Discovery and Mechanism of a Nematicide Candidate (): A Novel Amide Compound Containing a Cyclopropyl Moiety.

To find novel nematicides, we screened the nematicidal activity of compounds in our laboratory compound library. Interestingly, the compound -((1,2)-2-(2-fluoro-4-(trifluoromethyl)phenyl)cyclopropyl)-2-(trifluoromethyl)benzamide () showed a broad spectrum and excellent nematicidal activity. The LC values of compound against second-stage juveniles of (), , and are 1.30, 1.63, and 0.72 mg/L, respectively. Nematicidal activities of compound against second-stage juveniles of were 87.66% at 100 mg/L. Meanwhile, compound can not only observably inhibit the feeding, reproduction, and egg hatching of but can also effectively promote the oxidative stress adverse reactions of nematodes and cause intestinal damage. Compound can promote the production of MDA and inhibit the activities of defense enzymes SOD and GST in . Compound can affect the transcription of genes involved in regulating the tricarboxylic acid cycle in nematodes, resulting in weakened nematode respiration and reduced nematode activity and even death. In addition, compound had good inhibitory activity against five pathogenic fungi. Among them, the EC of compound against was 8.4 mg/L. In the future, we will devote ourselves to the toxicological and structural optimization research of the candidate nematicide .