Linolenic acids, esters

Fell et al. presented a micellar two-phase system in which fatty acid esters can be hydroformylated [30]. Short fatty acids react in a mixture of water and the substrate without adding any surfactants. The rhodium/NaTPPTS catalyst system was able to conduct the reaction of methyl 10-undecenoate at 100°C with 30-bar synthesis gas pressure with a conversion of 99% without any surfactant. The reaction of linolenic acid ester was hindered by phase transfer problems which could be overcome by employing surfactants. The addition decreased the reaction time, so the same rhodium catalyst could achieve a conversion for linolenic methyl ester of 100%. The authors... 

D6751 Biodiesel blend stock (B1 00) for middle distillate fuels EN 14103 Ester and linolenic acid ester content... 

We have made it our objective to develop UV stabilizers that could be added to urushi and "cocured" to obtain a photo-stabilized oriental lacquer. We have synthesized several 2(2-hydroxyphenyl)2H-benzotriazole UV stabilizers, stearic, oleic, linoleic and linolenic acid esters of 2[2-hydroxy-3-tert-butyl-5(3 -hydroxypropyl)-phenyl]2H-benzotriazole [Equation] [7]. The compounds, pale yellow oils were characterized by their UV and K IDS mass spectra [Figure 6] [7]. All four compounds showed nearly identical UV spectra with two maxima at 305 and 340 nm. Those UV stabilizers have aliphatic side chains that are by six carbon atoms longer than the carbon side chains of the catechol derivatives of the urushi components. The unsaturated esters, especially the linolenic ester could readily be incorporated into urushiol or drying oil compositions and the unsaturated esters can be "co-cured" into UV stabilized oriental lacquer films. They could also be added to linseed oil and cured into films of drying oils. 

Acetic acid, butyl ester Acetic acid, pentyl ester Acetic acid, decyl ester Acetic acid, benzyl ester Acetic acid, benzyl ester Acetic acid, 1-cyclohexenyl ester Acetic acid, 3-cyclohexenyl ester Butyric acid, benzyl ester Phenylacetic acid, propyl ester Oleic acid, methyl ester Linoleic acid, methyl ester Linolenic acid, methyl ester Adipic acid, methyl ester Adipic acid, ethyl ester Adipic acid, diethyl ester Adipic acid, dipropyl ester Adipic acid, (methylethyl)ester Adipic acid,... 

Soybean oil is a statistical mixture of glycerol esters of palmitic acid (10%), stearic acid (3%), oleic acid (23%), linoleic acid (55%), and linolenic acid (9%). 

The investigation carried out on some Chinese animals used for CNS symptoms similar to those seen in AD resulted in the isolation of long chain fatty acids from the centipede Scolopendra subspinipes mutilans which had weak AChEl activity.A series of fatty acids was tested to discern any structure-activity relationships and it was found that only free acids, not esters, had AChEl activity. The presence of unsaturated bonds and a chain length of not less than 16 C were was necessary for activity. The most active compound tested was linolenic acid (71) with IC50 of 59.9 xM against AChE. 

Linalool, cis, oxide 0 , 1 S172 Linalool, trans, oxide 1 3172 Linalool Pi , Resin , Lf 0 ° Linoleic acid methyl ester 1 73172 Linoleic acid 1 73172 gjCSl34 Linolenic acid methyl ester 0 Linolenic acid 1 3172 gjCSl34 Longifolene, (+) 1 3068 Longifolene 1 3172 qCS156 Inflorescence... 

The flavour of distillates from apple and pear is characterised by typical aroma compounds from these fruits formed by enzymatic degradation of fatty acids to C6-fragments like hexanol, trans-2-hexenol, as well as ethyl esters and acetates of hexanoic acid. In distillates of pears, especially of the variety Bartlett pear, the characteristic pear flavour is mainly dominated by the ethyl and methyl esters of frans-2-czs-4-decadienoic acid and trans-2-trans-A-decadienoic acid [27-29], The biogenesis of these monounsaturated, diunsaturated, and triunsaturated esters may be explained by -oxidation of unsaturated linoleic and linolenic acid in the fruits. The sesquiterpene compound a-farnesene, which is formed during postharvest ripening and storage of Bartlett pears [28], shows that quality and intensity of distilled pear spirits is mainly influenced by the quality and degree of ripeness of the fruits. 

A mixture of palladium chloride and triphenylphosphine effectively catalyzes carboxylation of linoleic and linolenic acids and their methyl esters with water at 110°-140°C and carbon monoxide at 4000 psig. The main products are 1,3-and 1,4-dicarboxy acids from dienes and tricarboxy acids from trienes. Other products include unsaturated monocar-boxy and dicarboxy acids, carbomethoxy esters, and substituted a,J3-unsaturated cyclic ketones. The mechanism postulated for dicarboxylation involves cyclic unsaturated acylr-PdCl-PhsP complexes. These intermediates control double bond isomerization and the position of the second carboxyl group. This mechanism is consistent with our finding of double bond isomerization in polyenes and not in monoenes. A 1,3-hydrogen shift process for double bond isomerization in polyenes is also consistent with the data. 

Lipid standards (2°/o solutions in chloroform) a triacylglycerol (triolein), cholesterol ester (cholesterol linoleate), fatty acid (palmitoleic, oleic, etc.), fatty acid methyl ester (linolenic acid, methyl ester), a glycerophosphatide (phosphatidylcholine, phosphatidylethano-lamine, etc.), a diacylglycerol (diolein), and a monoacylglycerol (monoolein). 

Figure D1.6.3 TLC-FID separation of a range of standard lipids. The mobile phase was 91 6 3 1 (v/v/v/v) hexane/ethyl acetate/diethyl ether/formic acid. Time refers to scanning time of the Chromarod. Abbreviations CE, cholesterol ester CHO, cholesterol DG, 1,2-diglyceride 1,3-DG, 1,3-diglyceride FFAU, highly unsaturated free fatty acid FFAS, less unsaturated free fatty acid MG, 1-monoglyceride PL, phosphatidylcholine TGU, highly unsaturated triglyceride TGS, saturated triglyceride. Tripalmitin and palmitic acid were used to complement trilinolenin and linolenic acid. Reproduced from Ackman and Heras (1997) with permission from AOCS Press.

For example, the LIFDI mass spectrum of biodiesel from oilseed rape revealed methyl esters of long-chain fatty acids as typical plant lipid constituents (Figure 14.3). The most prominent signal originated from the methyl ester of oleic acid (Ci i, m/z 296.4), accounting to 42.6% of the TII, followed by the methyl esters of linoleic acid (Ciga,m/z 294.4,23.8%), linolenic acid (Cm-,m/z 292.4,4.4%), stearic acid (Ci8 o, m/z 298.5, 2.8%), palmitic acid (Ci6 0, m/z 270.4, 1.4%), and gondoic acid (C2o i,... 

I Average conversion yield Linolenic acid methyl ester Linoleic acid methyl ester Oleic acid methyl ester... 

Reaction temperature and time were significant operating parameters, which are closely related to the energy costs, of the biodiesel production process. Figure 7 shows the effect of reaction time on the transesterification of rapeseed oil at a catalyst concentration of 1%, molar ratio of 1 6, and 60°C. Within 5 min, the reaction was rapid. Rapeseed oil was converted to above 85% within 5 min and reached equilibrium state after about 10 min. Several researchers reported that the conversion of vegetable oils to FAME was achieved above 80% within 5 min with a sufficient molar ratio (8,11). For a reaction time of 60 min, linoleic acid methyl ester was produced at a low conversion rate, whereas oleic and linolenic methyl ester were rapidly produced. 

A considerable amount of knowledge has accumulated about how pheromone components are produced in female moths since the first pathway was identified some 20 years ago. It appears that most female moths produce their pheromone through modifications of fatty acid biosynthesis pathways. For moths that utilize aldehydes, alcohols, or esters biosynthesis occurs in the pheromone gland. The exceptions are those that utilize linoleic or linolenic acids, which must be obtained from the diet. However, modifications of these fatty acids occur in the gland. For moths that utilize hydrocarbons or epoxides of hydrocarbons, the hydrocarbon is produced in oenocyte cells and then transported to the pheromone gland where the epoxidation step takes place. 

Rapeseed methyl ester (RME) is another alternative biofuel that can be used in diesel engines. RME has the advantages that it is renewable compared to diesel, non-toxic and less flammable compared with many other fuels, like ethanol. RME has the same cetane number, viscosity and density as diesel, contains no aromatic compounds and is biologically degradable with minor contamination in soil. RME can be produced from vegetable oils, but is mostly produced from rapeseed oil by pressing of the seeds or by extraction. Up to 3 tons of rapeseed can be produced from one hectare. The fatty acids in rapeseed oil are mostly oleic acid, linoleic acid and linolenic acid. The oil is pressed from the plant and after some purification allowed to react with methanol in the presence of potassium hydroxide as a catalyst, to produce a methyl ester, see Figure 6.6. 

Write the formulas of the reaction, converting linolenic acid to its methyl ester. 

Table 4.6 Formation of geometrical isomers of y-linolenic acid in borage oil deodorized at different temperatures as determined by gas liquid chromatography of fatty acid isopropyl esters on a 30 m long DB-wax capillary column...

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