A New UPLC-MS/MS Method for the Characterization and Discrimination of Polysaccharides from Genus Ephedra Based on Enzymatic Digestions

Ephedra sinica polysaccharides have been reported to possess important activities, so quality evaluation of polysaccharides from the genus Ephedra is urgent. In this study, enzymatic digestions were performed to establish multiple saccharide fingerprints by ultra-performance liquid chromatography with electrospray ionization triple quadrupole linear ion trap mass spectrometry (UPLC-ESI-TQ-MS/MS) based on a multiple-reaction monitoring in negative mode. Under optimum UPLC-ESI(-)-TQ-MS/MS conditions, excellent separation and quantification of 21 constituents were achieved within 20 min on a solid core column with a 1.6 μm particle using pre-column derivatization with a PMP reagent. This method, coupled with enzymatic digestions and principal component analysis, has been successfully applied to characterize and discriminate Ephedra polysaccharides attributed to different species and plant parts. The results suggest that the proposed analytical strategy could achieve a quality evaluation of plant polysaccharides from traditional Chinese medicines.