HWY-289 is a semisynthetic protoberberine derivative, has broad-spectrum and potent activities against phytopathogenic fungi, particularly Botrytis cinerea (EC₅₀ = 1.34 μg/mL). HWY-289 changes the morphology of the mycelium and the internal structure of cells. HWY-289 reduces ATP content, ATPase activities, and key enzyme activities in the TCA cycle^[1].