2N2O5Cu

C12H8Cl2N2O5Cu, triclinic, P 1 ‾ $P‾{1}$ (no. 2), a = 6.800(2) Å, b = 9.086(3) Å, c = 11.363(4) Å, α = 86.701(6)°, β = 84.830(5)°, γ = 77.353(5)°, V = 681.7(4) Å3, Z = 2, R gt (F) = 0.0250, wR ref(F 2) = 0.0655, T = 296(2) K.

Design, synthesis and biological evaluation of 1H-pyrrolo[2,3-b]pyridine derivatives as potent fibroblast growth factor receptor inhibitors

Abnormal activation of FGFR signaling pathway plays an essential role in various types of tumors. Therefore, targeting FGFRs represents an attractive strategy for cancer therapy. Herein, we report a series of 1H-pyrrolo[2,3-b]pyridine derivatives with potent activities against FGFR1, 2, and 3. Among them, compound 4h exhibited potent FGFR inhibitory activity (FGFR1–4 IC₅₀ values of 7, 9, 25 and 712 nM, respectively). In vitro, 4h inhibited breast cancer 4T1 cell proliferation and induced its apoptosis. In addition, 4h also significantly inhibited the migration and invasion of 4T1 cells. Furthermore, 4h with low molecular weight would be an appealing lead compound which was beneficial to the subsequent optimization. In general, this research has been developing a class of 1H-pyrrolo[2,3-b]pyridine derivatives targeting FGFR with development prospects.

Discovery of a new class of 1H- pyrrorole [2,3-b]pyridine FGFR inhibitors with high ligand efficiency.

Inhibition of FGF-FGFR and VEGF-VEGFR signalling in cancer treatment

The sites of targeted therapy are limited and need to be expanded. The FGF‐FGFR signalling plays pivotal roles in the oncogenic process, and FGF/FGFR inhibitors are a promising method to treat FGFR‐altered tumours. The VEGF‐VEGFR signalling is the most crucial pathway to induce angiogenesis, and inhibiting this cascade has already got success in treating tumours. While both their efficacy and antitumour spectrum are limited, combining FGF/FGFR inhibitors with VEGF/VEGFR inhibitors are an excellent way to optimize the curative effect and expand the antitumour range because their combination can target both tumour cells and the tumour microenvironment. In addition, biomarkers need to be developed to predict the efficacy, and combination with immune checkpoint inhibitors is a promising direction in the future. The article will discuss the FGF‐FGFR signalling pathway, the VEGF‐VEGFR signalling pathway, the rationale of combining these two signalling pathways and recent small‐molecule FGFR/VEGFR inhibitors based on clinical trials.

Recent advances of dual FGFR inhibitors as a novel therapy for cancer

Fibroblast growth factor receptor (FGFR) includes four highly conserved transmembrane receptor tyrosine kinases (FGFR1-4). FGF and FGFR regulate many biological processes, such as angiogenesis, wound healing and tissue regeneration. The abnormal expression of FGFR is related to the tumorigenesis, tumor progression and drug resistance of anti-tumor treatments in many types of tumors. Nowadays there are many anti-cancer drugs targeting FGFR. However, traditional single-target anti-tumor drugs are easy to acquire drug resistance. The therapeutic effect can be enhanced by simultaneously inhibiting FGFR and another target (such as VEGFR, EGFR, PI3K, CSF-1R, etc.). We know drug combination can bring problems such as drug interactions. Therefore, the development of FGFR dual target inhibitors is an important direction. In this paper, we reviewed the research on dual FGFR inhibitors in recent years and made brief comments on them.

Recent Advances in the Discovery of Multitargeted Tyrosine Kinase Inhibitors as Anticancer Agents

The treatment of cancer has been one of the most significant challenges for the medical field. Further research on the signal transduction pathway of tumor cells is driving the rapid development of antitumor agents targeting tyrosine kinases. However, most of the currently approved tyrosine kinase inhibitors based on the "single target/single drug" design are becoming less and less effective in the treatment of complex, heterogeneous, and multigenic cancers; this also results in resistance to chemotherapy. In contrast, multitargeted tyrosine kinase inhibitors (MT-TKIs) can effectively block multiple pathways of intracellular signal transduction. Therefore, they have therapeutic advantages over single-targeted inhibitors and have become a hotspot in antitumor drug research in recent years. This minireview summarizes recent advances in the discovery of MT-TKIs based on their chemical structures. In particular, we describe the kinase inhibitory and antitumor activity of promising compounds, as well as their structure - activity relationships (SARs).

Fibroblast growth factor receptor inhibitors: patent review (2015-2019)

Introduction: fibroblast growth factor receptors (FGFRs) are a family of tyrosine-kinase receptors whose signaling cascade regulates cellular proliferation, differentiation, and survival. Deregulation of the FGFR pathway is recognized as a driving factor in tumor development. On this basis, FGFR is an attractive target for anti-cancer small-molecule therapeutic agents.Areas covered: This review summarizes patent and literature publications spanning from 2015 to 2019 pertaining to small-molecule FGFR kinase inhibitors.Expert opinion: The first generation of non-covalent FGFR inhibitors is characterized by a broad spectrum of activity and a relatively high toxicity profile. The second generation of FGFR inhibitors shows higher selectivity and a more favorable toxicity profile, but the clinical use appears restricted only to small subsets of cancers strongly dependent on FGFR signaling. Nevertheless, erdafitinib has been approved for the treatment of metastatic urothelial carcinoma, becoming the first marketed selective FGFR inhibitor. The insurgence of mutant kinases, resistant to available therapies, has led to the development of irreversible FGFR inhibitors. The adoption of safer and more selective covalent inhibitors might supersede reversible inhibitors in specific therapeutic areas. Alternative strategies, such as FGF trapping by protein or small-molecule therapeutics, deserve attention and further investigations to unravel their potential.

Synthesis, biological evaluations and molecular modelling studies of novel indolin-2-ones designing as FGFR inhibitors

A series of novel 3,5-disubstituted indolin-2-ones were designed and synthesized as selective FGFR inhibitors. In the design process of 3,5-disubstituted indolin-2-ones for FGFRs, molecular docking studies were performed to generate and optimize novel compounds which have FGFR inhibitory potency, theoretically. In vitro enzyme inhibitory and selectivity profiles of the synthesized compounds, and their cytotoxicity against NIH-3T3 cells were evaluated. According to enzyme inhibition assay, compound A1 (FGFR1-4; IC50 = 19.82; 5.95; 1419; 37150 nM), compound A5 (FGFR1-4; IC50 = 1890; Nd; 6.50; 18590 nM) and compound A13 (FGFR1-4; IC50 = 6.99; 1022; 17090; 8993 nM) have displayed best inhibitory potency against FGFR2, FGFR3 and FGFR1, respectively. The studied compounds have displayed low affinity to FGFR4 in comparison with other isoforms. Molecular docking study data were used to determine the binding orientations of the synthesized compounds inside FGFRs in accordance with enzyme inhibition assay data. Molecular dynamics simulations and free energy calculations were performed to determine stability, binding modes and dynamics behaviors of compound A1, A5 and A13 inside FGFR-2, FGFR-3 and FGFR-1, respectively. The compounds bearing aromatic groups at the C5 position of indolin-2-one could be lead compounds for the development of more effective and selective FGFR1-3 inhibitors.

Sustainable Synthetic Approach for (Pyrazol-4-ylidene)pyridines By Metal Catalyst-Free Aerobic C(sp2)-C(sp3) Coupling Reactions between 1-Amino-2-imino-pyridines and 1-Aryl-5-pyrazolones

A novel, metal catalyst-free, and efficient method has been developed for the synthesis of (pyrazol-4-ylidene)pyridine derivatives. The process involves dehydrogenative coupling of 1-amino-2-imino-pyridines with 1-aryl-5-pyrazolone derivatives utilizing O2 as the sole oxidant. The new method benefits from a high atom economy, efficiency, and substrate scope, as well as the simplicity of reaction and product purification procedures.

Cascade Reaction of 1,1-Enediamines with 2-Benzylidene-1H-indene-1,3(2H)-diones: Selective Synthesis of Indenodihydropyridine and Indenopyridine Compounds

A concise and environmentally friendly route for the synthesis of diverse indenodihydropyridines (3) via a cascade reaction of 1,1-eneamines (1) with benzylidene-1H-indene-1,3(2H)-diones (BIDs) (2) in ethanol media was developed. The targeted compounds were efficiently obtained by only filtration without any further post-treatment. In the one-step cascade reaction, C-C and C-N bonds were constructed. In addition, when 1,4-dioxane was used as a solvent and the mixture of 1,1-eneamines (1) was refluxed with benzylidene-1H-indene-1,3(2H)-diones (BIDs) (2) for about 12 h, indenopyridine compounds (4) were produced. Two kinds of indenopyridine derivatives 3-4 resulted from alternative solvents and temperatures. The reaction had the following features: mild temperature, atom economy, high yields, and potential biological activity of the product.

Three-Component Cascade Reaction of 1,1-Enediamines, N,N-Dimethylformamide Dimethyl Acetal, and 1,3-Dicarbonyl Compounds: Selective Synthesis of Diverse 2-Aminopyridine Derivatives

A novel approach has been developed for the synthesis of three kinds of highly functionalized 2-aminopyridine derivatives (APDs) through a three-component reaction of 1,1-enediamines (EDAMs) 1, N,N-dimethylformamide dimethyl acetal (DMF-DMA) 2, and 1,3-dicarbonyl compounds 3-5 via a base-promoted cascade reaction, producing the desired products in good to excellent yields. This method represents a route to obtain a novel class of APDs in a concise, rapid, and practical manner. This approach is particularly attractive because of the following features: low cost, mild temperature, atom economy, high yields, and potential biological activity of the product.

l-Proline catalyzed one-pot synthesis of polysubstituted pyridine system incorporating benzothiazole moiety via sustainable sonochemical approach

The efficient, highly convenient synthesis of polysubstituted pyridine derivatives was established via the reaction of N-(benzothiazol-2-yl)-2-cyanoacetamides with an assortment of arylidene malononitriles and arylidene ethyl cyanoacetates in the presence of l-proline as an efficient organocatalyst for this type of ultrasonic-mediated Michael addition. The mechanistic pathway and factors affecting this reaction were also established. The main characteristics of this procedure are high yields, use of a cost-effective catalyst, and easy work-up and purification.