SYNTHESIS, CHARACTERIZATION AND BIOLOGICAL EVALUATION OF NOVEL5, 6-DIHYDRO-3-(SUBSTITUTED PHENYL) [1, 2, 4] TRIAZOLE (3, 4-B) [1, 3, 4] THIADIAZINE-7-ONE DERIVATIVES FOR ANTIMICROBIAL AND FREE RADICAL SCAVENGING ACTIVITY

The present research aims to synthesize novel 5, 6-dihydro-3-(substituted phenyl) [1, 2, 4] triazolo (3, 4-b) [1, 3, 4] thiadiazine-7-one derivatives and their physiochemical evaluation for antibacterial and antioxidant activities. Novel synthetic schemes were designed to synthesize compounds (1-6), which were then characterized using physicochemical and spectroscopic methods (IR, 1HNMR). In-vitro antimicrobial activity was performed against Gram-positive (Staphylococcus aureus, Bacillius subtilis), Gram-negative (Escherichia coli) bacterial strains and fungal strains (Aspergilus niger, Candida albicans) of all synthesized compounds. In addition, Minimum inhibition concentration (MIC) and Minimum fungicidal concentration (MFC) values were determined using tube dilution methods using standards such as norfloxacin and fluconazole. The free radical scavenging activity was also assessed using the DPPH assay, with vitamin C serving as a reference molecule. Compound 3 was discovered to have the best antibacterial activity (IC₅₀– 80.27) of all the compounds, while the rest compounds showed modest scavenging activity.