Design, synthesis and antibacterial evaluation of N-substituted indole derivatives containing 1,3,4-thiadiazole and amide moieties

Abstract

A total of eighteen novel 2-(1H-indol-1-yl)-N-(5-phenyl-1,3,4-thiadiazol-2-yl) acetamide derivatives were synthesized through the condensation reaction of 2-(1H-indol-1-yl) acetic acid and 5-phenyl-1,3,4-thiadiazol-2-amine via fragment-based design strategy. The target compounds were subjected to screening for antibacterial activity against Xanthomonas oryzae pv. Oryzae, Xanthomonas axonopodis pv. Citri and Pseudomonas syringae pv. Actinidiae. The preliminary antibacterial evaluation of the target compounds showed that some target compounds possessed moderate to good activities against Xoo and Xac. Among them, compound 3p exhibited best inhibition effects against Xoo (77.85% and 62.15%, respectively) and Xac (52.51% and 36.48%, respectively) at 100 μg/mL and 50 μg/mL, which were superior to Thiodiazole-copper and Bismerthiazol. To the best of our knowledge, it is the first report on the design, synthesis, and antibacterial evaluation of novel indole-derived compounds containing 1,3,4-thiadiazole and amide moieties.

Graphical Abstract

Keywords:

• Indole
• 1,3,4-thiadiazole
• amide
• plant bacterial disease
• antibacterial activity

Disclosure statement

The authors declare no conflict of interest.

Additional information

Funding

The study was performed under financial support by the Youth Science and Technology Talent Growth Program of Guizhou Province’s Department of Education (Qian Jiaohe KY [2022]074), the Qiandongnan Science and Technology Plan Project (Qiandongnan kejichu [2021]17) and the Qiandongnan Science and Technology Plan Project (Qiandongnan kehe J [2022]40).