新喜树碱衍生物的核磁共振谱分析与结构鉴定

以20(S)-喜树碱(CPT)为起始原料,对其进行结构修饰,合成了一种新的喜树碱衍生物CPT-A.并利用1D(~1H、~(13)C和DEPT135)和2D(异核单量子相关谱和异核多碳相关谱)核磁共振(NMR)技术对该化合物进行了结构确定,详细归属了CPT-A~1H和~(13)C NMR谱的化学位移,喜树碱骨架的指认结果与文献报道基本一致,并发现喜树碱骨架6位碳与取代基苯环3’位碳的化学位移相同,谱峰完全重叠,这在~(13)C谱中是不常见的.研究结果可为喜树碱类天然产物的发现和结构鉴定提供NMR数据支持和方法指引.

Structure Identification of New Camptothecin Derivatives by Nuclear Magnetic Resonance Spectrometry

A new camptothecin(CPT) derivative CPT-A was synthesized by modifying camptothecin, one of the most important natural products. Its chemical structure was identified using 1D and 2D nuclear magnetic resonance(NMR) techniques. Both ¹H and ¹³C chemical shifts of CPT-A were exactly assigned. The results of the identification of camptothecin skeleton are basically consistent with those reported in the literature. In this study, the number 6 carbon of camptothecin skeleton and the number 3'' carbon of benzene are completely overlapped. This phenomenon is seldom seen in the ¹³C NMR spectra. NMR data support for the discovery and structural identification of natural products of camptothecin derivatives can be obtained in the study. Furthermore, a methodology was involved in the analysis of NMR spectra.