Metabolic Alterations in Two Cirsium Species Identified at Distinct Phenological Stages using UPLC-QTOF/MS.

Abstract

Cirsium chanroenicum and C. setidens are commonly used both in traditional folk medicine and as a food source. The quality of different species of Cirsium at different harvest times is a function of their metabolite composition, which is determined by the phenological stage. We sought to determine the differences in the metabolite composition of two species of Cirsium during different phenological stages using ultra-performance liquid chromatography (UPLC) quadrupole time-of-flight (QTOF) mass spectrometry (MS). Cirsium chanroenicum and C. setidens plants were collected at the floral budding and full flowering stages. Metabolic profiles of Cirsium extracts were determined using UPLC-QTOF/MS to characterise the differences between phenological stages, and the major metabolites were quantified using UPLC-QTOF/MS-multiple reaction monitoring (MRM). At the full flowering stage, the levels of phenolic acids as well as components of the phenylpropanoid pathway were increased. Flavonoids predominated at the full flowering stage in both species. The levels of coumaric acid, kaempferol, and pectolinarigenin differed between the two species of Cirsium. Overall, these results suggest that components of the phenylpropanoid metabolic pathway are upregulated in the full flowering stage in Cirsium, although we did observe some variation between the species. These results will help elucidate the metabolic pathways related to the different phases of the vegetative cycle, and may help determine the optimal season for the harvest of Cirsium with the highest levels of bioactive compounds. Copyright © 2017 John Wiley & Sons, Ltd.