Egan Joseph M, Kaur Amninder, Raja Huzefa A, Kellogg Joshua J, Oberlies Nicholas H, Cech Nadja B
Department of Chemistry and Biochemistry, the University of North Carolina at Greensboro, Greensboro, NC 24702.
Phytochem Lett. 2016 Sep;17:219-225. doi: 10.1016/j.phytol.2016.07.031. Epub 2016 Aug 6.
The potential of fungal endophytes to alter or contribute to plant chemistry and biology has been the topic of a great deal of recent interest. For plants that are used medicinally, it has been proposed that endophytes might play an important role in biological activity. With this study, we sought to identify antimicrobial fungal endophytes from the medicinal plant goldenseal ( L., Ranunculaceae), a plant used in traditional medicine to treat infection. A total of 23 fungal cultures were obtained from surface-sterilized samples of roots, leaves and seeds. Eleven secondary metabolites were isolated from these fungal endophytes, five of which had reported antimicrobial activity. plant material was then analyzed for the presence of fungal metabolites using liquid chromatography coupled to high resolving power mass spectrometry. The antimicrobial compound alternariol monomethyl ether was detected both as a metabolite of the fungal endophyte spp. isolated from seeds, and as a component of an extract from the seed material. Notably, fungi of the genus were isolated from three separate accessions of plant material collected in a time period spanning 5 years. The concentration of alternariol monomethyl ether (991 mg/kg in dry seed material) was in a similar range to that previously reported for metabolites of ecologically important fungal endophytes. The seed extracts themselves, however, did not possess antimicrobial activity.
真菌内生菌改变或影响植物化学和生物学特性的潜力已成为近期大量研究的热点。对于药用植物而言，有观点认为内生菌可能在其生物活性方面发挥重要作用。在本研究中，我们试图从药用植物白毛茛（毛茛科，L.）中鉴定出具有抗菌活性的真菌内生菌，白毛茛是一种用于传统医学治疗感染的植物。我们从经过表面消毒处理的根、叶和种子样本中总共获得了23种真菌培养物。从这些真菌内生菌中分离出了11种次生代谢产物，其中5种具有已报道的抗菌活性。然后，使用液相色谱联用高分辨质谱法分析植物材料中真菌代谢产物的存在情况。抗菌化合物交替单甲醚既被检测为从种子中分离出的真菌内生菌spp.的代谢产物，也被检测为种子材料提取物的一种成分。值得注意的是，在跨越5年时间收集的三个不同批次的植物材料中均分离出了属真菌。交替单甲醚在干燥种子材料中的浓度（991 mg/kg）与先前报道的具有重要生态意义的真菌内生菌代谢产物的浓度范围相似。然而，种子提取物本身并不具有抗菌活性。
