Photoprotection by carotenoids during photosynthesis: Motional dependence of intramolecular energy transfer

Ana L Moore, Anna Joy, Roderick Tom, John Devens Gust, Thomas A Moore, René V. Bensasson, Edward J. Land

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A new carotenoporphyrin has been prepared in which a synthetic carotenoid is joined to a tetraarylporphyrin through a flexible trimethylene linkage. This molecule exists primarily in an extended conformation with the carotenoid chromophore far from the porphyrin π-electron system. In benzene solution, where large-amplitude molecular motions are rapid, the molecule can momentarily assume less stable conformations which favor triplet energy transfer, and quenching of the porphyrin triplet by the carotenoid is fast. In a polystyrene matrix or frozen glass such motions are slow, and energy transfer cannot compete with other pathways for depopulating the triplet state. These observations help establish the requirements for biological photoprotection.

Original languageEnglish
Pages (from-to)982-984
Number of pages3
Issue number4549
Publication statusPublished - 1982


ASJC Scopus subject areas

  • General

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