Synthesis, In Silico Prediction, and In Vitro Evaluation of Anti-tumor Activities of Novel 4'-Hydroxybiphenyl-4-carboxylic Acid Derivatives as EGFR Allosteric Site Inhibitors.

INTRODUCTION: Allosteric inhibition of EGFR Tyrosine Kinase (TK) is currently among the most attractive approaches for designing and developing anti-cancer drugs to avoid chemoresistance exhibited by clinically approved ATP-competitive inhibitors. The current work aimed to synthesize new biphenyl-containing derivatives that were predicted to act as EGFR TK allosteric site inhibitors based on molecular docking studies. METHOD: A new series of 4'-hydroxybiphenyl-4-carboxylic acid derivatives, including hydrazine-1-carbothioamide (S3-S6) and 1,2,4-triazole (S7-S10) derivatives, were synthesized and characterized using IR, 1HNMR, 13CNMR, and HR-mass spectroscopy. Compound S4 had a relatively high pharmacophore-fit score, indicating that it may have biological activity similar to the EGFR allosteric inhibitor reference, and it scored a relatively low ΔG against EGFR TK allosteric site, indicating a high likelihood of drug-receptor complex formation. Compound S4 was cytotoxic to the three cancer cell lines tested, particularly HCT-116 colorectal cancer cells, with an IC50 value comparable to Erlotinib. Compound S4 induced the intrinsic apoptotic pathway in HCT-116 cells by arresting them in the G2/M phase. RESULT: All of the new derivatives, including S4, met the in silico requirements for EGFR allosteric inhibitory activity. CONCLUSION: Compound S4 is a promising EGFR tyrosine kinase allosteric inhibitor that warrants further research.

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 scaffolds for medicinal chemistry. A literature survey revealed that they possess a wide spectrum of biological activities including anti-inflammatory and antitumor effects. OBJECTIVES: To describe the synthesis and evaluation of two classes of new niflumic acid (NF) derivatives, the 1,3,4-oxadizole derivatives (compounds 3 and (4A-E) 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. RESULTS: The cytotoxicity results indicated that the newly synthesized NF derivatives were cytotoxic against the two cancer cell lines, with compound 6 being the most cytotoxic, achieving the lowest IC50 concentration. Furthermore, compound 6 targeted EGFR tyrosine kinase leading to cell cycle arrest at the G2/M cell cycle phase and induction of apoptosis. The in vitro biological investigation results matched those of the molecular docking analysis. In conclusion, the new NF derivatives, specifically compound 6, exhibited favorable pharmacokinetic features and are promising EGFR tyrosine kinase inhibitors. 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 most tested compounds have a good pharmacokinetic profile. Results of compound 6 in vitro antitumor activities showed that it is a promising EGFR tyrosine kinase inhibitor.}