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@INPROCEEDINGS{Thiele:828636,
      author       = {Thiele, Björn and Neuwohner, Andrea and Janzik, Ingar and
                      Jahnke, Siegfried and Matsubara, Shizue},
      title        = {{Q}uantitative turnover analysis of chlorophylls,
                      carotenoids and tocopherol in green leaves by {LC}-{MS} and
                      {FTICR}-{MS}},
      reportid     = {FZJ-2017-02534},
      year         = {2017},
      abstract     = {Quantitative turnover analysis of chlorophylls, carotenoids
                      and tocopherol in green leaves by LC-MS and FTICR-MSBjörn
                      Thiele*, Andrea Neuwohner, Siegfried Jahnke, Ingar Janzik,
                      Shizue MatsubaraIBG-2: Pflanzenwissenschaften,
                      Forschungszentrum Jülich, D-52425 Jülich, GermanyAbstract:
                      Chlorophylls and carotenoids are belonging to the
                      photosynthetic pigments in chloroplasts of plants playing
                      central roles in light absorption and photoprotection.
                      Synthesis and degradation of photosynthetic pigments
                      (chlorophylls and carotenoids) have been mostly studied in
                      leaves during greening or senescence but not in mature
                      leaves. The question how much biosynthesis and degradation
                      of different photopigments occurs in photosynthesizing green
                      leaves is still open. In order to gain insight into
                      photopigment turnover of mature leaves we conducted
                      long-term 13CO2 labelling with peppermint (Mentha x
                      piperita) and analyzed the 13C/12C signature of chlorophylls
                      (Chls), carotenoids and tocopherols (Toc) by LC-MS and
                      FTICR-MS.Materials and Methods: Peppermint plants were
                      cultivated in a 13CO2 containing atmosphere for 34 d [1].
                      Hereupon they were transferred to ambient CO2 where samples
                      were collected from mature leaves over 7 days. Leave samples
                      from day 0, 1, 2 and 7 were extracted and analyzed by
                      LC-PDA-ESI(+)-MS using a C30 column. High resolved FTICR
                      mass spectra were obtained from some exemplary samples in
                      order to distinguish peaks of pigment isotopomers from those
                      of co‐eluting matrix compounds and to assign mass peaks to
                      distinct empirical formulae. The 13C degrees of labelling
                      (DoL) of various photopigments over time were determined
                      from the mass spectra. Additional MS/MS experiments were
                      performed to gain insight into the position of 13C in the
                      photopigment molecules. Results: The main photopigments in
                      peppermint extracts were Chls a and b, -Toc and the
                      xanthophylls lutein, zeaxanthin, antheraxanthin, neoxanthin
                      (Neo) and violaxanthin and finally -carotene (-Car).
                      While Chls and -Toc predominantly formed [M + H]+ adducts
                      in the positive ESI mode, [M]+ and [M + H – H2O]+ adducts
                      were additionally detected for carotenoids. After clearing
                      up the mass spectra from matrix compound derived peaks DoLs
                      were determined. Their time courses showed a high turnover
                      for Chl a and -Car, a lower non-linear decline in DoL for
                      xanthophylls but almost no change in the DoL for Neo. A
                      distinct maximum peak in the mass spectra of -Toc from
                      day 1 – 7 located between the extreme values for
                      non-labelling and full labelling indicated a recycling of
                      the phytol moiety during turnover of -Toc [2]. MS/MS
                      experiments supported this hypothesis. Further results
                      concerning turnover of Chls and xanthophylls will be also
                      presented and discussed in the biological context.New
                      Aspects: Regulation of photopigment metabolism in mature
                      leavesReferences:[1] Gleichenhagen et al. (2013) Food Chem.
                      141: 2582‐2590.[2] Ischebeck et al. (2006) J. Biol. Chem.
                      281: 2470‐2477.Keywords: Turnover of photopigments, 13C
                      labelling, LC-MS, FTICR-MS},
      month         = {Mar},
      date          = {2017-03-05},
      organization  = {DGMS Jahrestagung, Kiel (Germany), 5
                       Mar 2017 - 8 Mar 2017},
      subtyp        = {Other},
      cin          = {IBG-2},
      cid          = {I:(DE-Juel1)IBG-2-20101118},
      pnm          = {582 - Plant Science (POF3-582)},
      pid          = {G:(DE-HGF)POF3-582},
      typ          = {PUB:(DE-HGF)24},
      url          = {https://juser.fz-juelich.de/record/828636},
}