Kyekyeku James Oppong, Kusari Souvik, Adosraku Reimmel Kwame, Bullach Anke, Golz Christopher, Strohmann Carsten, Spiteller Michael
Department of Pharmaceutical Chemistry, Faculty of Pharmacy and Pharmaceutical Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana; Institute of Environmental Research (INFU), Department of Chemistry and Chemical Biology, Chair of Environmental Chemistry and Analytical Chemistry, TU Dortmund, Otto-Hahn-Straße 6, 44221 Dortmund, Germany.
Institute of Environmental Research (INFU), Department of Chemistry and Chemical Biology, Chair of Environmental Chemistry and Analytical Chemistry, TU Dortmund, Otto-Hahn-Straße 6, 44221 Dortmund, Germany.
Fitoterapia. 2017 Jun;119:108-114. doi: 10.1016/j.fitote.2017.04.007. Epub 2017 Apr 6.
Extensive chemical investigation of the endophytic fungus, Fusarium solani JK10, harbored in the root of the Ghanaian medicinal plant Chlorophora regia, using the OSMAC (One Strain Many Compounds) approach resulted in the isolation of seven new 7-desmethyl fusarin C derivatives (1-7), together with five known compounds (8-12). The structures of the new compounds were elucidated by analysis of their spectroscopic data including 1D, 2D NMR, HRESI-MS and IR data. The relative configuration of compounds 1/2 was deduced by comparison of their experimental electronic circular dichroism (ECD) and optical rotation data with those reported in literature. The absolute configuration of solaniol (10), a known compound with undefined absolute stereochemistry, was established for the first time by X-ray diffraction analysis of a single-crystal structure using Cu-Kα radiation. The antibacterial activities of the crude fungal extract and the compounds isolated from the fungus were evaluated against some clinically important bacterial strains such as Staphylococcus aureus and Bacillus subtilis, as well as an environmental strain of Escherichia coli and the soil bacterium Acinetobacter sp. BD4. Compounds 3/4 and 6 exhibited antibacterial efficacies against the soil bacterium Acinetobacter sp., comparable to the reference standard streptomycin. All the tested compounds (1-9) demonstrated antibacterial activity against the environmental strain of E. coli, whereas no antibacterial activity was observed against S. aureus and B. subtilis. The antibacterial activity of the isolated compounds typically against E. coli and Acinetobacter sp. provides further insight into the possible involvement of root-borne endophytes in chemical defense of their host plants in selected ecological niches.
采用OSMAC（一种菌株多种化合物）方法，对加纳药用植物非洲绿柄桑根部内生真菌茄病镰刀菌JK10进行了广泛的化学研究，从中分离出7种新的7-去甲基镰刀菌素C衍生物（1-7）以及5种已知化合物（8-12）。通过分析其光谱数据（包括一维、二维核磁共振、高分辨电喷雾电离质谱和红外数据）阐明了新化合物的结构。通过将化合物1/2的实验电子圆二色光谱（ECD）和旋光数据与文献报道的数据进行比较，推断出它们的相对构型。通过使用Cu-Kα辐射对单晶结构进行X射线衍射分析，首次确定了绝对立体化学构型未知的已知化合物茄病镰刀菌醇（10）的绝对构型。对粗真菌提取物和从该真菌中分离出的化合物针对一些临床重要细菌菌株（如金黄色葡萄球菌和枯草芽孢杆菌）以及环境大肠杆菌菌株和土壤细菌不动杆菌BD4进行了抗菌活性评估。化合物3/4和6对土壤细菌不动杆菌表现出与参考标准链霉素相当的抗菌效果。所有测试化合物（1-9）对环境大肠杆菌菌株均表现出抗菌活性，而对金黄色葡萄球菌和枯草芽孢杆菌未观察到抗菌活性。所分离化合物对大肠杆菌和不动杆菌的典型抗菌活性进一步深入了解了根内生菌在特定生态位中其宿主植物化学防御中的可能作用。
