人参皂苷Rg3的拉曼光谱研究

Raman Spectroscopy Study on the Structure of Ginsenoside Rg3

人参皂苷是人参的有效化学成分,其中人参皂苷Rg3因具有显著的生理活性而备受关注。运用拉曼光谱的方法,对人参皂苷Rg3的两种异构体20-(R)-Rg3和20-(S)-Rg3进行了测量和分析。因20位羟基空间位置不同,20-(R)-Rg3与20-(S)-Rg3相比,归属于亚甲基的振动峰发生了明显的变化,表明两种异构体的堆积方式不同。归属于CC振动的1674cm-1峰的强度明显降低,表明在20-(S)-Rg3中,C27和C28较20-(R)-Rg3处于分子内部。对比拉曼光谱还发现,这一对异构体中糖环的空间结构基本相同。两种异构体拉曼光谱的明显差异,使得拉曼光谱技术成为鉴别人参皂苷Rg3异构体的一种快速、简便的分析方法。

Ginsenoside Rg3,discovered from Red Panax ginseng,is a new anticancer agent,which shows inhibitive activities of tumor metastasis in mice and in vitro tumor cell invasion.There are two isomers for ginsenoside Rg3：20-（R）-Rg3 and 20-（S）-Rg3.The research on the Rg3 structure is limitted,with no report on the use of Raman spectroscopy in such molecules.In the present article,the authors employed the Raman spectroscopy to study the structure of ginsenoside Rg3.Compared with 20-（R）-Rg3,the hydrocarbon chain of 20-（S）-Rg3 is located in the inner of molecules.In addition,there are significant differences in band location and relative intensity between the spectra of 20-（R）-Rg3 and 20-（S）-Rg3,and this indicates that Raman spectroscopy can be used as a simple,fast and accurate analytical tool to identify ginsenoside Rg3 isomers.