title: Mass spectrometric imaging of ginsenosides localization in Panax ginseng root.
abstract: We performed mass spectrometric imaging (MSI) to localize ginsenosides (Rb(1), Rb(2) or Rc, and Rf) in cross-sections of the Panax ginseng root at a resolution of 100 microm using matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). Tandem mass spectrometry (MS/MS) of alkali metal-adducted ginsenoside ions revealed structural information of the corresponding saccharides and aglycone. MALDI-MSI confirmed that ginsenosides were located more in the cortex and the periderm than that in the medulla of a lateral root. In addition, it revealed that localization of ginsenosides in a root tip (diameter, 2.7 mm) is higher than that in the center of the root (diameter, 7.3 mm). A quantitative difference was detected between localizations of protopanaxadiol-type ginsenoside (Rb(1), Rb(2), or Rc) and protopanaxatriol-type ginsenoside (Rf) in the root. This imaging approach is a promising technique for rapid evaluation and identification of medicinal saponins in plant tissues.
authors.affiliation: Japan Advanced Institute of Science and Technology, Nomi, Ishikawa, Japan.
authors.forename: Shu
authors.initials: S
authors.lastname: Taira
authors.forename: Ryuzo
authors.initials: R
authors.lastname: Ikeda
authors.forename: Naohiko
authors.initials: N
authors.lastname: Yokota
authors.forename: Issey
authors.initials: I
authors.lastname: Osaka
authors.forename: Manabu
authors.initials: M
authors.lastname: Sakamoto
authors.forename: Mitsuro
authors.initials: M
authors.lastname: Kato
authors.forename: Yuko
authors.initials: Y
authors.lastname: Sahashi
mesh_terms: D036145:Ginsenosides / Q000032:analysis* / Q000737:chemistry; D018519:Meristem / Q000033:anatomy & histology / Q000737:chemistry; D015394:Molecular Structure; D005894:Panax / Q000033:anatomy & histology / Q000737:chemistry*; D018517:Plant Roots / Q000033:anatomy & histology / Q000737:chemistry*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D052584:Xylem / Q000033:anatomy & histology / Q000737:chemistry
chemical_list: D036145:Ginsenosides