New Bioactive Oxylipins Formed by Non‐Enzymatic Free‐Radical‐Catalyzed Pathways: the Phytoprostanes

Abstract

In animals and plants, fatty acids with at least three double bonds can be oxidized to prostaglandin-like compounds via enzymatic and non-enzymatic pathways. The most common fatty acid precursor in mammals is arachidonic acid (C20:4) (AA) which can be converted through the cyclooxygenase pathway to a series of prostaglandins (PG). Non-enzymatic cyclization of arachidonate yields a series of isoprostanes (IsoP) which comprises all PG (minor compounds) as well as PG isomers that cannot be formed enzymatically. In contrast, in plants, alpha-linolenic acid (C18:3) (ALA) is the most common substrate for the allene oxide synthase pathway leading to the jasmonate (JA) family of lipid mediators. Non-enzymatic oxidation of linolenate leads to a series of C18-IsoPs termed dinor IsoP or phytoprostanes (PP). PP structurally resemble JA but cannot be formed enzymatically. We will give an overview of the biological activity of the different classes of PP and also discuss their analytical applications and the strategies developed so far for the total synthesis of PP, depending on the synthetic approaches according to the targets and which key steps serve to access the natural products.

9-Lipoxygenase-derived oxylipins activate brassinosteroid signaling to promote cell wall-based defense and limit pathogen infection

“…The biosynthesis of plant oxylipins is initiated by the action of 9-and 13-lipoxygenases, a-dioxygenases (a-DOX), or monooxygenases, all of which predominantly catalyze the oxygenation of linolenic acid (18:3) and linoleic acid (18:2) into reactive hydroperoxides, followed by secondary modification catalyzed mainly by cytochrome P450 enzymes or peroxygenases (Blée, 2002;Hamberg et al, 2002Hamberg et al, , 2003Andreou et al, 2009;Zoeller et al, 2012). Oxylipins can also be produced nonenzymatically from polyunsaturated fatty acids in the presence of singlet oxygen or by free radical-mediated oxygenation (Durand et al, 2009).…”

Defense Activated by 9-Lipoxygenase-Derived Oxylipins Requires Specific Mitochondrial Proteins

“…Oxylipins are produced by initial oxidation of fatty acids, mainly linolenic and linoleic acids, by the action of lipoxygenases (9-lipoxygenase [9-LOX] and 13-lipoxygenase), a-dioxygenases, or monooxygenases followed by secondary modifications catalyzed mainly by cytochrome P450 enzymes or peroxygenase (Blée, 2002;Hamberg et al, 2002;Andreou et al, 2009). In addition, production of oxylipins from polyunsaturated fatty acids can take place nonenzymatically in the presence of singlet oxygen or by free radical-mediated oxygenation (Durand et al, 2009).…”

Valorization Strategy of Banana Passion Fruit Shell Wastes: An Innovative Source of Phytoprostanes and Phenolic Compounds and Their Potential Use in Pharmaceutical and Cosmetic Industries

“…In the current study, the total PhytoPs content in banana passion fruit shell samples (2318.63 ± 71.51 µg/ 100 g DW) was in the range higher than dry macroalgae species (from 0.0056 to 1.38 µg/ 100 g DW) [23] or in almonds samples of different cultivars (from 4.0 to 23.8 µg/ 100 g DW) [15] or in gulupa shell (from 0.13 to 6.76 µg/ 100 g DW) [27]. This fact is very important due to these wastes from banana passion fruit represented a valuable source of PhytoPs -with higher content than other matrices studiedand it could have a number of repercussions, especially for the future applications of these wastes in pharmaceutical and cosmetic industries because their high content in these compounds with multiple biological activities [8,9]. On the other hand, in previous reports, GC-MS has been the most widely used analytical technique to detect PhytoPs.…”

“…The PhytoPs (oxylipins) are formed by non-enzymatic peroxidation of α-linolenic acid (C18: 3, n-3, ALA) -the predominant polyunsaturated fatty acids (PUFA) in plants- [8]. In addition, several researchers have proposed that PhytoPs have multiple functions in both plants and humans [8,9,10]. In plants, these bioactive compounds participates in an archaic signaling system that serves to protect plants form oxidative stress (OS), detoxification pathways and they contributes on phytoalexins accumulation in a variety of vegetables species [11].…”