74784-20-6Relevant academic research and scientific papers
Oxidation of Octadecatrienoic Acids in the Red Alga Lithothamnion corallioides: Structural and Stereochemical Studies of Conjugated Tetraene Fatty Acids and Bis Allylic Hydroxy Acids
Hamberg, Mats
, p. 3065 - 3072 (1993)
Enzymatic oxidation of (6Z,9Z,12Z)-octadeca-6,9,12-trienoic acid (γ-linolenic acid; 1a) in a preparation of the red alga Lithothamnion corallioides Crouan led to the formation of (6Z,8E,10E,12Z)-octadeca-6,8,10,12-tetraenoic acid 2a and (11R,6Z,9Z,12Z)-hydroxyoctadeca-6,9,12-trienoic acid 3a as the main products. (9Z,12Z,15Z)-Octadeca-(9,12,15)-trienoic acid (α-linolenic acid; 4a) was oxidized in an analogous way to yield (9Z,11E,13E,15Z)-octadeca-9,11,13,15-tetraenoic acid (α-parinaric acid; 5a), (11S,9Z,12Z,15Z)-hydroxyoctadeca-9,12,15-trienoic acid 6a, and (14R,9Z,12Z,15Z)-hydroxyoctadeca-9,12,15-trienoic acid 7a.Isotope studies demonstrated that enzymatic conversion of the acid 1a into the tetraene 2a was accompanied by stereospecific eliminations of the pro-S and pro-R hydrogens from C-8 and C-11, respectively.The bis-allylic hydroxy acid 3a was formed from acid 1a by a reaction involving stereospecific elimination of the pro-S hydrogen from C-11 and incorporation of 1 atom of oxygen from water in the C-11 hydroxy group.Although the bis allylic hydroxy esters 3b, 6b, and 7b were chemically convertible into conjugated tetraenes by rapid acid-catalysed dehydration, enzymatic formation of conjugated tetraenes and hydroxy acids in Lithothamnion occured by independent pathways.
Regiospecificity of a novel bacterial lipoxygenase from Myxococcus xanthus for polyunsaturated fatty acids
An, Jung-Ung,Hong, Seung-Hye,Oh, Deok-Kun
, p. 823 - 833 (2018/05/14)
Lipoxygenase (LOX) is the key enzyme involved in the synthesis of oxylipins as signaling compounds that are important for cell growth and development, inflammation, and pathogenesis in various organisms. The regiospecificity of LOX from Myxococcus xanthus, a gram-negative bacterium, was investigated. The enzyme catalyzed oxygenation at the n-9 position in C20 and C22 polyunsaturated fatty acids (PUFAs) to form 12S- and 14S-hydroxy fatty acids (HFAs), respectively, and oxygenation at the n-6 position in C18 PUFAs to form 13-HFAs. The 12S-form products of C20 and C22 PUFAs by M. xanthus LOX is the first report of bacterial LOXs. The residues involved in regiospecificity were determined to be Thr397, Ala461, and Ile664 by analyzing amino acid alignment and a homology model based on human arachidonate 15-LOX with a sequence identity of 25%. Among these variants, the regiospecificity of the T397Y variant for C20 and C22 PUFAs was changed. This may be because of the reduced size of the substrate-binding pocket by substitution of the smaller Thr to the larger Tyr residue. The T397Y variant catalyzed oxygenation at the n-6 position in C20 and C22 PUFAs to form 15- and 17-hydroperoxy fatty acids, respectively. However, the oxygenation position of T397Y for C18 PUFAs was not changed. The discovery of bacterial LOX with novel regiospecificity will facilitate the biosynthesis of regiospecific?oxygenated signaling compounds.
Asymmetric synthesis of unnatural (Z,Z,E)-octadecatrienoid and eicosatrienoid by lipoxygenase-catalyzed oxygenation
Nanda,Yadav
, p. 1799 - 1806 (2007/10/03)
The asymmetric synthesis of unnatural 13-hydroxy-(6Z,9Z,11E,13S)-octadecatrienoid and 15-hydroxy-(8Z,11Z,13E,15S)-eicosatrienoid is described using a biomimetic oxidation route. The main highlights of this synthesis are the asymmetric hydroxylation of the substrate with soybean lipoxygenase and cis selective Wittig olefination.
