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.     

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.     

Comprehensive two dimensional gas chromatographic separation of fatty acids methyl esters with online reduction

The accurate analysis of complex fats and oils often requires combining data from multiple GC separations, fractionation by LC prior to GC analysis, and identifying fatty acids or confirming their identities by mass spectrometry and synthetic reference materials. Comprehensive two dimensional gas chromatography markedly increases the number of resolved fatty acid methyl esters (FAME) in a single separation experiment by combining the separations of two capillary columns. The addition of a capillary reducer in front of the second capillary column provides unique separation patterns and structural information for fatty acids based on simple elution rules.     

Microwave induced synthesis of thieno[2,3-b]quinoline-2-carboxylic acids and alkyl esters and their antibacterial activity

A series of thieno[2,3-b]quinoline-2-carboxylic acids and alkyl esters, (3a–i) have been synthesized by the condensation of 2-chloro-3-formyl quinolines (1a–c) with thioglycolic acid/alkyl esters under microwave irradiation using anhydrous potassium carbonate. These compounds were characterized by elemental analysis, IR, ¹H NMR, and mass spectral studies. Their antibacterial activity was also evaluated.     

7-对氟苯甲酰基-喜树碱烷基酯的合成

为降低喜树碱对正常细胞的毒性,提高抗肿瘤活性和溶解性.以20(S)-喜树碱和对氟苯甲醛为起始原料,经Minisci反应和酯化反应得到目标化合物,其结构经MS、1HNMR和IR确证.通过四因素三水平的正交试验优化并确定了Minisci反应的最佳条件:0.5 g喜树碱,30 mL75%H2SO4,1.5 mL对氟苯甲醛,30%H2O2/FeSO4·7H2O物质的量比为20:1,1.0 mL 30%H2Ｏ2,反应温度0～2℃,反应时间6 h,收率55.2%.     

Allylic esters of polymeric fat acids

Summary 1. Allyl, β-methallyl, and β-chlorallyl esters have been prepared from polymeric soybean fat acids by direct esterification and from dilinoleic acid by transesterification of methyl dilinoleate. 2. The method of polymerizing the esters and the properties of the polymers are described. One of the laboratories of the Bureau of Agricultural and Industrial Chemistry, Agricultural Research Administration, U. S. Department of Agriculture.     

Epoxidation of alkyl esters of 12,13-epoxyoleic acids and evaluation of the diepoxides as plasticizers for poly(vinyl chloride)

Methyl, propyl, butyl, isobutyl, hexyl, cyclohexyl, octyl and 2-ethylhexyl esters of 9,10:12,13-diepoxystearic acid were prepared by peracetic acid oxidation of the corresponding esters of 12,13-epoxyoleic acid. Using a 60 mole per cent excess of peracid at 30 C in chloroform as solvent, epoxidation was complete in 5 hr. A small aqueous phase was observed in the reaction mixture which decreases the amount of peracid available for reaction. This is due to the water and H₂O₂ present in the commercial peracetic acid used. Thin-layer and gas chromatographic analysis showed that the diepoxides formed as isomers. These did not react quantitatively with HBr by the Durbetaki method. Isomers of methyl and propyl diepoxy esters were separated by crystallization. The methyl (pure and mixed isomers), isobutyl, 2-ethylhexyl and octyl (all mixed isomers) diepoxy esters were evaluated as plasticizers of poly (vinyl chloride). Delta values showed that these esters have good compatibility. Results are compared with commercial epoxidized soybean oil control. These diepoxy esters show better low temperature properties and have higher migration and volatility values than the control. They are more efficient plasticizers than the control. The liquid isomer of the methyl ester, as well as the 2-ethylhexyl ester, should be useful as primary plasticizers and in combination with other plasticizers as plasticizer stabilizers. E. Utiliz. Res. Dev. Div., ARS, USDA.     

Long-chain alkyl phthalic acids and their derivatives

The synthesis of alkyl phthalic acids by the oxidation of alkyl ortho-xylenes is described. The evaluation of their derivatives as detergent actives (surfactants), builders (water softeners), fabric-softeners and as PVC plasticisers is discussed. A brief mention is made of some aspects of their biodegradation.     

Long-chain alkyl phthalic acids and their derivatives

The synthesis of alkyl phthalic acids by the oxidation of alkyl ortho-xylenes is described. The evaluation of their derivatives as detergent actives (surfactants), builders (water softeners), fabric-softeners and as PVC plasticisers is discussed. A brief mention is made of some aspects of their biodegradation.