Design, synthesis, and biological activity of novel 1,2,4-oxadiazole derivatives.

ABSTRACT:

Background

Plant diseases seriously threaten food security, it is urgent to discover efficient and low-risk chemical pesticides. 1,2,4-Oxadiazole derivatives exhibit broad spectrum of agricultural biological activities. For discovering novel molecules with excellent agricultural activities, novel 1,2,4-oxadiazole derivatives were synthesized and evaluated for their agricultural activities.

Result

Bioassays results showed that the title compounds exhibited moderate nematocidal activity against Meloidogyne incognita and anti-fungal activity to Rhizoctonia solani. It's worth noting that compounds 5m, 5r, 5u, 5v, 5x and 5y showed strong antibacterial effects on Xanthomonas oryzae pv. oryzae (Xoo), with EC₅₀ values of 36.25, 24.14, 28.82, 19.44, 25.37 and 28.52 ?g/mL, respectively, superior to bismerthiazol (BMT, EC₅₀?=?77.46 ?g/mL) and thiodiazole copper (TDC, EC₅₀?=?99.31 ?g/mL). Compounds 5p, 5u and 5v exhibited excellent antibacterial ability against Xanthomonas oryzae pv. oryzicola (Xoc), with EC₅₀ values of 31.40, 19.04 and 21.78 ?g/mL, respectively, better than that of BMT (EC₅₀?=?68.50 ?g/mL) and TDC (EC₅₀?=?91.05 ?g/mL). In addition, compound 5v exerted moderate antibacterial effects on rice bacterial leaf blight.

Conclusions

Twenty-six novel 1,2,4-oxadiazole derivatives were obtained and their biological activities were evaluated. Compound 5u and 5v exhibited excellent antibacterial activity Xoo and Xoc. These results indicated that 1,2,4-oxadiazole derivatives containing a trifluoromethyl pyridine moiety could be as potential alternative templates for discovering novel antibacterial agents.

SUBMITTER: Zhu L 

PROVIDER: S-EPMC7680602 | biostudies-literature | 2020 Nov

REPOSITORIES: biostudies-literature