Sodium Linoleate Research Articles

Using sodium linoleate as a nucleating agent to improve the properties of PBAT/CaCO3 composites

Using sodium linoleate as a nucleating agent to improve the properties of PBAT/CaCO3 composites

Discovery of benzothiazole-based thiazolidinones as potential anti-inflammatory agents: anti-inflammatory activity, soybean lipoxygenase inhibition effect and molecular docking studies

ABSTRACT Despite the greatest achievement in the development of anti-inflammatory agents in the last two decades, the current clinical drugs suffer from a variety of complications in community settings and hospital. There is still an urgent need to design novel molecules with better safety profile and with different molecular targets from those in current clinical use. The aim of this research was to discover a series of benzothiazole-based thiazolidinones with lipoxygenase (LOX) inhibitory activity as a mechanism of anti-inflammatory action. Carrageenan-induced mouse foot paw oedema assay was carried out to determine the anti-inflammatory activity, while LOX inhibition was examined through the conversion of sodium linoleate to 13-hydroperoxylinoleic acid. Molecular docking studies were performed using AutoDock 4.2 software. The anti-inflammatory activity of the title compounds was determined in a range of 18.4%-69.57%, where compound #3 was found to be the most potent (69.57%) and also to be more active than the reference drug indomethacin (47%). Moreover, compound #3 showed the highest LOX inhibitory activity with IC50 of 13 μM being less potent to that of the reference NDGA (IC50 = 1.3 μM). Compound #3 has been identified as lead compound for further modification in an attempt to improve anti-inflammatory and LOX inhibitory activities.

Molecular insights into the loss of phytosterols during the neutralisation of corn oil

Herein, the physical migration and chemical conversion of phytosterols during the alkali neutralisation process of corn oil were investigated with molecular insights. A significant decrease in the phytosterol content was attributed to the migration from oil to the soapstock, along with slight chemical conversions between free phytosterols and phytosteryl esters in the heterogeneous system. Moreover, the migration of phytosterols was positively correlated with the water content in a model system through low-field nuclear magnetic resonance spectroscopy, which was attributed to the hydrogen bonding between free phytosterols and water. Compared to sodium oleate and sodium linoleate, sodium palmitate caused a higher loss of phytosterols due to its low solubility. X-ray diffraction analysis confirmed the formation of a bilayer structure of the sodium salt of fatty acids, suggesting the aggregation of the sodium salt of fatty acids and phytosterols at neutralisation temperatures. Small-angle X-ray scattering analysis suggested that the concentration of the NaOH solution affected the structure of sodium oleate and the area of the polar head base, which was associated with the loss of free phytosterols. The study presents an important fundamental scientific basis for the retention of phytosterols toward the development of more healthy and nutritious edible oils.

A facile approach to realize simultaneously chain extension and crystallization promotion of poly (ethylene terephthalate)

A synergic strategy combining chemical nucleation with chain extension was employed for Poly (ethylene terephthalate) (PET). In this study, sodium linoleate (Na-LL), as chemical nucleating agent, was selected to promote the nucleation process, and an ultraviolet-induced chain extension approach was simultaneously employed to maintain the molecular weight of PET with the aid of glycidyl methacrylate (GMA) / trimethylolpropane triacrylate (TMPTA). The rheological properties, crystallization behaviors and mechanical properties of PET composites were systematically explored. The rheological results showed that GMA/TMPTA blend is effective for PET chain extension reaction and the addition of Na-LL would not badly offset the chain extension effect of GMA/TMPTA. The non-isothermal and isothermal crystallization studies demonstrated that Na-LL is an effective organic nucleating agent for PET. Low loading of Na-LL can considerably improve the crystallization properties of PET. At last, the combination of GMA/TMPTA/Na-LL could also maintain the excellent comprehensive mechanical properties of PET.

Sodium oleate, arachidonate, and linoleate enhance fibrinogenolysis by Russell's viper venom proteinases and inhibit FXIIIa; a role for phospholipase A2 in venom induced consumption coagulopathy

Life-threatening symptoms produced by Russell's viper (RV, Daboia russelii) envenomation result largely from venom induced consumption coagulopathy (VICC). VICC is thought to be mediated to a large degree by venom serine and metalloproteinases, as well as by snake venom phospholipase A2 (svPLA2), the most abundant constituent of RV venom (RVV). The observation that the phenolic lipid anacardic acid markedly enhances proteolytic degradation of fibrinogen by RVV proteinases led us to characterize the chemical basis of this phenomenon with results indicating that svPLA2 products may be major contributors to VICC. ResultsOf the chemical analogs tested, the anionic detergents sodium dodecyl sulfate, sodium deoxycholate, N-lauryl sodium sarcosine, and the sodium salts of the fatty acids arachidonic, oleic and to a lesser extend linoleic acid were able to enhance fibrinogenolysis by RVV proteinases. Enhanced Fibrinogenolysis (EF) was observed with various venom size exclusion fractions containing different proteinases, and also with trypsin, indicating that conformational changes of the substrate and increased accessibility of otherwise cryptic cleavage sites are likely to be responsible for EF. In addition to enhancing fibrinogenolysis, sodium arachidonate and oleate were found to partially inhibit thrombin induced, factor XIIIa (FXIIIa) mediated ligation of fibrin chains. In clotting experiments with fresh blood RVV was found to disrupt normal coagulation, leading to small, partial clot formation, whereas RVV pretreated with the PLA2 inhibitor Varespladib induced rapid and complete clot formation (after 5 min) compared to blood alone. ConclusionThe observations that fatty acid anions and anionic detergents induce conformational changes that render fibrin(ogen) more susceptible to proteolysis by RVV proteinases and that RVV-PLA2 activity (which produces FFA) is required to render blood incoagulable in clotting experiments with RVV indicate a mechanism by which the activity of highly abundant RVV-PLA2 promotes degradation and depletion of fibrin(ogen) resulting in incoagulable blood seen following RVV envenomation (VICC).

A Soap‐Free Strategy for One‐Pot Synthesizing Conjugated Linoleic Acid: Alkali Isomerization of Linoleic Acid through Preferential Esterification Pathway

AbstractConjugated linoleic acid (CLA) exhibits beneficial biological activities but possesses poor natural abundance, which is usually obtained by alkali isomerization of linoleic acid (LNA). The one‐pot alkali isomerization consists two reactions, firstly saponifying LNA and then isomerizing linoleate. This current process has been limited by two drawbacks, the overconsumption of both alkali and solvent, as well as the weak mass/heat transfer of the viscous paste of reaction mixture that limits the synthesis scale. The present study alternated the reaction pathway with a soap‐free preferential esterification pathway, that is, firstly employing slight NaOH to induce the esterification of LNA and diol (the reaction solvent), then conducting alkali isomerization of the intermediate alkyl linoleate instead of sodium linoleate. In this developed one‐pot procedure, a CLA yield of 90% and the selectivity of the desired isomers (“c9, t11” and “t10, c12” CLA) of 82.4% were obtained; and it reduced the consumption of NaOH and the solvent by 60% and 25% comparing to the current soap pathway, respectively; Yet the result is comparative to that obtained with assistant of microwave/ultrasound in even longer reaction time. In this way, the two drawbacks can be overcome and the green characteristics of the current process was well kept.

Adsorption of Anions of Higher Carboxylic Acids on Magnesium from Weakly Alkaline Aqueous Solutions

The adsorption of sodium salts of higher carboxylates on oxidized magnesium is studied via in situ reflective ellipsometry. It is shown that the free energies of adsorption of sodium oleyl sarcosinate (OsS) and sodium linoleate (LiS) is >55 kJ/mol, indicating the chemisorption of carboxylates on oxidized magnesium surfaces. Electrochemical impedance spectra, voltammetry, and corrosion testing show that sodium oleate (OlS) has the best protective properties on pure and oxidized magnesium. The strong protective properties of OlS are confirmed by Mg plate testing under conditions of a wet atmosphere with daily condensation. Tentative passivation of chemically oxidized Mg in a 16 mmol/L OlS solution protects against corrosion for 92–96 h.

Characteristics of the catalytic fast pyrolysis of vegetable oil soapstock for hydrocarbon-rich fuel

Hydrocarbon-rich fuel from vegetable oil soapstock is potentially a good alternative to conventional fossil-derived fuels. This paper reported on pyrolysis experiments with compounds including vegetable oil soapstock, sodium stearate(C18), sodium palmitate(C16), sodium oleate(C18:1), and sodium linoleate(C18:2). The effects of pyrolysis temperature, HZSM-5 catalyst, unsaturation degree and carbon chain length on the formation of aromatic hydrocarbons were explored. Experimental results indicated that the relative content of oxygenated compounds significantly decreased in the condensable organic compounds of soapstock pyrolysis, and aromatic hydrocarbons increased when the HZSM-5 catalyst was used, in which toluene and xylene had the highest relative selectivity. High catalytic pyrolysis temperature was beneficial to the relative selectivity of benzene and toluene, but inhibited the relative selectivity of xylene and ethylbenzene. The increase in saturation of fatty acid salts promoted the reaction toward the production of polycyclic aromatic hydrocarbons, which were a kind of typical precursor of catalyst coking deactivation and carcinogenic pollutants.

Evaluation of fatty acid derivatives in the remediation of aged PAH-contaminated soil and microbial community and degradation gene response

In this study, derivatives of two common fatty acids in plant root exudates, sodium palmitate and sodium linoleate (sodium aliphatates), were added to an aged Polycyclic aromatic hydrocarbons (PAHs) contaminated soil to estimate their effectiveness in the removal of PAHs. Sodium linoleate was more effective in lowering PAHs and especially high-molecular-weight (4–6 ring) PAHs (HMW-PAHs). Principal coordinates analysis (PCoA) indicates that both amendments led to a shift in the soil bacterial community. Moreover, linear discriminant effect size (LEfSe) analysis demonstrates that the specific PAHs degraders Pseudomonas, Arenimonas, Pseudoxanthomonas and Lysobacter belonging to the γ-proteobacteria and Nocardia and Rhodococcus belonging to the Actinobacteria were the biomarkers of, respectively, sodium linoleate and sodium palmitate amendments. Correlation analysis suggests that four biomarkers in the sodium linoleate amendment treatment from γ-proteobacteria were all highly linearly negatively related to HMW-PAHs residues (p < 0.01) while two biomarkers in the sodium palmitate amendment treatment from Actinobacteria were highly linearly negatively related to LMW-PAHs residues (p < 0.01). Higher removal efficiency of PAHs (especially HMW-PAHs) in the sodium linoleate amendment treatment than in the sodium palmitate amendment treatment might be ascribed to the specific enrichment of microbes from the γ-proteobacteria. The bacterial functional KEGG orthologs (KOs) assigned to PAHs metabolism and functional C23O and C12O genes related to cleavage of the benzene ring were both up-regulated. These results provide new insight into the mechanisms of the two sodium aliphatate amendments in accelerating PAHs biodegradation and have implications for practical application in the remediation of PAHs-contaminated soils.

Improvement of calcium mineral separation contrast using anionic reagents: electrokinetics properties and flotation

The flotation separation of salt type calcium minerals is problematic, due to the similarities in their same active Ca2+ related site for interaction with anionic collectors and similar physicochemical characteristics such as solubility, zero-point charge, surface speciation and Ca-site density. The work was performed to achieve effective and selective separation of the calcium-minerals using pure minerals samples: orange calcite with Mg impurities, optic calcite with impurities level and an apatite. The pure samples surface was examined using techniques sensitive near-surface like infrared spectroscopy (FTIR) and chemical composition was obtained by ICPMS. The isoelectric point (IEP) and point of zero charge (PZC) in electrolyte were recorded using electrophoresis method at different ionic strengths of the solution. Mechanisms of charge development at the mineral-water interface are discussed. The time of contact as important parameter for the charge equilibrium was deduced from kinetics study and fixed to 30 minutes. The difference in the values obtained between IEP and PZSE can be explained by the presence of a specific adsorption of cations and anions on the surface. The effect of pure anionic collectors such as oleic and linoleic acid were studied. At low pH, both collectors lead to a good recovery for the calcites. The flotation recovery of optic calcite at pH 9 with sodium oleate is higher than with sodium linoleate. At alkaline pH, apatite showed a better recovery with sodium linoleate.

Effect of unsaturation degree on microwave-assisted pyrolysis of fatty acid salts

This work is aimed to study the effect of unsaturation degree on microwave-assisted pyrolysis (MAP) of fatty acid salts. Sodium stearate, sodium oleate, and sodium linoleate were selected as model compounds. MAP of sodium oleate obtained the highest yield of liquid product. GC–MS analysis of liquid product revealed that MAP of unsaturated fatty acid salt could produce alkadienes, cycloalkanes, cycloalkenes, alkynes and aromatics, which could not appear in liquid product obtained from MAP of saturated fatty acid salt, and unsaturation degree had a great influence on liquid product composition. Analysis of the gas product indicated that MAP of sodium oleate produced more CO2 and CO, while the MAP of sodium linoleate produced more gaseous hydrocarbons and H2. Analysis of the solid char showed that MAP of unsaturated fatty acid salts favors the cyclization and aromatization of pyrolysis vapours. The properties of liquid product were measured and analyzed, which confirmed that MAP of fatty acid salts is a feasible technology to produce high-quality renewable hydrocarbon fuels.

Plant volatile eliciting FACs in lepidopteran caterpillars, fruit flies, and crickets: a convergent evolution or phylogenetic inheritance?

Fatty acid amino acid conjugates (FACs), first identified in lepidopteran caterpillar spit as elicitors of plant volatile emission, also have been reported as major components in gut tracts of Drosophila melanogaster and cricket Teleogryllus taiwanemma. The profile of FAC analogs in these two insects was similar to that of tobacco hornworm Manduca sexta, showing glutamic acid conjugates predominantly over glutamine conjugates. The physiological function of FACs is presumably to enhance nitrogen assimilation in Spodoptera litura larvae, but in other insects it is totally unknown. Whether these insects share a common synthetic mechanism of FACs is also unclear. In this study, the biosynthesis of FACs was examined in vitro in five lepidopteran species (M. sexta, Cephonodes hylas, silkworm, S. litura, and Mythimna separata), fruit fly larvae and T. taiwanemma. The fresh midgut tissues of all of the tested insects showed the ability to synthesize glutamine conjugates in vitro when incubated with glutamine and sodium linolenate. Such direct conjugation was also observed for glutamic acid conjugates in all the insects but the product amount was very small and did not reflect the in vivo FAC patterns in each species. In fruit fly larvae, the predominance of glutamic acid conjugates could be explained by a shortage of substrate glutamine in midgut tissues, and in M. sexta, a rapid hydrolysis of glutamine conjugates has been reported. In crickets, we found an additional unique biosynthetic pathway for glutamic acid conjugates. T. taiwanemma converted glutamine conjugates to glutamic acid conjugates by deaminating the side chain of the glutamine moiety. Considering these findings together with previous results, a possibility that FACs in these insects are results of convergent evolution cannot be ruled out, but it is more likely that the ancestral insects had the glutamine conjugates and crickets and other insects developed glutamic acid conjugates in a different way.

The mitigating effects of phosphatidylcholines on bile salt- and lysophosphatidylcholine-induced membrane damage.

The effects, at pH 7.0, of a series of 0.2 mM phosphatidylcholines (PC), namely dicaproyl-PC (DCPC), didecanoyl-PC (DDPC), dilauroyl-PC (DLaPC), dimyristoyl-PC (DMPC), dipalmitoyl-PC (DPPC), dioleoyl-PC (DOPC) and dilinoleoyl-PC (DLPC) and a series of 0.2 mM fatty acid salts (namely sodium myristate, palmitate, stearate, oleate and linoleate) upon the erythrocyte haemolysis induced by 2 mM sodium taurodeoxycholate (STDC) were determined. The influence of egg PC and dihexadecyl phosphate (DHDP) concentration upon the haemolysis induced by 1.4 mM sodium deoxycholate (SDC), 2 mM STDC and 0.1 mM lysophosphatidylcholine (LPC) were also established. A bile salt:egg PC mole ratio of 0.5 virtually abolished the haemolysis induced by SDC and STDC, whereas the same ratio of LPC:egg PC only reduced haemolysis from 65 to 40% (maximum haemolysis). DHDP had no effect on the haemolytic action of SDC or STDC. The salts of the fatty acids were non-haemolytic, and when mixed with STDC did not affect the level of haemolysis induced by the bile salt. In contrast, DDPC and DLaPC enhanced the haemolysis of STDC and DCPC had no effect, whereas DMPC, DPPC, DSPC, DOPC, DLPC and egg PC all reduced haemolysis. Maximum reduction was determined for DMPC and egg PC. The mixed micelle preparation temperature (either room or 60 degrees C) and temperature of incubation (either 20 degrees C for 30 min or 37 degrees C for 5 min) had only minor effects on the net haemolysis induced by STDC. These findings may be of significance in understanding the aetiology of certain gastrointestinal diseases and in determining whether mixed bile salt micelles have a role as drug penetration enhancers.

Preparation and Antibacterial Activity of Silver Nanoparticles

Uniform silver nanoparticles have been prepared through the chemical reduction of silver ions by ethanol in presence of sodium linoleate. TEM micrograph shows a uniform distribution of the particles with an average size of 12 nm. Further, the antimicrobial activity of silver nanoparticles shows that these nanoparticles can be used as effective growth inhibitors against Staphylococcus Basillus, Staphylloccoccus Aureus, and Pseudimonas Aureginosa.

Comparative kinetics of fatty acid–amino acid conjugate elicitor biosynthesis by midgut tissue microsomes of Lepidopterous caterpillar larvae

N-Linolenoyl-L-glutamine is one of several structurally similar fatty acid-amino acid conjugate (FAC) elicitors found in the oral secretions of Lepidopterous caterpillars and its biosynthesis is catalyzed by membrane-associated alimentary tissue enzyme(s). FAC elicitors comprise 17-hydroxylated or non-hydroxylated linolenic acid coupled with L-glutamine or L-glutamate by an amide bond. We demonstrate in vitro biosynthesis of N-linolenoyl-L-glutamine by Manduca sexta, Heliothis virescens, and Helicoverpa zea tissue microsomes. Comparison of N-linolenoyl-L-glutamine biosynthesis kinetics for these species suggests that concurrent biosynthesis and hydrolysis contribute to proportions of FAC elicitors found in their oral secretions. The apparent K(m) values for coupling of sodium linolenate were 8.75±0.79, 14.3±3.7 and 20.7±3.4 mM and V(max) values were 2.92±0.14, 6.81±1.2 and 4.95±0.55 nmol/min/mg protein for H. zea, H. virescens and M. sexta, respectively. The K(m) values for coupling of L-glutamine were 10.5±0.26, 22.3±2.0 and 18.9±2.4 mM and V(max) values were 1.78±0.21, 3.71±0.50 and 2.49±0.41 nmol/min/mg of protein for H. zea, H. virescens and M. sexta, respectively.

Optical Properties of Linoleic Acid Protected Gold Nanoparticles

Linoleic acid-protected gold nanoparticles have been synthesized through the chemical reduction of tetrachloroaurate ions by ethanol in presence of sodium linoleate. The structure of these nanoparticles is investigated using transmission electron microscopy, which shows that the Au nanoparticles are spherical in shape with a narrow size distribution which ranges from 8 to 15 nm. Colloidal dispersion of gold nanoparticles in cyclohexane exhibits absorption bands in the ultraviolet-visible range due to surface plasmon resonance, with absorption maximum at 530 nm. Fluorescence spectra of gold nanoparticles also show an emission peak at 610 nm when illuminated at 450 nm. UV-Vis spectroscopy reveals that these nanoparticles remain stable for 10 days.

The low concentration aggregation of sodium oleate–sodium linoleate aqueous mixtures

Sodium oleate (NaOL, C18H33O2Na)–sodium linoleate (NaLin, C18H31O2Na) mixtures were studied in the micellar and in the air/water interface states at 298.15 K. Three aggregation steps were found: a premicellar aggregation, the critical micelle concentration (CMC), and a structural change of micelles. Micelles, both at the CMC and at the structural change concentration, are richer in oleate than the overall mixture composition. Micelles are strongly non-ideal and the interaction is repulsive. The non-ideal behavior and the dependence of the micelle ionization degree with micelle composition are explained on the basis of the interaction of the π electrons of the surfactants’ chains with water at the hydrocarbon/water micellar interface. The air/solution adsorbed monolayer is also non-ideal, but the interaction is attractive and there is a preferential composition with a mole fraction of sodium oleate of about 0.7. The surface pseudophase behaves as if oleate were the solvent and linoleate a strongly soluble solute. This behavior and the dependence of the average area per adsorbed molecule were explained on the basis of the interaction of the double bonds with water. At the air/solution interface, the linoleate molecule area was similar to that of a heterogemini surfactant having a spacer with seven carbon atoms.

Adamantane derivatives of thiazolyl- N-substituted amide, as possible non-steroidal anti-inflammatory agents

A series of adamantane derivatives of thiazolyl- N-substituted amides were synthesized in a three-step reaction and tested for anti-inflammatory activity as well as lipoxygenase and cycloxygenase inhibitory actions. Theoretical calculation of their lipophilicity, as C log P was performed. The effect of the synthesized compounds on inflammation, using the carrageenin-induced mouse paw oedema model was studied and compared to indomethacin. In general, the studied compounds were found to be potent anti-inflammatory agents (29.6–81.5%). Anti-inflammatory activity was influenced by some structural characteristics of the synthesized compounds. The lipoxygenase inhibitory activity was tested by the conversion of sodium linoleate to 13-hydroperoxylinoleic acid. Low inhibitory activity was observed. Evaluation of COX-1 and COX-2 inhibitory activities of the compounds revealed a COX-1 inhibitory potential, comparable to that of naproxen for some of the compounds and a low to moderate COX-2 inhibitory potential. Comparison of the in vivo and in vitro results leads to the conclusion that most compounds of this series may be involved in other mechanisms of inflammation, too.

Detection of free fatty acids following a conditioned taste aversion in rats

A gustatory transduction mechanism for free fatty acids (FFAs) has been described in isolated rat taste receptor cells; however, the ability of behaving rats to detect FFAs has not been characterized. Through conditioned taste aversion (CTA) methodology, this study defines the ability of rats to detect and avoid the two principal FFA components of corn oil, linoleic and oleic acid. Following taste aversion conditioning, rats avoided both linoleic and oleic acid at greater than or equal to 66 μM and failed to avoid either 44 μM linoleic or oleic acid. Rats demonstrated generalized avoidances between 88 μM linoleic and oleic acid irrespective of presenting the FFAs as either unesterified acids dissolved in 5 mM ethanol or aqueous sodium salts, sodium linoleate and sodium oleate. Following a CTA to linoleic acid, rats did not show generalized avoidance of NaCl or ethanol, two potentially concomitant tastants in the oral cavity. A CTA to linoleic or oleic acid did produce a generalized avoidance to the other FFA. These results support the ability of rats to detect linoleic and oleic acid (> 44 μM) and suggest that the two FFAs share common orosensory properties. Furthermore, it is unlikely that the detection of the FFAs is due to an enhancement of other concomitant tastants such as saliva or the delivery solution.

Interactive Adsorption Behavior of β-Lactoglobulin and Linoleate at a 316L Stainless Steel Surface

The work presented gives new fundamental and applied information on the interactive behavior of sodium linoleate (LA) and β-lactoglobulin (β-Lg) at a stainless steel (SS316L) surface, which has significance in both medical and industrial applications. It is shown that β-Lg interacts strongly with LA on the SS316L surface, presumably through hydrophobic interactions (forces). It is also shown that the electrochemical techniques of cyclic voltammetry and electrochemical impedance spectroscopy can be effectively employed to study the adsorption behavior of small (LA) and large (β-Lg) molecules at solid electrically conductive surfaces.