鸦胆子废渣抑菌活性成分分析

Antifungal active chemical constituents of Brucea javanica residue

【目的】探究鸦胆子去油后废渣的抑菌活性成分,为开发生物药肥提供理论依据。【方法】采用菌丝生长速率法、孢子萌发法和滤纸片法等测定鸦胆子废渣粗提物及不同溶剂萃取物对禾谷镰刀菌、茄子黄萎病菌和西瓜枯萎病菌等18种供试植物病原真菌的生物活性,并通过生物活性跟踪对其乙酸乙酯萃取物的化学成分进行分离及鉴定。【结果】在10 mg/mL浓度下鸦胆子甲醇提取物仅对水稻纹枯病菌具有抑制活性,其抑制率为33.33%;但在5 mg/mL浓度下其石油醚萃取物和乙酸乙酯萃取物对供试病原真菌均具有一定的抑制作用,以乙酸乙酯萃取物的抑菌活性最明显,对12种供试病原真菌菌丝生长均具有一定的抑制作用,其中对火龙果溃疡病菌、苦瓜枯萎病菌和水稻纹枯病菌的抑制率分别达75.71%、56.47%和51.72%,对应的致死中浓度(EC_(50))分别为2.65、3.48和2.10 mg/mL。乙酸乙酯萃取物对火龙果溃疡病菌孢子萌发的抑制作用随浓度的升高而增强,在浓度为2.5000 mg/mL时抑制率达100.00%;在紫外光和自然光条件下乙酸乙酯萃取物对火龙果溃疡病菌的抑菌活性稳定。从乙酸乙酯萃取物中分离得到catechol(1)、benzofuran-2-carboxaldehyde(2)、1H-Indazole(3)、vanillic acid(4)、cleomiscosin A(5)等5种化合物,其中,化合物2和3为首次从鸦胆子中分离获得,但化合物1、2、4和5对供试火龙果溃疡病菌、苦瓜枯萎病菌和水稻纹枯病菌均无显著抑菌活性(P>0.05)。【结论】鸦胆子废渣中含有抑菌活性成分,在植物病害防控上具有良好的应用前景。

【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),1 H-Indazole(3),vanillic acid(4),cleomiscosin A(5),were isolated from the ethyl acetate extracts,and the benzofuran-2-carboxaldehyde(2)and1 H-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.