title: Localization of ginsenosides in Panax ginseng with different age by matrix-assisted laser-desorption/ionization time-of-flight mass spectrometry imaging.
abstract: 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.
authors.affiliation: 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.
authors.forename: Hangrui
authors.initials: H
authors.lastname: Bai
authors.affiliation: State Key Laboratory Breeding Base-Shenzhen Key Laboratory of Chemical Biology, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, China.
authors.forename: Shujuan
authors.initials: S
authors.lastname: Wang
authors.affiliation: Key Laboratory of Modern Toxicology of Shenzhen, Shenzhen Center for Disease Control and Prevention, Shenzhen 518055, China.
authors.forename: Jianjun
authors.initials: J
authors.lastname: Liu
authors.affiliation: State Key Laboratory Breeding Base-Shenzhen Key Laboratory of Chemical Biology, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, China.
authors.forename: Dan
authors.initials: D
authors.lastname: Gao
authors.affiliation: School of Medicine, Tsinghua University, Beijing 100084, China.
authors.forename: Yuyang
authors.initials: Y
authors.lastname: Jiang
authors.affiliation: State Key Laboratory Breeding Base-Shenzhen Key Laboratory of Chemical Biology, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, China. Electronic address: liuhx@sz.tsinghua.edu.cn.
authors.forename: Hongxia
authors.initials: H
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Environmental and Biological Analysis, Department of Chemistry, Hong Kong Baptist University, Kowloon Tong, Hong Kong SAR, China. Electronic address: zwcai@hkbu.edu.hk.
authors.forename: Zongwei
authors.initials: Z
authors.lastname: Cai
mesh_terms: D036145:Ginsenosides / Q000378:metabolism*; D005894:Panax / Q000378:metabolism*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*
chemical_list: D036145:Ginsenosides
keywords: Age; Differentiation; Ginsenosides; Matrix-assisted laser-desorption/ionization time-of-flight mass spectrometry imaging; Panax ginseng