ethyl-arachidonate and ethyl-linoleate

A kinetic study of the prooxidant effect of alpha-tocopherol was performed. The rates of allylic hydrogen abstraction from various unsaturated fatty acid esters (ethyl stearate 1, ethyl oleate 2, ethyl linoleate 3, ethyl linolenate 4, and ethyl arachidonate 5) by alpha-tocopheroxyl radical in toluene were determined, using a double-mixing stopped-flow spectrophotometer. The second-order rate constants (k (p)) obtained are <1 x 10(-2) M(-1 )s(-1) for 1, 1.90 x 10(-2) M(-1 )s(-1) for 2, 8.33 x 10(-2 )M(-1 )s(-1) for 3, 1.92 x 10(-1) M(-1 )s(-1) for 4, and 2.43 x 10(-1 )M(-1 )s(-1) for 5 at 25.0 degrees C. Fatty acid esters 3, 4, and 5 contain two, four, and six -CH(2)- hydrogen atoms activated by two pi-electron systems (-C=C-CH(2)-C=C-). On the other hand, fatty acid ester 2 has four -CH(2)- hydrogen atoms activated by a single pi-electron system (-CH(2)-C=C-CH(2)-). Thus, the rate constants, k (abstr)/H, given on an available hydrogen basis are k (p)/4 = 4.75 x 10(-3 )M(-1 )s(-1) for 2, k (p)/2 = 4.16 x 10(-2) M(-1 )s(-1) for 3, k (p)/4 = 4.79 x 10(-2 )M(-1 )s(-1) for 4, and k (p)/6 = 4.05 x 10(-2 )M(-1 )s(-1) for 5. The k (abstr)/H values obtained for 3, 4, and 5 are similar to each other, and are by about one order of magnitude higher than that for 2. From these results, it is suggested that the prooxidant effect of alpha-tocopherol in edible oils, fats, and low-density lipoproteins may be induced by the above hydrogen abstraction reaction.

Topics: alpha-Tocopherol; Arachidonic Acids; Free Radicals; Hydrogen; Linoleic Acids; Linolenic Acids; Lipids; Oleic Acids; Oxidants; Stearates; Vitamin E

To determine the relationship between fatty acid ethyl esters (FAEE) in meconium and neurodevelopment in infants exposed to alcohol in utero at 6.5 months, 1 year, and 2 years of age.. A secondary analysis of a prospective cohort of mothers at high risk and their infants recruited after admission to a labor and delivery unit. Mothers were screened for drug and alcohol use during pregnancy by clinical interview and urine screening. Meconium was analyzed for FAEE in 216 newborn infants. Outcome measures included the Bayley Scales of Infant Development Mental (MDI) and Psychomotor (PDI) Developmental Index scores in infants at 6.5 months, 1 year, and 2 years of age.. After controlling for prenatal visits and maternal factors, increasing concentrations of FAEE were significantly associated with poorer mental and psychomotor development (beta +/- standard error) at all follow-up visits: ethyl myristate (MDI -2.46 +/- 1.24, P = .05; PDI -3.88 +/- 1.67, P = .02), ethyl oleate (MDI -1.94 +/- 0.65, P < .01; PDI -2.60 +/- 0.93, P < .01), ethyl linoleate (MDI -1.92 +/- 0.60, P < .01; PDI -2.28 +/- 0.84, P < .01), ethyl linolenate (MDI -1.99 +/- 0.74, P < .01; PDI -2.98 +/- 1.04, P < .01), and ethyl arachidonate (MDI -2.40 +/- 1.11, P = .03; PDI -3.32 +/- 1.51, P = .03).. FAEE in meconium may be a marker for identifying newborns at risk for neurodevelopmental delay from alcohol exposure in utero.

Topics: Arachidonic Acids; Child, Preschool; Developmental Disabilities; Follow-Up Studies; Humans; Infant; Linoleic Acids; Linolenic Acids; Meconium; Myristates; Oleic Acids; Palmitic Acids; Prognosis; Prospective Studies; Psychomotor Performance

The role of fatty acid ethyl esters (FAEE), the nonoxidative ethanol metabolites, as mediators of alcohol-induced organ damage is increasingly being recognized. FAEE are detectable in the blood and in liver and adipose tissue after ethanol ingestion, and on that basis, FAEE can be used as markers of ethanol intake. In this study, 10 samples of human brain were collected at autopsy at the Massachusetts Medical Examiner's Office and analyzed for FAEE. FAEE were isolated and quantified as mass per gram of wet weight. The blood ethanol level was also obtained in each case along with the other drugs detected in routine postmortem toxicology screening tests. Ethyl arachidonate was the predominant FAEE species in the brain, representing up to 77.4% of total FAEE in the brain. The percent age of ethyl arachidonate of the total FAEE in the brain was significantly higher than what has been found in all other organs and tissues previously analyzed. Linoleate, the precursor of arachidonate, was a poor substrate for FAEE synthesis, as the percentage of ethyl linoleate of the total FAEE content was extremely low. Thus, this reflects preferred incorporation of arachidonate into newly synthesized FAEE in the brain. Since arachidonate is derived from linoleate, which is depleted in FAEE while arachidonate is enriched, the synthesis of FAEE may be linked to the desaturation and elongation of linoleate to arachidonate.

Topics: Adipose Tissue; Alcoholic Intoxication; Arachidonic Acids; Autopsy; Brain; Ethanol; Humans; Linoleic Acids; Liver

Ethyl linoleate, ethyl linolenate, ethyl arachidonate and cod liver oil were oxidized with Fenton's reagent. Acrolein, malonaldehyde and 4-hydroxynonenal formed were derivatized to N-methylpyrazoline, N-methylpyrazole and 5-(1'-hydroxyhexyl)-1-methyl-2-pyrazoline with N-methylhydrazine, respectively. The derivatives were simultaneously analysed by gas chromatograph equipped with a fused silica capillary column and a nitrogen-phosphorus detector. The maximum amounts of acrolein (9.7 +/- 2.11 nmol/ml) and malonaldehyde (61.18 +/- 6.51 nmol/ml) were formed from cod liver oil. The highest amount of 4-hydroxynonenal (6.83 +/- 0.53 nmol/ml) was produced from ethyl arathidonate.

Topics: Acrolein; Aldehydes; Arachidonic Acids; Chromatography, Gas; Cod Liver Oil; Cross-Linking Reagents; Hydrogen Peroxide; Iron; Linoleic Acids; Linolenic Acids; Lipid Peroxidation; Malondialdehyde; Oxidation-Reduction; Reference Standards

The inhibitory effect of 2"-O-glycosyl isovitexin (2"-O-GIV), isolated from young barley leaves, on glyoxal formation from the oxidative degradation of three fatty acid ethyl esters was measured. Ethyl linoleate, ethyl linolenate and ethyl arachidonate were oxidized by Fenton's reagent. Glyoxal formed from these fatty acid esters was analysed by gas chromatography after it had been derivatized to quinoxaline with 1,2-phenylenediamine. The comparative study was performed using alpha-tocopherol. Generally, alpha-tocopherol exhibited a greater inhibitory effect at lower levels, whereas 2"-O-GIV showed a greater effect than alpha-tocopherol at higher levels. 2"-O-GIV was more effective than alpha-tocopherol towards fatty acid esters with high numbers of double bonds. 2"-O-GIV exhibited a dose-response effect but alpha-tocopherol did not. Maximum inhibition of 82% was obtained from oxidation of ethyl arachidonate at 8 mumol 2"-O-GIV, whereas maximum inhibition of 77% was observed from oxidation of ethyl arachidonate at 0.25 mumol alpha-tocopherol.

Topics: Arachidonic Acids; Carbohydrate Sequence; Flavonoids; Glyoxal; Hydrogen Peroxide; Iron; Isoflavones; Linoleic Acids; Linolenic Acids; Lipid Peroxidation; Molecular Sequence Data; Oxidation-Reduction; Vitamin E