title: cPPB-aE is discovered from photosynthetic benthic dinoflagellates.
abstract: Although chlorophyll degradation pathways in higher plants have been well studied, little is known about the mechanisms of chlorophyll degradation in microalgae. In this article, we report the occurrence of a chlorophyll a derivative that has never been discovered in photosynthetic organisms. This chlorophyll derivative emits no fluorescence and has a peculiar absorbance peak at 425, 451, 625, and 685 nm. From these features, it was identified as 13(2) ,17(3) -cyclopheophorbide a enol (cPPB-aE), reported as a degradation product of chlorophyll a derived from prey algal cells in heterotrophic protists. We discovered cPPB-aE in six benthic photosynthetic dinoflagellates that are phylogenetically separated into four clades based on SSU rDNA molecular phylogeny. This is the first report of this chlorophyll derivative in photosynthetic organisms and we suggest that the derivative is used to quench excess light energy.
authors.affiliation: Department of Natural History Sciences, Graduate School of Science, Hokkaido University, Sapporo 060-0810, Japan.
authors.forename: Norico
authors.initials: N
authors.lastname: Yamada
authors.affiliation: Institute of Low Temperature Science, Hokkaido University, Sapporo 060-0819, Japan.
authors.forename: Ayumi
authors.initials: A
authors.lastname: Tanaka
authors.affiliation: Department of Natural History Sciences, Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan.
authors.forename: Takeo
authors.initials: T
authors.lastname: Horiguchi
keywords: HPLC; benthic; cPPB-aE; dinoflagellate; molecular phylogeny; photosynthetic