948310-68-7Relevant articles and documents
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 (2004)
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.
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.
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
