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, People's Republic of 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, People's Republic of China.
J Chromatogr A. 2018 Oct 12;1571:213-222. doi: 10.1016/j.chroma.2018.08.026. Epub 2018 Aug 11.
Specific analytical approaches that enable untargeted profiling of modified metabolites are in great need. An untargeted profiling strategy, by integrating in-source collision-induced dissociation (ISCID)-MS, mass tag-MS, and neutral loss scan-MS, is established on a linear ion-trap/Orbitrap mass spectrometer coupled to ultra-high performance liquid chromatography. This strategy is applied to screen malonylginsenosides from three reputable Panax species (P. ginseng, P. quinquefolius, and P. notoginseng). In light of the preferred neutral elimination of CO and entire malonyl substituent (CHO) in the negative electrospray ionization mode, a pseudo-neutral loss scan (PNL) method was established by applying ISCID energy 40 V in MS, mass tag 43.9898 Da oriented CID-MS at normalized collision energy (NCE) 30%, and neutral loss 43.9898 Da-triggered high-energy C-trap dissociation-MS at NCE 70%. The PNL approach achieved a high coverage of targeted malonylginsenosides but introduced less false positives. It displayed comparable performance to a precursor ions list-driven targeted approach we have reported in the profiling and characterization of malonylginsenosides, but could avoid complex data processing. Totally 178 malonylginsenosides were characterized from the roots, leaves, and flower buds of P. ginseng, P. quinquefolius, and P. notoginseng, and most of them possess potentially new structures. The compositions of malonylginsenosides identified from these three Panax species are similar, and only malonylginsenoside Rb2 and some minor may have potential chemotaxonomic significance. In conclusion, we provide a potent analytical strategy for the direct and efficient screening of modified metabolites, which may have broad applications in the fields of metabolomics, drug metabolism, and natural product research.
需要特定的分析方法来对修饰代谢物进行非靶向分析。本研究在配有线性离子阱/轨道阱质谱仪的超高效液相色谱系统上建立了一种基于源内碰撞诱导解离（ISCID）-MS、质量标签-MS 和中性丢失扫描-MS 的非靶向分析策略。该策略用于从三种著名的人参属物种（人参、西洋参和三七）中筛选丙二酰基人参皂苷。鉴于在负离子电喷雾电离模式下 CO 和整个丙二酰基（CHO）的优先中性消除，本研究采用 MS 中的 ISCID 能量 40 V、归一化碰撞能（NCE）30%下导向 CID-MS 的质量标签 43.9898 Da、以及 NCE 70%下中性丢失 43.9898 Da 触发的高能 C 阱解离-MS，建立了一种伪中性丢失扫描（PNL）方法。该 PNL 方法实现了对靶向丙二酰基人参皂苷的高覆盖率，同时引入的假阳性较少。它与我们之前报道的用于丙二酰基人参皂苷分析和鉴定的前体离子列表驱动靶向方法具有相当的性能，但可以避免复杂的数据处理。从人参、西洋参和三七的根、叶和花蕾中鉴定出 178 种丙二酰基人参皂苷，其中大多数具有潜在的新结构。这三种人参属植物中鉴定出的丙二酰基人参皂苷组成相似，只有丙二酰基人参皂苷 Rb2 和一些次要成分可能具有潜在的化学分类学意义。总之，本研究提供了一种强大的分析策略，可直接、高效地筛选修饰代谢物，在代谢组学、药物代谢和天然产物研究等领域具有广泛的应用前景。
