Metabolite profiling of steroidal glycosides in the rhizome of Aspidistra sichuanensis using UPLC/Q-TOF MSE

Abstract

This study aimed to perform metabolite profiling of steroidal glycosides in the rhizome of Aspidistra sichuanensis using liquid chromatography coupled with a quadrupole time-of-flight mass spectrometry (UPLC/Q-TOF MS). Steroidal glycosides are one of the largest classes of plant natural products with structural diversity and significant bioactivities. This study summarized the fragmentation rules of six major groups of saponins from Aspidistra. The fragment ions provided a wealth of structural information indicative of the sugar types and number, connecting sequence of sugar units, and types of aglycones. Based on the exact mass information, reliable molecular formulas of the detected compounds could be predicted, and fragmentation ions generated in MSE spectra together with the retention times of the peaks and the structures of steroidal glycosides isolated from the plants belonging to the family Convallariaceae, the structures of 60 constituents were tentatively identified from A. sichuanensis. Also, 34 potential new compounds and 15 pairs of isomers were discovered.