Plant and fungal oxylipins
Enzymatic and non-enzymatic lipid peroxidation is a major event occurring in lipid metabolism. It results in the formation of oxygenated fatty acids and oxygenated complex lipids, collectively so-called oxylipins. They represent a structurally highly diverse group of compounds including metabolites like fatty acid hydroperoxides, epoxides, ketones, divinyl ethers and the plant hormone jasmonic acid. Oxylipins are involved in plant growth and development as well as in plants response to environmental stimuli such as wounding and pathogen attack.
The developed method for oxylipin profiling covers the analysis of 120 markers for autoxidation as well as of the so-called lipoxygenase (LOX) pathway which is the most prominent pathway of enzymatic lipid peroxidation in plants. The LOX-derived hydroperoxides of polyunsaturated C16- and C18-fatty acids are substrates of six different enzyme families within the LOX pathway. The oxylipin analysis starts with an organic extraction of frozen plant tissue followed by a set of HPLC, HPLC-MS/MS, GC and/or GC-MS separation and detection steps. The sequential analysis of the plant material by reversed-phase (RP), straight-phase (SP) and chiral-phase (CP) chromatography leads to the unequivocal identification of constitutional isomers as well as stereoisomers of oxylipin species.
Analysis of oxylipins by straight-phase (SP)-HPLC analysis
Separation of oxylipin stereoisomers (R- and S-enantiomers) by chiral-phase (CP)-HPLC analysis