Lipoxygenase fromZea mays: 9-d-hydroperoxy-trans-10,cis-12-octadecadienoic acid from linoleic acid

Lipids ◽  
1970 ◽  
Vol 5 (8) ◽  
pp. 678-683 ◽  
Author(s):  
H. W. Gardner ◽  
D. Weisleder
Keyword(s):  
Linoleic Acid ◽  
Octadecadienoic Acid

A new conjugated linoleic acid isomer, 7 trans, 9 cis-octadecadienoic acid, in cow milk, cheese, beef and human milk and adipose tissue

Lipids ◽  
1998 ◽  
Vol 33 (8) ◽  
pp. 803-809 ◽  
Author(s):  
Martin P. Yurawecz ◽  
John A. G. Roach ◽  
Najibullah Sehat ◽  
Magdi M. Mossoba ◽  
John K. G. Kramer ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Linoleic Acid ◽  
Human Milk ◽  
Conjugated Linoleic Acid ◽  
Octadecadienoic Acid ◽  
Cow Milk ◽  
Conjugated Linoleic Acid Isomer ◽  
Linoleic Acid Isomer

scholarly journals In silico characterization of linoleic acid biotransformation to rumenic acid in food derived Lactobacillus plantarum YW11

2020 ◽  
Author(s):  
Tariq Aziz ◽  
Abid Sarwar ◽  
Muhammad Fahim ◽  
Sam Al Dalali ◽  
Zia Ud Din ◽  
...  
Keyword(s):  
Linoleic Acid ◽  
Conjugated Linoleic Acid ◽  
Lactobacillus Plantarum ◽  
In Silico ◽  
Octadecadienoic Acid ◽  
Scale Up ◽  
Octadecenoic Acid ◽  
Acid Ethyl Ester ◽  
Dependent Manner ◽  
In Silico Characterization

Lactobacillus plantarum YW11 capability to convert linoleic acid into conjugated linoleic acid and other metabolites was studied in a dose-dependent manner by supplementing LA at different concentrations. L. plantarum YW11 displayed a uniform distinctive growth curve of CLA and other metabolites at concentrations of LA ranging from 1% (w/v) to 10% (w/v), with slightly increased growth at higher LA concentrations. The biotransformation capability of L. plantarum YW11 evaluated by GC-MS revealed a total of one CLA isomer, i.e. 9-cis,11-trans-octadecadienoic acid, also known as the rumenic acid (RA), one linoleic acid isomer (linoelaidic acid), and LA metabolites: (E)-9-octadecenoic acid ethyl ester, trans, trans-9,12-octadecadienoic acid, propyl ester and stearic acid. All the metabolites of linoleic acid were produced from 1 to 10% LA supplemented MRS media, while surprisingly the only conjugated linoleic acid compound was produced at 10% LA. To assess the presence of putative enzymes, responsible for conversion of LA into CLA, in silico characterization was carried out. The in silico characterization revealed presence of four enzymes (10-linoleic acid hydratase, linoleate isomerase, acetoacetate decarboxylase and dehydrogenase) that may be involved in the production of CLA (rumenic acid) and LA isomers. The biotransformation ability of L. plantarum YW11 to convert LA into RA has great prospects for biotechnological and industrial implications that could be exploited in the future scale-up experiments.

scholarly journals Regio- and stereo-chemical oxidation of linoleic acid by human myoglobin and hydrogen peroxide: Tyr103 affects rate and product distribution

2004 ◽  
Vol 381 (2) ◽  
pp. 365-372 ◽  
Author(s):  
Benjamin S. RAYNER ◽  
Roland STOCKER ◽  
Peter A. LAY ◽  
Paul K. WITTING
Keyword(s):  
Linoleic Acid ◽  
Lipid Oxidation ◽  
Octadecadienoic Acid ◽  
Total Yield ◽  
Product Distribution ◽  
Chemical Oxidation ◽  
Wild Type ◽  
Type Protein ◽  
Wild Type Protein ◽  
Lipid Oxidation Products

Mb (myoglobin) plus H2O2 catalyses the oxidation of various substrates via a peroxidase-like activity. A Y103F (Tyr103→Phe) variant of human Mb has been constructed to assess the effect of exchanging an electron-rich oxidizable amino acid on the peroxidase activity of human Mb. Steady-state analyses of reaction mixtures containing Y103F Mb, purified linoleic acid and H2O2 revealed a lower total yield of lipid oxidation products than mixtures containing the wild-type protein, consistent with the reported decrease in the rate constant for reaction of Y103F Mb with H2O2 [Witting, Mauk and Lay (2002) Biochemistry 41, 11495–11503]. Irrespective of the Mb employed, lipid oxidation yielded 9(R/S)-HODE [9(R,S)-hydroxy-10E,12Z-octadecadienoic acid] in preference to 13(R/S)-HODE [13(R,S)-hydroxy-9Z,11E-octadecadienoic acid], while 9- and 13-keto-octadecadienoic acid were formed in trace amounts. However, lipid oxidation by the Y103F variant of Mb proceeded with a lower Vmax value and an increased Km value relative to the wild-type control. Consistent with the increased Km, the product distribution from reactions with Y103F Mb showed decreased selectivity compared with the wild-type protein, as judged by the decreased yield of 9(S)-relative to 9(R)-HODE. Together, these data verify that Tyr103 plays a significant role in substrate binding and orientation in the haem pocket of human Mb. Also, the midpoint potential for the Fe(III)/(II) one-electron reduction was shifted slightly, but significantly, to a higher potential, confirming the importance of Tyr103 to the hydrogen-bonding network involving residues that line the haem crevice of human Mb.

Comparison of Methylation Methods for the Quantitation of Conjugated Linoleic Acid Isomers

1993 ◽  
Vol 76 (3) ◽  
pp. 644-649 ◽  
Author(s):  
Nalur Chandrasekaran Shantha ◽  
Eric Andrew Decker ◽  
Bernhard Hennig
Keyword(s):  
Linoleic Acid ◽  
Conjugated Linoleic Acid ◽  
Sodium Methoxide ◽  
Boron Trifluoride ◽  
Acetyl Chloride ◽  
Octadecadienoic Acid ◽  
Methyl Esters ◽  
Low Concentrations ◽  
Cla Isomers ◽  
In Cis

Abstract Four methylation methods were evaluated for use in the gas chromatographic (GC) quantitation of conjugated linoleic acid (CLA) isomers, which are potential anticarcinogen. The methods were (1) sodium methoxide in methanol (NaOMe-MeOH), (2) American Oil Chemists' Society (AOCS) procedure Ce 2-66, which involves methanolic sodium hydroxide followed by boron trifluoride in methanol, (3) tetramethylguanidine in methanol (TMG-MeOH), and (4) direct transesterification with methanolbenzene- acetyl chloride (DAC). Purified methyl esters of isomerized linoleic acid containing 86% CLA isomers were methylated and analyzed by GC. The AOCS and DAC methods resulted in 3 and 50% losses in cis-9,trans-11-octadecadienoic acid (9c, 111 CLA isomer) and trans-10,cis-12 octadecadienoic acid (10t, 12c CLA isomers), respectively. Compared with the control, the AOCS and DAC methods increased the yield of the trans,trans CLA isomers (trans-9,trans-11- and trans-10, trans-12-octadecadienoic acid) by 1.07-fold and a 10-fold, respectively. A non-CLA artifact that eluted close to CLA peaks was formed during methylation by the AOCS and DAC methods. Thus, the DAC and AOCS methods are not suitable for quantitation of CLA isomers. The NaOMe-MeOH and TMG-MeOH methods, however, are suitable for quantitation of CLA isomers in fats containing low concentrations of free fatty acids.

Oxidized linoleic acid regulates expression and shedding of syndecan-4

2005 ◽  
Vol 288 (2) ◽  
pp. C458-C466 ◽  
Author(s):  
Michelle Houston ◽  
Matheau A. Julien ◽  
Sampath Parthasarathy ◽  
Elliot L. Chaikof
Keyword(s):  
Linoleic Acid ◽  
Cell Surface ◽  
Mrna Expression ◽  
Prolonged Exposure ◽  
Octadecadienoic Acid ◽  
Vascular Wall ◽  
Cell Surface Receptor ◽  
Cell Surface Expression ◽  
Oxidized Lipids ◽  
Matrix Remodeling

Syndecan-4, a heparan sulfate proteoglycan that is widely expressed in the vascular wall and as a cell surface receptor, modulates events relevant to acute tissue repair, including cell migration and proliferation, cell-substrate interactions, and matrix remodeling. While syndecan-4 expression is regulated in response to acute vascular wall injury, its regulation under chronic proatherogenic conditions such as those characterized by prolonged exposure to oxidized lipids has not been defined. In this investigation, arterial smooth muscle cells were treated with 13-hydroperoxy-9,11-octadecadienoic acid (HPODE) and 13-hydroperoxy-10,12-octadecadienoic acid, oxidized products of linoleic acid, which is the major oxidizable fatty acid in LDL. Both oxidized fatty acids induced a dose-dependent, rapid upregulation of syndecan-4 mRNA expression that was not attenuated by cycloheximide. This response was inhibited by pretreatment with N-acetylcysteine, catalase, or MEK1/2 inhibitors, but not by curcumin or lactacystin, known inhibitors of NF-κB. These data suggest that oxidized linoleic acid induces syndecan-4 mRNA expression through the initial generation of intracellular hydrogen peroxide with subsequent activation of the extracellular signal-regulated kinase signaling pathway via MEK1/2. Notably, the HPODE-induced enhancement of syndecan-4 mRNA was accompanied by accelerated shedding of syndecan-4. In principle, alterations in both the cell surface expression and shedding of syndecan-4 may augment a variety of proatherogenic events that occur in response to oxidized lipids.

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