To find pesticidal lead compounds with high activity, a series of novel benzamides substituted with pyridine-linked 1,2,4-oxadiazole were designed by bioisosterism, and synthesized easily via esterification, cyanation, cyclization and aminolysis reactions. The structures of the target compounds were confirmed by 1H-NMR, 13C-NMR and HRMS. The preliminary bioassay showed that most compounds had good larvicidal activities against mosquito larvae at 10 mg/L, especially compound 7a, with a larvicidal activity as high as 100%, and even at 1 mg/L was still 40%; at 50 mg/L, all the target compounds showed good fungicidal activities against the eight tested fungi. Moreover, compound 7h exhibited better inhibitory activity (90.5%) than fluxapyroxad (63.6%) against Botrytis cinereal. Therefore, this type of compound can be further studied.
To discover new compounds with broad spectrum and high activity, we designed a series of novel benzamides containing 1,2,4-oxadiazole moiety by bioisosterism, and 28 benzamides derivatives with antifungal activity were synthesized. These compounds were evaluated against four fungi: Botrytis cinereal, FusaHum graminearum, Marssonina mali, and Thanatephorus cucumeris. The results indicated that most of the compounds displayed good fungicidal activities, especially against Botrytis cinereal. For example, 10a (84.4%), 10d (83.6%), 10e (83.3%), 10f (83.1%), 10i (83.3%), and 10l (83.6%) were better than pyraclostrobin (81.4%) at 100 mg/L. In addition, the acute toxicity of 10f to zebrafish embryo was 20.58 mg/L, which was classified as a low-toxicity compound.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.