Discovery of N-(2-phenyl-1H-benzo[d]imidazol-5-yl)quinolin-4-amine derivatives as novel VEGFR-2 kinase inhibitors

In silico insights into design of novel VEGFR-2 inhibitors: SMILES-based QSAR modelling, and docking studies on substituted benzo-fused heteronuclear derivatives

Eight QSAR models (M1-M8) were developed from a dataset of 118 benzo-fused heteronuclear derivatives targeting VEGFR-2 by Monte Carlo optimization method of CORALSEA 2023 software. Models were generated with hybrid optimal descriptors using both SMILES and Graphs with zero- and first-order Morgan extended connectivity index from a training set of 103 derivatives. All statistical parameters for model validation were within the prescribed limits, establishing the models to be robust and of excellent quality. Among all models, split-2 of M5 was the best-fit as reflected by   r v a lidation 2 ,   Q v a lidation 2 and MAE . Mechanistic interpretation of this model assisted the identification of structural descriptors as promoters and hinderers for VEGFR-2 inhibition. These descriptors were utilized to design novel VEGFR-2 inhibitors (YS01-YS07) by bringing modifications in compound MS90 in the dataset. Docking of all designed compounds, MS90 and sorafenib with VEGFR-2 binding site revealed favourable binding interactions. Docking score of YS07 was higher than that of MS90 and sorafenib. Molecular dynamics simulation study revealed sustained interactions of YS07 with key amino acids of VEGFR-2 at a run time of 100 ns. This study concludes the development of a best fit QSAR model which can assist the design of new anticancer agents targeting VEGFR-2.

Recent development of multi-target VEGFR-2 inhibitors for the cancer therapy

Vascular epidermal growth factor receptor-2 (VEGFR-2), as an important tyrosine transmembrane protein, plays an important role in regulating endothelial cell proliferation and migration, regulating angiogenesis and other biological functions. VEGFR-2 is aberrantly expressed in many malignant tumors, and it is also related to the occurrence, development, and growth of tumors and drug resistance. Currently, there are nine VEGFR-2 targeted inhibitors approved by US.FDA for clinical use as anticancer drugs. Due to the limited clinical efficacy and potential toxicity of VEGFR inhibitors, it is necessary to develop new strategies to improve the clinical efficacy of VEGFR inhibitors. The development of multitarget therapy, especially dual-target therapy, has become a hot research field of cancer therapy, which may provide an effective strategy with higher therapeutic efficacy, pharmacokinetic advantages and low toxicity. Many groups have reported that the therapeutic effects could be improved by simultaneously inhibiting VEGFR-2 and other targets, such as EGFR, c-Met, BRAF, HDAC, etc. Therefore, VEGFR-2 inhibitors with multi-targeting capabilities have been considered to be promising and effective anticancer agents for cancer therapy. In this work, we reviewed the structure and biological functions of VEGFR-2, and summarized the drug discovery strategies, and inhibitory activities of VEGFR-2 inhibitors with multi-targeting capabilities reported in recent years. This work might provide the reference for the development of VEGFR-2 inhibitors with multi-targeting capabilities as novel anticancer agents.

Discovery of novel conjugates of quinoline and thiazolidinone urea as potential anti-colorectal cancer agent

Based on the obtained SARs, further structural optimisation of compound BC2021-104511-15i was conducted in this investigation, and totally ten novel quinoline derivates were designed, synthesised and optimised for biological activity. Among them, compound 10a displayed significant in vitro anticancer activity against COLO 205 cells with an IC₅₀ value of 0.11 μM which was over 90-fold more potent than that of Regorafenib (IC₅₀>10.0 μM) and Fruquintinib (IC₅₀>10.0 μM). Furthermore, compound 10a exhibited over 90-fold selectivity towards COLO 205 relative to human normal colorectal mucosa epithelial cell FHC cells. Flow cytometry study demonstrated that compound 10a could induce apoptosis in COLO 205 cells, however, it could not induce cell cycle arrest in COLO 205 cells. The results of preliminary kinase profile study showed that compound 10a was a potential HGFR and MST1R dual inhibitor, with IC₅₀ values of 0.11 μM and 0.045 μM, respectively.

Pharmacophore Modeling of Targets Infested with Activity Cliffs via Molecular Dynamics Simulation Coupled with QSAR and Comparison with other Pharmacophore Generation Methods: KDR as Case Study

Activity cliffs (ACs) are defined as pairs of structurally similar compounds with large difference in their potencies against certain biotarget. We recently proposed that potent AC members induce significant entropically-driven conformational modifications of the target that unveil additional binding interactions, while their weakly-potent counterparts are enthalpically-driven binders with little influence on the protein target. We herein propose to extract pharmacophores for ACs-infested target(s) from molecular dynamics (MD) frames of purely "enthalpic" potent binder(s) complexed within the particular target. Genetic function algorithm/machine learning (GFA/ML) can then be employed to search for the best possible combination of MD pharmacophore(s) capable of explaining bioactivity variations within a list of inhibitors. We compared the performance of this approach with established ligand-based and structure-based methods. Kinase inserts domain receptor (KDR) was used as a case study. KDR plays a crucial role in angiogenic signaling and its inhibitors have been approved in cancer treatment. Interestingly, GFA/ML selected, MD-based, pharmacophores were of comparable performances to ligand-based and structure-based pharmacophores. The resulting pharmacophores and QSAR models were used to capture hits from the national cancer institute list of compounds. The most active hit showed anti-KDR IC50 of 2.76 µM.

Synthesis, biological evaluation, and molecular docking of new series of antitumor and apoptosis inducers designed as VEGFR-2 inhibitors

Based on quinazoline, quinoxaline, and nitrobenzene scaffolds and on pharmacophoric features of VEGFR-2 inhibitors, 17 novel compounds were designed and synthesised. VEGFR-2 IC₅₀ values ranged from 60.00 to 123.85 nM for the new derivatives compared to 54.00 nM for sorafenib. Compounds 15_a, 15_b, and 15_d showed IC₅₀ from 17.39 to 47.10 µM against human cancer cell lines; hepatocellular carcinoma (HepG2), prostate cancer (PC3), and breast cancer (MCF-7). Meanwhile, the first in terms of VEGFR-2 inhibition was compound 15_d which came second with regard to antitumor assay with IC₅₀ = 24.10, 40.90, and 33.40 µM against aforementioned cell lines, respectively. Furthermore, Compound 15_d increased apoptosis rate of HepG2 from 1.20 to 12.46% as it significantly increased levels of Caspase-3, BAX, and P53 from 49.6274, 40.62, and 42.84 to 561.427, 395.04, and 415.027 pg/mL, respectively. Moreover, 15_d showed IC₅₀ of 253 and 381 nM against HER2 and FGFR, respectively.

Research Progresses of Targeted Therapy and Immunotherapy for Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors worldwide, with nearly one million new cases and deaths every year. Owing to the complex pathogenesis, hidden early symptoms, rapidly developing processes, and poor prognosis, the morbidity and mortality of HCC are increasing yearly. With the progress being made in modern medicine, the treatment of HCC is no longer limited to traditional methods. Targeted therapy and immunotherapy have emerged to treat advanced and metastatic HCC in recent years. Since Sorafenib is the first molecular targeting drug against angiogenesis, targeted drugs for HCC are continually emerging. Moreover, immunotherapy plays a vital role in clinical trials. In particular, the application of immune checkpoint inhibitors, which have received increasing attention in the field of cancer treatment, is a possible research path. Interestingly, these two therapies generally complement each other at some stages of HCC, bringing new hope for patients with advanced HCC. In this paper, we discuss the research progress of targeted therapy and immunotherapy for HCC in recent years, which will provide a reference for the further development of drugs for HCC.

Design, synthesis and molecular modeling of new quinazolin-4(3H)-one based VEGFR-2 kinase inhibitors for potential anticancer evaluation

Globally cancer is the second leading cause of death. So that this work is an attempt to develop new effective anti-cancer agents. In line with pharmacophoric features of VEGFR-2 kinase inhibitors, new nineteen quinazolin-4-one derivatives were designed, synthesized and biologically evaluated for their potential anticancer activity. All target compounds were evaluated in vitro for VEGFR-2 tyrosine kinase inhibition. Then, nine compounds of best results were further investigated by in vitro assay against three human cancer cell lines, namely HepG2, PC3 and MCF. N^'-{2-](3-Ethyl-6-nitro-4-oxo-3,4-dihydroquinazoline-2-yl)thio[acetyl}benzohydrazide (36) was found to be the most potent candidate as it showed IC₅₀ = 4.6 ± 0.06 µM against VEGFR-2 kinase. It also exhibited IC₅₀ = 17.23 ± 1.5, 26.10 ± 2.2 and 30.85 ± 2.3 µg/mL against HepG2, PC3 and MCF, respectively. At the same time it showed IC₅₀ = 145.93 ± 1.1 µg/mL against the normal human lung fibroblasts cell line (WI-38), indicating good selectivity index. Further investigation into HepG2 cell cycle showed the ability of compound 36 to induce apoptosis and arrest cell growth at G2/M phase. Moreover, docking studies demonstrated the ability of compound 36 to bind VEGFR-2 in a correct manner making three essential hydrogen bonds with the key residues Glu885, Asp1046 and Cys919. In sum, this work suggests that compound 36 can serve as a lead for development of effective anticancer agents targeting VEGFR-2.

Recent Progress of Benzimidazole Hybrids for Anticancer Potential

This review presents the detailed account of factors leading to cancer and design strategy for the synthesis of benzimidazole derivatives as anticancer agents. The recent survey for cancer treatment in Cancer facts and figures 2017 American Chemical Society has shown progressive development in fighting cancer. Researchers all over the world in both developed and developing countries are in a continuous effort to tackle this serious concern. Benzimidazole and its derivatives showed a broad range of biological activities due to their resemblance with naturally occurring nitrogenous base i.e. purine. The review discussed benzimidazole derivatives showing anticancer properties through a different mechanism viz. intercalation, alkylating agents, topoisomerases, DHFR enzymes, and tubulin inhibitors. Benzimidazole derivatives act through a different mechanism and the substituents reported from the earlier and recent research articles are prerequisites for the synthesis of targeted based benzimidazole derivatives as anticancer agents. The review focuses on an easy comparison of the substituent essential for potency and selectivity through SAR presented in figures. This will further provide a better outlook or fulfills the challenges faced in the development of novel benzimidazole derivatives as anticancer.

Versatile mechanisms of 2-substituted benzimidazoles in targeted cancer therapy

Background

The aim of this review is to provide an overview on diverse anticancer activities of 2-substituted benzimidazole derivatives.

Main body

This review provides a correlation between the various mechanisms of action of benzimidazoles as anticancer and the substitution pattern around the nucleus.

Conclusion

The linker group and substitution at N-1, C-2, C-5, and C-6 positions have been found to be the most contributory factors for anticancer activity. This will help in the further design to afford more selective, potent, and multi-target anticancer of 2-substituted benzimidazole-based compounds.

Discovery of arylamide-5-anilinoquinazoline-8-nitro derivatives as VEGFR-2 kinase inhibitors: Synthesis, in vitro biological evaluation and molecular docking

Herein, we embarked on a structural optimization campaign aiming at the discovery of novel anticancer agents with our previously reported XL-6f as a lead compound. A library of 23 compounds has been synthesized based on the highly conserved active site of VEGFR-2. Several title compounds exhibited selective inhibitory activities against VEGFR-2, which also displayed selective anti-proliferation potency against HepG2 cell. All synthesized compounds were evaluated for anti-angiogenesis capability. Compound 7o showed the most potent anti-angiogenesis ability, the efficient cytotoxic activities (in vitro against HUVEC and HepG2 cell lines with IC₅₀ values of 0.58 and 0.23 µM, respectively). The molecular docking analysis revealed 7o is a Type-II inhibitor of VEGFR-2 kinase. In general, these results indicated these arylamide-5-anilinoquinazoline-8-nitro derivatives are promising inhibitors of VEGFR-2 for the potential treatment of anti-angiogenesis.

Switchable Access to Amines and Imines from Reductive Coupling of Nitroarenes with Alcohols Catalyzed by Biomass-Derived Cobalt Nanoparticles

Cobalt nanoparticles modified with N-doped hierarchical porous carbon derived from biomass are found to be a highly efficient, reusable heterogeneous catalyst for the coupling of nitroarenes with alcohols, selectively affording imines and amines via the borrowing hydrogen strategy for the first time. The product selectivity between imine and amine may be precisely tuned by simple alteration of the reaction conditions without changing the catalyst in one reaction system. In this study, a broad set of complex imines and amines was successfully synthesized in good to high yields with various functional groups tolerated for both nitroarenes and alcohols, highlighting the potentially practical utility of the protocol. This heterogeneous catalyst can be easily removed from the reaction medium by external magnet and can be reused at least four times without significant loss in activity and selectivity.

Synthesis and cytotoxic evaluation of novel quinozalinone derivatives with substituted benzimidazole in position 3

Quinazolinone and benzimidazole are both fused heterocyclic compounds which have shown valuable biological properties including cytotoxic, antibacterial, and antifungal activities. In this study, a series of novel quinazolinone derivatives substituted with benzimidazole were synthesized in two parts. In the first part 2 - phenyl - 1H - benzimidazol - 6 - amine (4) was synthesized from the reaction of 4-nitro-o-phenylenediamine and benzoic acid. In the second part, new 3-(2-phenyl-1H benzoimidazol-5-yl)- 3H-quinazolin-4-one derivatives (8a-8f) were also prepared. Finally compound 4 was reacted with the different benzoxazinone derivatives (8a-8f) to give the target compounds. The structures of the synthesized compounds were confirmed by IR and ¹HNMR. Cytotoxic activities of the final compounds were assessed at 100, 200, 300, 400, and 500 μM against MCF-7 and HeLa cell lines using the MTT colorimetric assay. Almost all compounds exhibited good cytotoxic activity against both cell lines. Compound 9d demonstrated the highest cytotoxic activity against MCF7 and Hela cell lines with IC₅₀ 70 μM and 50 μM, respectively.

Metal Nanoparticles Supported on Biomass-Derived Hierarchical Porous Heteroatom-Doped Carbon from Bamboo Shoots: Design, Synthesis and Applications

Heteroatom-doped porous carbon derived from biomass have recently received increasing attention due to their unique properties such as high electrical conductivity, large specific surface area, high porosity, and easy availability, which are appealing materials for versatile applications in catalysis, energy, separation and adsorption, and life sciences as well. On the basis of our previous work in this field, we summarized in this account our recent progress on design, synthesis of metal (e. g., Pd, Co) nanoparticles supported heteroatom-doped hierarchical porous carbon material derived from bamboo shoots and their applications for important organic transformations, including chemoselective semihydrogenation of alkynes, hydrosilylation of alkynes, cascade synthesis of benzofurans from terminal alkynes and iodophenols, selective hydrogenation of functionalized nitroarenes to form anilines, imines, and formamides. Finally, the current state and future challenges in this field are discussed. We hope this account could shed light on the rational design of novel non-noble metal based heterogeneous catalysts derived from biomass for efficient and sustainable organic transformations.

Identification of new pyrrolo[2,3-d]pyrimidines as potent VEGFR-2 tyrosine kinase inhibitors: Design, synthesis, biological evaluation and molecular modeling

Vascular endothelial growth factor receptor-2 (VEGFR-2) plays a crucial role in cancer angiogenesis. In the current study, a series of novel pyrrolo[2,3-d]pyrimidine based-compounds was designed and synthesized as VEGFR-2 inhibitors, in accordance to the structure activity relationship (SAR) studies of known type II VEGFR-2 inhibitors. The newly synthesized compounds were evaluated for their ability to inhibit VEGFR-2 kinase enzyme in vitro. All the tested compounds demonstrated highly potent dose-related VEGFR-2 inhibition with IC₅₀ values in nanomolar range. Among these compounds, pyrrolo[2,3-d]pyrimidine derivatives carrying biaryl urea moieties (12d and 15c) exhibited IC₅₀ values of 11.9 and 13.6 nM respectively. Additionally, most of the newly synthesized final compounds were tested on 60 human cancer cell lines. Docking of these compounds into the inactive conformation of VEGFR-2 was performed which showed comparable binding modes to that of the FDA approved VEGFR-2 kinase inhibitors. These newly discovered potent kinase inhibitors could be considered as potential candidates for the development of new targeted anticancer agent.

A practical multi-step synthesis of ethyl N-functionalized [Formula: see text]-amino benzimidazole acrylate derivatives as promising cytotoxic agents

A series of 16 new ethyl [Formula: see text]-amino benzimidazole acrylate derivatives 12(a-p) with a (2E)-s-cis/trans conformation and bearing two points of diversity was designed and synthesized by using a multi-step strategy (reductive amination, deprotection in acidic media and transamination) in moderate to good yields from ethyl 3-dimethylamino-2-(1H-benzimidazol-2-yl)acrylate (5) and monosubstituted N-Boc diamines (7a,7b) as starting building blocks. Products 12 were evaluated for their in vitro cytotoxic potential against six selected human cell lines (Huh7-D12, Caco2, MDA-MB231, HCT116, PC3 and NCI-H727). Compounds 12a, 12e and 12l exhibited selective and micromolar antitumor activities against Huh7-D12 and Caco2 cell lines.

Design, synthesis and molecular modeling study for some new 2-substituted benzimidazoles as dual inhibitors for VEGFR-2 and c-Met

Aim: Computer-aided drug design techniques were adopted to design three series of 2-substituted-5-nitrobenzimidazole derivatives hybridized with piperzine 5a,b, oxadiazole 7a,b, 9, 14a–c and triazolo-thiadiazole moieties 12a–d, as VEGFR-2/c-Met kinase inhibitors. Materials & methods: The designed compounds were synthesized adopting the chemical pathways outlined in schemes 1 and 2 to afford the desired three series followed by evaluating their inhibitory activities against VEGFR-2 and c-Met and in vitro anticancer activities. Result: Analogs bearing substituted phenyl ring attached to oxadiazole ring 14a showed the greatest inhibitory activities against non-small-cell lung cancer NCI-H522 and melanoma SK-MEL-2 with inhibition percent of 48.70 and 42.62, respectively. Moreover, unsubstituted phenoxymethyl derivative 12d exhibited promising inhibitory activity against VEGFR-2 and c-Met (35.88 and 88.48%), respectively. Conclusion: The above results revealed that 2-substituted-5-nitrobenzimidazole hybridized with various heterocyclic scaffolds could be a potential anticancer agent.

Therapeutic evolution of benzimidazole derivatives in the last quinquennial period

Benzimidazole, a fused heterocycle bearing benzene and imidazole has gained considerable attention in the field of contemporary medicinal chemistry. The moiety is of substantial importance because of its wide array of pharmacological activities. This nitrogen containing heterocycle is a part of a number of therapeutically used agents. Moreover, a number of patents concerning this moiety in the last few years further highlight its worth. The present review covers the recent work published by scientists across the globe during last five years.

Design, synthesis and biological evaluation of N-phenylquinazolin-4-amine hybrids as dual inhibitors of VEGFR-2 and HDAC

A single agent that simultaneously inhibits multiple targets may offer greater therapeutic benefits in cancer than single-acting agents through interference with multiple pathways and potential synergistic action. In this work, a series of hybrids bearing N-phenylquinazolin-4-amine and hydroxamic acid moieties were designed and identified as dual VEGFR-2/HDAC inhibitors. Compound 6fd exhibited the most potent inhibitory activity against HDAC with IC50 of 2.2 nM and strong inhibitory effect against VEGFR-2 with IC50 of 74 nM. It also showed the most potent inhibitory activity against a human breast cancer cell line MCF-7 with IC50 of 0.85 μM. Docking simulation supported the initial pharmacophoric hypothesis and suggested a common mode of interaction at the active binding sites of VEGFR-2 and HDLP ((Histone Deacetylase-Like Protein), which demonstrates that compound 6fd is a potential agent for cancer therapy deserving further researching.

Predicting hydration propensities of biologically relevant α-ketoamides

Quantum chemical calculations coupled to experiments were used to predict covalent hydration propensities of biologically relevant α-ketoamides. Experimentally determined hydration equilibrium constants for related ketones and aldehydes were compared to computationally determined values to develop a method for predicting hydration equilibrium constants. This method was used on six newly synthesized α-ketoamides to experimentally verify computational predictions. A correlation between calculation and experiment was observed and applied to models of several pertinent APIs. Our results indicate that the keto form is favored for practically all α-ketoamides in biological environs.

Discovery of new 4-alkoxyquinazoline-based derivatives as potent VEGFR2 inhibitors

VEGFR2 has been proved to play a major role in the regulation of tumor angiogenesis. Twenty-one 4-alkoxyquinazoline-based derivatives have been designed and synthesized as vascular endothelial growth factor receptor 2 (VEGFR2) inhibitors, and their biological activities were evaluated. Among these compounds, compound 3h exhibited the most potent inhibitory activities against VEGFR2 tyrosine kinase and cell proliferation, with the IC50 values of 2.89 nm (for VEGFR2) and 0.25 μm (for MCF-7), which were comparable with the control compound. Docking simulation was performed to position compound 3h into the 4ASE active site, and the result showed that compound 3h could bind well at the 4ASE active site.

Discovery of biphenyl-based VEGFR-2 inhibitors. Part 3: design, synthesis and 3D-QSAR studies

VEGFR-2 plays an essential role in angiogenesis and is a central target for anticancer drug discovery. In order to develop novel VEGFR-2 inhibitors, we designed and synthesized 33 biphenyl amides based on our previously reported lead compound. The biological results indicated that four compounds (18b, 20e, 20h and 20j) are potent VEGFR-2 inhibitors which are comparable to positive control. Compound 18b displayed the most potent VEGFR-2 inhibition with IC50 value of 2.02nM. Moreover, it exhibited promising antiproliferative activity against MCF-7 and SMMC-7721 cells with IC50 values of 1.47μM and 5.98μM, respectively. Molecular docking and 3D-QSAR studies were also carried out. The results indicated that these biphenyl amides could serve as promising leads for further optimization as novel VEGFR-2 inhibitors.

Discovery of novel VEGFR-2 inhibitors. Part II: biphenyl urea incorporated with salicylaldoxime

A series of novel VEGFR-2 inhibitors containing oxime as hinge binding fragment were described. A strategy of pseudo six-membered ring formed through intramolecular hydrogen bond was employed to mimic the planar quinazoline. The oxime group was firstly introduced to interact with hinge region of VEGFR-2. Most of compounds tested showed moderate to high VEGFR-2 inhibitory activity. In particular, 12l, 12p and 12y exhibited significant enzymatic inhibitory activity as well as potent antiproliferative activity against cancer cells. Molecular docking suggested that the salicylaldoxime formed two hydrogen bonds with hinge region. These biphenylureas could serve as promising lead compounds for developing novel anticancer agents.