A Dioxobilin‐Type Fluorescent Chlorophyll Catabolite as a Transient Early Intermediate of the Dioxobilin‐Branch of Chlorophyll Breakdown in Arabidopsis thaliana |
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Authors: | Iris Süssenbacher Prof. Dr. Stefan Hörtensteiner Prof. Dr. Bernhard Kräutler |
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Affiliation: | 1. Institut für Organische Chemie und Centrum für Molekulare Biowissenschaften, Universit?t Innsbruck, Innrain 80/82, 6020 Innsbruck (Austria);2. Institut für Pflanzenbiologie, Universit?t Zürich, Zollikerstrasse 107, 8008 Zürich (Switzerland) |
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Abstract: | Chlorophyll breakdown in higher plants occurs by the so called “PaO/phyllobilin” path. It generates two major types of phyllobilins, the characteristic 1‐formyl‐19‐oxobilins and the more recently discovered 1,19‐dioxobilins. The hypothetical branching point at which the original 1‐formyl‐19‐oxobilins are transformed into 1,19‐dioxobilins is still elusive. Here, we clarify this hypothetical crucial transition on the basis of the identification of the first natural 1,19‐dioxobilin‐type fluorescent chlorophyll catabolite (DFCC). This transient chlorophyll breakdown intermediate was isolated from leaf extracts of Arabidopsis thaliana at an early stage of senescence. The fleetingly existent DFCC was then shown to represent the direct precursor of the major nonfluorescent 1,19‐dioxobilin that accumulated in fully senescent leaves. |
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Keywords: | chlorophylls isomerization phyllobilin structure elucidation tetrapyrrole |
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