SDH-IN-17 (compound C32) is a flavonol derivative containing an acylhydrazone, serving as an effective succinate dehydrogenase (SDH) inhibitor with an IC50 of 8.42 μM. This compound can bind to the active site and form strong interactions with key residues of SDH. Additionally, it exhibits antifungal activity against Fusarium graminearum (EC50=0.170 μg/mL). SDH-IN-17 disrupts normal fungal growth by compromising the structural integrity of the cell membrane and cellular respiration. The potential of SDH-IN-17 for plant disease control research is noteworthy.