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.

中文翻译：

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激子手性法建立的前硅化物AF的绝对构型的修正

在这个杂志（最近的贡献J.纳特。PROD。2017年，80（1531-1540），Noumeur等人。报道了六种新型聚酮化合物的分离和结构解析，这些聚酮化合物具有很强的抗增殖活性，被称为普鲁西利德A–F。新化合物的绝对构型主要是通过分析激子耦合的电子圆二色性（ECD）光谱来确定的。但是，激子手性方法（ECM）的应用是不正确的，因为由过渡矩定义的手性是错误分配的。ECM的正确应用得到了ECD光谱的时变密度泛函理论（TDDFT）计算的证实，导致我们修改了Preussilides AF的绝对构型。还简要讨论了正确应用ECM所需的标准。