title: Fragmentation study of noscapine derivatives under electrospray conditions.
abstract: BACKGROUND
  Noscapine is a biologically active molecule with anticancer activity among other things. Therefore, from an analytical point of view, knowledge of the mass spectrometric properties of noscapine and its derivatives is essential. The goal of the present study is to describe the collision-induced dissociation behavior of noscapine and its seven derivatives ionized by protons and lithium and sodium ions.
  
  
  METHODS
  Protonated noscapines were produced using electrospray ionization (ESI) mass spectrometry (MS). For the tandem mass spectrometry (MS/MS) experiments nitrogen was used as the collision gas and the collision energies were varied in the range of 1-53 eV (in the laboratory frame).
  
  
  RESULTS
  The ESI-MS/MS measurements showed that the MS/MS spectra of the protonated noscapines were more informative than the lithiated and sodiated ones. Based on the MS/MS studies, the main fragmentation channels of the protonated noscapines were found to be the loss of water and the loss of a meconine moiety from the precursor ion; furthermore, methyl transfer was also observed in the MS/MS spectra.
  
  
  CONCLUSIONS
  The MS/MS study of the protonated noscapines gives more structural information than that of lithiated and sodiated noscapines. However, the most important fragmentation channel, which leads to the formation of the most intensive product ion in the MS/MS spectra, is independent of the ionization agent.
authors.affiliation: Department of Applied Chemistry, University of Debrecen, Egyetem tér 1, H-4032, Debrecen, Hungary.
authors.forename: Lajos
authors.initials: L
authors.lastname: Nagy
authors.forename: Ákos
authors.initials: Á
authors.lastname: Kuki
authors.forename: Katalin
authors.initials: K
authors.lastname: Szabó
authors.forename: Attila
authors.initials: A
authors.lastname: Sipos
authors.forename: Miklós
authors.initials: M
authors.lastname: Zsuga
authors.forename: Sándor
authors.initials: S
authors.lastname: Kéki
mesh_terms: D007477:Ions / Q000737:chemistry*; D008094:Lithium; D008958:Models, Molecular; D009665:Noscapine / Q000737:chemistry*; D012964:Sodium; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D053719:Tandem Mass Spectrometry / Q000379:methods; D014867:Water
chemical_list: D007477:Ions; D014867:Water; D009665:Noscapine; D008094:Lithium; D012964:Sodium