Objective  Possibility of applying Ailanthus altissima alkaloids for controlling 5 plant pathogenic fungi was studied.

  Method  Crude ethanol extract of alkaloids from the bark of A. altissima was obtained. Extract was separated using the vacuum liquid chromatography. Antifungal activities of the crude alkaloids and the elution fractions on Fusarium oxysporum f. sp. cucumerinum, F. graminearum, F. oxysporum f. sp. benincasae, Botrytis paeoniae, and Gloeosporium sp. were determined according to the fungal mycelium growth rate.

  Result  The crude ethanol-extracted alkaloids and canthin-6-one fraction exhibited inhibitory effects on the tested fungi, except B. paeoniae. The antimicrobial effects were particularly strong on Gloeosporium sp. and F. graminearum and especially toxic toward the latter with EC₅₀ values of 0.31 mg·mL⁻¹ by the crude alkaloids and 20.32μg·mL⁻¹ by canthin-6-one.

  Conclusion  The ethanol-extracted alkaloids from A. altissima barks could inhibit the growth and/or be lethal toward a variety of plant pathogenic fungi. Although the antifungal effect was not as potent as that of canthin-6-one, the crude extract perse appeared promising to be a new source for the development of a plant-based biocontrol agent.