Direct observation of the (forbidden) S-1 state in carotenoids

Research output: Contribution to journalArticle


Carotenoids are involved in a variety of biological functions, yet the underlying mechanisms are poorly understood, in part because of the long-standing difficulty in assigning the location of the first excited (S-1) state. Here, we present a method for determining the energy of the forbidden S-1 state, on the basis of ultrafast spectroscopy of the short lived level. Femtosecond transient absorption spectra and kinetics of the S-1 --> S-2 transition revealed the location of the intermediate level in two carotenoid species involved in the xanthophyll cycle, zeaxanthin and violaxanthin, and yielded surprising implications regarding the mechanism of photoregulation in photosynthesis.


Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Biological Sciences
  • Atom and Molecular Physics and Optics


  • dependence, photophysics, fluorescence, spectroscopy, energy, photosynthesis, spheroidene, dissipation, xanthophyll cycle, internal-conversion rate
Original languageEnglish
Pages (from-to)4914-4917
JournalProceedings of the National Academy of Sciences
Issue number9
Publication statusPublished - 1999
Publication categoryResearch

Bibliographic note

The information about affiliations in this record was updated in December 2015. The record was previously connected to the following departments: Biochemistry and Structural Biology (S) (000006142), Chemical Physics (S) (011001060)