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1.
A rapid quantitative method for the determination of oleic (9-cis-octadecenoic) and petroselinic (6-cis-octadecenoic) acids
was required for nutritional research. The methyl esters of these two acids have coincident emergence in GLC separations using
polyester columns. A method involving oxidation and GLC analysis of the resultant monocarboxylic acids has been developed.
Issued as N.R.C., No. 8813 相似文献
2.
A procedure to determine the petroselinic acid/oleic acid ratio in oils is described. The method is based on transesterification
of the constituent fatty acids to methyl esters. An aliquot of the solution of the esters is then analyzed by capillary gas
chromatography; another aliquot is used for epoxidation of the double bonds with 3-chloroperoxybenzoic acid and subsequent
opening of the oxirane ring with hydrochloric acid to obtain the chlorohydrin derivatives. The hydroxy groups are then silanized,
and the reaction mixture is analyzed by high-resolution gas chromatography-mass spectrometry. The procedure is precise, rapid,
and reproducible, and several samples can be analyzed in one working day. 相似文献
3.
4.
Birgit Reiter Marion Lechner Eberhard Lorbeer 《European Journal of Lipid Science and Technology》1998,100(11):498-502
Different varieties of fennel, caraway, and coriander (3 fennel, 7 caraway, and 4 coriander varieties), which belong to the Umbelliferae family, were analyzed on oil and water content, subsequently the fatty acid profiles of the oils were determined by automated gas chromatography. Using fatty acid butyl esters a complete fatty acid profile including petroselinic and cis-vaccenic acid was obtained. Furthermore, the obtained fatty acid contents were compared to those cited in literature, which were determined using different analysis procedures. 相似文献
5.
Carter Litchfield J. E. Lord A. F. Isbell Raymond Reiser 《Journal of the American Oil Chemists' Society》1963,40(10):553-557
The equilibrium composition ofcis andtrans isomers obtained by isomerizing oleic, linoleic, and linolenic acids with selenium or nitrous acid has been studied using
gas chromatography and infrared spectroscopy. The oleic/elaidic equilibrium mixture was found to contain 75–80% elaidic acid
instead of the generally accepted 66% value. It is felt that the greater accuracy of gas chromatography and infrared analyses
over older methods allows this equilibrium to be defined with greater precision.
Similar studies on thecis-trans isomerization of linoleic and linolenic acids indicated that their equilibrium mixtures also contained 75–80%trans double bonds. With linoleic acid, thesetrans bonds were shown to be randomly distributed among the double bonds present.
Cis-trans isomerization of linoleic or linolenic acids with selenium produced by-products having elution times equivalent to 18∶2,
18∶1, and 18∶0 on a gas chromatograph. No such by-products were observed when oleic acid was isomerized. Apparently some type
of hydrogen-transfer reaction accompanies thecis-trans isomerization of polyunsaturated acids with selenium.
Presented at the AOCS meeting in Toronto, Canada, 1962. 相似文献
6.
Hydrogenolysis of saturated,oleic and ricinoleic acids to the corresponding alcohols 总被引:1,自引:0,他引:1
Fatty acids are hydrogenolysed to correspond-ing alcohols in 90% yield at 220-250C at pres-sures of 3500-4000 psi. For saturated
acids the catalyst is one per cent of copper and for oleic and ricinoleic acids 2% of copper and one per cent of cadmium,
all present as their soaps. Only 10% of the unsaturation is lost. The main side product is the acid-alcohol ester. In hydrogenoly-sis
of ricinoleic acid, the alcohol obtained con-tains 15% of ester and 10% of lower alcohols such as undecenyl. 相似文献
7.
Robert L. Wolff Frederic F. Vandamme 《Journal of the American Oil Chemists' Society》1992,69(12):1228-1231
Petroselinic (cis-6 18:1) and oleic (cis-9 18:1) acids that occur together in Umbelliferae seeds can be resolved by gasliquid chromatography (GLC) of their methyl
or isopropyl esters on a 50 m × 0.25 mm fused-silica capillary column coated with a 100% cyanopropyl polysiloxane stationary
phase (CP Sil 88). The use of isopropyl esters instead of methyl esters increases the difference between equivalent chainlengths
from 0.06 carbon unit up to 0.08. This is sufficient to obtain an almost base-line resolution between the two components.cis-Vaccenic acid is completely separated from oleic acid in both derivative forms. GLC of fatty acid isopropyl esters on an
appropriate capillary column thus appears to be the simplest means to simultaneously and accurately quantitate petroselinic,
oleic andcis-vaccenic acids. 相似文献
8.
9.
R. W. Riemenschneider C. E. Swift Chas E. Sando 《Journal of the American Oil Chemists' Society》1941,18(10):203-206
Summary Thiocyanogen values were determined on the methyl esters of oleic, linoleic and linolenic acids and on six different mixtures
of these esters, using 0.1 and 0.2 normal thiocyanogen solutions. The values determined with 0.1 N solutions showed less variation
than those determined with 0.2 N.
The composition of the mixtures calculated from equations based on the found thiocyanogen values of the esters agreed with
the known composition within reasonable limits. Comparisons were made with the composition calculated with the Kaufmann-theory
values.
It is suggested that the F.A.C. consider adopting tentatively the values 89.4 for oleic acid, 93.9 for linoleic acid, and
162.0 for linolenic acid when 0.1 N thiocyanogen solutions are used; the values 89.4, 96.8, and 167.5 when 0.2 N solutions
are employed. These represent the average of the values for these acids which have been reported in the literature.
Agricultural Chemical Research Division Contribution No. 15 相似文献
10.
Edward T. Roe Benjamin B. Schaeffer Joseph A. Dixon Waldo C. Ault 《Journal of the American Oil Chemists' Society》1947,24(2):45-48
Summary Monohydroxystearic acids were prepared by sulfation and subsequent hydrolysis of oleic acid, and the effect of reaction conditions
on yield was studied. Monohydroxystearic acids were obtained from commercial oleic acid in 72% yield and from pure oleic acid
in 86% yield. Conditions for the best yields apparently gave increased amounts of isomeric hydroxy acids.
Hydroxy acids prepared by the sulfation and subsequent hydrolysis of linoleic acid were converted to methyl esters, and purified
by fractional distillation and low temperature crystallization. Experimental evidence indicates that sulfuric acid reacts
with one double bond of linoleic acid to form isomeric monohydroxyoleic acids and with both double bonds to form dihydroxystearic
acids. The by-products formed by the sulfation of linoleic acid include both ester-type polymers and additional polymeric
material which cannot be converted to monomers by alkaline saponification.
When commercial oleic acid is sulfated and subsequently hydrolyzed, the monohydroxystearic acid thus obtained presumably contains
monohydroxyoleic acids and dihydroxystearic acids resulting from the linoleic acid present in the starting material. The formation
of an unsaponifiable polymer during the sulfation of linoleic acid accounts in part for the lower yield of hydroxy acids obtained
from commercial oleic acid, as compared with that of purified oleic acid.
One of the laboratories of the Bureau of Agricultural and Industrial Ohemistry, Agricultural Research Administration, U. S.
Department of Agriculture. 相似文献
11.
Summary 1. The melting points of binary mixtures of oleic, linoleic, and linolenic acids have been reported.
2. The oleic-linoleic acid system has eutectics for the α and β forms of oleic acid of 75.2 and 76.3 mole per cent linoleic
acid, at −10.0° and −9.8°, respectively.
3. Linoleic and linolenic acid mixtures show only melting points intermediate between the pure acids.
4. The oleic-linolenic acid system has eutectics for the α and β forms of oleic acid of 82.7 and 85.5 mole per cent linolenic
acid, at −15.7° and −15.1°, respectively.
A cooperative organization participated in by the Bureaus of Agricultural Chemistry and Engineering and Plant Industry of
the U. S. Department of Agriculture, and the Agricultural Experiment Stations of the North Central States of Illinois. Indiana,
Iowa, Kansas. Michigan, Minnesota, Missouri, Nebraska, North Dakota, Ohio, South Dakota, and Wisconsin. 相似文献
12.
Synthesis of estolides from oleic and saturated fatty acids 总被引:4,自引:4,他引:0
Oleic acid and various saturated fatty acids, butyric through stearic, were treated with 0.4 equivalents of perchloric acid
at either 45 or 55°C to produce complex estolides. Yields varied between 45 and 65% after Kugelrohr distillation. The estolide
number (EN), i.e., the average number of fatty acid units added to a base fatty acid, varied as a function of temperature
and saturated fatty acid. The shorter-chain saturated fatty acids, i.e., butyric and hexanoic, provided material with higher
degrees of oligomerization (EN=3.31) than stearic acid (EN=1.36). The individual, saturated fatty acid estolides each have
very different characteristics, such as color and type of by-products. The higher-temperature reactions occurred at faster
rates at the expense of yield, and lactones were the predominant side products. At 55°C, lactone yields increased, but the
δ-γ-lactone ratio decreased; this led to lower estolide yields. The opposite trend was observed for the 45°C reaction. The
saturate-capped, oleic estolides were then esterified with 2-ethylhexyl alcohol, and the chemical composition of these new
estolides remained consistent throughout the course of the reaction. 相似文献
13.
H Alosta JA Lalman D Jing D Bellmer 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2004,79(4):327-334
Long Chain Fatty Acid (LCFA) mixtures containing linoleic, oleic and stearic acids plus carbohydrates are found in a variety of effluents arising from fried food manufacture and milk processing. Accumulation of Volatile Fatty acids (VFAs) due to the presence of LCFAs may impair the operation of an anaerobic system treating effluents containing a mixture of triglycerides and carbohydrates. In this study, the effects of linoleic (C18:2), oleic (C18:1), and stearic (C18:0) acids on glucose fermentation were investigated at 21 °C using a culture acclimated to glucose. In cultures receiving ≥300 mg dm?3 LCFAs, residual amounts of glucose remained after approximately 8 h and none was detected after 24 h. Acetate degradation was inhibited in the presence of 300 or more mg dm?3 linoleic acid (LA), oleic acid (OA), or stearic acid (SA) with more acetate accumulation observed in cultures receiving LA. In comparison to the controls, similar amounts of propionate accumulation were observed in cultures receiving ≤100 mg dm?3 of each LCFA. However, in cultures receiving ≥300 mg dm?3 LCFAs, more propionate accumulated with complete removal observed within 20 days for only those cultures receiving oleic or stearic acids. Butyrate accumulation was observed only in cultures receiving ≥300 mg dm?3 LA and none was detected after 10 days of incubation. Copyright © 2004 Society of Chemical Industry 相似文献
14.
Role of oleic acid in the metabolism of essential fatty acids 总被引:1,自引:0,他引:1
Groups of young male guinea pigs were fed diets containing corn oil, coconut oil, coconut oil plus elaidic acid, and coconut
oil plus oleic acid. The oleic acid-fed group showed signs of essential fatty acid deficiency after four weeks and severe
signs after eight weeks. The elaidic acid-fed group did not show these symptoms. It is proposed that oleic acid competes competitively
with linoleic acid as a substrate for the enzymes involved in linoleate transformations when only a very limited supply of
linoleic acid is available to the animals and oleic acid is made available in relatively large amounts.
A detailed analysis of the serum, liver, and adipose tissue lipid and a study of the incorporation of acetate-1-C14 into different lipids is presented.
This paper is based on work supported in part by United States Public Health Grant No. HTS 5306 and by a grant from the Nutrition
Foundation Inc., New York. 相似文献
15.
P. Scano M. Casu A. Lai G. Saba M. A. Dessi M. Deiana F. P. Corongiu G. Bandino 《Lipids》1999,34(7):757-759
The presence of 11-cis monoenoic fatty acids was detected in olive oil samples by means of 13C nuclear magnetic resonance spectroscopy, and the positional isomery on the glycerol backbone was derived. The 11-cis vaccenic and eicosenoic fatty acid resonances were recognized and the amounts of the fatty acids quantified. For comparison
purposes, a quantitative analysis was also made by gas chromatography. 相似文献
16.
Carter Litchfield 《Journal of the American Oil Chemists' Society》1971,48(9):467-472
Correlation studies on lipolysis data from 24 species of Cruciferae seed triglycerides have revealed very regular positional
distribution patterns for oleic, linoleic and linolenic acids. When the ratio % 18:1 in β-position/% 18:1 in total triglycerides
for each species is plotted vs. the content of Category I acids (16:0, 18:0, plus all C20, C22 and C24 acids) in the total triglycerides, a smooth curve is obtained. Application of suitable statistical procedures yields a best-fitting
curve, from which an equation expressing the % 18:1 in the β-position as a function of the fatty acid composition of the total
triglycerides can be derived. The % 18:1 in the α-position is then readily calculated by difference. Similar distinctive relationships
have also been developed for linoleic and linolenic acids. Comparison of calculated and experimental results shows that the
relationships developed here are considerably more accurate than the previous Gunstone-Mattson and Evans hypotheses for estimating
the α,β-distributions of 18:1, 18:2 and 18:3 in Cruciferae seed triglycerides.
Presented in part at the AOCS meeting in San Francisco, California, April 1969. 相似文献
17.
A. J. Stirton B. B. Schaeffer Anna A. Stawitzke J. K. Weil Waldo C. Ault 《Journal of the American Oil Chemists' Society》1948,25(10):365-368
Summary Twenty-six aromatic compounds were compared in the synthesis of arylstearic acids from oleic acid by the Friedel and Crafts
reaction. Xylylstearic acid was the arylstearic acid obtained in the highest yield (92.4%) from technical m-xylene and commerical
oleic acid. The various side reactions are disussed including the possible conversion of oleic acid into products which on
vacuum distillation of the crude arylstearic acid appear as a forerun and as a still residue. Oleic acid of about 98% purity
did not improve the yield but resulted in nearly colorless, rather than yellow viscous oils.
Crystalline arylstearic acids have for first time been isolated from the reaction products but only in small yields.
Presented at the 39th Annual Meeting of the American Oil Chemists' Society, New Orleans, La., May 4–6, 1948.
One of the laboratories of the Bureau of Agricultural and Industrial Chemistry, Agricultural Research Administration. U. S.
Dept. of Agriculture. 相似文献
18.
D. H. Wheeler D. Potente Harold Wittcoff 《Journal of the American Oil Chemists' Society》1971,48(3):125-128
The adsorption isotherms of solutions of dimer, trimer, stearic, oleic, linoleic, nonanoic and azelaic acids in organic solvents,
(mostly hexane) have been determined on an alpha ferric oxide with a surface area (B.E.T. N2 adsorption) of 99 m2 (99 × 1020 A2) per gram. They all showed limiting adsorption as grams adsorbed per gram of iron oxide beyond a concentration of about 1
g/100 cc, analagous to the Langmuir type monolayer isotherm. Areas per molecule were calculated and compared with areas of
close-packed models in positions parallel to and perpendicular to the surface. The calculated areas corresponded more closely
to the flat or parallel positions. Heats of adsorption were determined and were in the range of 27–71 kcal/eq, suggesting
chemisorption of the COOH group at the surface. The value of dimer acid suggests that both COOH groups are chemisorbed. Models
show that the parallel position permits both COOH groups to touch the surface. The perpendicular position generally does not
permit both COOH groups to touch the surface. Dimer acid showed a value (71 kcal/eq) higher than the monobasic acids (44–55
kcal/eq), possibly due to interaction of the ring structure (partly aromatic) with the surface. Azelaic acid from an 80–20t-butanol-hexane solvent showed a lower value of 27 kcal/eq, possibly due to adsorption of a hydrogenbonded alcohol-acid moiety
as such.
Journal Series No. 547, General Mills, Inc. Research Laboratories. 相似文献
19.
Alasdair R. Macrae Jean E. Visicchio Alexandra Lanot 《Journal of the American Oil Chemists' Society》1998,75(11):1489-1494
Protein extracts from potato tubers contain a lipid acyl hydrolase (LAH) with an unusual selectivity. The component responsible
for the enzyme activity is a group of closely related glycoproteins, known as patatin. Potato LAH catalyzes the rapid hydrolysis
of monoacylglycerols (MAG), but in contrast expresses only low activity with di- and triacylglycerols. The selectivity of
the LAH can be exploited for the synthesis of MAG from fatty acids and glycerol in microaqueous reaction systems. Oleic, linoleic,
linolenic, capric, lauric, and myristic acids can be used as reactants, and in each case the reaction products contain >95
mol% MAG and <5 mol% diacylglycerol. By removing water from the reaction mixture by distillation under vacuum, excellent conversions
of fatty acids into MAG are possible. Low conversions are observed with palmitic and stearic acids, because of the necessity
to use a high temperature (70°C) to maintain a liquid reaction mixture. Potato LAH is rapidly inactivated at 70°C in the microaqueous
reaction systems. Potato LAH also catalyzes the selective synthesis of monoesters from oleic acid and simple diols. With oleic
acid and diglycerol, monoesters are again the main reaction products, but 17 mol% diesters are also formed. 相似文献
20.
Miriam D. Rosenthal 《Lipids》1980,15(10):838-848
Fetal human fibroblasts were grown in culture medium containing 10% fetal bovine serum supplemented with [1-14C] linoleate or [1-14C] oleate. At all concentrations of exogenous fatty acids, the incorporation of oleate was greater than that of linoleate.
With increased medium fatty acid concentrations, linoleate in triacylglycerol (TAG) could be increased from 13 to 75% of the
total incorporated; at each concentration, relatively more linoleate than oleate was in TAG. When the cells were exposed to
exogenous oleate/linoleate mixtures, the composition of the mixture determined the extent of incorporation of both fatty acids.
When the mixture was primarily linoleate, scarce oleate was used preferentially for phospholipids (PL); no such specificity
for scarce linoleate was observed. Addition of exogenous fatty acids resulted in a shift of previously incorporated14C fatty acids from phospholipid into TAG; retention of oleate in PL was greater than that of linoleate. Incorporation of oleate
into phospholipids was also higher than that of linoleate from exogenous fatty acid mixtures which were 80% saturated. It
is suggested that normal human fibroblasts have adapted to the low levels of exogenous polyunsaturated fatty acids in culture
media by increased use of oleate in phospholipid. Even when the cells aresupplemented with linoleate, the preferential use
of oleate in phospholipid groups is retained.
Presented in part at the ASBC Meeting, Dallas, april 1979. 相似文献