The effect of two isomeric octadecenoic acids on alkyl diacyl glycerides and neutral glycosphingolipids of Novikoff hepatoma cells

The addition of 150 μg ofcis-6-octadecenoic acid (6–18∶1) per milliliter to the growth medium of Novikoff hepatoma cells reduced the rate of multiplication of these cells, whereas the same level ofcis-9-octadecenoic acid (9–18∶1) was without effect. The quantity of alkyl diacyl glycerols in cells grown in medium containing 100 μg/ml of either 6–18∶1 or 9–18∶1 was reduced to about 10% of that observed in cells grown in unsupplemented media. The presence of 6–18∶1 acid led to an increase in the concentration of the dihexosyl ceramide and a corresponding decrease in that of the monohexosyl ceramides of the cells; whereas the presence of 9–18∶1 resulted in an increase in the relative amount of tetraglycosyl ceramide and corresponding reductions in those of mono- and dihexosyl ceramide. Possible causes for these changes are discussed.     

Salts of alkyl esters ofa-sulfopalmitic anda-sulfostearic acids

Lithium, ammonium, sodium, potassium, magnesium, and calcium salts of methyl, ethyl, propyl, isopropyl, butyl, isobutyl and secondary butyl esters ofa-sulfopalmitic anda-sulfostearic acids were prepared for a study of structureproperty relations. The esters are easily biodegradable, have good foaming, detergent and lime soap dispersing properties and resist acid and alkaline hydrolysis. Thea-sulfopalmitates are more soluble. Differences in the cation and the alcohol influence melting point, aqueous solubility, solubility in organic solvents, surface and interfacial tension, critical micelle concentration and emulsifying properties. Presented at the AOCS Meeting in Houston, 1965. Eastern Util. Res. and Dev. Div., ARS, USDA.     

Long Chaina-phosphono fatty acids,salts and esters

A series of α-phosphono fatty acids and their salts and esters was prepared from pelargonic, capric, lauric, myristic, palmitic, and stearic acids. In comparison to correspondingα-sulfo fatty acids theα-phosphono fatty acids are white solids of higher melting point, weaker acids, less hygroscopic, have a lower critical micelle concentration and are less resistant to hard water. Methyl, isopropyl, and amyl esters RCH. [PO (OH)₂] CO₂R′, were prepared from the α-phosphono fatty acids ; a sulfuric acid catalyst was required in the case of lower boiling alcohols. Hydrolysis studies with sodium methylα-phosphonomyristate showed the a-phosphono ester to be 50 times as stable towards alkali as the correspondingα-sulfo ester, but only one-tenth as stable toward acid hydrolysis. Wetting, foaming, detergent, and other surface active properties of theα-phosphono fatty acids, salts, and esters were measured and compared with those of analogousα-sulfo compounds.     

X-ray diffraction study of some normal alkyl esters of long-chain acids

X-ray powder diffraction data are reported for 15 normal long-chain esters. The compounds represent all combinations of acid and alcohol where the acid portion is n-tetradecanoic, n-hexadecanoic, or n-octadecanoic acid, and the alcohol portion is n-tetradecanol, n-pentadecanol, n-hexadecanol, n-heptadecanol, or n-octadecanol. The individual compounds can be identified and distinguished by the diffraction data. Several of the esters have long spacings that are a linear function of the number of carbon atoms in the molecule and are consistent with a similar function for ethyl esters of long-chain acids. The remainder of the compounds crystallize in other polymorphic forms and therefore do not follow this function. Presented at AOCS Meeting, Philadelphia, October 1966. E. Utiliz. Res. Dev. Div., ARS, USDA.     

The composition of beeswax alkyl esters

The alkyl esters of beeswax, after isolation from the unhydrolyzed wax by preparative layer chromatography (PLC), have been analyzed directly by high temperature GLC using 1.5% OV1 as liquid phase. In two commercial wax samples examined the ester homologues are predominantly even carbon numbered ranging from C₃₆ to C₅₄. The principal alkyl esters are C₄₀, C₄₂, C₄₄, C₄₆ and C₄₈. The GLC analysis of the ester hydrolysis products revealed that the variations in ester chain length are produced by variations in the esterified primary alcohol chain lengths. The esterified fatty acid is chiefly hexadecanoic acid. The esterified fatty acids differ in composition from the free fatty acids which are also present in the wax.     

The metabolism of triglycerides containing cis and trans octadecenoic fatty acids

Summary Weanling rats were fed diets containing triglycerides composed of bothcis andtrans fatty acids for 16 days. The animals were sacrificed, and the lipides were extracted quantitatively from the heart, liver, feces, and the rest of the carcass. Infrared analyses were carried out to determine the fate of thetrans acids.Trans acids with the double bond either in the 8 or 9 position are metabolized efficiently by the rat organism. Armour Fellow, University of Illinois, 1955–56.     

A study of octadecenoic acids by gas-liquid partition chromatography and infrared spectrophotometry

Summary The separation of methyl esters of octadecenoic acids by G.L.P.C. on a capillary column is shown for a sample of hydrogenated commercial vegetable oil. Comparisons are made with a regular packed column G.L.P.C., a capillary column G.L.P.C., and with infrared analysis. Good separation of methyl oleate and methyl elaidate was accomplished, using a capillary column. The amount of elaidate found by G.L.P.C. compared well with thetrans-acid found by infrared analysis. In addition, a small amount of a component was detected that is possibly another isomer of methyl oleate.     

Surface components of chylomicrons from rats fed glyceryl or alkyl esters of fatty acids: Minor components

The lipid class, fatty acid and molecular species composition of the minor polar surface components of rat lymph chylomicrons were determined during absorption of menhaden oil and corn oil or of the corresponding fatty acid ethyl esters. In addition to the previously reported minor polar lipids (sphingomyelin, phosphatidylserine, phosphatidylinositol, phosphatidic acid and lysophosphatidylcholine), we identified phosphatidylglycerol, dimethyl-phosphatidylethanolamine, ceramide and cholesteryl sulfate in the chylomicrons from both oil and ester feeding. The dietary fatty acids were found to be incorporated to a variable extent into the different phospholipid classes, the proportions of which remained the same during both types of feeding. No evidence was obtained for the presence of the minor glycerophospholipids characteristic of the lysosomal membranes (e.g., bis-phosphatidic, lysobisphosphatidic and semilysobis-phosphatidic acids), although special efforts were made to identify them. These results indicate that the chylomicrons arising from the monoacylglycerol and phosphatidic acid pathways of triacylglycerol biosynthesis become enveloped in closely similar monolayers of phospholipids. Hence, all triacylglycerols may be secreted from the villus cellsvia a common mechanism as suggested by the previously demonstrated convergence (at the 2-monoacylglycerol stage) of the monoacylglycerol and the phosphatidic acid pathways of mucosal triacylglycerol formation [Yang, Y.L., and Kuksis, A. (1991)J. Lipid Res. 32, 1173–1186]. Part of this work was presented at the Annual AOCS Meeting, Baltimore, MD, April, 1990 (ref. 1).     

Synthesis of octadecynoic acids and [1-14C] labeled isomers of octadecenoic acids

Geometric and positional isomers of [1-¹⁴C] octadecenoic acids have been synthesized by modifications of published procedures. Positional isomers of octadecynoic acids also have been synthesized to obtain the geometric and positional isomers of the unlabeled octadecenoic acid analogs. The syntheses were accomplished by coupling a haloalkyl compound with a substituted acetylene using n-butyl lithium in hexamethylphosphoramide. The coupled product, either a 17-or 18-carbon acetylenic alcohol, could be semihydrogenated and chain extended to afford a carboxy labeled derivative, could be partially hydrogenated and chain extended to afford a carboxyl labeledcis-ortrans-octadecenoic acid in the former case. In the latter case, octadecynoic,cis-octadecenoic ortrans-octadecenoic acids could be obtained by the appropriate reactions. The methods used in this study enabled the synthesis of¹⁴C-labeled fatty acids in generally higher yields and by simpler reactions than were previously possible.     

Properties of alkyl esters base on castor oil

Castor oil is a non‐traditional raw material for the preparation of methyl and ethyl esters of higher fatty acids as alternative fuels for diesel engines. Castor oil contains ricinoleic acid (12‐hydroxy octadecene acid) with a major share of about 90%. The article presents the parameters of castor oil‐based methyl esters (COME) and ethyl esters (COEE) defined by the standard EN 14 214. The densities of COME and COEE are higher than the limit defined by the standard EN 14 214. The viscosities are more than twice as high as the limit value. The cetane numbers are lower than defined by the standard EN 14 214. For the remaining parameters, COME and COEE meet, in principle, the standard EN 14 214. The presence of the free hydroxyl group has virtually no effect on the values of such parameters as carbon residue, filterability at low temperatures and oxidation stability, for which some influence was expected. The physicochemical parameters of the castor oil esters are discussed in comparison to the analogous esters of high‐oleic sunflower oil, which contain about 80% of oleic acid. Both the methyl and ethyl esters of high‐oleic sunflower oil meet the standard EN 14 214 in all prescribed parameters.     

Key fuel properties of palm oil alkyl esters

Methyl esters of vegetable oils have been successfully evaluated as diesel substitute. In the present study, other alkyl esters, namely ethyl and isopropyl esters of crude palm oil and crude palm stearin were synthesized via chemical transesterification reactions and subsequently evaluated for their fuel properties. Generally, these alkyl esters exhibit higher viscosity (4.4×10⁻⁶m²/s–5.2×10⁻⁶ m²/s) compared to that of petroleum diesel (4.0×10⁻⁶ m²/s). However, compared to petroleum diesel, these alkyl esters exhibit acceptable gross heat of combustion (39–41 MJ/kg). Originated from renewable origin, the low sulfur content in alkyl esters emits much lower SO₂. These alkyl esters are much safer than petroleum diesel in terms of safety for storage and transportation as they possess high flash points. They may find applications in the fuel industry besides utilization as oleochemicals.     

Sodium salts of alkyl esters ofa-sulfo fatty acids. Wetting,lime soap dispersion,and related properties

A series of esters of the general formula RCH(SO₃Na)-CO₂R′ of 14–19 carbon atoms prepared by the α-sulfonation of propionic, butyric, pelargonic, lauric, myristic, palmitie, and stearic acids and esterification with normal primary alcohols were compared for critical micelle concentration, surface and interfacial tension, Ca⁺⁺ stability, wetting properties, foam height, detergency, and lime soap dispersing properties. Comparison of position isomers showed that as the hydrophilic portion moved from the center toward either end, cmc and wetting efficiency decreased, surface and interfacial tension increased, and Ca⁺⁺ stability and lime soap dispersing properties improved. A coconut oil fatty acid forerun sulfonated with SO₃ vapor and esterified with 2-ethylhexanol gave a product with useful wetting properties in soft and hard water. Presented at the fall meeting, American Oil Chemists' Society, Chicago, October 30–November 1, 1961. Eastern Utilization Research and Development Division, Agricultural Research Service, U. S. Department of Agriculture.     

Low-temperature properties of alkyl esters of tallow and grease

The low-temperature properties of mono-alkyl esters derived from tallow and recycled greases were determined for neat esters and 20% ester blends in No. 2 low-sulfur diesel fuel. Properties studied included cloud point, pour point, cold filter plugging point, low-temperature flow test, crystallization onset temperature, and kinematic viscosity. Compositional properties of the alkyl esters determined included water, residual free fatty acids, and free glycerol content. In general, the secondary alkyl esters of tallow showed significantly improved cold-temperature properties over the normal tallow alkyl ester derivatives. The low-temperature flow test did not show a 1:1 correlation with cloud point as previously observed with methyl soyate and methyl tallowate. For the homologous series methyl to n-butyl tallowate, ethyl tallowate had the best broad-spectrum low-temperature properties, both neat and when blended in diesel fuel. For the greases studied, both the normal and branched alkyl ester derivatives showed improved properties over corresponding tallow esters, especially with neat esters.     

Dialkyl esters of alpha-sulfofatty acids

Lower olefins, especially ethylene and propylene, have been found to add to alpha-sulfofatty acids in the presence of boron trifluoride or its etherate to give dialkyl alpha-sulfofatty esters. Some of the reaction variables studied include catalyst, catalyst concentration, and solvent. The esters were obtained as colorless, low melting solids after purification by low temperature crystallization.     

The preparation of alkyl esters from highly unsaturated triglycerides

The alcoholysis reaction has been applied to the preparation of highly unsaturated alkyl esters from menhaden oil. This reaction proceeded very rapidly, and nearly quantitative yields were obtained with virtually, no loss in double-bond structure. The formation of esters was studied, using straight- and branched-chain alcohols having 1–6 carbon atoms. The reactions were monitored by the technique of thin-layer chromatography (TLC). Maximum conversion of straight-chain esters was found to be a linear function with respect to the number of carbon atoms in the alcohol. Reaction time varied from 2 min for methanol to 60 min for n-hexanol. Branched-chain alcohols reacted more slowly than did the corresponding straight-chain compounds. This reaction was found to be applicable to laboratory and large scale preparations of highly unsaturated alkyl esters. Presented at the AOCS meeting, St. Louis, Mo., 1961.     

The effect of positional and geometrical isomerism on the dilatometric properties of some octadecenoic acids

Summary Four isomeric octadecenoic acids, oleic, elaidic, petroselinic, and petroselaidic, were prepared and their expansibility determined. The melting dilation of each acid was calculated and found to increase in the order oleic, petroselinic, petroselaidic, and elaidic. In each instance the melting dilation of the trans acid was greater than that of its cis isomer. Of the two cis acids studied, the melting dilation was less for the acid with the double bond farther from the carboxyl end of the carbon chain. The trans acids did not follow this pattern. At temperatures above 52°C., at which all acids were liquid, the absolute specific volumes of the acids were very nearly equal whereas at temperatures below −7°C, at which all were in the solid state, the specific volumes of petroselinic and elaidic acids were at variance with the specific volumes of oleic and petroselaidic acids. This variance must be attributed to differences in crystal packing. Oleic acid clearly showed the two polymorphic forms previously recognized and, in addition, apparently reversibly transformed at about −5°C., indicating the possible existence of a third polymorphic form. These transformations of oleic acid occurred regardless of tempering, and without visual melting. The other three acids did not exhibit polymorphism under the conditions employed in the dilatometric measurements. Presented at the 44th Annual Meeting of the American Oil Chemists' Society New Orleans, La., May 4–6, 1953. One of the laboratories of the Bureau of Agricultural and Industrial Chemistry, Agricultural Research Administration, U. S. Department of Agriculture.     

Functionalization of soy fatty acid alkyl esters as bioplasticizers

The combination of various functional groups, such as epoxy, acetoxy, methoxy, thiirane, and aziridine, on the fatty acyl chain of soy fatty acid alkyl esters have been synthesized and evaluated as plasticizers in poly(vinyl chloride) (PVC) applications. Numerous synthetic procedures, such as epoxidation, methoxylation, acetylation, thiiration, and aziridination, were used for synthesizing multifunctional soy fatty acid alkyl esters. Epoxidized soybean oil fatty acid alkyl ester served as the key intermediate for functionalization. Partial or complete ring opening of the epoxide by reacting with methanol and the subsequent etherification or acetylation of the hydroxyl function produced epoxy, alkoxy, and acetoxy derivatives. The nucleophilic substitution of epoxide with sulfur by reacting with ammonium thiocyanate produced thiirane and epoxy thiiranes. Although the aziridine derivatives were synthesized by reacting unsaturated fatty acid alkyl esters with chloramine‐T, the compounds were fully characterized and their physical and analytical properties were determined. The high viscosity and darker color of aziridine and thiirane derivatives limit their usefulness, whereas the physical properties of the other derivatives were acceptable. The plasticizer evaluation of methoxy and acetoxy soy fatty acid esters (methyl and n‐butyl) demonstrated good compatibility with PVC, high efficiency (Shore hardness), and gelling properties were comparable to commercial plasticizer, di‐isoonyl phthalate. The abundant availability and cost‐effectiveness of starting materials and the readily adoptable chemical processes make the fatty acid ester derivatives viable bioplasticizers to replace the fossil fuel‐derived phthalates. J. VINYL ADDIT. TECHNOL., 23:93–105, 2017. © 2015 Society of Plastics Engineers