Design and Discovery of Novel Antifungal Quinoline Derivatives with Acylhydrazide as a Promising Pharmacophore.

Inspired by natural 2-quinolinecarboxylic acid derivatives, a series of quinoline compounds containing acylhydrazine, acylhydrazone, sulfonylhydrazine, oxadiazole, thiadiazole, or triazole moieties were synthesized and evaluated for their fungicidal activity. Most of these compounds exhibited excellent fungicidal activity . Significantly, compound displayed the superior antifungal activity against , , , and with the EC values of 0.39, 0.46, 0.19, and 0.18 μg/mL, respectively, and were more potent than those of carbendazim (EC, 0.68, 0.14, >100, and 0.65 μg/mL, respectively). Moreover, compound could inhibit spore germination of . Preliminary mechanistic studies showed that compound could cause abnormal morphology of cell walls and vacuoles, loss of mitochondrion, increases in membrane permeability, and release of cellular contents. These results indicate that compound displayed superior fungicidal activities and could be a potential fungicidal candidate against plant fungal diseases.