ethyl-arachidonate and ethyl-oleate

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

Purified rat pancreas protein kinase C (PKC) is activated by unsaturated free fatty acids (oleic and arachidonic). The ethyl esters of these fatty acids are ineffective as enzyme activators. However, when the ethyl esters are added in combination with a free fatty acid, there is significant enhancement of enzyme activation. Nearly optimal PKC activation was obtained when non-activating ethyl oleate or ethyl arachidonate was added to sub-optimally activating concentrations of oleic or arachidonic acids. In addition to the ethyl esters, 1-monooleylglycerol also had a potentiating effect on PKC activation by oleic acid. However, the degree of activation observed in the presence of a free fatty acid and an acyl ester of the fatty acid quantitatively never surpassed that produced by sn-1,2-dioleylglycerol. Our findings indicate that significant PKC activation can be achieved by presenting the enzyme with an environment which we believe approximates the structural characteristics of the endogenous activator, sn-1,2-diacylglycerol.

Topics: Animals; Arachidonic Acid; Arachidonic Acids; Diglycerides; Drug Synergism; Enzyme Activation; Esters; Oleic Acid; Oleic Acids; Pancreas; Protein Kinase C; Rats; Structure-Activity Relationship