NEW SULFONAMIDO-BENZOXAZOLE DERIVATIVES AS ANTIMICROBIAL AGENTS: DESIGN, SYNTHESIS AND BIOLOGICAL EVALUATION

Abstract

Objective: Many investigations are conducted in the battle against infectious diseases in order to develop new drug-active ingredient candidate compounds and to identify leading compounds. The goal of this study was to synthesis a total of seven compounds, six of which are novel, with the general structure 2-(4-tert-butylphenyl)-5-(4-substitutedphenylsulfonamido)benzoxazole, to elucidate their structures, and to test their antimicrobial activities using the microdilution method. Material and Method: The synthesis of the compounds was carried out in two stages. In the first stage, under PPA catalyst 2,4-diaminophenol and 4-tert-butylbenzoic acid were refluxed, and target compounds were produced in the second step by reacting 4-substitutedbenzenesulfonyl chloride with 5-Amino-2-(4-tert-butylphenyl)benzoxazole. The compounds' antimicrobial activity was determined by using Enterococcus faecalis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Candida albicans, and drug-resistant strains of these microorganisms in vitro antimicrobial activity studies. Furthermore, estimated ADME profiles were calculated using the SwissADME online software. Result and Discussion: The structures of the synthesized compounds were elucidated using 1H-NMR, 13C-NMR and Mass spectroscopy, and also their melting points were determined. The antimicrobial activities of the compounds ranged from 64 µg/ml to ˃512 µg/ml and were weaker than the reference drugs. The best antimicrobial activity was reported against an isolate of E. faecalis, with all compounds having MIC values of 64 µg/ml. The fact that six of the seven synthesized compounds are novel and that their antimicrobial activity will be tested for the first time will make a significant contribution to studies to develop new or alternative antimicrobial agents.