Shanghai Research Center for Modernization of Traditional Chinese Medicine, National Engineering Laboratory for TCM Standardization Technology, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Haike Road 501, Shanghai 201203, China.
Shanghai Research Center for Modernization of Traditional Chinese Medicine, National Engineering Laboratory for TCM Standardization Technology, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Haike Road 501, Shanghai 201203, China.
J Pharm Biomed Anal. 2020 Jan 5;177:112813. doi: 10.1016/j.jpba.2019.112813. Epub 2019 Aug 14.
Differentiated composition in precursor ions for different subclasses of ginsenosides in the negative electrospray-ionization mode has been reported, which lays a foundation for the sorted and untargeted identification of ginsenosides. Carboxyl-free ginsenosides simultaneously from Panax ginseng, P. quinquefolius, and P. notoginseng, were comprehensively characterized and statistically compared. A neutral loss/product ion scan (NL-PIS) incorporated untargeted profiling approach, coupled to ultra-high performance liquid chromatography, was developed on a linear ion-trap/Orbitrap mass spectrometer for characterizing carboxyl-free ginsenosides. It incorporated in-source fragmentation (ISF) full scan-MS, mass tag-MS, and product ion scan-MS. Sixty batches of ginseng samples were analyzed by metabolomics workflows for the discovery of ginsenoside markers. Using formic acid (FA) as the additive, carboxyl-free ginsenosides (protopanaxadiol-type, protopanaxatriol-type, and octillol-type) gave predominant FA-adducts, while rich deprotonated molecules were observed for carboxyl-containing ginsenosides (oleanolic acid-type and malonylated) when source-induced dissociation (SID) was set at 0 V. Based on the NL transition [M+FA‒H] > [M-H] and the characteristic sapogenin product ions, a NL-PIS approach was established. It took advantage of the efficient full-information acquisition of ISF-MS (SID: 50 V), the high specificity of mass tag (NL: 46.0055 Da)-induced MS fragmentation, and the substructure fragmentation of product ion scan-MS. We could characterize 216 carboxyl-free ginsenosides, and 21 thereof were potentially diagnostic for the species differentiation. Conclusively, sorted and untargeted characterization of the carboxyl-free ginsenosides was achieved by the established NL-PIS approach. In contrast to the conventional NL or PIS-based survey scan strategies, the high-accuracy MS data obtained can enable more reliable identification of ginsenosides.
在负离子电喷雾模式下，不同人参皂苷亚类的前体离子存在差异，这为人参皂苷的分类和非靶向鉴定奠定了基础。本文综合比较了来源于人参、西洋参和三七的无羧基人参皂苷，并对其进行了全面的表征。本研究建立了一种基于中性丢失/产物离子扫描（NL-PIS）的无羧基人参皂苷非靶向分析方法，该方法结合超高效液相色谱-线性离子阱/轨道阱质谱，通过源内碎裂（ISF）全扫描-MS、质量标签-MS 和产物离子扫描-MS 对无羧基人参皂苷进行分析。采用代谢组学工作流程对 60 批人参样品进行分析，以发现人参皂苷标志物。当源内诱导解离（SID）设置为 0 V 时，使用甲酸（FA）作为添加剂，无羧基人参皂苷（原二醇型、原三醇型和八角二醇型）主要给出 FA 加合物，而含羧基人参皂苷（齐墩果酸型和丙二酰化）则观察到丰富的去质子分子。基于 NL 跃迁 [M+FA-H] > [M-H]和特征甾体皂苷产物离子，建立了 NL-PIS 方法。该方法利用 ISF-MS（SID：50 V）的高效全信息采集、质量标签（NL：46.0055 Da）诱导 MS 碎裂的高特异性以及产物离子扫描-MS 的亚结构碎裂的优势。共鉴定了 216 种无羧基人参皂苷，其中 21 种可能用于物种鉴别。综上所述，采用建立的 NL-PIS 方法实现了无羧基人参皂苷的分类和非靶向鉴定。与传统的 NL 或 PIS 基于调查扫描策略相比，所获得的高精度 MS 数据可实现更可靠的人参皂苷鉴定。
