title: Biosynthesis and characterization of ¹⁵N₆-labeled phomopsin A, a lupin associated mycotoxin produced by Diaporthe toxica.
abstract: The hepatotoxin phomopsin A (PHO-A), a secondary metabolite mainly produced by the fungus Diaporthe toxica, occurs predominantly on sweet lupins. Along with the growing interest in sweet lupins for food and feed commodities, concerns have been raised about fungal infestations, and consequently, about the determination of PHO-A. High performance liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) represents the most suitable analytical technique for sensitive and selective detection of mycotoxins including PHO-A. However, isotopic labeled substances are needed as internal standards for a reliable and convenient quantification. As no isotope standard for PHO-A is currently available, a biosynthesis of fully (15)N6-labeled PHO-A was established by cultivation of D. toxica on defined media containing Na(15)NO3 and (15)N-labeled yeast extract as the only nitrogen sources. The identity of (15)N6-PHO-A was confirmed by high resolution mass spectrometry. The new (15)N6-labeled standard will facilitate the method development for PHO-A including a more accurate quantification by LC-MS/MS.
authors: BAM Federal Institute for Materials Research and Testing, Richard-Willstätter-Straße 11, 12489 Berlin, Germany.
authors: Svenja
authors: S
authors: Schloß
authors: BAM Federal Institute for Materials Research and Testing, Richard-Willstätter-Straße 11, 12489 Berlin, Germany.
authors: Ines
authors: I
authors: Wedell
authors: BAM Federal Institute for Materials Research and Testing, Richard-Willstätter-Straße 11, 12489 Berlin, Germany.
authors: Matthias
authors: M
authors: Koch
authors: University of Hamburg, Hamburg School of Food Science, Institute of Food Chemistry, Grindelallee 117, 20146 Hamburg, Germany.
authors: Sascha
authors: S
authors: Rohn
authors: BAM Federal Institute for Materials Research and Testing, Richard-Willstätter-Straße 11, 12489 Berlin, Germany; Leibniz-Institute of Vegetable and Ornamental Crops Großbeeren/Erfurt e.V., Theodor-Echtermeyer-Weg 1, 14979 Großbeeren, Germany. Electronic address: maul@igzev.de.
authors: Ronald
authors: R
authors: Maul
mesh_terms: D001203:Ascomycota / Q000378:metabolism*; D002853:Chromatography, Liquid / Q000379:methods; D009183:Mycotoxins / Q000096:biosynthesis* / Q000737:chemistry; D009587:Nitrogen Isotopes; D053719:Tandem Mass Spectrometry / Q000379:methods; D009842:Oligopeptides
chemical_list: D009183:Mycotoxins; D009587:Nitrogen Isotopes; C035753:phomopsin; D009842:Oligopeptides
keywords: Biosynthesis; Diaporthe toxica; Isotopic labeled internal standard; Lupins; Phomopsin A; Stable isotope dilution assay