Analysis of 12-Oxo-phytodienoic Acid Enantiomers in Biological Samples by Capillary Gas Chromatography–Mass Spectrometry Using Cyclodextrin Stationary Phases
✍ Scribed by Dietmar Laudert; Peter Hennig; Boguslawa A. Stelmach; Axel Müller; Leo Andert; Elmar W. Weiler
- Publisher
- Elsevier Science
- Year
- 1997
- Tongue
- English
- Weight
- 160 KB
- Volume
- 246
- Category
- Article
- ISSN
- 0003-2697
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✦ Synopsis
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.