Abstract: Seventeen benzaldehyde benzoyl hydrazone compounds were designed and synthesized from substituted benzoyl hydrazides. The structures of the target compounds were determined by ¹H NMR and ¹³C NMR. The in vitro inhibitory activities of all compounds against 9 common plant pathogenic fungi Fusarium oxysporium f. sp. Niveum, Alternaria solani, Alternaria alternate, Curvularia lunata, Colletotrichum gloeosporioides, Fusarium bulbigenum, Valsa mali, Pyricularia oryza, and Physalospora piricola were determined using kresoxim-methyl as the positive control. The results showed that 17 compounds had different degrees of inhibitory activities, and compound A11 had the highest activity. The inhibition rate of 8 tested fungi was higher than that of kresoxim-methyl except Fusarium oxysporium f. sp. Niveum, and its EC₅₀ was also lower than that of kresoxim-methyl. Preliminary analysis of the activity data showed that the antifungal activity of the corresponding compounds was significantly improved by introducing -F and -Me active groups.

Key words: benzoyl benzaldehyde hydrazone compounds, synthesis, plant pathogenic fungi, antifungal activity