Antifungal active chemical constituents of Brucea javanica residue

【Objective】This study attempted to find antifungal active components of Brucea javanica residue(oil was removed), which could provide reference for development and utilization of biological medicine and fertilizer.【Method】Mycelium growth rate method, spore germination method and filter paper method were used to determine the biological activities of the extracts of B. javanica residue against 18 tested pathogenic fungi, such as Fusarium graminearum Schw, Verticillium dahliae Kleb and F. oxysporum f. sp. niveum(E. F. Smith) Synder& Hansen, etc. And through biological activity tracking, the chemical composition of its ethyl acetate extract was separated and identified.【Result】The results indicated that the methanol extracts of B. javanica only had antifungal activity against Thanatephorus cucumeris(Frank) Domk with the inhibition rate of 33.33% at the concentration of 10 mg/mL. However, the extracts of petroleum ether and ethyl acetate had obvious inhibitory effect on the tested pathogenic fungi activity at the concentration of 5 mg/mL, especially the extracts of ethyl acetate, which had antifungal activity against 12 tested pathogenic fungi including Neoscytalidium dimidiatum(Penz.) Crous& Slippers, F. oxysporum f. sp. momordicae Sun& Huang J Wand T. cucumeris with inhibition rates of 75.71%, 56.47%, 51.72% andmedial lethal concentration(EC₅₀) values were 2.65, 3.48, 2.10 mg/mL, respectively. The inhibitory effect of ethyl acetate extract on the spore germination of N. dimidiatum could be enhanced with the increase of concent ration. At the concentration of 2.5000 mg/mL, the inhibition rate could reach 100.00%. The antifungal activity against N. dimidiatum of ethyl acetate extract remained stable under the conditions of ultraviolet light and natural light. Five chemical components, catechol(1), benzofuran-2-carboxaldehyde(2), 1H-Indazole(3), vanillic acid(4), cleomiscosin A(5), were isolated from the ethyl acetate extracts, and the benzofuran-2-carboxaldehyde(2) and 1H-Indazole(3) were isolated from B. javanica for the first time. Catechol(1), benzofuran-2-carboxaldehyde(2), vanillic acid(4), and cleomiscosin A(5) had no significant antifungal activity against N. dimidiatum, F. oxysporum f. sp. momordicae and T. cucumeris(P>0.05). 【Conclusion】B. javanica residue contains antifungal activity components, providing a good application prospect for controlling plant diseases.