Li Yue-Lan, Zhu Rong-Xiu, Li Gang, Wang Ning-Ning, Liu Chun-Yu, Zhao Zun-Tian, Lou Hong-Xiang
Department of Natural Product Chemistry, Key Lab of Chemical Biology (MOE), School of Pharmaceutical Sciences, Shandong University Jinan 250012 People's Republic of China
School of Chemistry and Chemical Engineering, Shandong University Jinan 250100 People's Republic of China.
RSC Adv. 2019 Jan 31;9(8):4140-4149. doi: 10.1039/c8ra10329a. eCollection 2019 Jan 30.
The isolation of the cytotoxic fractions from the endolichenic fungus yielded six new metabolites, including five polyketides (ophiofuranones A (1) and B (2), with unusual furopyran-3,4-dione-fused heterocyclic skeletons, ophiochromanone (3), ophiolactone (4), and ophioisocoumarin (5)), one sesquiterpenoid ophiokorrin (10), and nine known compounds. Their structures were established on the basis of the analysis of HRESIMS and NMR spectroscopic data. ECD calculations, GIAO NMR shift calculations and single-crystal X-ray diffraction were employed for the stereo-structure determination. A plausible biogenetic pathway for the ophiofuranones A (1) and B (2) was proposed. The cytotoxic assay suggested that the five known perylenequinones mainly contributed to the cytoxicity of the extract. Further phytotoxic studies indicated that ophiokorrin inhibited root elongation in the germination of with an IC value of 18.06 μg mL.
从地衣内生真菌中分离出的细胞毒性组分产生了六种新的代谢产物，包括五种聚酮化合物（ophiofuranones A（1）和B（2），具有不寻常的呋喃并吡喃 - 3,4 - 二酮稠合杂环骨架，ophiochromanone（3），ophiolactone（4）和ophioisocoumarin（5）），一种倍半萜ophiokorrin（10）和九种已知化合物。它们的结构是在对高分辨电喷雾电离质谱（HRESIMS）和核磁共振（NMR）光谱数据进行分析的基础上确定的。使用电子圆二色（ECD）计算、GIAO NMR位移计算和单晶X射线衍射来确定立体结构。提出了ophiofuranones A（1）和B（2）可能的生源合成途径。细胞毒性试验表明，五种已知的苝醌主要促成了提取物的细胞毒性。进一步的植物毒性研究表明，ophiokorrin抑制种子萌发时的根伸长，其IC值为18.06 μg/mL。
