Lipid Peroxidation
Robert A. Greenwald in CRC Handbook of Methods for Oxygen Radical Research, 2018
Another method which can be used to assess in vitro lipid peroxidation is measurement of the relative content of unsaturated fatty acids in the sample as lipid peroxidation proceeds. The assays are conducted on a Folch extract5 by GC analysis of fatty acid methyl esters. A sample of the Folch extract is evaporated to dryness under a stream of argon in a culture tube and 3 mℓ of methanolic H2SO4 (1.6 mℓ concentrated H2SO4 in 80 mℓ of anhydrous methanol) are added. The tube is flushed with argon, tightly capped with a Teflon®-lined cap, and incubated at 60°C for 24 hr. Hexane is then added and the sample is washed with water until the pH of the water is neutral. The sample is then ready for fatty acid analysis on a 6-ft by 1/4-in. silanized glass column packed with 10% DEGS on 80/100 Supelcoport (Supelco, Bellefonte, Pa.). The data can be expressed as the percent of a saturated fatty acid (unable to undergo lipid peroxidation).
Lipids of Histoplasma Capsulatum
Rajendra Prasad, Mahmoud A. Ghannoum in Lipids of Pathogenic Fungi, 2017
Each of the compounds was analyzed for fatty acid, long-chain base and inositol. The results are summarized in Table 2. All of the compounds yielded one mol of long-chain base which was identified as phytosphingosine. Additionally, compounds II and III also possessed a small amount of DL-erythrodihydrosphingosine. The thin layer chromatography solvent system of benzene:chloroform:acetic acid (90:10:1, v/v) separates the methyl esters of nonhydroxylated fatty acids from mono-and dihydroxy fatty acids. When this was employed with the methyl esters of the Histoplasma compounds, compound II exhibited only non-hydroxy fatty acids whereas only monohydroxy fatty acid methyl esters were evident in the methanolysates of the other four compounds. Each compound exhibited one mol of fatty acid/mol of phosphorous and one mol of inositol/mol of phosphorous (Table 2). The fatty acid moiety of all of the compounds was lignoceric acid (24:0). Compound II had a nonhydroxlyated 24:0 fatty acid in the ceramide moiety whereas the others contained mostly hydroxylated 24:0.
Cenostigma pyramidale: Ethnomedicinal Properties and Perspectives on A Legume Tree Highly Adapted to Semiarid ‘Caatinga’ Region
Mahendra Rai, Shandesh Bhattarai, Chistiane M. Feitosa in Ethnopharmacology of Wild Plants, 2021
Oliveira et al. (2016) investigated the chemical composition of the methanolic extract of root barks of C. pyramidale, resulting in the isolation of 3,3’-dimethylellagic acid and 3,3’-dimethylellagic acid-4’-O-β-D-xyloside. Lupeol, β-sitosterol/stigmasterol, and a mixture of fatty acid methyl ester derivatives were also obtained. In this same study, chromatographic procedures of the methanolic extract of the flowers of this species led to obtaining an unusual mixture of fatty alcohols, β-sitosterol/stigmasterol, α-amyrin, β-amyrin and methyl gallate. This was the first report of 3,3’-dimethylellagic acid, 3,3’-dimethylellagic acid-4’-O-β-D-xyloside and free fatty alcohols in the Fabaceae family.
Human charcoal-stripped serum supplementation enhances both the stearoyl-coenzyme a desaturase 1 activity of cumulus cells and the in vitro maturation of oocytes
Published in Human Fertility, 2019
Alireza Mardomi, Mohammad Nouri, Laya Farzadi, Nosratollah Zarghami, Amir Mehdizadeh, Mehdi Yousefi, Dariush Shanebandi, Maghsod Shaaker, Masoud Darabi
Lipids of cumulus cells were extracted after 48 h treatment using the Bligh-Dyer method, then were esterified as previously described (Lepage & Roy, 1986). Fatty acid methyl esters were analyzed for composition by gas-liquid chromatography (Mohammadzadeh etal., 2014). Briefly, cellular lipids were separated on a Teknokroma (Barcelona, Spain) TR CN100 column (60 m × 0.25 mm × 0.2 µm) with a Buck Scientific model 610 gas chromatograph (SRI Instruments, Torrance, CA) equipped with a split injector and a flame ionization detector (FID). The oven temperature was increased at 1 °C/min from 190–210 °C, then was maintained stable for 20 min. Tridecanoic acid (13:0) was used as the internal control. Peak retention times were identified by injecting known standards. The ratio of the main product oleate (18:1) to the corresponding substrate stearate (18:0) was calculated to reflect the SCD1 metabolic activity in cumulus cells.
Circulating fatty acids as biomarkers of dairy fat intake: data from the lifelines biobank and cohort study
Published in Biomarkers, 2019
Ilse G. Pranger, Eva Corpeleijn, Frits A. J. Muskiet, Ido P. Kema, Cécile Singh-Povel, Stephan J. L. Bakker
EDTA-plasma samples were collected at baseline and stored frozen at −80 °C until use for assessment of fatty acid profiles. Analyses of fatty acids were performed in the Department of Laboratory Medicine of the University Medical Center Groningen, The Netherlands using the methodology as described by Hoving etal. (1988). In short, total lipids were extracted by the method of Folch etal., using 6 ml of chloroform-methanol (2:1) and a 200 µl EDTA-plasma sample (Folch etal.1957). After that, a shortened version of the method of Kaluzny etal. was used to isolate plasma cholesterol esters (CE), triglycerides (TG) and phoshpolipids (PL), using aminopropyl SPE columns (Isolute, Biotage) (Kaluzny etal. 1985). Fatty acids were transmethylated with methanolic-HCL into fatty acid methyl esters (FAME). The samples were extracted with hexane and eventually redissolved into 100 µl hexane. Internal standards for the quantification of fatty acids in CE (100 µl of a solution of 50.1 mg C17:0/100 ml chloroform-methanol, 2:1 v/v) and TG (100 µl of a solution of 19.9 mg of C19:0/100 ml chloroform-methanol, 2:1 v/v), both obtained from Sigma-Aldrich (Zwijndrecht, The Netherlands), were added before isolation of lipid classes. An internal standard for the quantification of fatty acids in PL (100 µl of a solution of 50.0 mg free fatty acid 19:0/100 ml methanol), obtained from Larodan (Solna, Sweden), was added after isolation of lipid classes. 100 µl Butylated Hydroxytoluene (1 g/100 ml methanol) from Sigma-Aldrich (Zwijndrecht, The Netherlands) was added to prevent fatty acid oxidation.
Plasma fatty acids as markers for desaturase and elongase activities in spinal cord injured males
Published in The Journal of Spinal Cord Medicine, 2019
Lynnette M. Jones, Michael Legge
The analysis of the fatty acid methyl esters was based on the previously described method described by Holub and Skeaff (1987)21 and Hodson et al. (2004).22 Briefly, prior to analysis by gas chromatography the fatty acid containing hexane was evaporated to dryness under a stream of oxygen free nitrogen and reconstituted in 45μl of hexane. The fatty acid methyl esters were separated using a DB225 capillary column (30mx0.53mm; id 0.25μm film) obtainable from Agilent Technologies, USA. The gas chromatograph (HP 5890) was equipped with and autosampler (HP7673) and a Chem Station integration (Hewlett Packard, Avondale, PA). Following injection the column was held at an isothermal temperature of 190OC for 30 minutes and fatty acid peaks were identified by retention time compared with matching authenticated fatty acid standards (NuCheck Prep, Elyson, Minnessota, USA and Sigma Chemical Co, St Louis USA). All results were transferred using a Microsoft Excel macro programme into a spreadsheet for further analysis.
