Synthesis and characterization of Mn3O4 nanosheets using thyme leaves extract: Antibacterial, antioxidant, molecular docking and molecular dynamics studies

In the present work, Mn3O4 NPs were synthesized via an eco-friendly green synthesis approach using thyme leaf extract. Mn3O4 NPs have been identified by several different analytical techniques. The results proved that Mn3O4 NPs had an average crystallite size of 27.53 nm. The surface morphology of Mn3O4 NPs was nanosheets with a thickness of 20-22 nm composed of quasi-spherical particles (17-22 nm) arranged in alignment with each other to confer this unique shape. The Mn3O4 NPs were used in various biological applications; Mn3O4 NPs had the ability to inhibit different bacteria. The DPPH method was used for the radical scavenging activity, the results confirmed the ability of Mn3O4 NPs to scavenge free radicals, with an IC50 value of 36.41µg/mL, furthermore, the use of molecular docking and molecular dynamics simulations, which were conducted to investigate the interaction between the green-synthesized Mn₃O₄ NPs and the bacterial PBP2a protein of Staphylococcus aureus, which is not previously reported in the literature. Results demonstrated a favorable binding energy of (-8.6 kcal/mol), characterized by powerful hydrogen bonding between the O atom of Mn3O4 NPs and key interactions with amino acid residues, indicating the potential inhibitory effect of Mn3O4 NPs on bacterial resistance mechanisms. KEY WORDS: Antibacterial, Antioxidant, Molecular docking, Nano-biotechnology, Plant-based nanoparticles Bull. Chem. Soc. Ethiop. 2026, 40(2), 469-483 DOI: https://dx.doi.org/10.4314/bcse.v40i2.15