New 1,3,4-oxadiazole-chalcone/benzimidazole hybrids as potent antiproliferative agents

Design, synthesis, in silico studies, and apoptotic antiproliferative activity of novel thiazole-2-acetamide derivatives as tubulin polymerization inhibitors

Introduction

Tubulin polymerization inhibitors have emerged as interesting anticancer therapies. We present the design, synthesis, and structural elucidation of novel thiazole-based derivatives to identify novel tubulin inhibitors with potent antiproliferative efficacy and strong inhibition of tubulin polymerization.

Methods

The novel compounds consist of two scaffolds. Scaffold A compounds 10a-e and scaffold B compounds 13a-e. the structures of the newly synthesized compounds 10a-e and 13a-e were validated using 1H NMR, 13C NMR, and elemental analysis.

Results and Discussion

The most effective antitubulin derivative was 10a, exhibiting an IC50 value of 2.69 μM. Subsequently, 10o and 13d exhibited IC50 values of 3.62 μM and 3.68 μM, respectively. These compounds exhibited more potency than the reference combretastatin A-4, which displayed an IC50 value of 8.33 μM. These compounds had no cytotoxic effects on normal cells, preserving over 85% cell viability at 50 μM. The antiproliferative experiment demonstrated that compounds 10a, 10o, and 13d displayed significant activity against four cancer cell lines, with average GI50 values of 6, 7, and 8 μM, equivalent to the reference's doxorubicin and sorafenib. Compounds 10a, 10o, and 13d were demonstrated to activate caspases 3, 9, and Bax, while down-regulating the anti-apoptotic protein Bcl2. Molecular docking studies demonstrated superior binding affinities for 10a (-7.3 kcal/mol) at the colchicine binding site of tubulin, forming key hydrophobic and hydrogen bonding interactions that enhance its activity. ADMET analysis confirmed favorable drug-like properties, establishing these compounds as promising candidates for further development as anticancer agents targeting tubulin polymerization.

Benzimidazole scaffold as a potent anticancer agent with different mechanisms of action (2016-2023)

Benzimidazole scaffolds have potent anticancer activity due to their structure similarity to nucleoside. In addition, benzimidazoles could function as hydrogen donors or acceptors and bind to different drug targets that participate in cancer progression. The literature had many anticancer agents containing benzimidazole cores that gained much interest. Provoked by our endless interest in benzimidazoles as anticancer agents, we summarized the successful trials of the benzimidazole scaffolds in this concern. Moreover, we discuss the substantial opportunities in cancer treatment using benzimidazole-based drugs that may direct medicinal chemists for a compelling future design of more active chemotherapeutic agents with potential clinical applications. The uniqueness of this work lies in the highlighted benzimidazole scaffold hybridization with different molecules and benzimidazole-metal complexes, detailed mechanisms of action, and the IC50 of the developed compounds determined by different laboratories after 2015.

New antiproliferative 1,3,4-oxadiazole/benzimidazole derivatives: Design, synthesis, and biological evaluation as dual EGFR and BRAFV600E inhibitors

A new series of benzimidazole-oxadiazole-small molecules were synthesized and confirmed with various spectroscopic techniques. The prepared derivatives exhibited significant inhibitory activity against the proliferation of different cancer cells. The benzimidazoles 10f, 10 h, 10 g, and 10i showed broad anticancer activity with no selectivity in five-dose assays. All prepared compounds displayed potent inhibitory activity against proliferation of a panel of four human cancer cells (HT-29, Panc-1, MCF-7, and A-549) with IC50 values ranging from 24 nM to 80 nM and with significant safety profile against MCF-10 A normal cells. According to the mechanistic study, the most potent compounds (9a, 9b, 10e, 10f, & 10i) displayed remarkable inhibitory effectiveness against EGFR and BRAFV600E and were more potent than reference drugs erlotinib and vemurafenib. Molecular docking study for compounds 9a, 9b, 10e, 10f, and 10i agreed with mechanistic results.

Design, synthesis, antiproliferative activity, and molecular dynamics simulation of pyrazoline-based derivatives as dual EGFR and HER-2 inhibitors

The dual targeting of EGFR and HER2 is an established anticancer strategy. A novel series including two distinct scaffolds, A (chalcone-based compounds, 4a-n) and B (pyrazoline-based compounds, 5a-n), was developed and synthesized. The antiproliferative efficacy of 4a-n and 5a-n was examined against a panel of four cancer cell lines. The findings indicated that pyrazoline derivatives 5a-n exhibited more efficacy than chalcone compounds 4a-n. Compounds 4n, 5d, and 5g were identified as the most effective antiproliferative derivatives. These compounds were further investigated as dual EGFR/Her2 inhibitors. Compound 5d inhibited EGFR-TK and HER2 significantly, with IC50 values of 0.126 and 0.061 μM, respectively. Moreover, compound 5d can induce a percentage of pre-G1 apoptosis by 78.53% in cell cycle analysis and cause early apoptosis with necrosis percent of 5.28. Docking and MD simulation illustrated the significant cytotoxic activity of the 5d compound and how it can be a promising scaffold with anticancer activity.

Design and Synthesis of New Dihydropyrimidine Derivatives with a Cytotoxic Effect as Dual EGFR/VEGFR-2 Inhibitors

We developed and synthesized tetrahydropyrimidine derivatives as possible cytotoxic agents to inhibit EGFR and VEGFR-2 in the present study. Our study completely assesses the cytotoxic efficiency of pyrimidine-based derivatives 4-15 against various cancer cell lines, revealing derivatives 12 and 15 for their remarkable activity with GI50 values of 37 and 35 nM, respectively, when compared to the reference erlotinib (33 nM). In vitro enzyme assays showed that target compounds, particularly 12, 14, and 15, effectively inhibited EGFR and VEGFR-2. In vitro enzyme testing revealed that compound 15 was the most promising, with IC50 values of 84 and 3.50 nM for EGFR and VEGFR-2, respectively. Additionally, an in vitro assessment of the novel targets' apoptotic potential revealed that both pro-apoptotic and antiapoptotic behaviors were promising, indicating that the apoptotic induction pathway is a strongly proposed action method for the newly developed targets. Finally, molecular docking experiments are elaborately discussed to corroborate the exact binding interactions of the most active hybrids 12 and 15 with the EGFR and VEGFR-2 active sites.

Rational Design and Synthesis of Isatin-Chalcone Hybrids Integrated with 1H-1,2,3-Triazole: Anti-Proliferative Profiling and Molecular Docking Insights

In this study, a series of isatin-chalcone linked triazoles were synthesized using Cu-promoted Azide-Alkyne Cycloaddition (CuAAC) reaction and evaluated for their cytotoxicity against various cancer cell lines. The most potent compound displayed approximately 2.5 times greater activity compared to both reference compounds against ovarian cancer cell lines. These findings were supported by caspase-mediated apoptosis and molecular docking analyses. Docking revealed comparable VEGFR-2 affinities for 5 b and 5-FU but highlighted stronger interaction of 5 b with EGFR, evident from its lower docking score. Overall, these results signify the notable anti-proliferative potential of most synthesized hybrids, notably emphasizing the efficacy of compound 5 b in suppressing cancer cell growth.

Current scenario of chalcone hybrids with antibreast cancer therapeutic applications

Breast cancer, an epithelial malignant tumor that occurs in the terminal ducts of the breast, is the most common female malignancy. Currently, approximately 70%-80% of breast cancer with early-stage, nonmetastatic disorder is curable, but the emergency of drug resistance often leads to treatment failure. Moreover, advanced breast cancer with distant organ metastases is incurable with the available therapeutics, creating an urgent demand to explore novel antibreast cancer agents. Chalcones, the precursors for flavonoids and isoflavonoids, exhibit promising activity against various breast cancer hallmarks, inclusive of proliferation, angiogenesis, invasion, metastasis, inflammation, stemness, and regulation of cancer epigenetics, representing useful scaffolds for the discovery of novel antibreast cancer chemotherapeutic candidates. In particular, chalcone hybrids could act on two or more different biological targets simultaneously with more efficacy, lower toxicity, and less susceptibility to resistance. Accordingly, there is a huge scope for application of chalcone hybrids to tackle the present difficulties in breast cancer therapy. This review outlines the chalcone hybrids with antibreast cancer potential developed from 2018. The structure-activity relationships as well as mechanisms of action are also discussed to shed light on the development of more effective and multitargeted chalcone candidates.

Benzimidazole-Based Derivatives as Apoptotic Antiproliferative Agents: Design, Synthesis, Docking, and Mechanistic Studies

A new class of benzimidazole-based derivatives (4a-j, 5, and 6) with potential dual inhibition of EGFR and BRAFV600E has been developed. The newly synthesized compounds were submitted for testing for antiproliferative activity against the NCI-60 cell line. All newly synthesized compounds 4a-j, 5, and 6 were selected for testing against a panel of sixty cancer cell lines at a single concentration of 10 µM. Some compounds tested demonstrated remarkable antiproliferative activity against the cell lines tested. Compounds 4c, 4e, and 4g were chosen for five-dose testing against 60 human tumor cell lines. Compound 4c demonstrated strong selectivity against the leukemia subpanel, with a selectivity ratio of 5.96 at the GI50 level. The most effective in vitro anti-cancer assay derivatives (4c, 4d, 4e, 4g, and 4h) were tested for EGFR and BRAFV600E inhibition as potential targets for antiproliferative action. The results revealed that compounds 4c and 4e have significant antiproliferative activity as dual EGFR/BRAFV600E inhibitors. Compounds 4c and 4e induced apoptosis by increasing caspase-3, caspase-8, and Bax levels while decreasing the anti-apoptotic Bcl2 protein. Moreover, molecular docking studies confirmed the potential of compounds 4c and 4e to act as dual EGFR/BRAFV600E inhibitors.

Chalcone/1,3,4-Oxadiazole/Benzimidazole hybrids as novel anti-proliferative agents inducing apoptosis and inhibiting EGFR & BRAFV600E

INTRODUCTION

One of the most robust global challenges and difficulties in the 21st century is cancer. Treating cancer is a goal which continues to motivate researchers to innovate in design and development of new treatments to help battle the disease.

OBJECTIVES

Our objective was developing new antiapoptotic hybrids based on biologically active heterocyclic motifs "benzimidazole?oxadiazole-chalcone hybrids'' that had shown promising ability to inhibit EGFR and induce apoptosis. We expected these scaffolds to display anticancer activity via inhibition of BRAF, EGFR, and Bcl-2 and induction of apoptosis through activation of caspases.

METHODS

The new hybrids 7a-x were evaluated for their anti-proliferative, EGFR & BRAFV600E inhibitory, and apoptosis induction activities were detected. Docking study & dynamic stimulation into EGFR and BRAFV600E were studied.

RESULTS

All hybrids exhibited remarkable cell growth inhibition on the four tested cell lines with IC50 ranging from 0.95 μM to 12.50 μM. which was comparable to Doxorubicin. Compounds 7k-m had the most potent EGFR inhibitory activity. While, compounds 7e, 7g, 7k and 7l showed good inhibitory activities against BRAFV600E. Furthermore, Compounds 7k, 7l, and 7m increased Caspases 3,8 & 9, Cytochrome C and Bax levels and decreased Bcl-2 protein levels. Compounds 7k-m received the best binding scores and showed binding modes that were almost identical to each other and comparable with that of the co-crystalized Erlotinib in EGFR and BRAF active sites.

CONCLUSION

Compounds 7k-m could be used as potential apoptotic anti-proliferative agents upon further optimization.