七叶亭及其衍生物的NMR研究

七叶亭衍生物含有药效性较高的苯二酚基团，具有各种生物活性.本文以七叶亭（化合物1）为母体，通过将苯基引入到4位、将甲氧基与羟基分别引入到5、6、7和8位，得到一系列七叶亭衍生物2~14.首先以七叶亭为例，以DMSO-d₆作为溶剂，采集了它的多种核磁共振（NMR）谱图（包括¹H NMR、¹³C NMR、¹H-¹³C HSQC、¹H-¹³C HMBC），并进行了较详细的化学位移归属；然后对七叶亭衍生物2~14的¹H和¹³C NMR进行了全归属；另外，讨论了取代基变化对七叶亭及其衍生物上的¹H和¹³C NMR化学位移的影响；最后，使用GIAO和CSGT两种量子化学计算方法计算了七叶亭及其衍生物上的¹H和¹³C NMR化学位移，并与它们的实测值做了比较.

An NMR Study on Esculetin and It's Derivatives

The derivatives of esculetin contain hydroquinone groups that have various biological activities. In this study, the esculetin derivatives 2~14 were obtained by inducting the methoxy and hydroxyl groups into the 5, 6, 7 and 8 positions, and pheny group into the 4 position of esculetin (1), respectively. The structures of these derivatives were analyzed by the combined use of a number of nuclear magnetic resonance (NMR) spectroscopy techniques, including ¹H and ¹³C NMR, ¹H-¹³C HSQC and ¹H-¹³C HMBC. The ¹H and ¹³C NMR chemical shifts of the compounds were assigned. The effects of different substituents on the chemical shifts were discussed. The NMR shifts of esculetin derivatives were also calculated using the quantum chemical calculation method of gauge-invariant atomic orbitals (GIAO) and continuous set of gauge transformations (CSGT). And the calculated ¹H and ¹³C NMR chemical shifts were compared with their experimental values.