Dipartimento di Chimica e Chimica Industriale, Università di Pisa , Via Moruzzi 13, 56124 Pisa, Italy.
J Nat Prod. 2017 Oct 27;80(10):2855-2859. doi: 10.1021/acs.jnatprod.7b00740. Epub 2017 Oct 17.
In a recent contribution to this Journal (J. Nat. Prod. 2017, 80, 1531-1540), Noumeur et al. reported the isolation and structure elucidation of six novel polyketides named preussilides A-F, endowed with remarkable antiproliferative activity. The absolute configuration of the new compounds was established mainly by analyzing exciton-coupled electronic circular dichroism (ECD) spectra. However, the application of the exciton chirality method (ECM) was incorrect, because the chirality defined by transition moments was assigned in a wrong way. A correct application of the ECM, substantiated by time-dependent density functional theory (TDDFT) calculations of ECD spectra, led us to revise the absolute configuration of Preussilides A-F. A brief discussion on the criteria required for a correct application of the ECM is also presented.
在最近发表于本刊（J. Nat. Prod. 2017, 80, 1531-1540）的一篇论文中，Noumeur 等人报道了六种新型聚酮类化合物（Preussilides A-F）的分离和结构解析，这些化合物具有显著的抗增殖活性。新化合物的绝对构型主要通过分析外消旋电子圆二色性（ECD）光谱来确定。然而，外消旋手性方法（ECM）的应用是不正确的，因为由跃迁矩定义的手性是以错误的方式分配的。通过对 ECD 光谱进行时间依赖密度泛函理论（TDDFT）计算，对 ECM 的正确应用进行了验证，这导致我们对 Preussilide A-F 的绝对构型进行了修正。本文还简要讨论了正确应用 ECM 所需的标准。
