Adecatrieonic acid (), are converted into their hydroperoxide types through oxygenation by particular lipoxygenases (LOXs).The resulting (S)hydroxyperoxyoctadecadi(tri)enoic acid (HPOT) and (S)hydroperoxyhexadeca(tri)enoic acid (HPHT) in their turn form a large range of oxylipins, like JA, by way of at the very least six alternative pathways .The two JA precursors now follow two parallel pathways; the octadecanoid pathway from HPOT as well as the hexadecanoid pathway from HPHT .The first step is performed by allene oxide synthases (AOS) that catalyzes dehydrations to form the unstable allene oxides ,(S)epoxyoctadecaenoic acid (,EOT) and ,(S)epoxyhexadeca(tri)enoic acid (,EHT).In aqueous media, ,EOT undergoes cyclisation to type cisoxophytodienoic acid (cisOPDA), a reaction mediated by allene oxide cyclase (AOC).4 stereoisomers of OPDA may be formed, but only S,SOPDA is really a precursor for biologically active JA.The carbon homologue dinorOPDA (dnOPDA) is generated in the parallel pathway from ,EHT .OPDA and dnOPDA are then transported in to the peroxisomes, via a mechanism nevertheless unresolved.The Arabidopsis ATPbinding cassette (ABC) transporter COMATOSE (CTSPXAPED) has been showed to catalyze the ATPdependent import of fatty acids into peroxisomes as substrates for oxidation .But, other pathways for dnOPDA should exist, as knockout mutants lack JAdeficiency symptoms (which include male sterility).Once inside the peroxisomes, S,SOPDA is reduced by oxophytodienoate reductase (OPR) to yield oxo(‘(Z)pentenyl)cyclopentaneoctanoic acid (OPC), and dnOPDA is decreased to the corresponding hexanoic acid derivative (OPC) .OPC and OPC are then activated via CoA esterification of the carboxylic moiety assisted by OPC CoA ligase (OPCL) , plus a nonetheless unknown ligase for OPC.The hexanoic and octanoic side chains of OPC and OPC are shortened by two or 3 rounds of oxidation.The oxidation entails 3 core enzymes; acylCoA oxidase (ACX), a multifunctional protein (MFP, comprising enoylCoA hydratase and hydroxyacylCoA dehydrogenase activities) and ketoacylCoA thiolase (KAT) forming JACoA.The final biosynthetic step would be the release with the JACoA ester from JA, which is catalyzed by an acylthioesterase (ACH), forming the reactive epijasmonic acid that very easily epimerize for the far more steady epijasmonic acid .Upon the subsequent transport to the cytoplasm, JA is further modified to methylepijasmonate (MeepiJA) by means of the help of a JA methyl transferase, a epijasmonylLisoleucine (epiJALIle) PubMed ID:http://www.ncbi.nlm.nih.gov/pubmed/21601637 catalyzed by a JA amido synthetase, or other derivatives .Int.J.Mol.SciFigure .Biosynthesis of jasmonic acid in the Emixustat web chloroplast and peroxisome.Polyunsaturated fatty acids ( and ) released in the cell, chloroplast andor thylakoid membrane are precursors for the biosynthesis of jasmonic acid (JA).Inside the chloroplast, cisoxophytodienoic acid (cisOPDA) and dinorOPDA (dnOPDA) are formed by means of the octa and hexadecanoid pathways.Immediately after transport into the peroxisome, OPDA (dnOPDA) is decreased to OPC (OPC) and undergoes 3 (two) cycles of oxidation that final results within the production of epijasmonic acid.The reactions are catalyzed by lipoxygenases (LOX), allene oxide synthase (AOS), allene oxide cyclase (AOC), ATPbinding cassette (ABC) transporter COMATOSE (CTSPXAPED), oxophytodienoate reductase (OPR), OPC CoA ligase (OPCL), acylthioesterase (ACH), ketoacylCoA thiolase , acylCoA oxidase (ACX) and a multifunctional protein (MFP).Enzymes are shown in blue.Arrows show the well characterized reactions.
