Novel benzimidazole analogs as inhibitors of EGFR tyrosine kinase

Recent advances of benzimidazole as anticancer agents

Cancer is the second leading cause of death globally, with 9.6 million deaths yearly. As a life-threatening disease, it necessitates the emergence of new therapies. Resistance to current chemotherapies drives scientists to develop new medications that will eventually be accessible. Because heterocycles are so common in biological substances, compounds play a big part in the variety of medications that have been developed. The "Master Key" is the benzimidazole nucleus, which consists of a six-membered benzene ring fused with a five-membered imidazole/imidazoline ring, which is an azapyrrole. One of the five-membered aromatic nitrogen heterocycles identified in American therapies that have been approved by the Food and Drug Administration (FDA). Our results show that benzimidazole's broad therapeutic spectrum is due to its structural isosteres with purine, which improves hydrogen bonding, electrostatic interactions with topoisomerase complexes, intercalation with DNA, and other functions. It also enhances protein and nucleic acid inhibition, tubulin microtubule degeneration, apoptosis, DNA fragmentation, and other functions. Additionally, readers for designing the more recent benzimidazole analogues as prospective cancer treatments.

A Review of Approaches to the Metallic and Non-Metallic Synthesis of Benzimidazole (BnZ) and Their Derivatives for Biological Efficacy

Heterocyclic compounds are significant lead drug candidates based on their various structure-activity relationships (SAR), and their use in pharmaceutics is constantly developing. Benzimidazole (BnZ) is synthesized by a condensation reaction between benzene and imidazole. The BnZ structure consists of two nitrogen atoms embedded in a five-membered imide ring which is fused with a benzene ring. This review examines the conventional and green synthesis of metallic and non-metallic BnZ and their derivatives, which have several potential SARs, along with a wide range of pharmacological properties, including anti-cancer, anti-inflammatory, anti-microbial, anti-tubercular, and anti-protozoal properties. These compounds have been proven by pharmacological investigations to be efficient against different strains of microbes. Therefore, in this review, the structural variations of BnZ are listed along with various applications, predominantly related to their biological activities.

Search for potentially biased epidermal growth factor receptor (EGFR) inhibitors through pharmacophore modelling, molecular docking, and molecular dynamics (MD) simulation approaches

Epidermal growth factor receptor (EGFR), being one of the most crucial receptor in cancer therapy, has been selected as a potential target for the present study. Ligand-based pharmacophore model (n = 30, R²=0.93 with root mean square deviation = 1.14, ΔCost = 144.27 and configuration cost = 21) was developed and validated with Fischer's randomisation (at 95% confidence), test set (n = 225, R² pred = 0.81), external data set (n = 13, R² pred = 0.95) and decoy set (n = 70), further the model has been used to search for novel EGFR inhibitors. The validated model was used for virtual screening of zinc database. A pool of 115,948 candidate molecules was screened through the model. Subsequently, molecules having predicted IC₅₀<0.2 µM were selected for screening through drug-like properties filter. Based on pharmacokinetic profile (ADMET study), Lipinski's rule of five and Veber's rule, 62 molecules were shortlisted for molecular docking. Using consensus docking, five hit molecules were selected, which were further considered for molecular dynamics simulation. Additionally MM-GBSA analysis was carried which showed that affinity of hits towards the receptor of three compound mainly ZINC305, ZINC131796 and ZINC131785 were similar to the standard vanedtinib. The simulation, performed for 100 ns, revealed that two hit molecules, namely ZINC305 and ZINC131785, showing potential interactions at the ligand-binding domain of EGFR protein with good ligand-protein stability. Communicated by Ramaswamy H. Sarma.

Design and synthesis of novel N-[3-(benzimidazol-2-ylamino)phenyl]amine and N-[3-(benzoxazol-2-ylamino)phenyl]amine derivatives as potential anticancer agents

In this contribution, we report the design, synthesis and cytotoxicity studies of a series of N-[3-(benzimidazol-2-yl-amino)phenyl]amine and N-[3-(benzoxazol-2-ylamino)phenyl]amine derivatives. In vitro cytotoxicity assay of 26 selected compounds was carried out at National Cancer Institute (NCI), USA. Out of them, compounds 10e (NSC D-762842/1) and 11s (NSC D-764942/1) have shown remarkable cytotoxicity with GI₅₀ values ranging between "0.589-14.3 µM" and "0.276-12.3 µM," respectively, in the representative nine subpanels of human tumor cell lines. Further, flow cytometry analysis demonstrated that compound 10e exerted cell cycle arrest at G2/M phase and showed dose-dependent enhancement in apoptosis in K-562 leukemia cancer cells.

Ruthenium Complexes with 2-Pyridin-2-yl-1H-benzimidazole as Potential Antimicrobial Agents: Correlation between Chemical Properties and Anti-Biofilm Effects

Antimicrobial resistance is a growing public health concern that requires urgent action. Biofilm-associated resistance to antimicrobials begins at the attachment phase and increases as the biofilms maturate. Hence, interrupting the initial binding process of bacteria to surfaces is essential to effectively prevent biofilm-associated problems. Herein, we have evaluated the antibacterial and anti-biofilm activities of three ruthenium complexes in different oxidation states with 2-pyridin-2-yl-1H-benzimidazole (L1 = 2,2'-PyBIm): [(η6-p-cymene)RuIIClL1]PF6 (Ru(II) complex), mer-[RuIIICl3(CH3CN)L1]·L1·3H2O (Ru(III) complex), (H2L1)2[RuIIICl4(CH3CN)2]2[RuIVCl4(CH3CN)2]·2Cl·6H2O (Ru(III/IV) complex). The biological activity of the compounds was screened against Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa strains. The results indicated that the anti-biofilm activity of the Ru complexes at concentration of 1 mM was better than that of the ligand alone against the P. aeruginosa PAO1. It means that ligand, in combination with ruthenium ion, shows a synergistic effect. The effect of the Ru complexes on cell surface properties was determined by the contact angle and zeta potential values. The electric and physical properties of the microbial surface are useful tools for the examined aggregation phenomenon and disruption of the adhesion. Considering that intermolecular interactions are important and largely define the functions of compounds, we examined interactions in the crystals of the Ru complexes using the Hirshfeld surface analysis.

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.

Synthesis and Pharmacologic Evaluation of Some Benzimidazole Acetohydrazide Derivatives as EGFR Inhibitors

Objectives

In this study, some novel 2-(2-phenyl)-1H-benzo[d]imidazol-1-yl)-N'-(arylmethylene) acetohydrazide derivatives (1-12) were designed and synthesized.

Materials and Methods

Compounds 1-12 were obtained by condensing 2-(2-phenyl)-1H-benzo[d]imidazol-1-yl)acetohydrazide (III) with the corresponding aromatic aldehyde derivatives in the presence of catalytic amounts of hydrochloric acid in ethanol.

Results

Following the structure elucidation, epidermal growth factor receptor kinase inhibitor activity was measured. The ADP-Glo^TM kinase assay determines kinase activity based on the quantification of the amount of ADP produced during a kinase reaction.

Conclusion

Almost all of the compounds' kinase inhibitor activities were rather limited.

Benzimidazole Scaffold as Anticancer Agent: Synthetic Approaches and Structure-Activity Relationship

Cancer, also known as malignant neoplasm, is a dreadful disease which involves abnormal cell growth having the potential to invade or spread to other parts of the body. Benzimidazole is an organic compound that is heterocyclic and aromatic in nature. It is a bicyclic compound formed by the fusion of the benzene and imidazole ring systems. It is an important pharmacophore and a privileged structure in medicinal chemistry. According to the World Health Organisation (2015 survey), one in six deaths is due to cancer around the globe, accounting for 8.8 million deaths of which 70% of the cases were from low- and middle-income countries. In the efforts to develop suitable anticancer drugs, medicinal chemists have focussed on benzimidazole derivatives. This review article covers the current development of benzimidazole-based anticancer agents along with the synthetic approaches and structure-activity relationships (SAR).

Ruthenium(ii)-catalyzed C–H alkenylation/annulation cascade for the rapid synthesis of benzoimidazoisoindoles

A one pot synthesis of benzimidazole-fused isoindoles from 2-arylbenzimidazole and conjugated alkenes has been explored. The strategy involved the ruthenium-catalyzed formation of C–C and C–N bonds and a new five-membered ring.

A benzimidazole derivative exhibiting antitumor activity blocks EGFR and HER2 activity and upregulates DR5 in breast cancer cells

Aberrant expression or function of epidermal growth factor receptor (EGFR) or the closely related human epidermal growth factor receptor 2 (HER2) can promote cell proliferation and survival, thereby contributing to tumorigenesis. Specific antibodies and low-molecular-weight tyrosine kinase inhibitors of both proteins are currently in clinical trials for cancer treatment. Benzimidazole derivatives possess diverse biological activities, including antitumor activity. However, the anticancer mechanism of 5a (a 2-aryl benzimidazole compound; 2-chloro-N-(2-p-tolyl-1H-benzo[d]imidazol-5-yl)acetamide, C₁₆H₁₄ClN₃O, MW299), a novel 2-aryl benzimidazole derivative, toward breast cancer is largely unknown. Here, we demonstrate that 5a potently inhibited both EGFR and HER2 activity by reducing EGFR and HER2 tyrosine phosphorylation and preventing downstream activation of PI3K/Akt and MEK/Erk pathways in vitro and in vivo. We also show that 5a inhibited the phosphorylation of FOXO and promoted FOXO translocation from the cytoplasm into the nucleus, resulting in the G1-phase cell cycle arrest and apoptosis. Moreover, 5a potently induced apoptosis via the c-Jun N-terminal kinase (JNK)-mediated death receptor 5 upregulation in breast cancer cells. The antitumor activity of 5a was consistent with additional results demonstrating that 5a significantly reduced tumor volume in nude mice in vivo. Analysis of the primary breast cancer cell lines with HER2 overexpression further confirmed that 5a significantly inhibited Akt Ser473 and Bad Ser136 phosphorylation and reduced cyclin D3 expression. On the basis of our findings, further development of this 2-aryl benzimidazole derivative, a new class of multitarget anticancer agents, is warranted and represents a novel strategy for improving breast cancer treatment.