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

•Fragmentation pathways of six types of standard references were discussed and outlined.•60 saponins were identified from Aspidistra sichuanensis by UPLC-Q-TOF MSE.•34 predicted steroidal glycosides were potentially new compounds.

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.

Graphical abstractBased on the fragmentation rules of six major groups of steroidal saponins, and the exact mass, fragment ions, and the retention times of the peaks, together with the structures in the Convallariaceae, the structures of 60 constituents were identified or tentatively identified from Aspidistra sichuanensis by UPLC/Q-TOF MS. Also, 34 potential new compounds and 15 pairs of isomers were discovered.Download high-res image (170KB)Download full-size image