In this study, some 1,3,4-thiadiazine derivatives were synthesized by condensation of appropriate acetophenone derivatives and thiosemicarbazides because of their wide range of biological applications. Structures of synthesized compounds characterized by 1H NMR and FTIR techniques and evaluated as potential antibacterial or antioxidant agents. The activities of the compounds against Staphylococcus aureus (S. aureus), Bacillus cereus (B. cereus), Escherichia coli (E. coli), and Salmonella typhimurium (S. typhimurium) were evaluated by the Kirby-Bauer disk diffusion method. From the results, it is clear that the compounds (4) and (5) have stronger activity against Gram-positive bacteria but show no inhibition against Gram-negative bacteria. In addition, the DPPH radical scavenging activity of the compounds was determined by microplate assay with various concentrations of the test compounds. Among the synthesized compounds, (4), (5) and (2) showed the highest interactions. The result showed that the DPPH scavenging activity of compounds also appeared to depend on an increase in concentration. The findings of this work have significance in view of the possibility to design new 1, 3, 4-thiadiazine derivatives with improved potency and activity.
Buldu et al. (Thu,) studied this question.