七子花内生真菌的抗菌活性筛选及其活性先导化合物的发现(英文)

Screening of endophytic fungi with anti-phytopathogen activities from Heptacodium miconioides

【目的】从濒危植物七子花中分离出具有抗植物致病菌活性的内生真菌,并在其代谢产物中寻找具有抗菌活性的先导化合物。【方法】采用生长速率法测定内生真菌对植物病原菌的抑制活性。通过形态学和5.8S rRNA序列法对具有较好抗菌活性的内生真菌进行鉴定。运用多种色谱方法对发酵产物进行分离、纯化,利用质谱和核磁共振谱分析鉴定出化合物的结构。【结果】茄交链孢QZH 10对水稻纹枯病菌和苹果树腐烂病菌的抑制活性较好,抑制率分别为89.1%和67.9%。在供试浓度为100μg/m L时,QZH 10乙酸乙酯粗提物对稻瘟病菌具有强烈的抑制效果,抑制率为100.0%。从QZH 10中分离到2个单体化合物并分别被鉴定为altersolanol A和6-O-methylalaternin。在供试浓度为100μg/m L时,altersolanol A对稻瘟病菌具有较强的抑制效果,抑制率大于85%;6-O-methylalaternin对苹果树腐烂病菌具有强烈的抑制效果,抑制率为100.0%。【结论】当前结果表明Altersolanol A和6-O-methylalaternin具有开发成微生物源杀菌剂的潜力。

[ Objective ] To find anti-phytopathogen compounds from endophytic fungi associated with the endangered species Heptacodium miconioides. [ Methods] Fungi from H. miconioides with antifungal activities were isolated according to the plate growth inhibition method. The fungus with preferable antifungal activities was identified by morphological identification and 5.8S rRNA sequence analysis. The bioactive metabolites were isolated and purified by chromatographic methods; the structures were determined by spectroscopic analysis. [ Results] Alternaria solani QZH 10 showed better antifungal activity against Rhizoctorzia solani and Valsa mall with the inhibition rates of 89. 1% and 67.9% , respectively. The ethyl acetate crude extract of QZH 10 had strong antifungal activity against Magnaporthe oryzae with the rate of 100.0% under the concentration of 100 μg/mL. Two antifungal metabolites ahersolanol A and 6-O-methylalaternin were isolated and determined from QZH 10. Ahersolanol A possessed strong activity against M. oryzae with the inhibition rate of more than 85% , 6-O-methylalaternin had the mightily activity against V. mall with the inhibition rate of 100.0% under the concentration of 100 μg/mL. [ Conclusion] Ahersolanol A and 6-O-methylalaternin are potential fungicides originated from microorganisms.