Yuan Chao, Ding Gang, Wang Hai-Ying, Guo Yu-Hua, Shang Hai, Ma Xiao-Jun, Zou Zhong-Mei
Institute of Medicinal Plant Development, Yunnan Branch, Chinese Academy of Medical Sciences and Peking Union Medical College, Jinghong 666100, China.
Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100193, China.
Biomed Res Int. 2017;2017:6961928. doi: 10.1155/2017/6961928. Epub 2017 May 16.
Five new polyketide-terpene hybrid metabolites (-) with highly functionalized groups, together with six known derivatives (-), were isolated from the endolichenic fungus sp. Their structures were elucidated by extensive NMR experiments including H, C, HMQC, COSY, and HMBC. The relative configurations of the new compounds were determined by analysis of coupling constants and ROESY correlations. The absolute configurations especially the secondary alcohol at C-15 in and secondary alcohol at C-14 in were established via the CD experiments of the in situ formed [Rh(OCOCF)] complex with the acetonide derivatives. These compounds were tested for their inhibition activity against six plant pathogens. Compounds and exhibited pronounced efficiency against , and compounds and potently inhibited with MIC value of 8 g/mL, which revealed the plausible ecological role of endolichenic fungus in providing chemical protection for its host lichen in the fungus-plant relationship. The biosynthetic pathway of compounds - was postulated for the first time, which paved the way for its further biosynthesis research.
从内生地衣真菌中分离出了五种具有高度官能团化基团的新型聚酮-萜类杂合代谢产物（-）以及六种已知衍生物（-）。通过包括氢谱、碳谱、异核多量子相干谱、同核化学位移相关谱和异核多键相关谱在内的广泛核磁共振实验阐明了它们的结构。通过分析耦合常数和旋转异构体相关谱确定了新化合物的相对构型。通过原位形成的[Rh(OCOCF)]配合物与丙酮化物衍生物的圆二色性实验确定了绝对构型，特别是化合物中C-15位的仲醇和化合物中C-14位的仲醇的绝对构型。测试了这些化合物对六种植物病原体的抑制活性。化合物和对表现出显著的抑制效果，化合物和以8μg/mL的最低抑菌浓度有效抑制，这揭示了内生地衣真菌在真菌-植物关系中为其宿主地衣提供化学保护的合理生态作用。首次推测了化合物-的生物合成途径，为其进一步的生物合成研究铺平了道路。
