Analysis of 12-oxo-phytodienoic acid enantiomers in biological samples by capillary gas chromatography-mass spectrometry using cyclodextrin stationary phases.
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.
Laudert
D
D
Lehrstuhl für Pflanzenphysiologie, Ruhr-Universität, Bochum, Germany.
Hennig
P
P
Stelmach
B A
BA
Müller
A
A
Andert
L
L
Weiler
E W
EW
D003505:Cyclodextrins / Q000737:chemistry*; D005231:Fatty Acids, Unsaturated / Q000032:analysis*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D019746:Intramolecular Oxidoreductases; D007535:Isomerases / Q000378:metabolism
D003505:Cyclodextrins; D005231:Fatty Acids, Unsaturated; C025999:12-oxophytodienoic acid; D007535:Isomerases; D019746:Intramolecular Oxidoreductases; C021377:hydroperoxide isomerase