Computation-Assisted Structural Elucidation of Epoxyroussoeone and Epoxyroussoedione Isolated from Roussoella japanensis KT1651

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• 作者：Yuna Honmura ; Hiroto Takekawa ; Kazuaki Tanaka ; Hayato Maeda ; Tatsuo Nehira ; Warren Hehre ; Masaru Hashimoto
• 刊名：Journal of Natural Products
• 出版年：2015
• 出版时间：July 24, 2015
• 年：2015
• 卷：78
• 期：7
• 页码：1505-1510
• 全文大小：414K
• ISSN：1520-6025

文摘

The structures of epoxyroussoenone (1) and epoxyroussoedione (3) isolated from a culture broth of Roussoella japanensis KT1651 were determined. Although NMR spectra provided insufficient structural information, computation of the theoretical chemical shifts with DFT EDF2/6-31G* enabled us to elucidate not only the planar structure, but also the relative configuration. Their ECD (electric circular dichroism) spectra suggested the absolute configurations, which were confirmed with time-dependent DFT calculations employing BHandHLYP/TZVP. The ECD calculations for other stereoisomers yielded obviously different spectral profiles, thus confirming the relative structures of 1 and 3.