Seibert Simon F, König Gabriele M, Voloshina Elena, Raabe Gerhard, Fleischhauer Jörg
Institute for Pharmaceutical Biology, University of Bonn, Bonn, Germany.
Chirality. 2006 Jun;18(6):413-8. doi: 10.1002/chir.20266.
Two stereoisomers of ascolactone (A, B), natural products with two asymmetric carbon atoms, are isolated from the marine-derived fungus Ascochyta salicorniae. Although these compounds show virtually opposite CD spectra and [alpha]D, 1H- and 13C-NMR data exclude the presence of enantiomers and suggest ascolactone A and B to be epimeric lactones. By comparing the experimental CD spectra with those calculated employing time-dependent density functional theory (TDDFT), we elucidate the configuration at one of the asymmetric carbon atoms.
从海洋来源的真菌盐角草叶点霉中分离出了具有两个不对称碳原子的天然产物曲霉内酯的两种立体异构体（A、B）。尽管这些化合物显示出几乎相反的圆二色光谱和比旋光度，但1H和13C核磁共振数据排除了对映体的存在，并表明曲霉内酯A和B是差向异构内酯。通过将实验圆二色光谱与采用含时密度泛函理论（TDDFT）计算得到的光谱进行比较，我们阐明了其中一个不对称碳原子的构型。
