Simultaneous Identification of Multiple Celangulins from the Root Bark of Celastrus angulatus Using High-performance Liquid Chromatography-Diode Array Detector-Electrospray Ionisation-Tandem Mass Spectrometry

Introduction - Celangulins are a small family of beta-dihydroagarofuran sesquiterpenoids endowed with diverse polyoxygenated polyol esters and various biological properties. Since our research focuses on celangulins, the development of rapid and sensitive online analytical methods to analyse and characterise them is of great significance. Objective - To develop an HPLC-DAD-ESI-MS/MS method capable of simple and rapid analysis of celangulins in crude extract of root bark of C. angulatus extracts. Methodology - High-performance liquid chromatography coupled with a diode array detector and electrospray ionisation tandem mass spectrometry was established for the efficient and rapid identification of the celangulins. Chromatographic separations of celangulins were performed on a Hypersil Gold C(18) reverse-phase column by gradient elution with acetonitrile-water as mobile phase at a flow-rate 0.2 mL/min. Results - ESI/MS/MS analysis of sodium adduct ion ([M+Na](+)) of each celangulin shows that all the celangulins produced very similar fragmentation profiles, and that the characteristic fragments at m/z 245, m/z 229 and m/z 231 were defined as the diagnostic ions for celangulins. Simultaneously, 46 components in the extracts of this plant were separated, and 36 of them were characterised as celangulins by online ESI/MS/MS and by comparing their retention times, UV and MS spectra with those of authentic compounds. Conclusion - HPLC-DAD-ESI-MS/MS was demonstrated to be a powerful tool for the characterisation of minor celangulins in complex samples. Copyright (C) 2011 John Wiley & Sons, Ltd.