Design, Synthesis, Antibacterial and Antifungal Activity Evaluation of Novel 1,2,4-Triazole Derivatives Incorporating Sulfone and Thioether Moieties

A series of novel 1,2,4-triazole derivatives incorporating sulfone and thioether moieties were synthesized and characterized by 1H, 13C NMR, and HRMS data. The preliminary in vitro antibacterial activities of these compounds against Wickerhamomyces anomalus (Wa) and Bacillus cereus (Bc) were evaluated at concentrations of 200 and 100 μg/mL using the turbidimeter tests. The results revealed that the target compounds exhibited moderate to good antibacterial activities against Wa and Bc. Notably, compound 3-(benzylthio)-4-phenyl-5-(tosylmethyl)-4H-1,2,4-triazole demonstrated excellent in vitro antibacterial activities against Wa and Bc, with inhibition rates of 78.62 and 88.62% at 200 μg/mL, and 60.24 and 72.26% at 100 μg/mL, surpassing those of thiodiazole copper. Additionally, the in vitro antifungal activities of these compounds against Penicillium sumatraense (Ps) and Aspergillus fumigatus (Af) were assessed using the mycelium growth rate method. Bioassay results indicated that the target compounds exhibited certain antifungal activities against Ps and Af at 50 μg/mL. Specifically, compound 3-(benzylthio)-4-phenyl-5-(tosylmethyl)-4H-1,2,4-triazole showed moderate antifungal activities against Ps and Af at 50 μg/mL, with inhibition rates of 66.12 and 45.23%, which were lower than those of prochloraz. To the best of our knowledge, this is the first report on the synthesis and bioactivity evaluation of this series of novel 1,2,4-triazole derivatives incorporating sulfone and thioether moieties.