title: A yellow chlorophyll catabolite is a pigment of the fall colours.
abstract: Here we describe the detection and identification of a yellow chlorophyll catabolite (Cj-YCC) in fresh extracts of senescent leaves of Cercidiphyllum japonicum. In addition, we report its partial synthesis by oxidation of Cj-NCC-1, the major (colourless) "nonfluorescent" chlorophyll catabolite (NCC) found in degreened leaves of C. japonicum. The spectroscopic analysis and structural characterization indicated Cj-YCC to be a simple dehydrogenation product of Cj-NCC-1 (by formal removal of a hydrogen atom at the C(20)- and C(1)-positions). Indeed, NCCs are easily oxidized and were first called "rusty pigments", as they had a tendency to turn brown upon storage on a dry silica gel plate. The yellow tetrapyrrole Cj-YCC may thus come about by oxidation of Cj-NCC-1 in the leaves. Its presence in the yellow leaves of a deciduous tree provides the first evidence for the contribution of a coloured chlorophyll catabolite to the fall colours.
authors.affiliation: Institute of Organic Chemistry, Innrain 52a & Centre of Molecular Biosciences, University of Innsbruck, A-6020, Innsbruck, Austria.
authors.forename: Simone
authors.initials: S
authors.lastname: Moser
authors.forename: Markus
authors.initials: M
authors.lastname: Ulrich
authors.forename: Thomas
authors.initials: T
authors.lastname: Müller
authors.forename: Bernhard
authors.initials: B
authors.lastname: Kräutler
mesh_terms: D002734:Chlorophyll / Q000737:chemistry* / Q000302:isolation & purification; D002851:Chromatography, High Pressure Liquid; D003116:Color; D008958:Models, Molecular; D008968:Molecular Conformation; D010858:Pigmentation; D018515:Plant Leaves / Q000737:chemistry* / Q000254:growth & development; D031995:Saxifragaceae / Q000737:chemistry*; D012621:Seasons; D013053:Spectrophotometry
chemical_list: D002734:Chlorophyll