Design and synthesis of triazole conjugated novel 2,5-diaryl substituted 1,3,4-oxadiazoles as potential antimicrobial and anti-fungal agents

A series of triazole conjugated novel 2,5-diaryl 1,3,4-oxadiazole derivatives 8a-q are efficiently synthesized starting from methyl salicylate. All the synthesized compounds were characterized based on their H-1 NMR, C-13 NMR, Mass and IR data. All the compounds have been investigated for antibacterial activity against Staphylococcus aureus, Escherichia coli and Bacillus subtilis and antifungal activity against Aspergillus niger and Saccharomyces cerevisiae. It is interesting to note that all compounds 8a-q were found to be effective, potent and active against microbial growth when compared with standard antibacterial agents. Our findings suggest that compounds 8d-f, 81 and 8o are the major ones shown anti-fungal activity among all the synthesized compounds. From our results, it is found that all the compounds 8a-q have exhibited no appreciable potency towards clearing the free radicals in solution. Molecular docking studies of the synthesized compounds with penicillin-binding proteins (PDB ID: 3HUN and 3ITA) are in good agreement with their inhibition activity. The compounds 8p and 8q were found to be effective against microbial growth in gram-positive bacteria, whereas in gram-negative bacteria compound 8d shown good synergy with biological assays and docking studies. These novel series of compounds have shown promising features in inhibiting the microorganisms by interacting with enzymes involved in peptidoglycan synthesis and bacterial cell wall biosynthesis. (C) 2020 Elsevier B.V. All rights reserved.