title: Analysis of 12-oxo-phytodienoic acid enantiomers in biological samples by capillary gas chromatography-mass spectrometry using cyclodextrin stationary phases.
abstract: The octadecanoid plant growth regulator 12-oxo-phytodienoic acid (12-oxo-PDA), which is also an intermediate in the biosynthesis of jasmonic acid, is obtained from 13-hydroperoxylinolenic acid via an unstable allene oxide generated by the enzyme allene oxide synthase. Recombinant, bacterially expressed and purified allene oxide synthase from Arabidopsis thaliana yields racemic 12-oxo-PDA as a mixture of 94:6 cis:trans diastereomers. In the presence of allene oxide cyclase from Solanum tuberosum, a product of high enantiomeric purity was obtained, which was shown to be (+)-cis-12-oxo-PDA (98:2 cis:trans diastereomers). Based on this coupled reaction, a preparative procedure was developed that yields pure (+)-cis-12-oxo-PDA in milligram quantities. Furthermore, an analytical technique employing capillary gas chromatography-mass spectrometry and beta- or gamma-cyclodextrin stationary phases was developed that enables the direct analysis of nanogram amounts of enantiomers of 12-oxo-PDA, as their methyl esters, in plant tissues. In the species analyzed, endogenous cis-12-oxo-PDA is the (+)-enantiomer.
authors.affiliation: Lehrstuhl für Pflanzenphysiologie, Ruhr-Universität, Bochum, Germany.
authors.forename: D
authors.initials: D
authors.lastname: Laudert
authors.forename: P
authors.initials: P
authors.lastname: Hennig
authors.forename: B A
authors.initials: BA
authors.lastname: Stelmach
authors.forename: A
authors.initials: A
authors.lastname: Müller
authors.forename: L
authors.initials: L
authors.lastname: Andert
authors.forename: E W
authors.initials: EW
authors.lastname: Weiler
mesh_terms: D003505:Cyclodextrins / Q000737:chemistry*; D005231:Fatty Acids, Unsaturated / Q000032:analysis*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D019746:Intramolecular Oxidoreductases; D007535:Isomerases / Q000378:metabolism
chemical_list: D003505:Cyclodextrins; D005231:Fatty Acids, Unsaturated; C025999:12-oxophytodienoic acid; D007535:Isomerases; D019746:Intramolecular Oxidoreductases; C021377:hydroperoxide isomerase