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1.
Marcel S. F. Lie Ken Jie C. C. Lam Mohammed Khysar Pasha Kamen L. Stefenov I. Marekov 《Journal of the American Oil Chemists' Society》1996,73(8):1011-1017
The triacylglycerol fraction of three samples of margarine, namely “Flora” (Holland), “Kaliakra” (Bulgaria), and “Corona”
(Holland), were studied by13C nuclear magnetic resonance spectroscopy. By examining the various carbon chemical shifts of the saturated and unsaturated
carbon nuclei, “Flora” margarine was shown to contain a mixture of hydrogenated and unhydrogenated vegetable oils. This technique
allowed all major acyl groups (saturated, oleate, linoleate, and linolenate) and minor acyl components [different positional
isomers of long-chain (E)- and (Z)-monoenoic moieties, arising as by-products during catalytic hydrogenation] to be identified. The amount of each fatty acid
present in the margarine was also estimated from the relative intensities of the corresponding signals. “Kaliakra” margarine
consisted of a blend of unhydrogenated natural fats and oils that contained saturated fatty acids, oleate, and linoleate.
There were no signs in the spectrum of “Kaliakra” of any (E)-isomers, nor signals associated with positional unsaturated acyl groups (other than oleate and linoleate). The sample of
“Corona” margarine consisted of a mixture of hydrogenated and unhydrogenated vegetable oils and butter (1.3%). The presence
of butter in this sample was identified by the characteristic carbon shifts of the C-1 to C-4 carbon atoms of butyrate. The
distribution of the fatty acids on the glycerol “backbone” also was estimated by this technique. 相似文献
2.
Methyl ricinoleate (1) was treated with bromine and the dibromo derivative (2) was reacted with ethanolic KOH under ultrasonic irradiation to give 12-hydroxy-octadec-9-ynoic acid upon acidification with
dil. HCl. The latter compound was methylated with BF3/methanol to give methyl 12-hydroxy-octadec-9-ynoate (3). Compound3 was treated with methanesulfonyl chloride in the presence of triethylamine in CH2Cl2 to give methyl 12-mesyloxy-octadec-9-ynoate (4). Reaction of methyl 12-mesyloxy-octadec-9-ynoate with aqueous KOH under ultrasonic irradiation (20 kHz) gave (11E)-octadecen-9-ynoic acid (5, santalbic acid, 40%) and (11Z)-octadecen-9-ynoic acid (6, 60%) on acidification with dil. HCl. These isomers were separated by urea fractionation. The13C nuclear magnetic resonance (NMR) spectroscopic properties of the methyl ester and the triacylglycerol (TAG) esters of these
enynoic fatty acid isomers were studied. The carbon shifts of the unsaturated carbon nuclei of the methyl ester of theE-isomer were unambiguously assigned as 88.547 (C-9), 79.287 (C-10), 109.760 (C-11), and 143.450 (C-12) ppm while the unsaturated
carbon shifts of the (Z)-enynoate isomer appeared at 94.277 (C-9), 77.561 (C-10), 109.297 (C-11), and 142.668 (C-12) ppm. In the13C NMR spectral analysis of the TAG molecules of type AAA containing either the (Z)-or (E)-enyne fatty acid, the C-1 to C-6 carbon atoms on the α- and β-acyl positions were differentiated. The unsaturated carbon
atoms in the α- and β-acyl chains were also resolved into two signals except that of the C-11 olefinic carbon. Sandal (Santalum album) wood seed oil (a source of santalbic acid) was separated by silica chromatography into three fractions. The least polar
fraction (7.2 wt%) contained TAG which had a random distribution of saturated and unsaturated fatty acids, of which oleic
acid (69%) was the predominant component. The second fraction (3.8 wt%) contained santalbic acid (58%) and oleic acid (28%)
together with some other normal fatty acids. Santalbic acid in this fraction was found in both the α- and β-acyl positions
of the glycerol “backbone”. The most polar fraction (89 wt%) consisted of TAG containing santalbic acid only. The distribution
of the various fatty acids on the glycerol “backbone” was supported by the results from the13C NMR spectroscopic analysis. 相似文献
3.
The refractive indices of methyl oleate, linoleate, linolenate, erucate, and the saturated fatty acid methyl esters from acetate
to nonadecanoate have been measured at 20C and 40C for the Nad, H
α
, H
β
, H
γ
lines. The values for the saturated series have been correlated with the Smittenberg relation. Molar refractions have been
computed and checked for additivity. The limiting refractive indices obtained from the Smittenberg relation are compared to
those obtained from the molar refraction. 相似文献
4.
Toshihiro Akihisa Takeshi Kawashima Shushichi Takahashi Norio Sahashi Takahisa Okamoto Isao Niiya Toshitake Tamura 《Journal of the American Oil Chemists' Society》1992,69(12):1232-1235
The sterols and fatty acids ofPsilotum nudum were investigated. The 4,4-dimethyl- and 4α-methylsterol fractions contained 24β-methyl-Δ25-unsaturated sterols,viz., cyclolaudenol and 24β-methyl-25-dehydrolophenol, respectively, as dominant sterols among the other components common in
vascular plants. 24-Methylcholesterol (mixture of C-24 epimers) and sitosterol constituted the dominant sterols in the 4-demethylsterol
fraction. This is the first identification of 24-methylene-5α-lanost-8-en-3β-ol, 24β-methyl-25-dehydrolophenol, codisterol,
isofucosterol, 24-methylene-25-methylcholesterol and avenasterol in a fern. The major fatty acids were 16:0, 18:1, 18:2, 18:3
and 20:3. In addition, several C20 fatty acids with various unsaturation were found to be present in low concentrations. 相似文献
5.
S. M. Motshegwe J. Holmback S. O. Yeboah 《Journal of the American Oil Chemists' Society》1998,75(6):725-728
A preliminary investigation of the bulk properties of the oil from the edible mophane caterpillar (phane), Imbrasia belina, showed a significant difference in the iodine values of the oils from mature and young phane. Detailed analysis of the fatty
acid composition of the two oil samples was thus carried out by capillary gas chromatography (GC) and complemented with 1H and 13C nuclear magnetic resonance (NMR) studies to investigate the degree of unstauration in the two oil samples. While these studies
showed that the oil samples from the mature and young mophane caterpillar were much the same in fatty acid composition, the
data revealed a significant divergence from a literature report on phane oil. This earlier report puts the ratio of total
saturated to total unsaturated fatty acids at approximately 1:1 (48.2:48.8, in percentages) and estimates the fatty acid composition
for the major fatty acids as 16:0 (31.9%), 18:0 (15.2%), 18:1 (20.4%), 18:2 (9.9%), and 18:3 (19%). The data collected from
the present work, however, showed the fatty acid composition for total saturated and total unsaturated fatty acids to be 40.5
and 57.0%, respectively. This work estimated the fatty acid composition for the major fatty acids as 16:0 (27.2%), 18:0 (12.3%),
18:1 (16.1%), 18.2 (10.7%), and 18:3 (29.0%). Thus, linolenic acid was the most abundant fatty acid in the phane oil. The
GC results of the present analysis were largely corroborated by studies of the composition of fatty acid classes in the phane
oil estimated from integrals of 1H and 13C NMR signals. Oils from other edible Lepidoptera larvae are also known to be much richer in unsaturated than saturated fatty
acids. 相似文献
6.
A cDNA encoding the Arabidopsis extraplastidic linoleate desaturase (FAD3) was overexpressed in the seeds of wild-type Arabidopsis and in a mutant line that accumulates high levels of oleic acid. In the transformed wild-type plants, linolenic acid (18:3Δ9,12,15)
increased from 19% to nearly 40% of total seed fatty acids, with a corresponding decrease in linoleate content (18:2Δ9,12).
In the high oleate mutant, a large increase in the level of a fatty acid identified by gas-chromatography/mass-spectrometry
as mangiferic acid (18:2Δ9,15) was observed. The results demonstrate that the polymethylene-interrupted dienoic fatty acid,
mangiferic acid, can be produced in seed oil through the overexpression of a fatty acid n-3 desaturase.
相似文献
Mark A. SmithEmail: |
7.
T. H. Gouw J. C. Vlugter C. J. A. Roelands 《Journal of the American Oil Chemists' Society》1966,43(7):433-434
Kinematic viscosities at 20C, 40C and at 70C have been measured for methyl oleate, linoleate, linolenate, erucate, and for
the saturated fatty acid methyl esters acetate through nonadecanoate. Using a recently developed dynamic viscosity-temperature
criterion, log (1.200+log η)=A−S log (1+t/135), the viscosity-temperature behavior of the saturated compounds could be characterized
by one single parameter. 相似文献
8.
Stephen C. Cunnane 《Lipids》2001,36(9):975-979
New methods and analytical approaches are important to challenge and/or validate established beliefs in any field including
the metabolism of polyunsaturated fatty acids (PUFA; polyunsaturates). Four methods that have recently been applied toward
obtaining a better understanding of the homeostasis of PUFA include the following: whole-body fatty acid balance analysis,
magnetic resonance imaging (MRI), 13C nuclear magnetic resonance (NMR) spectroscopy, and gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS).
Whole-boby balance studies permit the measurement of both the percentage of oxidation of linoleate and α-linolenate and their
conversion to long-chain PUFA. This method has shown that β-oxidation to CO2 is normally the predominant metabolic fate of linoleate and α-linolenate. Furthermore, models of experimental undernutrition
in both humans and animals show that β-oxidation of linoleate and α-linolenate markedly exceeds their intake, despite theoretically
sufficient intake of linoleate or α-linolenate. Preliminary results suggest that by using MRI to measure body fat content,
indirect whole-body linoleate balance can be done in living humans, 13C NMR spectroscopy provided unexpected evidence that linoleate and α-linolenate were metabolized into lipids synthesized de novo, an observation later quantified by tracer mass balance done using GC-C-IRMS. This latter method showed that within 48 h
of dosing with 13C-α-linolenate, >80% underwent β-oxidation to CO2 by suckling rats, whereas 8–9% was converted to newly synthesized lipids and <1% to docosahexaenoate. Further application
of these recently developed methods in different models should clarify the emerging importance of β-oxidation and carbon recycling
in PUFA homeostasis in mammals including humans. 相似文献
9.
To investigate the heat induced formation of α,β-unsaturated 4-hydroxy-aldehydes (4-hydroxy-2-trans-hexenal (HHE), 4-hydroxy-2-trans-octenal (HOE), 4-hydroxy-2-trans-nonenal (HNE) and 4-hydroxy-2-trans-decenal (HDE)) fatty acid methyl esters (FAMEs) of stearic, oleic, linoleic and linolenic acids were heated separately at
185°C for 0 to 6 hrs. The formation of 2,4-decadienal, a suspected intermediate in HNE formation, was also measured in these
FAMEs. As expected methyl stearate (MS) and methyl oleate (MO) did not produce any of the α,β-unsaturated 4-hydroxy-aldehydes
as a consequence of thermally induced lipid peroxidation. The formation of HHE was detected in both methyl linoleate (ML)
and methyl linolenate (MLN), with concentration higher in MLN than in ML. The maximum HHE concentration was 3.99 μg HHE/g
ML after 2 h and 50.78 μg HHE/g MLN after 4 h of heat treatment. HOE was detected in both ML and MLN, and the maximum concentration
was 102.50 μg HOE/g ML after 6 h and 90.56 μg HOE/g MLN after 2 h of heating. HNE was found only in ML and its highest concentration
was 84.82 μg HNE/g ML after 3 h of heating. HDE was not detected in any of the four heat treated FAMEs. 2,4-Decadienal was
not found to be an intermediate in the formation of HNE in thermally induced oxidation of FAMEs. 相似文献
10.
Weidong An Jin Ki Hong P. N. Pintauro Kathleen Warner William Neff 《Journal of the American Oil Chemists' Society》1999,76(2):215-222
Soybean oil has been hydrogenated electrochemically in a solid polymer electrolyte (SPE) reactor at 60°C and 1 atm pressure.
These experiments focused on identifying cathode designs and reactor operation conditions that improved fatty acid hydrogenation
selectivities. Increasing oil mass transfer into and out of the Pd-black cathode catalyst layer (by increasing the porosity
of the cathode carbon paper/cloth backing material, increasing the oil feed flow rate, and inserting a turbulence promoter
into the oil feed flow channel) decreased the concentrations of stearic acid and linolenic acid in oil products [for example,
an iodine value (IV) 98 oil contained 12.2% C18:0 and 2.3% C18:3]. When a second metal (Ni, Cd, Zn, Pb, Cr, Fe, Ag, Cu, or Co) was electrodeposited on a Pd-black powder cathode, substantial
increases in the linolenate, linoleate, and oleate selectivities were observed. For example, a Pd/Co cathode was used to synthesize
an IV 113 soybean oil with 5.3% stearic acid and 2.3% linolenic acid. The trans isomer content of soybean oil products was in the range of 6–9.5% (corresponding to specific isomerization indices of 0.15–0.40,
depending on the product IV) and did not increase significantly for high fatty acid hydrogenation selectivity conditions. 相似文献
11.
M. Aursand J. R. Rainuzzo H. Grasdalen 《Journal of the American Oil Chemists' Society》1993,70(10):971-981
High-resolution13C nuclear magnetic resonance (NMR) spectra have been obtained and used to define the ω3 (n-3) fatty acid distribution in lipid
extract and white muscle from Atlantic salmon (Salmo salar). The13C spectrum of lipid extracted from muscle gives quantitative information about the individual n-3 fatty acids, 18:2n-6, 20:1/22:1
and groups of fatty acids. The quantitative data compare favorably with those obtained by gas-liquid chromatography. The1H NMR spectrum of the lipid extract gives information about the amount of 22:6n-3 and the total content of n-3 fatty acids.
The13C NMR technique also revealed the positional distribution (1,3- and 2-acyl) of the important 20:5n-3 and 22:6n-3 acids in
the triacylglycerol molecules. In the quantitative13C NMR spectrum of white muscle, the methyl region of the acyl chains of triacylglycerols gave rise to sufficiently resolved
signals to permit estimation of the total concentration of lipids and the n-3 fatty acid content. The NMR data are in good
agreement with corresponding data obtained by traditional methods. 相似文献
12.
Recent EU legislation (EC/2065/2001) requires that fish products, of wild and farmed origin, must provide consumer information
that describes geographical origin and production method. The aim of the present study was to establish methods that could
reliably differentiate between wild and farmed European gilthead sea bream (Sparus aurata). The methods that were chosen were based on chemical and stable isotopic analysis of the readily accessible lipid fraction.
This study examined fatty acid profiles by capillary gas chromatography and the isotopic composition of fish oil (δ13C, δ18O), phospholipid choline nitrogen (δ15N) and compound specific analysis of fatty acids (δ13C) by isotope ratio mass spectroscopy as parameters that could reliably discriminate samples of wild and farmed sea bream.
The sample set comprised of 15 farmed and 15 wild gilthead sea bream (Sparus aurata), obtained from Greece and Spain, respectively. Discrimination was achieved using fatty acid compositions, with linoleic
acid (18:2n-6), arachidonic acid (20:4n-6), stearic acid (18:0), vaccenic acid (18:1n-7) and docosapentaenoic acid (22:5n-3)
providing the highest contributions for discrimination. Principle components analysis of the data set highlighted good discrimination
between wild and farmed fish. Factor 1 and 2 accounted for >70% of the variation in the data. The variables contributing to
this discrimination were: the fatty acids 14:0, 16:0, 18:0, 18:1n-9, 18:1n-7, 22:1n-11, 18:2n-6 and 22:5n-3; δ13C of the fatty acids 16:0, 18:0, 16:1n-7, 18:1n-9, 20:5n-3 and 22:6n-3; Bulk oil fraction δ13C; glycerol/choline fraction bulk δ13C; δ15N; % N; % lipid. 相似文献
13.
Utilization of stearate as compared to various saturated fatty acids for cholesterol and lipid synthesis and β-oxidation was
determined in primary culture of rat hepatocytes. At 0.5 mmol/L in the medium, stearate (18:0) adequately solubilized by albumin
was less inhibitory to cholesterol synthesis from [2-14C] acetate than myristate (14:0) and palmitate (16:0) (68% vs. 91 and 88% inhibition, respectively). The rate of incorporation
into cholesterol from [1-14C] stearate (3.0±0.6 nmol/mg protein/4 h) was 37-, 1.8-, and 7.8-fold of that from myristate, palmitate, and oleate, respectively.
Conversely, the rate of [1-14C] stearate incorporation into total glycerolipids was 88–90% lower than that of labeled palmitate, myristate, and oleate.
The rate of [1-14C] stearate incorporation into triacylglycerol (3.6±0.4 nmol/mg protein/4 h) was 6–8% of that from myristate, palmitate, oleate,
and linoleate. The rate of stearate incorporation into phospholipids was the lowest among tested fatty acids, whereas the
rate of mono- and diacylglycerol synthesis was the highest with stearate treatment. The rate of β-oxidation as measured by
CO2 and acid soluble metabolite production was also the lowest with [1-14C] stearate treatment at 22.7 nmol/mg protein/4 h, which was 35–40% of those from other [1-14C] labeled fatty acids. A greater proportion of stearate than other fatty acids taken up by the hepatocytes remained free
and was not metabolized. Clearly, stearate as compared to shorter-chain saturated fatty acids was less efficiently oxidized
and esterified to triacylglycerol in cultured rat hepatocytes. 相似文献
14.
E. Fehling S. Schönwiese E. Klein K. D. Mukherjee N. Weber 《Journal of the American Oil Chemists' Society》1998,75(12):1757-1760
A method has been developed for the preparation of highly pure malvalic (cis-8,9-methyleneheptadec-8-enoic) and sterculic (cis-9,10-methyleneoctadec-9-enoic) acid methyl esters starting from Bombax munguba and Sterculia foetida seed oils. The methyl esters of these oils were prepared by sodium methylate-catalyzed transmethylation followed by cooling
(6°C) the hexane solution of crude methyl esters and separation of insoluble fatty acid methyl esters by centrifugation in
the case of B. munguba and by column chromatography in the case of S. foetida. Subsequently, the saturated straight-chain fatty acid methyl esters were almost quantitatively removed by urea adduct formation.
Finally, methyl malvalate and methyl sterculate were separated from the remaining unsaturated fatty acid methyl esters, in
particular methyl oleate and methyl linoleate, by preparative high-performance liquid chromatography on C18 reversed-phase using acetonitrile isocratically. Methyl malvalate and methyl sterculate were obtained with purities of 95–97
and 95–98%, respectively. 相似文献
15.
C. Bertoli L. B. Fay M. Stancanelli D. Gumy P. Lambelet 《Journal of the American Oil Chemists' Society》1998,75(8):1037-1040
The fatty acid composition, tocopherol and tocotrienol content, and oxidative stability of petroleum benzene-extracted Gevuina avellana Mol (Proteaceae) seed oil were determined. Positional isomers of monounsaturated fatty acids were elucidated by gas chromatography-electron
impact mass spectrometry after 2-alkenyl-4,4-dimethyloxazoline derivatization. This stable oil (Rancimat induction period
at 110°C: 20 h) is composed of more than 85% monounsaturated fatty acids and about equal amounts (6%) of saturated and polyunsaturated
(principally linoleic) fatty acids. Unusual positional isomers of monounsaturated fatty acids, i.e., C16:1 Δ11, C18:1 Δ12, C20:1 Δ11, C20:1 Δ15, C22:1 Δ17, and presumably C22:1 Δ19 were identified. The C18:1 Δ12 and C22:1 Δ19 fatty acids are described for the first time in G. avellana seed oil. While only minute quantities of α-, γ-tocopherols and β-, γ- and δ-tocotrienols were found, the oil contained a
substantial amount of α-tocotrienol (130 mg/kg). The potential nutritional value of G. avellana seed oil is discussed on the basis of its composition. 相似文献
16.
Saeree Jareonkitmongkol Sakayu Shimizu Hideaki Yamada 《Journal of the American Oil Chemists' Society》1993,70(2):119-123
A Δ12 desaturase-defective mutant of an arachidonic acid (AA)-producing fungus,Mortierella alpina 1S-4, converted α-linolenic acid (18:3ω3) to 5(Z),8(Z),11(Z),14(Z),17(Z)-eicosapentaenoic acid (EPA). On submerged cultivation at 20°C for 10 d in a 5-L fermentor containing medium comprising 1%
glucose, 1% yeast extract and 3% (vol/vol) linseed oil, EPA production amounted toca. 1 g/L culture broth (64 mg/g dry mycelium), which accounted forca. 20% of the total mycelial fatty acids. AA content was 26 mg/g dry mycelium (0.4 g/L), accounting for 7.8% of the total mycelial
fatty acids. The other major mycelial fatty acids were palmitic acid (4.5%), oleic acid (20.4%), linoleic acid (10.0%), 18:3ω3
(20.3%) and lignoceric acid (4.3%). Most of the EPA produced (ca. 90 mol%) was in triglyceride form. 相似文献
17.
Paresch Chandra Dutta Seved Helmersson Eshetu Kebedu Getinet Alema Lars-Åke Appelqvist 《Journal of the American Oil Chemists' Society》1994,71(8):839-843
Niger seed samples were collected from different regions in Ethiopia for determination of oil content, and of fatty acid,
tocopherol and sterol composition in the seed oil by gas-liquid chromatography and high-performance liquid chromatography
methods. There was a large variation in oil content, ranging from 29 to 39%. More than 70% of the fatty acids was linoleic
acid (18∶2) in all samples analyzed. The other predominant fatty acids were palmitic (16∶0), stearic (18∶0) and oleic (19∶1)
at a range of 6 to 11% each. Total polar lipids recovered after preparative thin-layer chromatography comprised a small fraction
of the total lipids. They had higher 16∶0 and lower 18∶2 contents than the triacylglycerols.α-Tocopherol was the predominant tocopherol in all samples, 94–96% of the total amounting to 630–800 μg/g oil. More than 40%
of the total sterols wasβ-sitosterol,ca. 2000μg/g oil. The other major sterols were campesterol and stigmasterol, ranging from 11 to 14%. The Δ5- and Δ7-avenasterols were
in the range of 4 to 7%. From the samples studied, no conclusion could be drawn regarding the influence of altitude or location
on oil content, tocopherol and/or sterol contents. The results of the present study on niger seed oil are discussed in comparison
with known data for common oils from Compositae,viz, safflower and sunflower. 相似文献
18.
S. D. Stamatov 《Journal of the American Oil Chemists' Society》1986,63(4):546-549
The radiolytic resistance of the DL-α-tocopherol irradiated by low (105rad), medium (106rad) and high (107rad) doses of gamma rays at a molar ratio of 1:1, 1:1 × 10−2 and 1:1 × 10−3 mole in methyl laurate, methyl oleate, methyl linoleate, methyl linolenate and benzene (chosen as solvent media) has been
studied.
Under the experimental conditions stated, it has been established that, contrary to ordinary autoxidation, the unsaturated
lipid systems exert a progressive, protective effect on DL-α-tocopherol as the number of double bonds increases.
When the DL-α-tocopherol was in a pure state, for example in benzene and in methyl esters of the fatty acids at a molar ratio
1:1, no effect of ionizing radiation was detected. 相似文献
19.
Dietary linoleate and linolenate were investigated for their ability to specifically inhibit liver and adipose tissue lipogenesis
in meal-fed (access to food 900-1,200 hr), essential fatty acid (EFA) adequate rats. Supplementing a high carbohydrate diet
containing 2.5% safflower oil with 3% palmitate 16∶0, oleate 18∶1, or linoleate 18∶2 did not affect in vivo liver or adipose
tissue fatty acid synthesis. However, 18∶2 addition to the basal diet did result in a significant (P<0.05) decline of liver
fatty acid synthetase (FAS) and glucose-6-phosphate dehydrogenase (G6PD) activities. When the safflower oil content of the
basal diet was reduced to 1%, the addition of 3% 18∶2 or linolenate 18∶3 significantly (P<0.05) depressed hepatic FAS, G6PD,
and in vivo fatty acid synthesis by 50%. Addition of 18∶1 caused no depression in hepatic FAS activity but did result in a
significant (P<0.05) decline in liver G6PD activity and fatty acid synthesis which was intermediate between basal and basal
+18∶2-or+18∶3-fed animals. Adipose tissue rates of lipogenesis were completely unaffected by dietary fatty acid supplementation.
Similarly, the addition of 3 or 5% 18∶3 to a basal diet for only one meal resulted in no change in lipogenesis relative to
that in animals fed the basal diet. The data indicate that, like rats fed EFA-deficient diets, dietary 18∶2 and 18∶3 exert
a specific capacity to depress rat liver FAS and G6PD activities and rate of fatty acid synthesis.
Michigan Agricultural Experiment station Journal Article No. 7581.
D.R. Romsos is the recipient of Career Development Award K04 AM 00112 相似文献
20.
Miriam D. Rosenthal 《Lipids》1981,16(3):173-182
The accumulation of neutral lipids by human skin fibroblasts grown in medium supplemented with fatty acids has been investigated.
GM-10 cells incorporated exogenous fatty acids into both phospholipids and neutral lipids. More [14C] oleate, linoleate, or linolenate was incorporated into triacylglycerol than was [14C] palmitate or stearate. Supplementation of medium containing delipidized serum with unsaturated fatty acids resulted in
far more stimulation of [14C] glycerol incorporation into triacylglycerol than did supplementation with saturated fatty acids. Palmitate- and stearate-fed
cells incorporated sizable amounts of [14C] fatty acids and [14C] glycerol into diacylglycerol as well as triacylglycerol, especially at higher fatty acid concentrations. Increased oleate
supplementation from 10–300 μM resulted in increased triacylglycerol synthesis and accumulation of discrete cytoplasmic lipid
droplets; palmitate concentrations above 70 μm were toxic. Micrographs of the palmitate-fed cells showed electron translucent
slits, suggesting solid depositions of saturated fat, rather than the discrete osmiophilic droplets found in oleate-fed cells.
Although GM-10 cells can synthesize fully saturated triacylglycerols, these data suggest that in cells fed saturated fatty
acids, solid depositions of neutral lipids may sequester diacylglycerols and thus limit triacylglycerol synthesis. 相似文献