Structural characterisation and screening of triterpene saponins in the bark of Ilex rotunda using high-performance liquid chromatography coupled to electrospray ionisation and quadrupole time-of-flight mass spectrometry.

Abstract

The bark of Ilex rotunda (BIr) has been used as a traditional Chinese medicine for a long time in China. Triterpene saponins (TSs) were considered to be the major bioactive ingredients and possessed antiplatelet aggregation activity. Identification of TSs in BIr is a necessary step to understand the biological properties. This article describes a method for the rapid identification of TSs in BIr. An analytical method based on high-performance liquid chromatography coupled to electrospray ionisation and quadrupole time-of-flight tandem mass spectrometry (HPLC-ESI-QTOF-MS/MS) was established to characterise the TSs in BIr. Chromatographic separation was performed on an Agilent poroshell 120 EC-C18 column with gradient elution using water containing 0.1% (v/v) formic acid and acetonitrile as the mobile phase. A total of 26 TSs were identified or tentatively identified from BIr. Of them, 23 TSs were first reported from BIr. This was the first comprehensive investigation on TSs in BIr, and the results formed the foundation for the further development and utilisation of BIr in the future.