Université de Corse, UMR CNRS 6134 Sciences Pour l'Environnement, Laboratoire Chimie des Produits Naturels, BP 52, 20250 Corte, France.
Molecules. 2022 Oct 27;27(21):7297. doi: 10.3390/molecules27217297.
Ziniolide, xantholide B (11α-dihydroziniolide), and 11β-dihydroziniolide, three sesquiterpene lactones with 12,8-guaianolide skeletons, were identified as volatile metabolites from the roots of L., an invasive plant harvested in Corsica. Essential oil, as well as hydrosol and hexane extracts, showed the presence of guaianolide analogues. The study highlights an analytical strategy involving column chromatography, GC-FID, GC-MS, NMR (1D and 2D), and the hemi-synthesis approach, to identify compounds with incomplete or even missing spectral data from the literature. Among them, we reported the H- and C-NMR data of 11β-dihydroziniolide, which was observed as a natural product for the first time. As secondary metabolites were frequently involved in the dynamic of the dispersion of weed species, the allelopathic effects of root's volatile metabolites were assessed on seed germination and seedling growth (leek and radish). Essential oil, as well as hydrosol- and microwave-assisted extracts inhibited germination and seedling growth; root metabolite phytotoxicity was demonstrated. Nevertheless, the phytotoxicity of root metabolites was demonstrated with a more marked selectivity to the benefit of the monocotyledonous species compared to the dicotyledonous species. Ziniolide derivatives seem to be strongly involved in allelopathic interactions and could be the key to understanding the invasive mechanisms of weed.
紫尼醇、黄烷醇 B（11α-二氢紫尼醇）和 11β-二氢紫尼醇，这三种具有 12,8-吉马烷内酯骨架的倍半萜内酯，被鉴定为从在科西嘉岛采集的入侵植物 根部分离出的挥发性代谢物。精油以及水醇和己烷提取物均显示出存在吉马烷内酯类似物。该研究强调了一种分析策略，包括柱层析、GC-FID、GC-MS、NMR（1D 和 2D）和半合成方法，以从文献中鉴定出具有不完整甚至缺失光谱数据的化合物。其中，我们报道了 11β-二氢紫尼醇的 H-和 C-NMR 数据，这是该化合物首次被观察到作为天然产物存在。由于次生代谢物经常参与杂草物种扩散的动态变化，因此评估了根挥发性代谢物对种子萌发和幼苗生长（韭菜和萝卜）的化感作用。精油以及水醇和微波辅助提取物抑制了种子萌发和幼苗生长；证明了根代谢物的植物毒性。然而，与双子叶植物相比，根代谢物的植物毒性对单子叶植物具有更强的选择性，这表明其对化感相互作用具有重要作用，可能是理解杂草入侵机制的关键。
