title: MALDI imaging for the localization of saponins in root tissues and rapid differentiation of three Panax herbs.
abstract: The roots of Panax genus with ginseng saponins as bioactive ingredients have been widely used as herbal medicines and food additives. Panax ginseng, Panax quinquefolius, and Panax notoginseng are three major commercial species in Panax genus, with similar morphological appearance but different pharmacological functions. Various methods have been developed and applied for the differentiation of these species. In this work, MALDI-TOF-MS imaging (MSI) was employed for the localization of saponins in root tissues and for the rapid differentiation of the three Panax species for the first time. After a simple sample preparation, MALDI-TOF-MSI analysis of root tissue allowed the detection of 51 saponins. Localization of saponins in the tissue was mapped in ion images, which were obviously related to botanical structure. The localization modes varied with Panax species, providing valuable information for the discrimination of ginseng species. Principal component analysis (PCA) of data collected from areas with abundant saponins based on ion images was applied for the differentiation. Nine characteristic saponin peaks were identified from the PCA analysis. The MALDI-TOF-MSI together with area-specific data analysis provided high potential for the rapid differentiation of Panax herbs.
authors.affiliation: State Key Laboratory Breeding Base-Shenzhen Key Laboratory of Chemical Biology, Graduate School at Shenzhen, Tsinghua University, Shenzhen, P. R. China.|Key Laboratory of Metabolomics at Shenzhen, Graduate School at Shenzhen, Tsinghua University, Shenzhen, P. R. China.
authors.forename: Shujuan
authors.initials: S
authors.lastname: Wang
authors.affiliation: State Key Laboratory Breeding Base-Shenzhen Key Laboratory of Chemical Biology, Graduate School at Shenzhen, Tsinghua University, Shenzhen, P. R. China.|Key Laboratory of Metabolomics at Shenzhen, Graduate School at Shenzhen, Tsinghua University, Shenzhen, P. R. China.
authors.forename: Hangrui
authors.initials: H
authors.lastname: Bai
authors.affiliation: State Key Laboratory of Environmental and Biological Analysis, Department of Chemistry, Hong Kong Baptist University, Kowloon Tong, Hong Kong, SAR, P. R. China.
authors.forename: Zongwei
authors.initials: Z
authors.lastname: Cai
authors.affiliation: State Key Laboratory Breeding Base-Shenzhen Key Laboratory of Chemical Biology, Graduate School at Shenzhen, Tsinghua University, Shenzhen, P. R. China.|Key Laboratory of Metabolomics at Shenzhen, Graduate School at Shenzhen, Tsinghua University, Shenzhen, P. R. China.
authors.forename: Dan
authors.initials: D
authors.lastname: Gao
authors.affiliation: State Key Laboratory Breeding Base-Shenzhen Key Laboratory of Chemical Biology, Graduate School at Shenzhen, Tsinghua University, Shenzhen, P. R. China.|School of Medicine, Tsinghua University, Beijing, P. R. China.
authors.forename: Yuyang
authors.initials: Y
authors.lastname: Jiang
authors.affiliation: Key Laboratory of Modern Toxicology of Shenzhen, Shenzhen Center for Disease Control and Prevention, Shenzhen, P. R. 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, P. R. China.|Key Laboratory of Metabolomics at Shenzhen, Graduate School at Shenzhen, Tsinghua University, Shenzhen, P. R. China.
authors.forename: Hongxia
authors.initials: H
authors.lastname: Liu
mesh_terms: D036145:Ginsenosides / Q000032:analysis; D005894:Panax / Q000737:chemistry*; D018517:Plant Roots / Q000737:chemistry*; D012503:Saponins / Q000032:analysis*; D013045:Species Specificity; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*
chemical_list: D036145:Ginsenosides; D012503:Saponins
keywords: Differentiation; Localization; MALDI imaging; Panax species; Saponins