Development of Oxadiazole-Sulfonamide-Based Compounds as Potential Antibacterial Agents.

In this work, substituted 1,2,4-oxadiazoles (-) were screened against five bacterial strains, identified to be and as growth inhibitors with minimum inhibitory concentration (MIC) values of 31.25 and 15.75 μg/mL, respectively. The growth inhibitory property of and was further validated by disk diffusion, growth curve, and time kill curve assays. Both disrupted biofilm formation with 92-100% reduction examined by the XTT assay were further visualized by scanning electron microscopy analysis. These compounds in combination with ciprofloxacin also exhibit synergy against cells. With insignificant cytotoxic behavior on HEK293 cells, human red blood cells, and larvae, was tested against 28 multidrug resistant environmental isolates of bacteria and showed inhibition of and strains with 32 and 16 μg/mL MIC values, respectively. The synergistic behavior of with ampicillin showed many fold reductions in MIC values against and multidrug resistant strains. Further, transmission electron microscopy analysis of -treated cells showed a significantly damaged cell wall, which resulted in the loss of integrity and cytosolic oozing. showed significant changes in the secondary structure of human serum albumin (HSA) in the presence of , enhancing HSA stability. Overall, the study provided a suitable core for further synthetic alterations and development as an antibacterial agent.