7576-35-4Relevant academic research and scientific papers
Selective Epoxidation of Fatty Acids and Fatty Acid Methyl Esters by Fungal Peroxygenases
Aranda, Carmen,Olmedo, Andrés,Kiebist, Jan,Scheibner, Katrin,del Río, José C.,Martínez, Angel T.,Gutiérrez, Ana
, p. 3964 - 3968 (2018/08/11)
Recently discovered fungal unspecific peroxygenases from Marasmius rotula and Chaetomium globosum catalyze the epoxidation of unsaturated fatty acids (FA) and FA methyl esters (FAME), unlike the well-known peroxygenases from Agrocybe aegerita and Coprinopsis cinerea. Reactions of a series of unsaturated FA and FAME with cis-configuration revealed high (up to 100 %) substrate conversion and selectivity towards epoxidation, although some significant differences were observed between enzymes and substrates with the best results being obtained with the C. globosum enzyme. This and the M. rotula peroxygenase appear as promising biocatalysts for the environmentally-friendly production of reactive FA epoxides given their self-sufficient monooxygenase activity and the high conversion rate and epoxidation selectivity.
Catalytic activities of mammalian epoxide hydrolases with cis and trans fatty acid epoxides relevant to skin barrier function
Yamanashi, Haruto,Boeglin, William E.,Morisseau, Christophe,Davis, Robert W.,Sulikowski, Gary A.,Hammock, Bruce D.,Brash, Alan R.
, p. 684 - 695 (2018/04/12)
Lipoxygenase (LOX)-catalyzed oxidation of the essential fatty acid, linoleate, represents a vital step in construction of the mammalian epidermal permeability barrier. Analysis of epidermal lipids indicates that linoleate is converted to a trihydroxy derivative by hydrolysis of an epoxy-hydroxy precursor. We evaluated different epoxide hydrolase (EH) enzymes in the hydrolysis of skin-relevant fatty acid epoxides and compared the products to those of acid-catalyzed hydrolysis. In the absence of enzyme, exposure to pH 5 or pH 6 at 37°C for 30 min hydrolyzed fatty acid allylic epoxyalcohols to four trihydroxy products. By contrast, human soluble EH [sEH (EPHX2)] and human or murine epoxide hydrolase-3 [EH3 (EPHX3)] hydrolyzed cis or trans allylic epoxides to single diastereomers, identical to the major isomers detected in epidermis. Microsomal EH [mEH (EPHX1)] was inactive with these substrates. At low substrate concentrations (10 μM), EPHX2 hydrolyzed 14,15-epoxye-icosatrienoic acid (EET) at twice the rate of the epidermal epoxyalcohol, 9R,10R-trans-epoxy-11E-13R-hydroxy-octadec-enoic acid, whereas human or murine EPHX3 hydrolyzed the allylic epoxyalcohol at 31-fold and 39-fold higher rates, respectively. These data implicate the activities of EPHX2 and EPHX3 in production of the linoleate triols detected as end products of the 12R-LOX pathway in the epidermis and implicate their functioning in formation of the mammalian water permeability barrier.
Identification and Quantitation of C=C Location Isomers of Unsaturated Fatty Acids by Epoxidation Reaction and Tandem Mass Spectrometry
Zhao, Yaoyao,Zhao, Hansen,Zhao, Xu,Jia, Jia,Ma, Qiang,Zhang, Sichun,Zhang, Xinrong,Chiba, Hitoshi,Hui, Shu-Ping,Ma, Xiaoxiao
, p. 10270 - 10278 (2017/10/13)
Unsaturated fatty acids (FAs) serve as nutrients, energy sources, and signaling molecules for organisms, which are the major components for a large variety of lipids. However, structural characterization and quantitation of unsaturated FAs by mass spectrometry remain an analytical challenge. Here, we report the coupling of epoxidation reaction of the C=C in unsaturated FAs and tandem mass spectrometry (MS) for rapid and accurate identification and quantitation of C=C isomers of FAs in a shotgun lipidomics approach. Epoxidation of the C=C leads to the production of an epoxide which, upon collision induced dissociation (CID), produces abundant diagnostic ions indicative of the C=C location. The total intensity of the same set of diagnostic ions for one specific FA C=C isomer was also used for its relative and absolute quantitation. The simple experimental setup, rapid reaction kinetics (90% for monounsaturated FAs), and easy-to-interpret tandem MS spectra enable a promising methodology particularly for the analysis of unsaturated FAs in complex biological samples such as human plasma and animal tissues.
Epoxidation, hydroxylation and aromatization is catalyzed by a peroxygenase from Solanum lycopersicum
Fuchs, Christopher,Schwab, Wilfried
, p. 52 - 60 (2013/10/22)
Plant peroxygenase (PXG) oxidizes unsaturated fatty acids by transferring an oxygen atom of a hydroperoxide to the double bond, thereby providing epoxides. In this work we investigated the potential of a PXG from tomato (Solanum lycopersicum, SlPXG) to catalyze the oxidation of a variety of natural products. A SlPXG gene was cloned from tomato, heterologously expressed in yeast and the membrane bound recombinant SlPXG protein was used as enzyme source. Unsaturated fatty acids, fatty acid derivatives, and terpenes were epoxidized by SlPXG in the presence of various hydroperoxides exclusively at their cis-double bonds. Terpenes with p-menthene skeleton were transformed in different ways depending on their molecular structures. R-(+)- and S-(-)-limonene were converted to R-(+)-limonene-trans-1,2-epoxide (97%) and cis-S-(-)-limonene-1,2- epoxide (88%), respectively whereas α-terpinenewas hydroxylated to cis-1,4-dihydroxy-p-menth-2-ene and γ-terpinene was aromatized to p-cymene. In the last reaction the hydroperoxide served as hydrogen acceptor rather than an oxygen donor. PXG appears to be a versatile biocatalyst able to perform different kinds of oxidation reactions. As no cofactors like NAD(P)H are required and H2O2is an environmentally friendly oxidant, PXG enables new applications for the synthesis of fine chemicals from renewable resources.
Molecular characterization of NbEH1 and NbEH2, two epoxide hydrolases from Nicotiana benthamiana
Huang, Fong-Chin,Schwab, Wilfried
, p. 6 - 15 (2013/07/11)
Plant epoxide hydrolases (EH) form two major clades, named EH1 and EH2. To gain a better understanding of the biochemical roles of the two classes, NbEH1.1 and NbEH2.1 were isolated from Nicotiana benthamiana and StEH from potato and heterologously expressed in Escherichia coli. The purified recombinant proteins were assayed with a variety of substrates. NbEH1.1 only accepted some aromatic epoxides, and displayed the highest enzyme activity towards phenyl glycidyl ether. In contrast, NbEH2.1 displayed a broad substrate range and similar substrate specificity as StEH. The latter enzymes showed activity towards all fatty acid epoxides examined. The activity (Vmax) of NbEH1.1 towards phenyl glycidyl ether was 10 times higher than that of NbEH2.1. On the contrary, NbEH2.1 converted cis-9,10-epoxystearic acid with Vmax of 3.83 μmol min mg-1 but NbEH1.1 could not hydrolyze cis-9,10- epoxystearic acid. Expression analysis revealed that NbEH1.1 is induced by infection with tobacco mosaic virus (TMV) and wounding, whereas NbEH2.1 is present at a relatively constant level, not influenced by treatment with TMV and wounding. NbEH1.1 transcripts were present predominantly in roots, whereas NbEH2.1 mRNAs were detected primarily in leaves and stems. Overall, these two types of tobacco EH enzymes are distinguished not only by their gene expression, but also by different substrate specificities. EH1 seems not to participate in cutin biosynthesis and it may play a role in generating signals for activation of certain defence and stress responses in tobacco. However, members of the EH2 group hydrate fatty acid epoxides and may be involved in cutin monomer production in plants.
Monooxygenase system of bacillus megaterium ALA2: Studies on linoleic acid epoxidation products
Hou, Ching T.
, p. 677 - 681 (2007/10/03)
Bacillus megaterium ALA2 produces many oxygenated FA from linoleic acid: 12, 13-dihydroxy- 9(Z)-octadecenoic acid; 12,13,17-trihydroxy-9(Z)-octadecenoic acid; 12,13,16-trihydroxy-9(Z)-octadecenoic acid; 12-hydroxy-13,16-epoxy-9(Z)- octadecenoic acid; and 12,17;13,17-diepoxy-16-hydroxy-9(Z)-octadecenoic acid. Recently, we studied the monooxygenase system of B. megaterium ALA2 by comparing its palmitic acid oxidation products with those of the well-studied catalytically self-sufficient P450 monooxygenase of B. megaterium ATCC 14581 (NRRL B-3712) and of B. subtilis strain 168 (NRRL B-4219). We found that their oxidation products are identical, indicating that their monooxygenase systems (hydroxylation) are similar. Now, we report that strain ALA2 epoxidizes linoleic acid to 12,13-epoxy-9(Z)-octadecenoic acid and 9,10-epoxy-12(Z)-octadecenoic acid, the initial products in the linoleic acid oxidation. The epoxidation enzyme did not oxidize specific double bond of the linoleic acid. The epoxidation activity of strain ALA2 was compared with the above-mentioned two Bacillus strains. These two Bacillus strain also produced 12,13-epoxy-9(Z)- octadecenoic acid and 9,10-epoxy-12(2)-octadecenoic acid, indicating that their epoxidation enzyme systems might be similar. The ratios of epoxy FA production by, these three strains (ALA2, NRRL B-3712, and NRRL B-4219) were, respectively, 5.56:0.66:0.18 for 12,13-epoxy-9(Z)-octadecenoic acid and 2.43:0.41:0.57 for 9,10-epoxy-12(Z)-octadecenoic acid per 50 mL medium per 48 h. Copyright
Epoxidation of polyunsaturated fatty acid double bonds by dioxirane reagent: Regioselectivity and lipid supramolecular organization
Grabovskiy, Stanislav A.,Kabal'nova, Natalia N.,Chatgilialoglu, Chryssostomos,Ferreri, Carla
, p. 2243 - 2253 (2007/10/03)
The use of dimethyldioxirane (DMD) as the epoxidizing agent for polyunsaturated fatty acids was investigated. With fatty acid methyl esters, this is a convenient method for avoiding acidic conditions, using different solvents, and simplifying the isolation procedures, with less contamination due to by-products. The reagent was also tested with free fatty acids in water. In this case, the supramolecular organization of fatty acids influenced the reaction outcome, and the epoxidation showed interesting regioselective features. The C=C bonds closest to the aqueous-micelle interface is the most favored for the interaction with dimethyldioxirane. The preferential epoxidation of linoleic acid (=(9Z,12Z)-octadeca-9,12-dienoic acid) to the 9,10-monoepoxy derivative was achieved, with a high yield and 65% regioselectivity. In case of arachidonic acid (=(5Z,8Z,11Z,14Z)-eicosa-5,8,11,14-tetraenoic acid) micelles, the regioselective outcome with formation of the four possible monoepoxy isomers was studied under different conditions. It resulted to be a convenient synthesis of 'cis-5,6-epoxyeicosatrienoic acid' (=3-[(2Z,5Z,8Z)-tetradeca-2,5,8- trienyl]oxiran-2-butanoic acid), whereas in reverse micelles, epoxidation mostly gave 'cis-14,15-epoxyeicosatrienoic acid (= (5Z,8Z,11Z)-13-(3-pentyloxiran-2- yl)trideca-5,8,11-trienoic acid).
Analysis of fatty acid epoxidation by high performance liquid chromatography coupled with evaporative light scattering detection and mass spectrometry
Orellana-Coca, Cecilia,Adlercreutz, Dietlind,Andersson, Maria M.,Mattiasson, Bo,Hatti-Kaul, Rajni
, p. 189 - 199 (2007/10/03)
Conventionally, epoxidation of unsaturated fatty acids has been studied either with titrimetric methods or in a lengthy procedure involving derivatization followed by gas chromatography (GC). We have developed a more rapid and descriptive analysis procedure for the substances using high performance liquid chromatography (HPLC) with evaporative light scattering detection (ELSD). Chemo-enzymatic epoxidation of unsaturated fatty acids (oleic, linoleic and linolenic acid, respectively) has been performed using hydrogen peroxide and immobilized lipase from Candida antarctica (Novozym 435). The fatty acids and their epoxidation products were separated by HPLC on a C-18 reversed-phase column using methanol-water containing 0.05% acetic acid as mobile phase. The method facilitated the simultaneous determination of fatty acids and epoxides differing from each other in the number of epoxide rings, the degree of unsaturation and the position of the epoxide rings and double bonds. An important aspect of the method development was the use of electrospray ionization and tandem mass spectrometry to confirm the structure of the epoxide products. It is suggested that the HPLC method, providing more information about the kind and concentration of fatty acids and their epoxides, represents a powerful complement to the existing methods for monitoring epoxidation processes on fatty acids.
Linoleic acid epoxide promotes the maintenance of mitochondrial function and active Na+ transport following hypoxia
Nowak, Grazyna,Grant, David F.,Moran, Jeffery H.
, p. 161 - 175 (2008/12/21)
Low concentrations of arachidonic acid monoepoxides protect against ischemia/reperfusion injury. This study examined whether low concentrations of the linoleic acid monoepoxide, cis-12,13-epoxy-9-octadecenoic acid (12,13-EOA), protect renal cells against decreases in mitochondrial and transport functions induced by hypoxia/reoxygenation. Primary cultures of rabbit renal proximal tubular cells (RPTC) were pretreated with diluent or 1, 5, or 10μM 12,13-EOA for 1h and exposed to 2h hypoxia/0.5h reoxygenation in the absence of 12,13-EOA. Basal respiration, oligomycin-sensitive oxygen consumption (QO2), and ATP content decreased 31, 35 and 65%, respectively, following hypoxia/reoxygenation. Hypoxia/reoxygenation also increased mitochondrial membrane potential (ΔΨm). Pretreatment with 12,13-EOA prevented decreases in basal and oligomycin-sensitive QO2s and increases in ΔΨm. Despite the protection against decreases in mitochondrial function, 12,13-EOA pretreatment did not prevent the initial decrease in intracellular ATP content following hypoxia. However, pretreatment did accelerate the recovery of intracellular ATP levels during reoxygenation. Pretreatment with 12,13-EOA also prevented hypoxia-induced decreases in active Na+ transport. Ouabain-sensitive QO2 (a marker of active Na+ transport) decreased 38% following hypoxia/reoxygenation but was maintained in RPTC pretreated with 1, 5 or 10μM 12,13-EOA prior to hypoxia. Pretreatment of RPTC with the hydrolyzed product of 12,13-EOA, 12,13-dihydroxyoctadecenoic acid, did not have any protective effects against mitochondrial dysfunction and decreases in active Na+ transport. Thus, this is the first report demonstrating that preconditioning of RPTC with low concentrations of 12,13-EOA, but not its hydrolyzed product, maintains mitochondrial respiration, accelerates restoration of ATP levels, and prevents decreases in active Na+ transport following hypoxia/reoxygenation.
Preparation of the enantiomers of hydroxy-C18 fatty acids and their anti-rice blast fungus activities
Kato, Tadahiro,Nakai, Toshio,Ishikawa, Rumiko,Karasawa, Aya,Namai, Tsuneo
, p. 2695 - 2701 (2007/10/03)
In order to examine the correlation between the anti-rice blast fungus activity and the chirality of allylic alcohols 1-3, which were characterized from the infected rice plants as an enantiomeric mixture with 10% e.e., a procedure for the chemical prepa
