10219-69-9Relevant academic research and scientific papers
Preparation of fatty acid cholesterol ester hydroperoxides by photosensitized oxidation
El Hafidi,Michel,Bascoul,Crastes De Paulet
, p. 127 - 138 (1999)
Preparation of fatty acid cholesterol ester hydroperoxides was undertaken with the purpose of evaluating their biological effects on cell growth. Cholesterol stearate, oleate, linoleate and α-linolenate were oxidized using methylene blue as a photosensitizer. The structures of all compounds were established by mass spectrometry and by nuclear magnetic resonance. The photosensitized oxidation of cholesterol oleate gave two hydroperoxide isomers: 9-hydroperoxy-trans-10-octadecenoate, and 10-hydroperoxy-trans-8-octadecenoate. In the case of the cholesterol linoleate, hydroperoxide isomers formed were: 9-hydroperoxy-trans-10, cis-12-octadecadienoate; 10-hydroperoxy-trans-8, cis-12-octadecadienoate; 12-hydroperoxy-cis-9, trans-13-octadecadienoate; 13-hydroperoxy-cis-9, trans-11-octadecadienoate. The oxidation of the cholesterol α-linolenate gave a mixture of six hydroperoxide isomers, at positions 9, 10, 12, 13, 15 and 16 of the fatty acid chain. The photosensitized oxidation of cholesterol stearate produced a formation of hydroperoxide at position 5α of cholesterol. The same hydroperoxide isomers on the fatty acid chain were obtained as described in the literature for the fatty acid methyl esters. Copyright (C) 1999 Elsevier Science Ireland Ltd.
Autoxidation of Model Membrane Systems: Cooxidation of Polyunsaturated Lecithins with Steroids, Fatty Acids, and α-Tocopherol
Weenen, Hugo,Porter, Ned A.
, p. 5216 - 5221 (1982)
The autoxidation of diL-PC and 1S,2A-PC in aqueous emulsion with several cosubstrates was investigated.Cholesterol, 7-dehydrocholesterol, linolic acid, and α-tocopherol were cosubstrates in the autoxidation of dilinoleoylphosphatidylcholine (diLP-PC).The distribution of the products, tc and tt diene hydroperoxides, was determined and evaluated.It was concluded that cholesterol has a lower H atom donating ability (Kp) and 7-dehydrocholesterol a much higher Kp than diL-PC.Linoleic acid when mixed with diL-PC, diP-PC, or a mixture of the two was found to behave analogous to a mixture of just the two lecithins.The cooxidation of diL-PC with a α-tocopherol in the bilayer gave only trans,cis (tc) hydroperoxides, which can be ascribed to a very high kinh for a α-tocopherol, a very efficient antioxidant. 1-Stearoyl-2-arachidonoylphosphatidilcholine (1S,2A-PC)bilayer autoxidation gave a product distribution very similar to arachidonic acid neat autoxidation.However the products from cooxidation of 1S,2A-PC bilayer with α-tocopherol unexpectedly did not include the 5-hydroperoxy eicosatetraenoic acid isomer (5-HPETE), although the 12, 15, 11, 9, and 8 isomers were present in almost equal amounts.
9-Oxooctadeca-10,12-dienoic acids as Acetyl-CoA carboxylase inhibitors from red pepper (Capsicum annuum L.)
Watanebe, Jun,Kawabata, Jun,Kasai, Takanori
, p. 489 - 493 (1999)
A methanol extract of red pepper showed potent acetylCoA carboxylase inhibitory activity. The active principles were isolated and identified as (E, E)- and (E, Z)-9-oxooctadeca-10,12-dienoic acids by instrumental analyses. The IC50 values of the compounds were 1.4 x 10-6 and 1.5 x 10-6 M, respectively, their activity being nearly sixty-times higher than that of the common fatty acids themselves. A comparative study of the structure-activity relationship among their related compounds showed that the inhibitory activity was influenced neither by the position and species of the oxygen functional group in the middle of the alkyl chain nor by the configurations of the double bonds. However, it was found that the presence of double bonds between the terminal carboxyl and the mid-chain oxygen functional group lowered the inhibitory activity which could be recovered by hydrogenation of the double bonds.
SOLUBILIZATION AND PROPERTIES OF THE ENZYME-CLEAVING 13-L-HYDROPEROXYLINOLENIC ACID IN TEA LEAVES
Hatanaka, A.,Kajiwara, T.,Sekiya, J.,Inouye, S.
, p. 13 - 18 (1982)
The membrane bound hydroperoxide lyase (E2'') which catalyses the cleavage of 13-L-hydroperoxides (18:3-OOH and 18:2-OOH) of linolenic and linoleic acids to C6-volatile aldehydes (hexenals and n-hexanal) was found to be localized in the chloroplast lamellae of tea leaves.It was selectively solubilized from the lamellae with 0.5percent (w/v) Tween 20.The enzymatic cleavage of the hydroperoxides occurred even under anaerobic conditions.The optimal pH of E2'' was 7-8.The common structural features shown by substrates of E2'' were the presence of a L-hydroperoxy group at ω-6 with a conjugated trans, cis-diene at ω-7 and ω-9 in a C18-fatty acid.E2'' had an apparent Km of 2.5 and 1.9 mM for 18:3-OOH and 18:2-OOH, respectively.No significant differences were found between chloroplast E2'' and solubilized E2''. - Key Word Index - Thea sinensis; Theaceae; tea; hydroperoxide lyase; hexenals; 13-L-hydroperoxylinolenic acid.
Regio- and stereoselective oxidation of linoleic acid bound to serum albumin: Identification by ESI-mass spectrometry and NMR of the oxidation products
Dufour, Claire,Loonis, Michele
, p. 60 - 68 (2005)
An efficient RP-HPLC method was developed for the detection of the oxidation products derived from the AAPH-initiated peroxidation of linoleic acid bound to human serum albumin. Diode array UV-detection allowed the quantification at 234 nm of four regioisomeric hydroperoxyoctadecadienoic acids (HPODE) and four hydroxyoctadecadienoic acids (HODE) while at 280 nm four oxooctadecadienoic acid isomers (KODE) were detected. Full identification of the different underivatized HODE, HPODE and KODE isomers was achieved by negative ESI-mass spectrometry outlining common fragmentation pathways for 9- and 13-regioisomers. Chemical synthesis of 9-(E,Z)-, 9-(E,E)-, 13-(Z,E)- and 13-(E,E)-KODE helped to their structural characterization by 1H NMR. Lipid peroxidation in the presence of albumin proved to be regioselective with a larger accumulation of 13-HPODE and 9-KODE isomers. Thermodynamically more stable E,E-stereoisomers were also favored by albumin for both HPODE and KODE.
Short and Efficient Syntheses of Coriolic Acid
Rao, A. V. Rama,Reddy, S. Pulla,Reddy, E. Rajarathnam
, p. 4158 - 4159 (1986)
Coriolic acid (1), a divalent cation ionophore and a self-defensive substance against blast disease in rice plant, has been synthesized by two convenient approaches.
Aromatase inhibitors from Urtica dioica roots
Gansser,Spiteller
, p. 138 - 140 (1995)
Methanolic extracts of stinging nettle (Urtica dioica L.) roots were investigated for aromatase inhibition. Enzyme inhibition was detected only after appropriate chromatographic separation. Inhibitory effects on aromatase could be demonstrated in vitro for a variety of compounds belonging to different classes. The following compounds developed weak to moderate activity: secoisolariciresinol (1), oleanolic and ursolic acid (2 and 3), (9Z,11E)-13-hydroxy-9,11-octadecadienoic acid (4), and 14-octacosanol (5). Inhibitory effects on aromatase have been known to date neither for pentacyclic triterpenes nor for secondary fatty alcohols. The potential physiological significance of the above findings is discussed. Compound 5 is a previously unknown constituent of plants.
Convergent Stereocontrolled Synthesis of 13-Hydroxy-9Z,11E-octadecadienoic Acid (13-HODE)
Chan, Cecil,Cox, Philip B.,Roberts, Stanley M.
, p. 971 - 972 (1988)
The readily available alkenes (4) and (5) were coupled using a palladium(II) catalyst to give the diene ester (6), a late-stage intermediate to 13-HODE.
Characterization of Bitter-Tasting Oxylipins in Poppy Seeds (Papaver somniferum L.)
Lainer, Johanna,Dawid, Corinna,Dunkel, Andreas,Glaser, Peter,Wittl, Stephanie,Hofmann, Thomas
, p. 10361 - 10373 (2020/01/31)
Activity-guided fractionation of poppy seed (Papaver somniferum L.) extracts and analysis of fatty acid oxidation model experiments, followed by liquid chromatography time-of-flight mass spectrometry, tandem mass spectrometry, and one-/two-dimensional nuclear magnetic resonance experiments, revealed the chemical structures of five bitter-tasting fatty acids (1-5), three monoglycerides (6-8), six C18-lipidoxidation products (9-14), and four lipid oxidation degradation products (15 and 17-19) as well as two previously unreported monoglyceride oxidation degradation products, namely, 9-(2′,3′-dihydroxypropyloxy)-9-oxononaic acid (1-azeloyl-rac-glycerol, 16) and 1-(2′,3′-dihydroxypropyl)-8-(5″-oxo-2″,5″-dihydrofruan-2″-yl)-octonoate (1-ODFO-rac-glycerol, 20). Sensory studies exhibited low bitter taste threshold concentrations between 0.08 and 0.29 mmol/L, particularly for the higher oxidated C18-fatty acids trihydroxyoctadecenoic acid (THOE, 12), 12,13-dihydroxy-9-oxo-10-octadecenoic acid (12,13-diOH-9-oxo, 13), and 9,10-dihydroxy-13-oxo-11-octadecenoic acid (9,10-diOH-13-oxo, 14) as well as for the lipidoxidation degradation products 4-hydroxy-2-noneic acid (4-HNA, 17), 4-hydroxy-2-docecendienoic acid (HDdiA, 18), and 8-(5′-oxo-2′,5′-dihydrofuran-2′-yl)-octanoic acid (ODFO, 20).
Oxygenation reactions catalyzed by the F557V mutant of soybean lipoxygenase-1: Evidence for two orientations of substrate binding
Hershelman, Dillon,Kahler, Kirsten M.,Price, Morgan J.,Lu, Iris,Fu,Plumeri, Patricia A.,Karaisz, Fred,Bassett, Natasha F.,Findeis, Peter M.,Clapp, Charles H.
, (2019/09/10)
Plant lipoxygenases oxygenate linoleic acid to produce 13(S)-hydroperoxy-9Z,11E-octadecadienoic acid (13(S)-HPOD) or 9-hydroperoxy-10E,12Z-octadecadienoic acid (9(S)-HPOD). The manner in which these enzymes bind substrates and the mechanisms by which they control regiospecificity are uncertain. Hornung et al. (Proc. Natl. Acad. Sci. USA 96 (1999) 4192–4197) have identified an important residue, corresponding to phe-557 in soybean lipoxygenase-1 (SBLO-1). These authors proposed that large residues in this position favored binding of linoleate with the carboxylate group near the surface of the enzyme (tail-first binding), resulting in formation of 13(S)-HPOD. They also proposed that smaller residues in this position facilitate binding of linoleate in a head-first manner with its carboxylate group interacting with a conserved arginine residue (arg-707 in SBLO-1), which leads to 9(S)-HPOD. In the present work, we have tested these proposals on SBLO-1. The F557V mutant produced 33% 9-HPOD (S:R = 87:13) from linoleic acid at pH 7.5, compared with 8% for the wild-type enzyme and 12% with the F557V,R707L double mutant. Experiments with 11(S)-deuteriolinoleic acid indicated that the 9(S)-HPOD produced by the F557V mutant involves removal of hydrogen from the pro-R position on C-11 of linoleic acid, as expected if 9(S)-HPOD results from binding in an orientation that is inverted relative to that leading to 13(S)-HPOD. The product distributions obtained by oxygenation of 10Z,13Z-nonadecadienoic acid and arachidonic acid by the F557V mutant support the hypothesis that ω6 oxygenation results from tail-first binding and ω10 oxygenation from head-first binding. The results demonstrate that the regiospecificity of SBLO-1 can be altered by a mutation that facilitates an alternative mode of substrate binding and adds to the body of evidence that 13(S)-HPOD arises from tail-first binding.
