Table1_Systematic Characterization and Identification of Saikosaponins in Extracts From Bupleurum marginatum var. stenophyllum Using UPLC-PDA-Q/TOF-MS.docx

Saikosaponins comprise a large group of chemical components present in the Bupleurum 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−CH2OH−OH−H]− and [aglycone−H2O−H]− fragment ions through neutral losses at positions C16 and C17. 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 Bupleurum marginatum var. stenophyllum (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, Bupleurum chinense DC (BC), and Bupleurum marginatum Wall. ex DC (BMW) were very similar. This work is of great significance for the basic research of the Bupleurum species and provides strong technical support to solve the resource problems associated with Radix Bupleuri.

薑黄素类化合物是一组存在于柴胡属植物中的化学成分，因其显著的生物活性在医药领域引起了广泛关注。鉴于其高极性、结构相似性以及该类成分存在多个异构体，其结构鉴定极具挑战性。在本研究中，通过使用24种标准物质，对不同类型的薑黄素类化合物的质谱裂解途径、紫外光谱特征和色谱行为进行了研究。含有羰基（C=O）的薑黄素类化合物通过失去30 Da产生碎片离子，此外，Ⅳ型薑黄素类化合物可通过在C16和C17位点的中性丢失产生[aglycone−CH2OH−OH−H]−和[aglycone−H2O−H]−碎片离子。上述特征离子可用于薑黄素类化合物的鉴定。尤为显著的是，薑黄素类化合物的鉴定过程得到了系统性的总结，利用此方法，从柴胡（Bupleurum marginatum var. stenophyllum，简称BMS）的薑黄素类化合物提取物中鉴定或暂定性地描述了109种薑黄素类化合物，其中25种为新化合物，60种首次在BMS中发现。进一步研究表明，BMS、柴胡（Bupleurum chinense DC，简称BC）和柴胡（Bupleurum marginatum Wall. ex DC，简称BMW）的薑黄素类化合物谱非常相似。本研究对于柴胡属植物的基础研究具有重要意义，并为解决与柴胡根资源相关的问题提供了强有力的技术支持。