College of Pharmaceutical Sciences, Key Laboratory of Pharmaceutical Quality Control of Hebei Province, Key Laboratory of Medicinal Chemistry and Molecular Diagnostics of Education Ministry of China, Hebei University, Baoding, 071002, People's Republic of China.
Key Laboratory of Marine Drugs, The Ministry of Education of China, School of Medicine and Pharmacy, Ocean University of China, Qingdao, 266003, People's Republic of China.
Sci Rep. 2018 Jul 13;8(1):10621. doi: 10.1038/s41598-018-28996-5.
Determination of the absolute configrations for natural products is one of the most important and challenging tasks, especially when the molecules display high conformational flexibility. In this paper, eight new prenylxanthones, aspergixanthones A-H (1-8), and one known analogue (9), were isolated from the marine-derived fungus Aspergillus sp. ZA-01. The absolute configurations of C-14 and C-15 in 1-8 were difficult to be assigned due to the high conformational flexibility of the chains. To solve this problem, the experimental ECD, ORD, and VCD spectra of 1 were combined for analysis with the corresponding theoretical predictions for its different diastereomers. This study suggested that a concerted application of more than one chiroptical methods could be used as a preferable approach for the stereochemical characterizations of flexible molecules. Compounds 1-9 were evaluated for their cytotoxic and antibacterial activities. Among them, 6 showed cytotoxicity against the A-549 cell line with the IC value of 1.1 μM, and 7 exhibited antibacterial activity against Micrococcus lysodeikticus with the MIC value of 0.78 μg/mL.
确定天然产物的绝对构型是最重要和最具挑战性的任务之一，特别是当分子表现出高度的构象灵活性时。在本文中，从海洋来源的真菌 Aspergillus sp. ZA-01 中分离得到了八个新的prenylxanthones，aspergixanthones A-H（1-8）和一个已知类似物（9）。由于链的高构象灵活性，1-8 中 C-14 和 C-15 的绝对构型难以确定。为了解决这个问题，对 1 的实验 ECD、ORD 和 VCD 光谱与相应的不同非对映异构体的理论预测进行了组合分析。这项研究表明，多种手性光学方法的协同应用可以作为对柔性分子的立体化学特征进行分析的首选方法。对 1-9 进行了细胞毒性和抗菌活性评价。其中，6 对 A-549 细胞系表现出细胞毒性，IC 值为 1.1 μM，7 对 Micrococcus lysodeikticus 表现出抗菌活性，MIC 值为 0.78 μg/mL。
