Simultaneous Determination of Thirteen Iridoid Glycosides in Crude and Processed Fructus Corni from Different Areas by UPLC–MS/MS Method

Fructus Corni (F. Corni) is the dried mature pulp of Cornus officinalis Sieb. et Zucc.(Cornaceae), which is rich in iridoids. In this study, a simple, sensitive and rapid UPLC-MS/MS method was developed for the simultaneous determination of 13 iridoid glycosides of F. Corni from different areas. Specifically, we included five new compounds (cornusdiridoid C, cornusdiridoid E, cornusdiridoid F, 3'',5''-dehydroxycornuside and 2'-O-p-coumaroyl-kingiside) and isomers (2'-O-p-E-coumaroylloganin and 2'-O-p-Z-coumaroylloganin) for the first time in the quality markers of F. Corni. A total of 13 compounds and two pairs of isomers were well isolated and tested within just 14 min. All calibration curves showed good linear regression (r2 ≥ 0.99) within the tested concentration ranges. The limit of detection and limit of quantification were in the range of 0.19-1.90 and 0.38-3.76 ng/mL, respectively. The intra-day and inter-day precision were <3.21% and 12.49%, the RSD values of repeatability did not exceed 6.81% and the average recoveries were 90.95-113.59% for the analytes. All iridoid glycosides stabilized within 12 h (RSD < 10.99%). This method has been successfully applied to the quality evaluation of crude and processed F. Corni from different areas. The determination of characteristic iridoid glycosides and isomers will provide a more reliable and comprehensive method for the evaluation of F. Corni.