title: Classification and characterization of unknown cytokinins into essential types by in-source collision-induced dissociation electrospray ionization ion trap mass spectrometry.
abstract: BACKGROUND
  Mass spectrometry is effective for determination of cytokinins, which are bioactive compounds with an adenine-core structure. However, it is difficult to characterize any cytokinin compound without the relevant standard or known molecular structure information. With a limited number of standards, an in-source collision-induced dissociation (CID) method for characterization and classification of unknown cytokinins was described in this study.
  
  
  METHODS
  Cytokinins were separated by high-performance liquid chromatography and then analyzed by electrospray ionization ion trap mass spectrometry using an in-source CID technique and multiple reaction monitoring (MRM) mode.
  
  
  RESULTS
  Based on the properties of multi-stage fragmentation in mass spectrometry, naturally occurring cytokinins were classified into four types (zeatin, dihydrogen zeatin, isopentenyl adenine and benzyl adenine) by losing their conjugated sugar, sugar phosphate and other substituents in the source region. Following this technique, seven unknown cytokinins were characterized from roots of maize (Zea mays) without standards and one of them was finally confirmed to be cis-zeatin-riboside.
  
  
  CONCLUSIONS
  An in-source CID technique combined with MRM mass spectrometry was developed to provide product ion information for identification of cytokinins and to afford guidance for the discovery of unknown cytokinins.
authors: College of Life Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, P.R. China.
authors: Shichang
authors: S
authors: Liu
authors: Weiqi
authors: W
authors: Chen
authors: Kai
authors: K
authors: Fang
authors: Xiangning
authors: X
authors: Jiang
authors: Ying
authors: Y
authors: Gai
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods; D003583:Cytokinins / Q000032:analysis / Q000737:chemistry / Q000145:classification*; D018517:Plant Roots / Q000737:chemistry; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D013403:Sugar Phosphates / Q000737:chemistry; D003313:Zea mays / Q000737:chemistry
chemical_list: D003583:Cytokinins; D013403:Sugar Phosphates