Instituto de Productos Naturales y Agrobiología, CSIC, Avda. Astrofísico F. Sánchez 3, 38206 La Laguna, Spain.
Instituto de Ciencias Agrarias, CSIC, 28006 Madrid, Spain.
Molecules. 2024 Sep 26;29(19):4568. doi: 10.3390/molecules29194568.
The search for natural product-based biopesticides from endophytic fungi is an effective tool to find new solutions. In this study, we studied a pre-selected fungal endophyte, isolate YCC4, from the paleoendemism , along with compounds present in the extract and the identification of the insect antifeedant and nematicidal ones. The endophyte YCC4 was identified as sp. by molecular analysis. The insect antifeedant activity was tested by choice bioassays against , and and the in vitro and in vivo mortality was tested against the root-knot nematode . Since the extract was an effective insect antifeedant, a strong nematicidal, and lacked phytotoxicity on tomato plants, a comprehensive chemical study was carried out. Two new metabolites, metguignardic acid () and (-)--guignardone I (), were identified along the known dioxolanones guignardic acid (), ethyl guignardate (), guignardianones A (), C (), D (), and E (), phenguignardic acid methyl ester (), the meroterpenes guignardone A () and B (), guignarenone B () and C (), (-)-guignardone I (), and phyllomeroterpenoid B (). Among these compounds, and were effective antifeedants against and , while was only active on the aphid . The nematicidal compounds were , , and . This is the first report on the insect antifeedant or nematicidal effects of these dioxolanone-type compounds. Since the insect antifeedant and nematicidal activity of the sp. extract depend on the presence of dioxolanone components, future fermentation optimizations are needed to promote the biosynthesis of these compounds instead of meroterpenes.
从内生真菌中寻找天然产物生物农药是寻找新解决方案的有效工具。在这项研究中，我们研究了一种预先选择的真菌内生菌，YCC4 分离株，来自古特有生物，以及提取物中的化合物和鉴定昆虫拒食剂和杀线虫剂。通过分子分析，内生真菌 YCC4 被鉴定为 种。通过选择生物测定法测试了昆虫拒食活性，针对 和 ，并在体内和体外测试了对根结线虫的致死率 。由于提取物是一种有效的昆虫拒食剂，具有很强的杀线虫活性，并且对番茄植物没有植物毒性，因此进行了全面的化学研究。鉴定出两种新的代谢物，metguignardic 酸 () 和 (-)--guignardone I (), 以及已知的二氧戊环酮 guignardic 酸 ()、乙基 guignardate ()、guignardianones A ()、C ()、D ()、E ()、phenguignardic 酸甲酯 ()、meroterpenes guignardone A () 和 B ()、guignarenone B () 和 C ()、(-)-guignardone I () 和 phyllomeroterpenoid B ()。在这些化合物中， 和 对 和 是有效的拒食剂，而 仅对蚜虫有效。杀线虫化合物为 、 、 。这是首次报道这些二氧戊环酮类化合物具有昆虫拒食或杀线虫作用。由于 sp. 提取物的昆虫拒食和杀线虫活性取决于二氧戊环酮成分的存在，因此需要进行未来的发酵优化，以促进这些化合物而不是 meroterpenes 的生物合成。
