Lipids oxylipins

The alcohol moiety is produced in a different manner from that of the acid moiety. The alcohol moiety resembles the plant hormone jasmonic acid (JA) (26) generated from linolenoyl moiety of lipids via (13,S )-hydroperoxy-linolenic acid (22), (12.13,S )-epoxylinolenic acid (23), and 12-oxo-cis-10.15-phytodienoic acid (24) by the oxylipin or octadecanoid pathway (Fig. 3) [31]. In fact, 13C was incorporated at pyrethrolone (1) carbon positions that agreed with those predicted to be labeled when the alcohol moiety is produced via the pathway (Fig. 3) [30]. Figure 3 illustrates that m-jasmone (25) is hydroxylated to yield jasmololone (4), which is then dehydrogenated to yield pyrethrolone (5). However, it has not yet been determined if this is actually the case. 

Lipopolysaccharides Human pathogenic and marine bacteria Lipid A + various attached oligosaccharide decorations Oxidative burst, and oxylipin production in L. digitata Kupper et al. 2006... 

Lipids can be oxidized by some ROS such as hydroxyl ( OH). but not by H202, NO, or 02 - (Halliwell and Gutteridge 1999). However, both enzymatic and nonenzymatic cellular mechanisms can oxidize fatty acids. Challenging L. digitata sporophytes with lipopolysaccharides from various sources resulted in a rapid release of free fatty acids (FFAs) with a concomitant accumulation of oxidized derivatives of linolenic (08 2) and eicosapentaenoic acid (C20 5) (Kiipper et al. 2006). Other strong inducers of the oxidative burst, such as oligoguluronates, in Laminaria could induce neither the release of FFAs nor the oxylipin production. These results... 

Faueonnier, M. L., Welti, R., Blee, E., Marlier, M. (2003a). Lipid and oxylipin profiles during aging and sprout development in potato tubers (Solanum tuberosum L.). Biochim. Biophys. Acta, 1633,118-126. 

Gerwick, W. H., Epoxy allylic carbocations as conceptual intermediates in the biogenesis of diverse marine oxylipins, Lipids, 31, 1215, 1996. 

Lipid-derived reactive electrophile species and nonenzymatically formed oxylipins Physiology... 

Jasmonate is one of several lipid-derived plant growth regulators referred to as oxylipins... 

Andreou A, Brodhun F, Feussner 1 (2009) Biosynthesis of oxylipins in non-mammals. Prog Lipid Res 48 148-170... 

Hamberg, M. (1993) Pathways in the biosynthesis of oxylipins in plants,]. Lipid Mediators 6, 375-384... 

Since AA is only a minor fatty acid in higher plants, eicosanoids are not of major importance for plant physiology. However, the oxygenation metabolites of linoleic acid and a-linolenic acid, called oxylipins [5,6], do play a role in plant defence reactions, in the formation of phytohormones and in the synthesis of cutin monomers [6,40-43]. Oxylipins constitute a family of lipids that are formed from free fatty acids by a cascade of reactions involving at least one step of dioxygen-dependent oxidation. The biosynthesis of oxylipins proceeds via a large number of metabolic pathways, most of which involve an unsaturated hydroperoxy fatty acid as intermediate (Scheme 10). Conversion of the hydroperoxide via the peroxide lyase pathway, the allene oxide pathway and the recently discovered peroxygenase pathway, leads to a complex pattern of oxidized lipid mediators. 

The localization of enzymes of the oxylipin pathway has yet to be unequivocally elucidated. Nonetheless, LOX has been localized in plastids, vacuoles and the cytoplasm, e.g. [1], and in lipid bodies [36,37]. Since enzymes of the jasmonic acid biosynthetic pathway are thought to be localized mainly in plastids, mechanisms must exist to shuttle fatty acids released from the plasma membrane to the plastids. Furthermore, since p-oxidation of fatty acids normally occurs in peroxisomes, transport vesicles that carry the cargo between organelles may exist in plant cells. It is tempting to speculate that there could be fusion or mixing of compartments that contain either enzymes, fatty acids, and/or intermediate products, thus resulting in oxylipin biosynthesis. Intensive research is needed to address these questions as well as the cell-specific and the subcellular localization of oxylipin synthesis and the mechanisms that regulate this process. 

Gene Database lipid metabolism including oxylipin and wax metabolism, evidence for activity, pathway schemes, tissue expression profiling msu.edu/... 

Jiang, Z.D. and Gerwick, W.H. (1997) Novel oxylipins from the temperate red alga Polyneura latissima - evidence for an arachidonate 9(S)-lipoxygenase. Lipids, 32, 231-235. 

Lipids Fatty Acids, Acyltunichlorins, Polyketides, and Oxylipins... 

Most of the literature on lipids concerns the sterol compositions and oxylipins. Some original and classical sterol have been isolated from Obdia longissima harvested in the Black Sea (De Rosa et al, 1999), and several... 

General Information on Lipids Hydrocarbons, Fatty Acids, Oxylipins, and Sterols ... 

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