Chem. J. Chinese Universities ›› 2009, Vol. 30 ›› Issue (8): 1566.

• Articles • Previous Articles     Next Articles

ESI Fragmentation Studies of Four Tea Catechins

LIU Guo-Qiang1, DONG Jing2, WANG Hong1, WAN Le-Ren2, HASHI Yuki2*, CHEN Shi-Zhong1*   

  1. 1. School of Pharmaceutical Science, Peking University, Beijing 100191, China;
    2. Shimadzu International Trading(Shanghai) Co. Limited, Beijing Office, Beijing 100020, China
  • Received:2008-12-12 Online:2009-08-10 Published:2009-08-10
  • Contact: CHEN Shi-Zhong. E-mail: chenshizhong66@163.com; HASHI Yuki. E-mail: y-hashi@shimadzu.co.jp
  • Supported by:

    国家“九七三”计划(批准号: 2006CB504707)资助.

Abstract:

The fragmentation pathways of tea catechins(two group stereoisomers ) were studied via the ion-trap time-of-flight(IT-TOF) mass spectrometer with the advantages of high mass accuracy, high resolution, multistage analysis. Hydrogen/deuterium exchange method was used to elucidate the fragmentation processes. The results show that catechin stereoisomers possess the same fragmentation pathways and cannot be differen-tiated even in MSn spectra. We can locate the loss of CO2 and C2H2O in MS2 spectra from EC/C to A ring and B ring, respectively. The ions of 1,4A-, 1,3A-, 1,2A- and [M-H-B ring]- were characteristic product ions for EC/C, and it could be used to propose the substituent group of A ring through the m/z shift of these ions. The ion at m/z 169 corresponding to the gallic acid anion was characteristic fragmentation of ECG/CG, which was great helpful for differentiating ECG/CG and EC/C.

Key words: EC/C; ECG/CG; Hydrogen/deuterium(H/D) exchange; Mass fragmentation

TrendMD: