Novel Schiff Bases: Synthesis, Characterization, Bioactivity, Cytotoxicity, and Computational Evaluations

Abstract

Hypopharyngeal cancer is rare subtype of head and neck cancers with relatively poor prognosis. Current therapeutic modalities lack the potential to provide patients with better clinical outcome and quality of life. This study was conducted on the synthesis of 2-methoxy-4-((3-alkyl(aryl)-5-oxo-1H-1,2,4-triazol-4(5H)-ylimino)-methyl)-phenyl-4-(2-methoxy-4-((3-alkyl(aryl)-5-oxo-1H-1,2,4-triazol-4(5H)-ylimino)-methyl)-phenyl)-4-oxobutanoates (3) using biologically important 1,2,4-triazole. The condensation of 3-alkyl(aryl)-4-amino-4,5-dihydro-1H-1,2,4-triazol-5-ones (1) with 4-formyl-2-methoxyphenyl-4-(4-formyl-2-methoxyphenyl)-4-oxobutanoate yielded the biologically active 2-methoxy-4-((3-alkyl(aryl)-5-oxo-1H-1,2,4-triazol-4(5H)-ylimino)-methyl)-phenyl-4-(2-methoxy-4-((3-alkyl(aryl)-5-oxo-1H-1,2,4-triazol-4(5H)-ylimino)-methyl)-phenyl)-4-oxobutanoates (3). The compounds obtained were analyzed via FT-IR,¹H-/¹³C-NMR spectrometers, elemental analysis, and HRMS spectroscopic techniques. Furthermore, we aimed at investigating the potential of compounds 3a-g against FaDu hypopharyngeal cancer cells. We demonstrated that compounds 3c, 3e, and 3 g had relatively lower IC₅₀ values compared to the remaining tested compounds and more importantly their IC₅₀ values were comparable to 5-FU, which suggests them as important therapeutic agent candidates. These newly synthesized compounds were assessed for their inhibitory activities toward two human carbonic anhydrase isoforms I and II (hCA I and II). Then, molecular docking calculations were made to compare the biological activities of studied molecules against cancer proteins. Compound 3c has a docking score of −7.15 against squamous cell carcinoma protein with ID: 2DO4 and −5.49 docking score against squamous cell carcinoma protein with ID:5PJZ. ADME/T analysis was performed to examine the drug properties of studied molecules.