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1.
P. Nuhn 《European Journal of Lipid Science and Technology》1996,98(10):335-338
Analytics and biophysics of branched fatty acids in lipids . Objects of our investigations are long chain fatty acids with methyl groups in different positions and fatty acids with a different length of the sidegroup in α-position. The separation of racemic branched fatty acid methyl esters by gas chromatography on a chiral column depends on the structure of the branched fatty acid. Diastereomeric amides and phosphatidylcholines with α-branched fatty acid residues were separated preparatively. The branched fatty acids were incorporated into 1,2-diacyl-, 1-acyl-2-hexadecyl- and 2-acyl-1-hexadecyl-glycerophosphocholines and characterized by differential scanning calorimetry and X-ray diffraction. 相似文献
2.
Skin surface lipids of the dog 总被引:1,自引:0,他引:1
The skin surface lipid of the dog has been reported to contain a high proportion of diol diesters having a lower mobility
on thin layer chromatography than diesters from other species in spite of containing similar fatty acid and diol components.
In the present study, dog skin surface lipid was separated by preparative thin layer chromatography into sterol esters (42%),
wax diesters (32%), free sterols (9%), polar lipids (7%), and unidentified components (10%). The diesters contained 1,2-diols,
each esterified with one long chain fatty acid and one isovaleric acid moiety. The diols were principally branched chain C21 and C22 compounds while the long chain fatty acids esterified with them were mainly C20 and C21 branched compounds. The fatty acids from the sterol esters were mostly saturated, branched chain C19 to C23, together with 7% of straight chain monoenoic acids, principally C21 and C22. There were only trace amounts of free sterols other than cholesterol, while the esterified sterols contained 96% cholesterol
and 4% lathosterol. 相似文献
3.
H. P. Nissen G. Ortel K. Macke H. W. Kreysel 《European Journal of Lipid Science and Technology》1983,85(1):39-42
The Skin-Surface Lipids in Psoriasis vulgaris (Ps) - Cholesterol Esters, Wax Esters, Triglycerides and Fatty Alcohols The composition of waxes and cholesterol esters, triglycerides and alcohols of hair lipids from subjects with psoriasis vulgaris and control group was determined by gas liquid chromatography. The amount of palmitoleic acid was lower in the lipid group of the waxes and cholesterol esters in psoriasis vulgaris. Triglycerides show two different changes in the fatty acid pattern by psoriasis: 1) the composition of shorter chain fatty acids was distinct lower but 2) patients with a heavy psoriasis show an increase of the shorter chain fatty acids especially lauric acid and a decrease of the longer chain fatty acids. The analysis of the alcohols indicates that psoriatic patients possess a higher content of alcohols with 12,13 and 14 carbonatoms than normal subjects. 相似文献
4.
The oil ofSalvia nilotica Jacq. (Labiatae) seed contains 0.6% α-hydroxyoleic, 4.2% α-hydroxylinoleic, and 5.4% α-hydroxylinolenic acids. The first two have not been found previously in seed oils. In addition to the common fatty acids, also identified were small amounts of three unsaturated C17 acids and one branched chain C17 acid. Methyl esters of the component fatty acids were fractionated by both column and thin-layer chromatography. These esters were identified by combination of gas chromatography, GC-mass spectrometry, ozonolysis-GC, infrared, and nuclear magnetic resonance. 相似文献
5.
Separation of sterol esters from wax esters in the lipids of vernix caseosa and adult human skin surface was accomplished
by column chromatography on MgO. The fatty acids of the sterol esters and wax esters of both samples were separated into saturates
and monoenes, and examined in detail by gas liquid chromatography (GLC). The saturated fatty acids of the wax esters of vernix
caseosa and of adult human skin surface were remarkably similar. They ranged in chain length from at least C11 to C30, six skeletal types being present: straight even, straight odd, iso, anteiso, other monomethyl branched and dimethyl branched.
A large number of patterns of monoenes were observed, each pattern consisting of desaturation of a specific chain at Δ6 or
Δ9 plus its extension or degradation products. The mole per cent of the total Δ6 and Δ9 patterns of wax ester fatty acid monoenes
of vernix caseosa were 87% and 12%, respectively, and 98% and 1%, respectively, for adult human skin surface lipid. The sterol
ester fatty acids of vernix caseosa were much different from those of adult human skin surface: vernix caseosa saturates were
largely branched and of lengths greater than C18, whereas the saturates of adult human surface lipid resembled the wax ester fatty acids. Of the vernix caseosa monoene patterns,
the mole per cent was 30% Δ6 and 70% Δ9, whereas of the adult human skin surface sterol ester fatty acids 89% were Δ6 and
11% Δ9. Chain extension was particularly pronounced in the sterol ester fatty acid monoenes of vernix caseosa amounting to
7–8 C2 units in some cases. The fatty acids of the sterol esters of both vernix caseosa and adult human skin surface appear to be
derived from the sebaceous gland and from the keratinizing epidermis, but those of the wax esters are from the sebaceous glands
only. 相似文献
6.
A concentrate of branched chain fatty acids (as methyl esters) was prepared from the triacylglycerols of subcutaneous adipose
tissue lipids of lambs receiving a carbohydrate-rich (cereal) diet. This was accomplished by procedures which allowed the
removal of unsaturated components by peroxidation and straight chain saturated components by urea-adduct formation. The concentrate
was analyzed by high resolution gas chromatography in combination with mass spectrometry and was shown to consist of a complex
mixture of saturated methyl-substituted fatty acids. Methyl substitution occurred on even-numbered carbon atoms (relative
to the carboxyl group) and the chain lengths of the acids ranged from 10 to 18 carbon atoms. Acids with one methyl substituent
in the fatty acyl chain were most abundant; di-, tri- and tetramethyl-substituted acids were also present. The biosynthesis
of these methyl-substituted acids is discussed briefly. 相似文献
7.
Isolation and Structure Determination of the Polybranched Fatty Acids from Fish Oil From a sample of sea fish oil, three saturated polymethyl branched fatty acids could be separated in pure state as methyl esters by using urea adduct, column chromatography and distillation methods. These could be identified as 4,8,12-trimethyl-tridecanoic acid, 2,6,10,14-tetramethyl-pentadecanoic acid and 3,7,11,15-tetramethyl-hexadecanoic acid, with the help of molecular weight determination, ultimate analysis, IR-, NMR- and mass-spectroscopy. The structures could be proved by synthesis. Many other branched chain fatty acids were synthesised for comparison. The synthesis and the infrared spectrums of these compounds are given in details. 相似文献
8.
Saturated branched FA and their derivatives are both biodegradable and stable to oxidation. Their m.p. are expected to be
enough lower than their straight-chain counterparts to make them ideal as biolubricants. But physical property data for branched
fatty esters are limited. In this study, a complex mixture of branched methyl esters was obtained from lanolin through saponification,
extraction of unsaponifiables, and methylation. Hydroxy compounds were removed by chromatography on alumina. Vacuum spinning-band
distillation separated the mixture roughly by chain length. Countercurrent urea complex formation and low-temperature crystallization
separated even-chain iso-and odd-chain anteiso-methyl esters of chain lengths 14 through 18 at >95% purity. Transesterification
was used to convert methyl esters to isopropyl esters. The m.p. and heat of fusion of each ester were determined by DSC. NMR
was used to verify the structure of branched esters. 相似文献
9.
Wax esters, isolated fromTetrahymena pyriformis, have been found to contain 45% branched chain alcohols and 76% branched chain fatty acids. No esters of tetrahymanol or of sterols were found. 相似文献
10.
J. L. Iverson J. Eisner D. Firestone 《Journal of the American Oil Chemists' Society》1965,42(12):1063-1068
The detection of trace fatty acids (<0.1%) in a fat or oil by gas-liquid chromatography is possible when the methyl esters
are fractionated with urea to provide a number of less complex fractions. Identification and estimation of trace fatty acids
is simplified by quantitative removal of other fatty acids having similar gas chromatographic retention times. A detailed
knowledge of the order in which inclusion compounds are formed was obtained by fractionating a complex mixture of marine and
vegetable fatty acids. In addition, lanolin was fractionated to determine the preferential order in which saturated, branched
chain (iso-, anteiso-) and hydroxy acids form inclusion compounds. Using urea fractionation and gas chromatography, 52 trace fatty acids were tentatively
identified in butter, 30 in lard, and 26 in walnut oil.
Presented at the AOCS Meeting in New Orleans, 1964. 相似文献
11.
The lipophilic components of choline phosphoglycerides and ethanolamine phosphoglycerides obtained from the salt gland of
herring gull and eider duck and from the rectal gland of spiny dogfish were investigated by means of thin-layer chromatography,
gas chromatography, and gas chromatography-mass spectrometry. All phospholipids analyzed were shown to contain small amounts
of plasmalogens, and mainly C16, C18, and C18∶1 aldehyde was detected. The fatty acids were composed of saturated, unsaturated,
straight chain, and branched chain types, ranging between 14–22 carbon atoms. The lipophilic composition of the rectal gland
phospholipids showed a higher degree of unsaturation and the presence of more branched chain fatty acids than that of the
birds, possibly related to body temperature. 相似文献
12.
The literature on the types of fatty chains that occur in skin lipids is reviewed and new data are presented.
To ascertain whether certain unusual fatty acids found in human skin surface lipids are truly products of the human skin or
are due to some type of external contamination (possibly bacterial), the fatty acids ofvernix caseosa, (the lipoidal material covering the human fetus) were analyzed and compared to those found in human skin surface lipid.
The same unusual fatty acids were found invernix caseosa. This indicates that these acids are products of human skin.
These acids consist of five classes of saturated branched chain acids and of three classes of monoenes: straight chain,iso andanteiso. All the monoenes are Δ6 or derivable from this position by addition of an integral number of 2 carbon units to the carboxyl group. On the polar phase
diethylene glycol succinate polyester, the saturated branched chain methyl esters have fractional carbon numbers (by gas chromatography)
of 0.15, 0.23, 0.45, 0.63 and 0.75. The series at 0.63 and 0.75 areiso andanteiso, respectively. The series at 0.15 and 0.23 appear to be two newly identified classes of branched chain fatty acids. 相似文献
13.
Gilles Barnathan Joseph Mirallès Emile M. Gaydou Nicole Boury-Esnault Jean-Michel Kornprobst 《Lipids》1992,27(10):779-784
The fatty acid composition of phospholipids from the Senegalese spongeCinachyrella alloclada was examined. Two new fatty acids not hitherto found in nature, namely 10,13-octadecadienoic acid and 16-tricosenoic acid,
were identified. 8-Hexadecenoic, 13-nonadecenoic and 5,9,13-trimethyltretradecanoic fatty acids were also found for the first
time in sponges. The latter compound (1.4% of the total fatty acid mixture), an isoprenoid fatty acid, accompanies the major
fatty acid 4,8,12-trimethyltridecanoic acid (19.7%). The monomethyl branched fatty acids (22%) identified include 23-methylpentacosanoic
acid (anteiso-26∶0), not previously observed in sponged. The major long-chain fatty acids encountered were the known 17-tetracosenoic
19-heptacosadienoic and 5,9,23-tricontatrienoic acid. Some sixty fatty acids were identified as methyl esters andN-acyl pyrrolidides by gas chromatography and gas chromatography/mass spectrometry. 相似文献
14.
Three of six kin were identified, by high performance thin layer chromatography, capillary gas chromatography and mass spectrometry,
as having phytanic acid storage disease. Phytanic acid was found in triacylglycerol and, to a lesser degree, in phosphatidylcholine
and free fatty acids. An unsaturated analogue of phytanic acid was additionally identified in plasma and erythrocyte triacylglycerols.
In plasma, branched chain fatty acids were primarily localized in the low density lipoprotein fraction. The concentration
of plasma major fatty acids was not affected by the presence of these branched chain fatty acids. In contrast to plasma, only
small amounts of phytanic acid were found in cerebrospinal fluid and biopsied sural nerve. The nerve phytanate was mainly
associated with triacylglycerol in epineurial and perineurial tissues. Lack of phytanate accumulation in sural endoneurium,
even in cases with severe fiber degeneration, suggests that demyelination in Refsum's disease may not be due to myelin instability
resulting from the incorporation of branched chain fatty acids into peripheral nerve membrane. 相似文献
15.
Lela M. Jeffrey 《Journal of the American Oil Chemists' Society》1966,43(4):211-214
Acidified and filtered sea water samples which were extracted with petroleum ether and ethyl acetate have been shown to contain
a variety of lipid compounds in trace amounts. Concentrations of these solvent-soluble substances ranged from 0.5 to 6.0 mg/liter,
the lower concentrations being found in offshore waters. The solvent extracts of the sea water were separated into eight lipid
classes by column chromatography on silicic acid. The fractions eluted with solvents of increasing polarity were characterized
by thin-layer chromatography, infrared and ultraviolet absorption and gas chromatography. These techniques revealed a complex
mixture of alkanes, alkenes, fatty acids, steroids, phospholipids and many as yet unidentified components. Twenty to thirty
alkanes were present as indicated by gas chromatography. No aromatic hydrocarbons were detected. Chromatography of the methyl
esters of the fatty acids indicated the presence of acids with chain lengths varying from 14 to 22 carbons, both saturated
and unsaturated. In many samples the unsaturated fatty acids containing 18 to 22 carbons predominated. The lipid components
varied somewhat in composition as well as concentration from location to location and with season and depth. 相似文献
16.
Cholesterol having a reactive hydroxyl group at C3-position can react with fatty acids to give the corresponding cholesteryl esters. Most of the natural cholesteryl esters consist of straight alkyl chain fatty acids with a high melting point. In oleochemistry it is well known that alkyl branched fatty acids, which are derived from petroleum or the fat and oil industry, have low melting points (mp.) and are chemically more stable if they are saturated acids. We designed alkyl branched fatty acid cholesteryl esters by means of common esterification and found some esters having a low mp. (mostly as a liquid). They had no irritative effect on both animal and human skin. They showed characteristic emulsification properties, namely the formation of either O/W or W/O emulsion coexistence together with other lipid components. Applying them onto human skin, they were able to penetrate towards the stratum corneum and improve the water-retaining ability and the barrier function of the stratum corneum. Based on these properties we have been applying the alkyl branched fatty acid cholesteryl ester, especially the methyl branched isostearic acid cholesteryl ester (IS-CE), to a shampoo and a rinse as hair cosmetics, skin care cosmetics and bath-additive products in the past decade. 相似文献
17.
High pressure reverse-phase liquid chromatography has been used to separate saturated fatty acids, their methyl esters, polyunsaturated
fatty acids, and triglycerides. Rapid separation of fatty acids differing in chain length and number of double bonds has been
accomplished. Analysis time was less than 10 min in most cases. The high pressure reverse chromatography resulted in better
separations of polyenoic acids than can be accomplished by conventional argentation silicic acid column chromatography. The
analyses were carried out on a chemically bonded reverse phase packing, VYDAC reverse phase. 相似文献
18.
D. M. Ottenstein L. A. Witting P. H. Silvis D. J. Hometchko N. Pelick 《Journal of the American Oil Chemists' Society》1984,61(2):390-394
Chromatography has developed into one of the principle methods of analysis of oleochemicals. Gas chromatography has been used
extensively for the analysis of long-chain fatty acids as well as for the analysis of triglycerides and plant sterols. In
recent years, high pressure liquid chromatography (HPLC) has been used for the analysis of triglycerides as well as for other
related materials. Specialized gas chromatography columns have been developed for the separation of long-chain fatty acids
such as the methyl esters. These columns have generally used high polarity stationary phases which separate fatty acids by
degree of unsaturation. A specialized use of these high polarity stationary phases is separation ofcis-trans isomers as well ascis-cis andtrans-trans isomers. In this paper, packed and capillary columns are compared for the separation of thecis-trans isomers of fatty acid methyl esters prepared from a hydrogenated vegetable oil. For HPLC separations, the presence of a double
bond is approximately equivalent chromatographically to shortening the alkyl chain by two carbons. The long-chain polyenic
acids or ethyl esters thus elute near but are resolved from the short-chain saturated fatty acids or esters. HPLC is the method
of choice for relatively complex, high molecular weight, or labile esters, such as those of retinyl or cholesterol. Glyceryl
esters are particularly well resolved by HPLC in terms of both total chain length and degree of unsaturation. This technique
is also useful for lipid class separations and for the analysis of modified fatty acid products, such as prostaglandins and
related materials. In general, these analyses are conducted with octadecyl bonded phase column packings. 相似文献
19.
2-Substituted 4,4-dimethyloxazolines (DMOX) have been found to be a useful alternative to the commonly used methyl esters
for the localization of unsaturated bounds and other substituents in the fatty chain by mass spectrometry. The powerful directed
fragmentation coupled with good gas chromatographic ability enables the structure elucidation of modified fatty acids in complex
mixtures. Continuing our previous study, 76 out of a total of 86 fatty acids obtained from the preen gland wax of shanghai
duck now have been identified by gas chromatography-mass spectrometry (GC-MS) of their oxazoline derivatives. The identification
was based on the interpretation of the mass spectra and comparison with the spectra and equivalent chain lengths (ECL) of
the corresponding methyl esters. Main components of this lipid mixture are straight chain fatty acids (8.22%), and 2-, 4-or
6-monomethyl branched acids (53.69%), amounting to 61.91% of the total acid fraction. In addition, a large number of dimethyl-substituted
fatty acids (31.4%) also have been found. Typical mass spectra, which are easily recognizable and highly specific for fatty
acids substituted at various positions, are presented and classified according to the structural feature of the chain.
Chemical Modification in Mass Spectrometry 6. For preceding paper in this series, see Ref. 17. 相似文献
20.
The fatty acid compositions of the blubber and melon oils from the beluga whale (Delphinapterus leucas) have been determined by gas liquid chromatography (GLC). The melon oil contains a high level (60.1 mole %) of isovaleric
acid, substantial amounts of long chain branched acids (16.9%), and very little polyunsaturated material (0.5%). The blubber
oil contains less isovaleric (13.2%), fewer long chain branched acids (2.7%), and appreciable amounts (10.9%) of the polyunsaturated
acids typical of marine oils. The blubber and melon oils were also examined for lipid class composition by thin layer chromatography
on silicic acid, direct GLC of the hydrogenated oil, and gel permeation chromatography. Both oils are composed almost entirely
of triglycerides, which can be separated chromatographically into molecules containing 0, 1 and 2 isovaleric acid moieties.
No triisovalerin could be detected. The blubber oil contains 68.9 mole % normal triacyl-, 24.2% diacyl-monoisovaleroyl-, and
7.0% monoacyl-diisovaleroyl-triglycerides (acyl=long chain acid). Monoacyl-diisovalerin constitutes 86.7 mole % of the melon
oil. This unusual compound may play a role in the echolocation system of the beluga whale. 相似文献