一株海绵共附生真菌Fusarium equiseti SCSIO 41019的次级代谢产物及其抑菌活性研究

Antibacterial secondary metabolites from a marine sponge-derived fungus Fusarium equiseti SCSIO 41019

目的研究海绵共附生真菌Fusarium equiseti SCSIO 41019的次级代谢产物及抑菌活性。方法采用中压硅胶柱色谱、中压反相ODS柱色谱及高效液相色谱等方法对发酵产物进行分离和纯化,运用核磁数据及文献对比的方法鉴定化合物结构。采用滤纸片琼脂扩散法、改良肉汤稀释法评价化合物的抑菌活性。结果从其大米发酵产物中分离并鉴定了8个化合物,分别为equisetin(1)、5'-epiequisetin(2)、lumichrome(3)、N-乙酰基色胺(4)、亚油酸(5)、methyl(4-hydroxyphenyl)acetate(6)、methyl(2-hydroxyphenyl)acetate(7)和graminin B(8)。化合物1、2和5对金黄色葡萄球菌(Staphylococcus aureus)和耐甲氧西林金黄色葡萄球菌(methicillin-resistant Staphylococcus aureus,MRSA)分别具有不同程度的抑制作用,最小抑菌浓度(minimal inhibitory concentration,MIC)为2.0~125μg/mL,其中化合物1的抑菌活性最强(MIC值分别为2.0和3.9μg/mL)。结论从菌株Fusarium equiseti SCSIO 41019分离得到两个具良好抑菌活性的化合物(1~2),为将其开发为耐甲氧西林金黄色葡萄球菌的先导化合物提供一定参考。

Objective To study secondary metabolites from the marine sponge-derived fungus Fusarium equiseti SCSIO 41019 and their antibacterial evaluation.Methods The fermented products of the strain were purified by various methods,such as the silica gel,ODS column chromatography,and HPLC.Structures of these obtained compounds were mainly determined by the analysis of NMR data and by comparison with literature data.Their antibacterial activity was evaluated by the Kirby-Bauer test and the improved broth dilution method.Results Eight compounds(1~8)were obtained from the rice-based fermentation products,which were identified as equisetin(1),5'-epiequisetin(2),lumichrome(3),N-acetyltryptamine(4),linoleicacid(5),methyl(4-hydroxyphenyl)acetate(6),methyl(2-hydroxyphenyl)acetate(7),and graminin B(8).Compounds 1,2 and 5 showed antibacterial activities against Staphylococcus aureus and methicillin-resistant S.aureus with MIC values ranging from 2.0 to 125.0μg/mL.Among them,compound 1 showed the strongest antibacterial activities with MIC values of 2.0 and 3.9μg/mL,respectively.Conclusion Two compounds(1~2)with significant antibacterial activities were obtained from Fusarium equiseti SCSIO 41019,which provides a basis for further developmentas antibacterial lead-compounds.