Synthesis, Characterization, and Antibacterial Activities of Novel Sulfonamides Derived through Condensation of Amino Group Containing Drugs, Amino Acids, and Their Analogs

Novel sulfonamides were developed and structures of the new products were confirmed by elemental and spectral analysis (FT-IR, ESI-MS, (1)HNMR, and (13)CNMR). In vitro, developed compounds were screened for their antibacterial activities against medically important gram (+) and gram (−) bacterial strains, namely, S. aureus, B. subtilis, E. coli, and K. pneumoniae. The antibacterial activities have been determined by measuring MIC values (μg/mL) and zone of inhibitions (mm). Among the tested compounds, it was found that compounds 5a and 9a have most potent activity against E. coli with zone of inhibition: 31 ± 0.12 mm (MIC: 7.81 μg/mL) and 30 ± 0.12 mm (MIC: 7.81 μg/mL), respectively, nearly as active as ciprofloxacin (zone of inhibition: 32 ± 0.12 mm). In contrast, all the compounds were totally inactive against the gram (+) B. subtilis.