Qualitative and quantitative analysis of sesquiterpene lactones in Centipeda minima by UPLC–Orbitrap–MS & UPLC-QQQ-MS

Abstract

An ultra-high performance liquid chromatography coupled with high-resolution Orbitrap mass spectrometry (UPLC–Orbitrap–MS) method has been used to identify sesquiterpene lactones in the methanolic extract of Centipeda minima. Fifteen sesquiterpene lactones were tentatively identified based on retention time and accurate mass of external standards or exact accurate mass searching (within 2 ppm) by comparison of some previous isolated sesquiterpene lactones. Meanwhile, a rapid, sensitive, precise, and reliable ultra-high performance liquid chromatography coupled with triple quadrupole mass spectrometry (UPLC-QQQ-MS) method has been developed to evaluate the quality of Centipeda minima through a simultaneous determination of five sesquiterpene lactones, namely brevilin A, arnicolide C, arnicolide D, microhelenin C, minimolide F. Chromatographic separation was achieved on a Waters Acquilty UPLC BEH C18 column (2.1 mm × 50 mm, 1.7 μm) with a mobile phase consisting of a) 0.1% formic acid and b) a mixture of acetonitrile and methanol 50:50 v/v under an isocratic elution (42:58) manner. Positive electrospray ionization mode with multiple reaction monitoring was applied for the detection of the five sesquiterpene lactones. Method validation for linearity, accuracy and precision was also carried out. Finally, the method was successfully used for the analysis of 10 batches of Centipeda minima samples collected in China. Brevilin A and arnicolide D were the dominant sesquiterpene lactones in Centipeda minima and could be proposed as suitable markers for the quality control of Centipeda minima.