title: Fragmentation investigation of seven arylnaphthalide lignans using liquid chromatography/tandem quadrupole time-of-flight mass spectrometry.
abstract: BACKGROUND
  The combination of fragmentation patterns in positive and negative ion modes could be helpful in understanding the structural features of these arylnaphthalide lignans.
  
  
  METHODS
  Fragmentation patterns of seven arylnaphthalide lignans were investigated using liquid chromatography/tandem time-of-flight mass spectrometry, and their fragmentation pathways were comprehensively characterized.
  
  
  RESULTS
  In the positive ion mode, the cleavage of the C-1'-C-7' bond was the most characteristic fragmentation pattern of the lignans with both 2'-hydroxy and 4',5'-methylenedioxy groups on the B ring. Arylnaphthalide lignans containing a methylenedioxy group on the B ring could lose C(2)H(2)O(2) easily. The characteristic mass losses of 58 Da (C(2)H(2)O(2)) could indicate the presence of a methylenedioxy group on the B ring. In the negative ion mode, the type of substituents at C-7 could affect the cleavage pattern of the lactone ring.
  
  
  CONCLUSIONS
  In search for new compounds, and also in quality control, there is a need to have reliable methodology for the analysis of arylnaphthalide lignans. These results should be useful in the analysis of natural products with similar substructures from Chinese herbs in the future.
authors.affiliation: Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing 100193, PR China.
authors.forename: Wei
authors.initials: W
authors.lastname: Li
authors.forename: Meihua
authors.initials: M
authors.lastname: Yang
authors.forename: Yuguo
authors.initials: Y
authors.lastname: Zheng
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D017705:Lignans / Q000737:chemistry*; D015394:Molecular Structure; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D017705:Lignans