Abstract
Microwave irradiation was used to efficiently synthesize certain 2-(furan-3-yl)-5-phenyl-1,3,4-oxadi-azole derivatives (3a-g), which were then tested against Mycobacterium tuberculosis using the Microplate Alamar Blue Assay (MABA) technique. Compounds 3a-g were synthesized by reacting furan-3-carboxylic acid (3-furoic acid) with ethanol to create furan-3-ethyl carboxylate (1), then hydrazinolysis was done with hydrazine hydrate to form furan-3-carbohydrazide (2). Finally, title compounds (3a-g) were produced by reacting compound 2 with a suitable aromatic acid in the presence of phosphorous oxychloride. Spectral data such as infrared (IR), proton nuclear magnetic resonance (1H-NMR), and mass spectrometry were used to determine the structure of the final compounds. All compounds except 3b were identified as antitubercular leads having a MIC of 50 mu g/mL against M. tuberculosis H37Rv, according to the results. The MIC value of compound 3b was determined to be 100 mu g/mL. This can be improved further to find new antimycobacterial drugs. The results of docking studies clearly showed that all com-pounds fit nicely into the active site and formed hydrogen bonds, van der Waals, pi-sigma and pi-alkyl interactions with the active site residues. The binding free energy of compounds 3a-g was found to be in the range of-7.0 to-9.2 kcal/ mol, indicating sufficient affinity between the oxadiazole analogue and the enzyme dihydrofolate reductase (DHFR).