AUTHOR=Liu Wenxi , Cheng Xianlong , Kang Rong , Wang Yadan , Guo Xiaohan , Jing Wenguang , Wei Feng , Ma Shuangcheng 

TITLE=Systematic Characterization and Identification of Saikosaponins in Extracts From Bupleurum marginatum var. stenophyllum Using UPLC-PDA-Q/TOF-MS

JOURNAL=Frontiers in Chemistry

VOLUME=9

YEAR=2021

URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2021.747987

DOI=10.3389/fchem.2021.747987

ISSN=2296-2646

ABSTRACT=<p>Saikosaponins comprise a large group of chemical components present in the <italic>Bupleurum</italic> species that have attracted attention in the field of medicine because of their significant biological activities. Due to the high polarity, structural similarity, and the presence of several isomers of this class of components, their structural identification is extremely challenging. In this study, the mass spectrometric fragmentation pathways, UV spectral features, and chromatographic behavior of different types of saikosaponins were investigated using 24 standard substances. Saikosaponins containing carbonyl groups (C=O) in the aglycone produced fragment ions by loss of 30 Da, and in addition, type IV saikosaponins could produce [aglycone−CH<sub>2</sub>OH−OH−H]<sup>−</sup> and [aglycone−H<sub>2</sub>O−H]<sup>−</sup> fragment ions through neutral losses at positions C<sub>16</sub> and C<sub>17</sub>. The above characteristic ions can be used to identify saikosaponins. More notably, the identification process of saikosaponins was systematically summarized, and using this method, 109 saikosaponins were identified or tentatively characterized from the saikosaponins extract of <italic>Bupleurum marginatum var. stenophyllum</italic> (BMS) using UPLC-PDA-Q/TOF-MS with both data-dependent acquisition (DDA) and data-independent acquisition (DIA) modes, of which 25 were new compounds and 60 were first discovered from BMS. Further studies revealed that the saikosaponins profiles of BMS, <italic>Bupleurum chinense</italic> DC (BC), and <italic>Bupleurum marginatum</italic> Wall. ex DC (BMW) were very similar. This work is of great significance for the basic research of the <italic>Bupleurum</italic> species and provides strong technical support to solve the resource problems associated with Radix Bupleuri.</p>