Bai Hangrui, Wang Shujuan, Liu Jianjun, Gao Dan, Jiang Yuyang, Liu Hongxia, Cai Zongwei
Department of Chemistry, Tsinghua University, Beijing 100084, China; State Key Laboratory Breeding Base-Shenzhen Key Laboratory of Chemical Biology, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, China.
State Key Laboratory Breeding Base-Shenzhen Key Laboratory of Chemical Biology, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, China.
J Chromatogr B Analyt Technol Biomed Life Sci. 2016 Jul 15;1026:263-271. doi: 10.1016/j.jchromb.2015.09.024. Epub 2015 Oct 23.
The root of Panax ginseng C.A. Mey. (P. ginseng) is one of the most popular traditional Chinese medicines, with ginsenosides as its main bioactive components. Because different ginsenosides have varied pharmacological effects, extraction and separation of ginsenosides are usually required for the investigation of pharmacological effects of different ginsenosides. However, the contents of ginsenosides vary with the ages and tissues of P. ginseng root. In this research, an efficient method to explore the distribution of ginsenosides and differentiate P. ginseng roots with different ages was developed based on matrix assisted laser desorption/ionization time-of-flight mass spectrometry imaging (MALDI-TOF-MSI). After a simple sample preparation, there were 18 peaks corresponding to 31 ginsenosides with distinct localization in the mass range of m/z 700-1400 identified by MALDI-TOF-MSI and MALDI-TOF-MS/MS. All the three types of ginsenosides were successfully detected and visualized in images, which could be correlated with anatomical features. The P. ginseng at the ages of 2, 4 and 6 could be differentiated finely through the principal component analysis of data collected from the cork based on the ion images but not data from the whole tissue. The experimental result implies that the established method for the direct analysis of metabolites in plant tissues has high potential for the rapid identification of metabolites and analysis of their localizations in medicinal herbs. Furthermore, this technique also provides valuable information for the component-specific extraction and pharmacological research of herbs.
人参（Panax ginseng C.A. Mey.）的根是最受欢迎的传统中药之一，人参皂苷是其主要生物活性成分。由于不同的人参皂苷具有不同的药理作用，因此通常需要对人参皂苷进行提取和分离，以研究不同人参皂苷的药理作用。然而，人参根中人参皂苷的含量会因根的年龄和组织不同而有所变化。在本研究中，基于基质辅助激光解吸/电离飞行时间质谱成像（MALDI-TOF-MSI），开发了一种高效的方法来探索人参皂苷的分布并区分不同年龄的人参根。经过简单的样品制备后，通过MALDI-TOF-MSI和MALDI-TOF-MS/MS在m/z 700-1400质量范围内鉴定出18个对应于31种人参皂苷的峰，这些峰具有明显的定位。所有三种类型的人参皂苷都在图像中成功检测到并可视化，并且可以与解剖特征相关联。基于离子图像而非整个组织的数据，通过对从栓皮收集的数据进行主成分分析，可以精细地区分2年、4年和6年生的人参。实验结果表明，所建立的植物组织中代谢物直接分析方法在快速鉴定药用植物中的代谢物及其定位方面具有很高的潜力。此外，该技术还为草药的成分特异性提取和药理研究提供了有价值的信息。
