New symmetrical acyclic and alicyclic bisurea derivatives of 4,4'-methylenebis(phenyl isocyanate): Synthesis, characterization, bioactivity and antioxidant activity evaluation and molecular docking studies

A family of bisurea derivatives of 4,4′-methylenebis(phenyl isocyanate) have been synthesized with simple, effective and efficient procedure in high yields. The new compounds showed moderate bioactivity (at 32.0 μg/μL concentration) against selected bacterial pathogens, viz., Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa; and two fungal species, Candida albicans and Cryptococcus neoformans var. grubii. Alternatively, their antioxidant activity was also evaluated by DPPH radical scavenging assay which revealed that the compounds, 10d, 10e, 10h and 10m exhibited moderate activity. However, the molecular docking studies of all the title compounds showed surprisingly higher binding energies with DNA gyrase A protein of E. coli when compared to the reference, streptomycin. Among the compounds 10e, 10f, 10g, 10k, 10l and 10m showed very good binding energies which implied that they could be promising next generation antimicrobials.