Design, synthesis, and molecular docking studies of new phenanthrene-linked oxadiazoles as potential antimicrobial agents

Oxadiazoles and phenanthrene-based tylophorine alkaloids exhibit diverse biological activities, and the combination of both provides significant biological activity. Herein, we report the novel synthesis of phenanthrene-linked oxadiazoles (7a-m). Molecular docking studies were performed, and the binding energy values with the protein β-ketoacyl-acyl carrier protein synthase III (FabH) enzyme provide an attractive new target for the development of antibacterial agents and support their biological activities. Most of the derived compounds adhere to "Lipinski's Rule of Five" for assessing drug-likeness. The newly synthesized analogues were assessed for their in vitro antibacterial and antifungal activities against selected gram-positive and gram-negative bacteria as well as fungal strains. Compounds 7b, 7e, 7j, and 7c demonstrate potential antimicrobial activity, while the remaining compounds show moderate activity. The selected derivatives (7b, 7e, 7j, and 7c) exhibit a promising zone of inhibition (mm) against the minimum inhibitory concentration.