Determination of the absolute configuration of natural products in solution using an integrated experimental and theoretical approach

确定天然产物的绝对构型仍然是一项艰巨的任务。在该方案中，提出了一种综合的方法：将实验光谱数据(核磁共振、ECD、UV-VIS、IR、VCD、旋光数据：所有这些数据都很容易从文献中获得)由DFT计算数据加倍。将对一系列著名的薄荷醇非对映异构体(薄荷醇、异薄荷醇、新薄荷醇、新异薄荷醇)进行统计评估。这样就建立了一种综合的方法，然后将其应用于当前研究的部分未知案例：水飞蓟总黄酮(Silyban marianum(L.)以及真核克隆家族。通过对一系列化合物的分析，可以确定确定绝对构型的置信度。基于这种方法，不仅可以区分已经分离和合成的异构体，而且可以区分不再有样品的天然产物。

The determination of the absolute configuration of natural products is still a formidable task. In this proposal an integrated approach is formulated: experimental spectroscopic data (NMR, ECD, UV-Vis, IR, VCD, optical rotation data: all easily available from literature) are doubled by DFT calculated data. A statistical evaluation will be conducted with the series of the well-known menthol diastereomers (menthol, isomenthol, neomenthol, neoisomenthol). In this way an integrated approach is established which will then be applied to partly unknown cases of current research: the flavones of Silybum marianum (L.) and the family of eupomatilones. The analysis of series of compounds allows the establishment of limits of confidence for the determination of the absolute configuration. Based on this approach not only already isolated and synthesized isomers can be differentiated, but also natural products for which samples are no longer available.