MS/MS技术快速发现和分析繁缕中的黄酮碳苷成分

Rapid Discovery and Analysis of C-glycosylflavones from Stellaria media(L.) Cyr. by MS/MS

目的 :快速发现和分析繁缕中的黄酮碳苷类成分 ,为今后的活性成分研究提供依据 ;同时 ,探讨天然活性成分研究的思路与方法。方法 :采用植化中的粗分离方法处理药材 ,进而以制备TLC与电喷雾串联质谱 (MS/MS)技术离线连接 ,获得目标成分并进行结构分析。结果 :从繁缕中分离得到并鉴定了三个黄酮碳苷类化合物。化合物I为 6 ,8 二葡萄糖基芹菜素 ;化合物II的苷元为芹菜素 ,苷元分别以碳苷键与两个糖连接 ,一个为五碳糖 ,一个为六碳糖 ;化合物III的苷元也是芹菜素 ,分别以碳苷键与两个糖连接 ,一个为五碳糖 ,一个为六碳糖 ,但六碳糖在A环上 ,五碳糖在B环上。在繁缕中 ,尚无这种黄酮碳苷的研究报道。结论 :制备TLC与串联质谱技术离线连接 ,可以较为快速地发现和分析天然活性成分。在苷类化合物的ESI MS/MS中 ,如果不首先出现脱糖基的碎片峰 ,而是有规律地产生脱去 6 0 ,90 ,1 2 0质量单位的碎片峰 ,就基本可以判断为六碳糖的碳苷类化合物。如果是五碳糖 ,则只能产生脱去 6 0 ,90质量单位的碎片峰 ,不产生脱1 2 0质量单位的碎片峰。

AIM:To explore the method of rapid discovery and analysis on C glycosylflavones from Stellaria media(L.) Cyr. METHOD: The crude drug was extracted with alcohol and water successively, and the water extract was treated simply on AB 8 macroreticular resin column chromatography. By combination of thin layer chromatography (TLC) and electrospray ionization tandem mass spectrometry (ESI MS/MS), three C glycosylflavones were found.The structures of them were analyzed by MS/MS and UV. RESULT: Three compounds were obtained from Stellaria media(L.) Cyr. I is vicenin 2, which is a C glycosylflavone. II and III have the same aglycone as I, but their glycosyl parts are different from I. II has one pentose and one hexose subsuitution. III has the same sugar substitution as II, but its pentose is linked to B ring of the flavone aglycone. They are all C glycosylflavones . CONCLUSION: The Rapid Discovery and Analysis of natural components can be achieved simply by combination of TLC and ESI MS/MS,on condition of some pretreatment of the crude drug. In the analysis of glycosylflavones by MS/MS, we can distinguish the C glycosylflavones from O glycosylflavones by comparing the differenes of their product ion scan spectra. The loss of 162 u or 132 u from the - ions indicated that they were O glycosylflavones which had one hexose or one pentose substituent.,whereas the simultaneous loss of 60 u,90 u, 120 u or 60 u, 90 u from the - ions indicated that they were C glycosylflavones which had one hexose or one pentose substituent.