title: Colorless chlorophyll catabolites in senescent florets of broccoli (Brassica oleracea var. italica).
abstract: Typical postharvest storage of broccoli (Brassica oleracea var. italica) causes degreening of this common vegetable with visible loss of chlorophyll (Chl). As shown here, colorless Chl-catabolites are generated. In fresh extracts of degreening florets of broccoli, three colorless tetrapyrrolic Chl-catabolites accumulated and were detected by high performance liquid chromatography (HPLC): two "nonfluorescent" Chl-catabolites (NCCs), provisionally named Bo-NCC-1 and Bo-NCC-2, and a colorless 1,19-dioxobilin-type "nonfluorescent" Chl-catabolite (DNCC), named Bo-DNCC. Analysis by nuclear magnetic resonance spectroscopy and mass spectrometry of these three linear tetrapyrroles revealed their structures. In combination with a comparison of their HPL-chromatographic properties, this allowed their identification with three known catabolites from two other brassicacea, namely two NCCs from oil seed rape (Brassica napus) and a DNCC from degreened leaves of Arabidopsis thaliana.
authors.affiliation: Institute of Organic Chemistry and Center for Molecular Biosciences, University of Innsbruck, Center of Chemistry and Biomedicine , Innrain 80/82, A-6020 Innsbruck, Austria.
authors.forename: Matthias H
authors.initials: MH
authors.lastname: Roiser
authors.forename: Thomas
authors.initials: T
authors.lastname: Müller
authors.forename: Bernhard
authors.initials: B
authors.lastname: Kräutler
mesh_terms: D001937:Brassica / Q000737:chemistry* / Q000378:metabolism; D002734:Chlorophyll / Q000737:chemistry / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D003116:Color; D005453:Fluorescence; D061353:Food Storage; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure
chemical_list: D002734:Chlorophyll
keywords: broccoli; chlorophyll catabolites; natural product; nutrition; structure elucidation; vegetable