Synthesis, quantum mechanical calculations, antimicrobial activities and molecular docking studies of five novel 2,5-disubstituted benzoxazole derivatives

Abstract

In this study, five new 2-(p-(Substituted)phenyl)-5-(3-(4-ethylpiperazine-1-yl) propionamido)benzoxazole derivatives (B7-B11) were designed, synthesized, and their antimicrobial activities were determined by the microdilution method. The novel benzoxazole compounds were characterized using FTIR, 1H NMR, and 13C NMR spectroscopy, mass spectroscopy, and elemental analysis. B7 and B11 showed promising activity against P. aeruginosa isolate at 16 µg/mL compared to the reference drugs. Quantum mechanical calculations were performed on five compounds in the ground state using density functional theory (DFT) with the B3LYP/6–311G(d,p) level. Molecular docking studies of the compounds were also performed a complex structure of the DNA gyrase enzyme with ciprofloxacin (PDB: 2XCT), and it was observed that the binding poses were similar to ciprofloxacin. Theoretical ADME profiles of the compounds conform to Lipinski and other limiting rules.