Carbon Atoms In Fatty Acid Research Articles

Using Gibbs Energy Additivity Methods for QSPR to Model the Density of Fatty Acid Ethyl Esters and Biodiesels

Liquid fuel density is an essential physical parameter in the design and application processes. This paper employed the Gibbs free energy technique with quantitative structure‐property relationship (QSPR) for determining the density of pure fatty acid ethyl ester (FAEE) and ethyl ester biodiesel at temperature 283.15–363.15 K. The density (ρ) of biodiesel can be estimated from (1) the number of carbon atoms of fatty acids (z) and the number of double bonds (nd): ln ρ = −0.4466–0.0009z + 88.28/T + 0.2092z/T + 0.01734nd–1.578nd/T or (2) the saponification number (SN) and iodine value (IV): ln ρ = −0.4436–3.60/SN + 87.594/T + 836.8/(T × SN) + 0.0380 IV/SN – 3.4222 IV/(T × SN), where T is the absolute temperature. The predicted densities at different temperatures for pure FAEEs and ethyl ester biodiesel have average absolute deviations (AAD) of 0.100% and 0.200%, respectively.

A student centric method for calculation of fatty acid energetics: Integrated formula and web tool.

Mitochondrial beta-oxidation is one of the most common modes of fatty acids' oxidation in most organisms, particularly mammals. Biochemistry undergraduate curriculum often contains the description of the process, with emphasis on ATP calculations for various types of fatty acids. During our decade long teaching experience in biochemistry, we observed the difficulty faced by students in calculating energetics of several fatty acids beyond palmitic acid. We developed a canonical formula by mathematical transformations and logical derivation to aid the calculation in a much simpler manner to ease both teaching and learning experience. ATP yield of even-numbered fatty acids may be calculated using a formula [(7C - 6 - 1.5 D) - 2(D-2)], andadenosine triphosphate (ATP) yield for odd-numbered fatty acids can be calculated using [(7C - 19 - 1.5 D) - 2(D-2)], where C is the number of carbon atoms in fatty acids, D is the number of double bonds. The unbold part of the formulae is limited to polyunsaturated fatty acids. Moreover, we integrated these formulae into an HTML based web-interface for handily calculations, which is likely to augment fatty acids oxidation learning-teaching processes easier. This tool has been recently tested in our classroom programs on biochemistry and received an excellent feedback from the learners. Also, the mathematical formula is ready for being incorporated into standard biochemistry textbooks. The webtool as an opensource biochemical calculator can be effectively used in classrooms by both instructors and students while solving comprehension based questions on lipid metabolism.

Enzymatic Synthesis of l-Ascorbyl Fatty Acid Esters Under Ultrasonic Irradiation and Comparison of Their Antioxidant Activity and Stability.

A series of novel l-ascorbyl fatty acid esters were synthesized by catalization of Novozym(®) 435 under ultrasonic irradiation and characterized by infrared spectroscopy, electrospray ionization mass spectra, and nuclear magnetic resonance. Their properties especially antioxidant activity and stability were investigated. The results showed that the reducing power, the scavenging activity of hydroxyl radical and 2,2-diphenyl-1-picrylhydrazyl radical were decreased with the increase of the number of carbon atoms in fatty acid. The hydroxyl radical scavenging activity and reducing power of l-ascorbyl saturated fatty acid esters were better than that of tert-butylhydroquinone. The induction period in lipid oxidation of l-ascorbyl saturated fatty acid esters and tert-butylhydroquinone were longer than that of l-ascorbyl unsaturated fatty acid esters and l-ascorbic acid both in soybean oil and lard. Besides, the l-ascorbyl fatty acid esters showed different stabilities in different conditions by comparing with l-ascorbic acid, and the l-ascorbyl saturated fatty acid esters were more stable than l-ascorbyl unsaturated fatty acid esters in ethanol solution.

Changes in lymphocyte properties after employment of the combination of carbamylation and oxidative stress, an in vitro study

It is well known that oxidative stress and carbamylation alter macromolecule properties and functions.We evaluated the influence of sodium cyanate (NaOCN) and the combination of cyanate and hydrogen peroxide (H2O2) on nonenzymatic antioxidant capacity (NEAC), total thiols, reduced glutathione (GSH) and hydroperoxide level in mononuclear blood cells (MNCs). We also examined plasma membrane properties of MNCs using the spin labeling method in EPR spectroscopy (electron paramagnetic resonance spectroscopy).We showed that MNCs are resistant to cyanate treatment up to a concentration of 2mM (survival test). On the other hand, a significant loss of antioxidant defense of cells, e.g. NEAC upon NaOCN, H2O2 and the combination of cyanate and hydrogen peroxide was observed. Carbamylation slightly decreased GSH and the free thiol level, but H2O2 and its combination with NaOCN lead to a decrease in their amounts. A markedly higher level of hydroperoxides was only observed in the cells treated with H2O2.We found a significant decrease in lipid membrane fluidity at the depth of 12th and 16th carbon atoms of fatty acids in lymphocytes treated with cyanate or H2O2. The combination of both substances acted synergistically and induced profound changes in comparison to cyanate and hydrogen peroxide used alone.

Solubilization of Thiamine Disulfide by Fatty Acid or Its Analog in 1,2-Dichloroethane.

The solubility change of thiamine disulfide (TDS) in 1, 2-dichloroethane by the addition of fatty acid (FA), fatty alcohol or fatty acid methyl ester was determined by phase solubility analysis at 25°C. The solubility of TDS increased linearly with added concentrations of stearic acid, palmitic acid or myristic acid, but the diagram did not exhibit a plateau due to the appearance of a solid complex. The dependency of the FA slope values on the number of carbon atoms in FA was very little. The solubility of TDS also incerased linearly with added concentrations of stearyl alcohol, while the value for the slope was smaller than FA. On the other hand, the solubility of TDS decreased by the addition of stearic acid methyl ester. The results agreed well with those for the solubilization of cycotiamine, a thiamine derivative, by FA and FA analogs in 1, 2-dichloroethane.

Formation of a cycotiamine complex with fatty acid in dichloroethane.

The formation of complexes between cycotiamine (CCT) and fatty acids (FA) (tetradecanoic acid, hexadecanoic acid, and octadecanoic acid) in 1, 2-dichloroethane was studied by phase solubility analysis and ultraviolet absorption spectroscopy. The apparent stability constants of the equimolar complexes between CCT and FA were determined at 288, 298, and 310 k, and thermodynamically discussed. The complex formation ability of FA depended on the number of carbon atoms in FA, but the differences were small. The ability of 1-octadecanol was very small, and octadecanoic acid methyl ester had none. From these results CCT-FA were concluded to be hydrogen bonded complexes in which FA act as hydrogen donors. The complex formation reactions were exothermic anc enthalpically controlled.

Synthesis of milk fat from beta-hydroxybutyrate and acetate in lactating goats.

SummaryThe relative importance of β-hydroxybutyric acid (BHBA) and acetate as precursors for milk-fat synthesis was studied in lactating goats by infusing separately tracer quantities of [3−14C]DL-BHBA and [1−14C]acetate into the jugular vein, and [1−14C]butyrate into the portal vein. The concentrations and specific radioactivities of blood plasma constituents, the yields and specific radioactivities of individual milk fatty acids and the relative radioactivities of individual carbon atoms of milk fatty acids were determined.The infusion of [1−14C]butyrate resulted in the appearance of labelled BHBA in the blood plasma which behaved almost identically with infused [14C]BHBA as a precursor for milk fatty acids.The relative radioactivity of carbon atoms of the fatty acids of milk fat following the infusions provided direct evidence that BHBA had provided an intact 4-carbon unit at the methyl end of each fatty-acid chain. Acetate provided 2-carbon units both for the elongation of the 4-carbon units and for completede novosynthesis. BHBA also provided 2-carbon units which behaved in a similar fashion to those from acetate.Acetate and BHBA together accounted for all of the C4–C12acids of milk fat, about 75% of the C14, 45% of the C16and 10% of the C18.The total contributions of the various precursors to the fatty acids of milk fat were: acetate 42%, BHBA 9·4% and other plasma precursors (by difference) 48·6%.

ON THE LUBRICATION OF FIBRE WITH FATTY ACIDS

The investigation were made of the friction of fibres lubricated with linear chain fatty acids, and the relations between the number of carbon atoms in fatty acid and the friction coefficient are discussed.1) The friction coefficient diminishes as the number of the carbon atoms increases, reaches a minimum value, and then increases slightly. The number of carbon atoms for the minimum value (i.e. transition carbon number) depends on the temperature, the higher the temperature the larger the carbon number at which the minimum value will be reached.It seems that the relation between the carbon number and the friction coefficient corresponds with the relation between the temperature and the friction coefficient. This means that the transition carbon number corresponds with the transition temperature.2) The static friction is higher than the kinetic friction, and the transition carbon number for the static friction is larger than that in the kinetic friction. It seems that the relation between the sliding speed and the transition carbon number corresponds with the relation between the sliding speed and the transition temperature.3) The transition carbon number increases as the pressure at the true area of friction contact increases.This fact corresponds with the relation between the load and the transition temperature.