New Combretastatin Analogs as Anticancer Agents: Design, Synthesis, Microtubules Polymerization Inhibition, and Molecular Docking Studies

A new series of 4-(4-methoxyphenyl)-5-(3,4,5-trimethoxyphenyl)-4H-1,2,4-triazole-3-thiol derivatives were synthesized as analogs for the anticancer drug combretastatin A-4 (CA-4) and characterized using FT-IR, 1 H-NMR, 13 CNMR, and HR-MS techniques. The new CA-4 analogs were designed to meet the structural requirements of the highest expected anticancer activity of CA-4 analogs by maintaining ring A 3,4,5-trimethoxyphenyl moiety, and at the same time varying the substituents effect of the triazole moiety (ring B). In silico analysis indicated that compound 3 has higher total energy and dipole moment than colchicine and the other analogs, and it has excellent distribution of electron density and is more stable, resulting in an increased binding affinity during tubulin inhibition. Additionally, compound 3 was found to interact with three apoptotic markers, namely p53, Bcl-2, and caspase 3. Compound 3 showed strong similarity to colchicine, and it has excellent pharmacokinetics properties and a good dynamic profile. The in vitro anti-proliferation studies showed that compound 3 is the most cytotoxic CA-4 analog against cancer cells (IC50 of 6.35 μM against Hep G2 hepatocarcinoma cells), and based on its selectivity index (4.7), compound 3 is a cancer cytotoxic-selective agent. As expected and similar to colchicine, compound 3-treated Hep G2 hepatocarcinoma cells were arrested at the G2/M phase resulting in induction of apoptosis. Compound 3 tubulin polymerization IC50 (9.50 μM) and effect on Vmax of tubulin polymerization was comparable to that of colchicine (5.49 μM). Taken together, the findings of the current study suggest that compound 3, through its binding to the colchicine-binding site at β-tubulin, is a promising microtubule-disrupting agent with excellent potential to be used as cancer therapeutic agent.

New Niflumic Acid Derivatives as EGFR Inhibitors: Design, Synthesis, In Silico Studies, and Anti-proliferative Assessment

Background:

1,3,4-oxadizole and pyrazole derivatives, are very important scaffold for medicinal chemistry. Literature survey revealed that they possess wide spectrum of biological activities among which are anti-inflammatory and antitumor.

Objectives:

To describe the synthesis and evaluation of two classes of new niflumic acid (NF) derivatives, the 1,3,4-oxadizole derivatives (compounds 4AE) and pyrazole derivatives (compounds 5 and 6) as EGFR tyrosine kinase inhibitors in silico and in vitro.

Methods:

The designed compounds were synthesized using conventional organic synthesis methods. The antitumor activities of the new NF derivatives against HepG2 hepatocellular carcinoma and A549 non-small cell lung cancer cell lines were assessed in vitro via MTT assay, flow cytometry, RT-PCR, as well as via molecular docking studies.

Conclusion:

A series of niflumic acid derivatives (3, 4A-E, 5 and 6) were successfully created and FT-IR, 1H, 13CNMR, and HRMS were used to confirm their chemical structures. According to molecular docking studies, compounds 3, 5, and 6 have the highest docking scores (ΔG) and the majority of the tested compounds have a good pharmacokinetic profile. Results of compound 6 in vitro antitumor activities show that it is a promising EGFR tyrosine kinase inhibitor.