Fatty acid ethyl esters in meconium: A biomarker of fetal alcohol exposure and effect

To determine if meconium fatty acid ethyl esters (FAEE) in rat pups is a good biomarker of prenatal exposure and effect to alcohol, three groups of pregnant rats were studied: one control (pair fed) and two treatment groups given 25% alcohol at 2.2 or 5.5 g−1 kg−1 d−1. The pups were delivered on day 20 and, for each dam, were separated into a male and female group. The body, brain, intestines, and placenta of the pups were obtained, weighed, and stored at −20°C. The pups’ intestines (as surrogate of meconium) from each group were pooled, and meconium was analyzed by gas chromatography/mass spectroscopy for FAEE. The meconium showed the following FAEE: ethyl palmitate, ethyl stearate, and ethyl linolenate and were only found in the alcohol-treated group and with high specificity but low sensitivity. Mean body weight of the pups was lower in the treatment groups compared to the control groups. Ethyl palmitate concentration correlated negatively to the pups’ mean body and brain weights. Therefore, ethyl palmitate, stearate, and linolenate, in meconium of rat pups prenatally exposed to alcohol, are useful biomarkers of prenatal alcohol exposure, with ethyl palmitate a good biomarker of adverse effect on the pups’ body and brain weight.

Non-ionic surfactant loaded on gel capsules to protect downhole tubes from produced water in acidizing oil wells

Gel capsules of calcium alginate as a matrix stuffed with a non-ionic surfactant, namely 2-(2-(3,4-bis(2-methoxyethoxy)tetrahydrofuran-2-yl)-2-(2-methoxyethoxy)ethoxy)ethyl stearate, Tween-60, as an inhibitor was prepared by a piercing-solidifying method for corrosion protection of carbon steel tubes from produced water in acidizing oil wells. The Fourier transform infrared and thermal gravimetric analysis techniques were used to study the properties of the capsules. The release of the inhibitor from the solid capsules to the corrosive acidizing produced water was studied gradually using ultraviolet-visible spectroscopy. A heavy additive was used to promote the sinking of the capsules in the oil well downhole tubes. The inhibitive effect of the released inhibitor on carbon steel in the corrosive produced water in acidizing oil wells was investigated using weight loss measurement, potentiodynamic polarization, electrochemical impedance spectroscopy, and morphologically by scanning electron microscopy. It was found that the inhibition efficiency increases with the increase of inhibitor release. The increase in temperature leads to partial desorption of inhibitor molecules at the metal surface, which causes increase in the corrosion rate. The positive sign of the activation enthalpy (ΔHa) reflects the endothermic nature of the carbon steel dissolution process.

Hydrodeoxygenation of ethyl stearate over Re-promoted Ru/TiO2 catalysts: rate enhancement and selectivity control by the addition of Re

The addition of Re to Ru/TiO2 could promote the reaction rate and product selectivity of n-C18H38via adjusting acid sites.

Anti-Diabetic Activity and Nuclear Magnetic Resonance (NMR) Characterization of Natural Esters from Hexane and Dichloromethane Crude Extracts from Calyces of Hibiscus sabdariffa Linn

Non-polar crude extracts obtained from the calyces of Hibiscus sabdariffa Linn. (Roselle) and their α-glucosidase inhibitory activity has been investigated. Roselle extracts potentially act as an anti-diabetic activity. However, most of the previous studies on Roselle were just focused on the polar crude extracts. Therefore, hexane and dichloromethane crude extracts were selected for these study. 3 kg of samples were air dried at room temperature, ground and serially extracted by solid-liquid extraction technique using hexane and dichloromethane. Compounds were isolated and purified by various chromatographic techniques. Their structures were elucidated with 1D and 2D-NMR, and other spectroscopic methods including MS, IR and UV as well as comparison with data reported in the literature. The phytochemical study has led to the isolation of three compounds namely squalene, triglyceride fatty acids (consist of ethyl oleate, ethyl linoleate and γ-ethyl linolenate) and ethyl stearate. Based on the literature, this is the first reported squalene isolated from the calyces of Roselle. The α-glucosidase inhibitory activity on the crude extracts was conducted and showed moderate inhibitory activity was detected on hexane crude extract. Thus, results from this study can be used as future references for the discovery of natural esters and the potential of Roselle as an anti-diabetic source.

Molecular Study on Dominant Fatty Acid Esters Characterized from Waste Beef Tallow Biodiesel – A Quantum Computational Approach

This study deals with computational analysis of dominant fatty acid ethyl esters characterized from the biodiesel produced from waste beef tallow by means of KOH catalyzed ethanol based transesterification. Ethyl palmitate, Ethyl Oleate, Ethyl Stearate and Ethyl Myristate were identified as dominant fatty acid esters and were computed for molecular analysis in Gaussian 09 software using Density Functional Theory (B3LYP method) with 6-31G* as basis set. Geometric parameters were in accordance with existing experimental values and population analysis exhibited negative charge for oxygen atoms, both positive & negative charge for carbon atoms in all ester molecules. The molecular dipole moment was higher for unsaturated ester molecule and quadruple moment proposed electronic dislocation in X+Y direction. Also, energy gap decreased slightly with increasing carbon chain but reduced drastically with increase in unsaturation. Electrostatic potential mapping displayed negative electrostatic potential for oxygen atoms in ester linkage of all ester molecules.

Experimental study on influence of dominant fatty acid esters in engine characteristics of waste beef tallow biodiesel

Biodiesel is regarded as the most promising renewable biofuel which can satisfy the worldwide energy demand through its robust net energy output with less impact on environment and also an effective alternative or supplement for existing diesel fuel for powering Compression Ignition engines. This present study aims to compare the performance, combustion and emission characteristics of beef tallow biodiesel with its dominant fatty acid esters and their influence on these characteristics. Ethyl stearate, ethyl palmitate and ethyl oleate were identified as dominant fatty acid esters available in a composition of 14.78, 37.36 and 25.17%, respectively. Two set of samples were prepared for testing purpose and were classified as (i) blend samples and (ii) ester samples, with plain diesel as base fuel. The maximum cylinder pressure was found to be in the range between 67 and 71 bar for all the samples and heat release rate was found to be highest for B20 blend. Slight decrease in efficiency along with marginal increase in fuel consumption was a result of long chained fatty acid esters (stearate and oleate esters) whereas increase in CO2 emission and decrease in NOX emission were because of higher oxygen content, cetane number and degree of unsaturation in the ester molecule.