Graduate School of Biomedical Sciences, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki, 852-8521, Japan.
Angew Chem Int Ed Engl. 2017 Sep 18;56(39):11855-11859. doi: 10.1002/anie.201706532. Epub 2017 Aug 18.
Goupiolones A and B are unique phenolic compounds with significant DNA-damaging activity. In this study, the structure of goupiolone B was revised on the basis of DFT calculations of the C NMR chemical shifts and biosynthetic considerations. The dibenzobicyclo[3.2.2]nonane skeleton of the revised structure suggested that goupiolone B was produced by oxidative coupling between catechol and goupiolone A, which was strongly supported by biomimetic synthesis. Furthermore, racemization of goupiolone B was observed during the attempted resolution of its racemic mixture. A plausible racemization mechanism involving α-ketol rearrangement is proposed.
钩藤酚 A 和 B 是具有显著 DNA 损伤活性的独特酚类化合物。在这项研究中，根据 C NMR 化学位移的 DFT 计算和生物合成考虑，对钩藤酚 B 的结构进行了修订。修订结构的二苯并[3.2.2]壬烷骨架表明，钩藤酚 B 是通过儿茶酚和钩藤酚 A 之间的氧化偶联产生的，这一观点得到了生物模拟合成的有力支持。此外，在尝试拆分其外消旋混合物时，观察到了钩藤酚 B 的外消旋化。提出了一个涉及 α-酮醇重排的合理外消旋化机制。
