Humaroz, Mohsin, Sonu Sagar
Chemistry
June 2025
The purpose of this research is to create a series of 1,3,4-oxadiazole derivatives—a type of heterocyclic molecule with demonstrated pharmacological activity—and to characterise them before testing their antibacterial activity. The two-step process for preparing the derivatives began with the synthesis of hydrazides acid, which could be either substituted alkyl or aromatic acid, from hydrazine hydrate and carboxylic acids. The second step involved cyclizing the compounds with phosphorus oxychloride (POCl₃) rather than other dehydrants and substituted aromatic carboxylic acids. The oxadiazole ring (CₜN₂O) and functional groups such as -NH, C=N, and C-O-C were confirmed by FTIR, ³H NMR, and mass spectrometry, which were used to characterise the synthesised compounds. The compounds' antimicrobial activity was assessed by testing them against four different bacteria strains using the agar well diffusion method: A variety of bacteria and yeasts, including E. coli, S. aureus, Pseudomonas aeruginosa, and Candida albicans. One compound- OXA-3 with the 4-chlorophenyl substituent, had the highest yield, highest melting point, and had the clear absorption zone around it implying the strongest antimicrobial activity indicating that the electron-withdrawing groups clearly have a pronounced effect on the biological activity. Structure-activity relationship (SAR) analysis suggested the nature of the substituents are very important in the modification of the chemical stability and antimicrobial biological activity. It is reasonably concluded that of the 1,3,4-oxadiazole derivatives produced, those which had electron-withdrawing substituents have an opportunity to be developed into a series of antimicrobial agents.
1232- 1243
© Airo Journals 2021
