Laudert D, Hennig P, Stelmach B A, Müller A, Andert L, Weiler E W
Lehrstuhl für Pflanzenphysiologie, Ruhr-Universität, Bochum, Germany.
Anal Biochem. 1997 Mar 15;246(2):211-7. doi: 10.1006/abio.1997.2012.
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.
十八碳酸植物生长调节剂12-氧代植物二烯酸（12-oxo-PDA）也是茉莉酸生物合成的中间体，它是由13-氢过氧亚麻酸通过丙二烯氧化物合酶产生的不稳定丙二烯氧化物得到的。从拟南芥中重组、细菌表达并纯化的丙二烯氧化物合酶产生外消旋的12-氧代-PDA，它是94:6顺式:反式非对映异构体的混合物。在存在来自马铃薯的丙二烯氧化物环化酶的情况下，获得了高对映体纯度的产物，经证明它是(+)-顺式-12-氧代-PDA（98:2顺式:反式非对映异构体）。基于这种偶联反应，开发了一种制备方法，可产生毫克量的纯(+)-顺式-12-氧代-PDA。此外，还开发了一种采用毛细管气相色谱-质谱联用以及β-或γ-环糊精固定相的分析技术，该技术能够直接分析植物组织中纳克量的12-氧代-PDA对映体（作为它们的甲酯）。在所分析的物种中，内源性顺式-12-氧代-PDA是(+)-对映体。
