91999-06-3Relevant academic research and scientific papers
Natural Estolides Produced by Pseudomonas sp. 42A2 Grown on Oleic Acid: Production and Characterization
Pelaez,Orellana,Marques,Busquets,Guerrero,Manresa
, p. 859 - 866 (2003)
Estolides are a group of FA polyesters resulting from ester bond formation between a hydroxyi or olefinic group of one FA and the terminal carboxyl group of a second FA. These products are commonly found in trace amounts, forming tetraglycerides in several oil seed plants, and have been produced by acid clay and enzymatic catalysis in vitro. In this study, natural estolides produced by a bacterial culture are presented for the first time. Pseudomonas sp. 42A2 produced (E)-10-hydroxy-8-octadecenoic acid and (E)-7,10-dihydroxy-8-octadecenoic acid when grown on oleic acid. It is suggested that these FA were polymerized in culture by a lipase produced by the bacterial strain, resulting in a mixture of estolides. These compounds amounted to 3.8 g/L after 72 h of incubation. LC-MS analysis indicated that the types of estolides formed were dimers (m/z 560-610), trimers (m/z 845-906), tetramers (m/z 1122-1202), pentamers (m/z 1328-1424), and hexarners (m/z 1554-1788), with a relative abundance of 27.5, 19.4, 15, 9.7, and 11%, respectively. This is the first report in which hexamers were detected in a bacterial culture.
Algicidal hydroxylated C18 unsaturated fatty acids from the red alga Tricleocarpa jejuensis: Identification, synthesis and biological activity
Ishibashi, Fumito,Kuwano, Kazuyoshi,Shibahara, Tomohiro,Zha, Shijiao
, (2020/06/05)
Bioassay-guided separation of a methanol extract of Tricleocarpa jejuensis by monitoring algicidal activity against the red tide phytoplankton Chattonella antiqua led to the isolation of an active fraction consisting of a mixture of four isomeric compounds. The active compounds were identified as (E)-9-hydroxyoctadec-10-enoic acid (1), (E)-10-hydroxyoctadec-8-enoic acid (2), (E)-11-hydroxyoctadec-12-enoic acid (3) and (E)-12-hydroxyoctadec-10-enoic acid (4) by NMR, IR and mass spectral data. The structures were confirmed by comparison of the NMR and MS data with those of authentic samples of 1–4 obtained by unambiguous syntheses. Synthesized hydroxy acids 1–4 and related compounds were assessed for algicidal activity against C. antiqua and it was found that all of 1–4 had high activity (>80% mortality at 24 h) at a concentration of 20 μg/mL. A structure–activity relationship study using 11 related compounds revealed that the presence of the hydroxyl group is important for the activity and the double bond may be replaced with a triple bond.
Preparation of fatty acid cholesterol ester hydroperoxides by photosensitized oxidation
El Hafidi,Michel,Bascoul,Crastes De Paulet
, p. 127 - 138 (2007/10/03)
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.
A gas-liquid chromatographic method for steric analysis of 2-hydroxy, 3-hydroxy, and 2,3-dihydroxy acids
Zhang, Lian-Ying,Hamberg, Mats
, p. 151 - 161 (2007/10/02)
A method was developed for assignment of the absolute configuration of oxylipin-derived 2-hydroxy acids, 3-hydroxy acids and 2,3-dihydroxy acids.The monohydroxy acids were converted into diastereomeric N-(propionoxyacyl)-L-phenylalanine-methyl ester (PAP) derivatives by coupling to the methyl ester of L-phenylalanine followed by propionylation, whereas 2,3-dihydroxy acids were derivatized by treatment with L-phenylalanine methyl ester followed by acetone and perchloric acid, to afford diastereomeric N-(2,3-isopropylidenedioxyacyl)-L-phenylalanine methyl ester (IAP) derivatives.The PAP and IAP derivatives were readily resolved by capillary gas-liquid chromatography.In addition, the method described allowed steric analysis of 3-hydroxy-3-methylheptanoic acid, a branched chain hydroxy acid derived from the prostaglandin analogue, misoprostol. - Keywords: Hydroxy acid; Phenylalanine; Steric analysis; Gas-liquid chromatography
ISOMERIZATION OF EPOXIDES TO ALLYLIC ALCOHOLS USING METHYLMAGNESIUM N-CYCLOHEXYLISOPROPYLAMIDE
Mosset, Paul,Manna, Sukumar,Viala, Jacques,Falck, J.R.
, p. 299 - 302 (2007/10/02)
The scope of methylmagnesium N-cyclohexylisopropylamide promoted isomerizations of epoxides to allylic alcohols is described.
