内生真菌SIIA-F13642产生的抗真菌次级代谢产物研究

Antifungal secondary metabolites produced by the endophytic fungus SIIA-F13642

目的研究植物内生真菌SIIA-F13642产生的抗真菌次级代谢产物。方法基于r DNA-ITS序列对菌株进行分子分类学鉴定;采用乙酸乙酯萃取、C_(18)硅胶柱层析和制备型HPLC分离目标化合物;采用波谱学数据解析其结构。结果鉴定SIIA-F13642为地杨梅粘鞭霉(Gliomastix luzulae(Fuckel)E.W.Mason ex S.Hughes),产生3个主要的已知抗真菌化合物virescenoside A,virescenoside B和[Thr^2,Leu^5,Ala^(10)]Cyclosporin,抗新型隐球菌SIA1017的MIC值分别为0.2、0.78和0.78mg/m L。结论地杨梅粘鞭霉SIIA-F13642产生3个主要次级代谢产物virescenoside B(1)、virescenoside A(2)和[Thr^2,Leu^5,Ala^(10)]Cyclosporin(3),具有抗新型隐球菌的活性。

Objective To investigate the antifungal secondary metabolites of the cultures of the endophytic fungus SIIA-F13642. Methods The strain SIIA-F13642 was identified by phylogenetic analysis based on its rDNA- ITS gene sequence. Bioassay-guided isolation and purification were performed through C18 column chromatography and preparative HPLC. Structures of the isolated compounds were determined by interpretation of HR-ESI-MS and 1D-, 2D-NMR spectroscopic data and comparison of their data with those reported. Results Three compounds were isolated from the culture of the endophyte Gliomastix luzulae SIIA-F13642 and their structures were identified as virescenoside B （1）, virescenoside A （2）, and [ThrE,LeuS,Ala10] cyclosporin （3）. Compounds 1, 2 and 3 have outstanding antifungal activity against Cryptococcus neoformans SIIA1017 with MIC values of 0.20, 0.78and 0.78mg/ ml, respectively. Conclusion Virescenoside A, virescenoside B and [Thr2, Leu5, Ala10] cyclosporin, produced by endophytic Gliomastix luzulae SIIA-F 13642, are main secondary metabolites with antifungl activity against Cryptococcus neoformans.