A Dioxobilin‐Type Fluorescent Chlorophyll Catabolite as a Transient Early Intermediate of the Dioxobilin‐Branch of Chlorophyll Breakdown in Arabidopsis thaliana. Issue 46 (1st October 2015)

• Record Type: Journal Article
• Authors: Süssenbacher, Iris; Hörtensteiner, Stefan; Kräutler, Bernhard
• Is Part Of: Angewandte Chemie international edition. Volume 54:Issue 46(2015)
• Page Start: 13777
• Page End: 13781
• Publication Date: 2015-10-01
• Subjects: chlorophylls -- isomerization -- phyllobilin -- structure elucidation -- tetrapyrrole; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201506299
• Languages: English
• ISSNs: 1433-7851

Abstract

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. Abstract : Chlorophyll breakdown in higher plants leads to phyllobilins, which are first formed as 1‐formyl‐19‐oxobilins. An enzyme‐catalyzed deformylation of the fleetingly existent "fluorescent catabolites" has been proposed for the subsequent generation of 1, 19‐dioxobilin‐type catabolites. A 1, 19‐dioxobilin‐type fluorescent catabolite that rapidly isomerizes to the nonfluorescent 1, 19‐dioxobilin was identified as a breakdown intermediate in Arabidopsis thaliana .