Structural characterization and identification of biflavones in Selaginella tamariscina by liquid chromatography-diode-array detection/electrospray ionization tandem mass spectrometry.

Abstract

Biflavonoids, a special class of flavonoids, are widely distributed in gymnosperm plants and have various biological activities. They are also major bioactive ingredients in Selaginella tamariscina. In this work, we report the use of high-performance liquid chromatography with a diode-array detector (HPLC-DAD) and electrospray ionization multi-stage tandem mass spectrometry (ESI-MS(n)) to study the fragmentation behavior of three main types of biflavonoids using seven biflavonoid reference compounds and analyze the biflavonoids in Selaginella tamariscina. The most useful fragmentations in terms of structural identification are those involving the C-ring cleavage of biflavonoids. For amentoflavone-type biflavonoids (containing flavonoid parts I and II), fragmentation on the flavonoid part II at positions 1/3 and 0/4 are the primary pathways, whereas the chances are greater for C-ring cleavage fragmentation occurring on flavonoid part I at positions 1/3 and 1/4 for robustaflavone-type biflavonoids. However, the predominant diagnostic ions of the specific C-O-C-connected hinokiflavone-type biflavonoids are a series of ions resulting from the rupture of the connective C-O bond. Based on the fragmentation patterns of these reference compounds, 17 biflavonoids were identified in an extract of Selaginella tamariscina, three of which have not been previously reported as constituents of this plant. This study provides a powerful approach for the online structural elucidation and identification of different types of biflavonoids and positional isomers from Selaginella tamariscina and other biflavonoids distributed in related plants and prescriptions.

• Authors: Yi-Xuan Zhang, Qiu-Yue Li, Li-Li Yan, Yue Shi
• Journal: Rapid communications in mass spectrometry : RCM (Rapid Commun Mass Spectrom) Vol. 25 Issue 15 Pg. 2173-86 (Aug 15 2011) ISSN: 1097-0231 [Electronic] England
• PMID: 21710597 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2011 John Wiley & Sons, Ltd.

Chemical References

• Biflavonoids
• Plant Extracts
• hinokiflavone

Topics

• Biflavonoids (chemistry, isolation & purification)
• Chromatography, High Pressure Liquid (methods)
• Models, Molecular
• Plant Extracts (chemistry)
• Selaginellaceae (chemistry)
• Spectrophotometry, Ultraviolet
• Tandem Mass Spectrometry (methods)