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1.
Partial glyceride mixtures, which include 1-monoglyceride, 2-monoglyceride, free fatty acid, 1,2-diglyceride, 1,3-diglyceride
and triglyceride, could be separated from each other on a 3% boric-acid-impregnated Chromarod S-II (silica gel sintered quartz
rod) with either chloroform/acetone (96∶4, v/v) or chloroform/acetone/acetic acid (100∶1∶1, v/v) as the developing solvent
mixtures. The components separated on the boric-acid-impregnated rod were automatically quantitated in a hydrogen flame ionization
detector (Iatroscan). The relative responses of 1,2-diglyceride, 1,3-diglyceride, free fatty acid and triglyceride were slightly
lower than theoretical responses based on weight percentage, whereas 1-monoglyceride and 2-monoglyceride showed slightly higher
responses. These responses were converged within a maximal error of 5–10% (SD). Boric-acid-impregnated rods could be used
repeatedly, ca. 5 times without any reconditioning procedure.
Part of this investigation was reported at the 2nd JOCS-AOCS joint meeting, San Francisco, May 1979. 相似文献
2.
Rapid separation of neutral lipids,free fatty acids and polar lipids using prepacked silica sep-Pak columns 总被引:6,自引:10,他引:6
A method is described for the separation of neutral lipid, free fatty acid and polar lipid classes using small (600 mg), prepacked
silica Sep-Pak columns. Combinations of hexane and methyltertiarybutylether were used to progressively elute cholesteryl ester
first then triglyceride from the column. After column acidification, fatty acids were eluted followed by cholesterol. Recoveries
of these lipids were 96% or greater. Polar lipids were eluted from the column using combinations of methyltertiarybutylether,
methanol and ammonium acetate. Phospholipid classes could not be separated completely from each other. Phosphatidylethanolamine
and phosphatidylinositol eluted together, whereas the more polar phosphatidylcholine, sphingomyelin and lysophosphatidylcholine
were eluted as a second fraction. Recoveries of each phospholipid was greater than 98%. 相似文献
3.
The separation conditions for hydrolysates of triglycerides by lipase and their quantitative determination are discussed for
a thin layer chromatography-flame ionization detector system utilizing internal standards. The complete separation of glyceride
hydrolysis mixtures (triolein 1,3-diolein, 1,2-diolein, 1-monoolein and oleic acid) was achieved on a 3% boric acid-impregnated
Chromarod S-II by development with benzene/chloroform/acetic acid (70∶30∶2, v/v/v) (mobile phase A) or hexane/ ether/acetic
acid (70∶30∶1, v/v/v) (mobile phase B). Mobile phase B had an advantage over mobile phase A in terms of free space to add
internal standards for simultaneous quantitation and was employed.p-Hydroxybenzoic acid andp-carboethoxy benzyl alcohol, which appeared between 1,2-diolein and 1-moloolein, were adopted as the internal standards. The
calibration curves relating internal standards to each glyceride were all approximated by the equations Y=aXb giving high correlations. The method was applied to hydrolysis of triolein by pancreatic lipase.
Part of this investigation was reported at the annual meeting of JOCS in Tokyo, November 1982. 相似文献
4.
Cholesterol and cholesteryl esters were separated according to their carbon number and number of double bonds by high performance
reversed-phase chromatography (HPRC) using acetonitrile/chloroform/methanol (1∶1∶1, v/v) as a mobile phase. It was found that
within the same equivalent carbon number (ECN) category, cholesterol esters with the highest number of double bonds eluted
ahead of those with a lower number of double bonds, and with thecis isomers eluting ahead of theirtrans partners. Thus, cholesteryl oleate (C27-18∶1c) elutes ahead of cholesteryl palmitate (C27-16∶0) and ahead of cholesteryl elaidate (C27-18∶1t). Human lipoprotein, as well as rat liver cholesteryl esters, were separated using this technique. 相似文献
5.
Milan Čertík Peter Andráši Ján Šajbidor 《Journal of the American Oil Chemists' Society》1996,73(3):357-365
The effect of extraction procedures on the lipid yield and fatty acid composition of total lipid and main lipid structures
(phospholipids, diacylglycerols, triacylglycerols, free fatty acids, and sterol esters) of fungal biomass (Mucor mucedo CCF-1384) containing γ-linolenic acid (GLA) was investigated. Seventeen extraction methods, divided into three groups, were
tested: six with chloroform/methanol, five with hexane/alcohols, and six with common solvents or mixtures. The chloroform/methanol
procedure (2∶1) was selected as standard, where lipid yield (TL/DCW, total lipid per dry cell weight) was 17.8%, considered
to be 100% of lipids present. All chloroform/methanol extractions yielded more than 83% recorvey of lipids. Use of hexane/isopropanol
solvent systems led to a maximum of 75% recovery. The best lipid yield was achieved by a two-step extraction with ethanol
and hexane (120%). Extraction efficiency of the other solvent systems reached a maximum of 73%. Triacylglycerols were the
main structures of lipid isolated; only methanol-extracted lipid contained 58.5% phospholipids. The fatty acid content of
total recovered lipid was variable and depended on both the lipid class composition and the solvent system. GLA concentrations
in total lipids isolated by hexane/alcohol procedures (7.3–10.7%) are comparable with classical chloroform/methanol systems
(6.5–10.0%). The maximal GLA yield was obtained with chloroform/methanol/n-butanol/water/0.1 M ethylenediaminetetraacetic acid (EDTA) (2∶1∶1∶1∶0.1, by vol) and after two-step extraction with ethanol
and hexane (14.3 and 13.7 g GLA/kg DCW, respectively). The highest GLA content was analyzed in the phospholipid fraction (16.1%)
after using chloroform/methanol/n-butanol/water/0.1 M EDTA (2∶1∶1∶1∶0.1, by vol). Remarkably low concentrations of polyunsaturated fatty acids were determined
in the free fatty acid fraction. 相似文献
6.
Extracting long-chain fatty acids from a fermentation medium 总被引:1,自引:0,他引:1
Several solvents were evaluated for extracting free long-chain FA (LCFA) from a fermentation medium. Chloroform, chloroform/methanol
(1∶1), hexane, and hexane/methyl tert-butyl ether (MTBE) (1∶1) were evaluated as alternative extraction solvents. Parameters considered for optimizing LCFA recoveries
included pH and ionic strength. Maximal LCFA recoveries were obtained by adding 2 mL of the hexane/MTBE (1∶1) solvent mixture,
80 μL of 50% H2SO4, and 0.05 g NaCl to 1 mL of the aqueous sample and mixing for 15 min at 200 rpm. This method quantified saturated LCFA [capric
acid (C10∶0) to stearic acid (C18∶0)] and unsaturated LCFA with 18 carbons [linoleic acid (C18∶2) and oleic acid (C18∶1)] with a 98 to 100% recovery. Caproic (C6∶0) and caprylic (C8∶0) acids were characterized by 27 and 76% recoveries, respectively. 相似文献
7.
Sheila M. Innis Roger Dyer Louis Wadsworth Paul Quinlan Deborah Diersen-Schade 《Lipids》1993,28(7):645-650
Platelet lipid composition is important to normal platelet morphology and function, and is influenced by dietary fatty acids
and cholesterol. The fatty acid composition and cholesterol content of infant formulas differs from those of human milk, but
the possible effects on platelet lipids in young infants is not known. This was studied in piglets fed from birth to 18 d
of age with one of eight formulas differing in saturated fatty acid chain length, or content of 18∶1, 20∶5n−3 plus 22∶6n−3,
or cholesterol. A reference group of piglets fed sow milk was also studied. Sow milk has a fatty acid composition and cholesterol
content similar to that of human milk. Piglets fed formulas high in 18∶1 (34.9–40.8% wt fatty acids) and low in 16.0 (≤6.5%
wt fatty acids) had lower platelet counts and greater platelet size than piglets fed sow milk (40.4% 18∶1, 30.7% 16∶0). Piglets
fed formulas high in 16∶0 (27–29.6%) and 18∶1 (40–40.6%), or low in both 16∶0 (5.9–6.1%) and 18∶1 (10.8–11.2%), had similar
platelet counts and size to piglets fed sow milk. Platelet phospholipid % 20∶4n−6 was lower in all the groups of piglets fed
formula than in the group fed sow milk. Addition of fish oil with 20∶5n−3 plus 22∶6n−3 to the formula further decreased platelet
phospholipid 20∶4n−6. Addition of cholesterol to the formula increased the platelet phospholipid % 20∶4n−6 and platelet volume. 相似文献
8.
Acetone powders prepared fromVernonia anthelmintica seed catalyzed the release of 6.4 to 9.6 μ-moles of free fatty acids per milligram of protein when blended with olive oil
and phosphate buffer and shaken for 20 min at 43 C. A 20 fold purification was achieved by differential centrifugation of
an ammonium hydroxide extract of the acetone powder. Results from Sephadex G-200 chromatography and polyacrylamide gel electrophoresis
suggested that the lipase activity was associated with a molecule of molecular weight greater than 200,000. Free fatty acids,
1,2- and 1,3-diglycerides, monoglycerides and glycerol were found in the digestion products. With most substrates the 1,2-to
1,3-diglyceride ratio was approximately 2∶1 and monoglycerides tended to accumulate. Analysis of the digestion products from
synthetic triglycerides of known structure indicated that both primary and secondary ester positions of the triglyceride molecule
were hydrolyzed and that considerable isomerization of 1,2-diglyceride to 1,3-diglyceride occurred. The monoglyceride was
consistently lower than the 1,2-diglyceride and in the majority of cases also lower than the 1,3-diglyceride in the fatty
acid originally present in the 2 position of the triglyceride. No fatty acid preference was observed.
Scientific contribution No. 316.
Presented in part at the AOCS Meeting, Philadelphia, October 1966. 相似文献
9.
The objective of this study was to test the effect of a novel fatty acid mixture, enriched with myristoleic and palmitoleic
acids, on plasma lipoprotein cholesterol concentrations. Weanling pigs were assigned to one of six groups and each group received
a diet differing in fatty acid composition. Diets were fed for 35 days and contained 10 g added cornstarch/100 g (to provide
baseline data) or 10 g added fatty acids/100 g. For those diets containing added fatty acids, extracted lipids contained 36%
myristoleic plus palmitoleic acid combined (14∶1/16∶1 diet), 52% palmitic acid (16∶0 diet), 51% stearic acid (18∶0 diet),
47% oleic acid (18∶1 diet), or 38% linoleic acid (18∶2 diet). Witht the exception of the cornstarch diet, all diets contained
approximately 30% myristic acid. There were no significant differences in weight gain across treatment groups (P=0.22). All diets caused a significant increase in triglycerides and in total, low density lipoprotein, high density lipoprotein,
and very low density lipoprotein cholesterol. The increase in total plasma cholesterol from pretreatment values was greatest
in pigs fed the 14∶1/16∶1 and 18∶1 diets. However, the increase in low density lipoprotein cholesterol from the pretreatment
concentration was greatest in the 14∶1/16∶1-fed pigs. Increases in very low density lipoprotein cholesterol above pretreatment
concentrations were lowest in 16∶0-fed pigs and greatest in 18∶1-fed pigs. Dietary fatty acids elicited changes in plasma
fatty acids which generally were reflective of the diets, although the 18∶0 diet did not alter plasma fatty acid concentrations
and the 16∶0 diet increased plasma 16∶0 only at the end of the study. These results demonstrated that the combination of myristoleic
plus palmitoleic acids increased plasma cholesterol in young pigs, suggesting that fatty acid chain length, rather than degree
of unsaturation, is primarily responsible for the effects of fatty acids on circulating lipoprotein cholesterol concentrations. 相似文献
10.
A study was made with sheep on the formation in vitro of long chain fatty acid esters of cholesterol by the lecithin-cholesterol-acyltransferase
system present in the plasma and the acyl CoA-cholesterol-acyltransferase system present in the liver. The rate of cholesterol
esterification in the plasma was 0.024 μmoles/ml/hr. The relative pattern of fatty acids esterified during incubation of the
plasma remained constant over the 8 hr period of incubation and was similar to the fatty acids in the plasma cholesteryl esters
before incubation began and to the fatty acids in the 2-position of the plasma lecithin. The predominant cholesteryl esters
synthesized contained monoenoic and dienoic fatty acids. Unlike the bovine, there was no apparent discrimination in favor
of the 18∶2 containing species of plasma lecithin as donors of fatty acids. This difference could be accounted for by the
similarity in the 18∶2 content of the phospholipids present in the high density (density >1.062 and < 1.21) and the low density
(density > 1.006 and <1.063) lipoprotein fractions of the sheep plasma. The possibility of some discrimination against 20∶4
during cholesterol ester synthesis in the plasma of the sheep cannot be excluded. In the liver, the predominant cholesteryl
esters synthesized contained saturated and monoenoic fatty acids; cholesteryl linoleate was synthesized to a very much less
extent. There was considerable similarity between the composition of the unesterified fatty acid fraction of the liver before
incubation began and the fatty acid composition of the cholesteryl esters synthesized during incubation. Addition of sonicated
suspensions of free fatty acids altered markedly the fatty acid pattern of the cholesteryl esters synthesized by the liver
slices. From the evidence presented it is concluded that the cholesteryl esters in sheep plasma are syntheized mainly by the
plasma lecithin-cholesterol-acyltransferase system. The results are discussed in relation to cholesterol esterification systems
demonstrated in the plasma and liver of monogastric animals. 相似文献
11.
Human endothelial cells in culture were examined in different growth conditions. The human endothelial cell line, EA.hy 926
cell line, was used and cells were studied either in exponential growth phase, at confluence, or growth-arrested by serum
deprivation. Phospholipids were separated and analyzed by high-performance thin-layer chromatography, and their fatty acids
were quantified by gas-liquid chromatography. No significant differences in the phospholipid distributions were found between
exponentially growing and confluent endothelial cells in which phosphatidylcholine (PC) represented the major phospholipid.
In comparison, serum-deprived cells exhibited higher proportions of sphingomyelin and lower content of PC. We also found that
among the total lipids, cholesterol level for dividing endothelial cells was lower than for cells growth-arrested either by
serum deprivation or by contact inhibition at confluence. The global fatty acid distribution was not affected by the growth
conditions. Thus, oleate (18∶1n−9 and 18∶1n-7), palmitate (C16∶0), and stearate (C18∶0) were the main components of endothelial cell membranes. However, the fatty acid distributions obtained from each phospholipid
species differed with the growth status. Altogether, the data indicated that subtle modulations of endothelial cell metabolism
appear upon cell growth. The resulting membrane-dependent cellular functions such as cholesterol transport and receptor activities
can be expected to be relevant for lipid trafficking within the vessel wall in vitro and in vivo. 相似文献
12.
T. P. Hensarling T. J. Jacks L. Y. Yatsu 《Journal of the American Oil Chemists' Society》1974,51(4):166-168
Hexane and mixtures of hexane and 2–25% acetic acid (v/v) were used to prepare oil and protein from glanded cottonseed by
solvent extraction. As the amount of acetic acid in the solvent increased, the amounts of total lipid, phospholipid, neutral
oil, and gossypol in each miscella increased, but the amount of free fatty acids did not change significantly. However, the
solubility of protein in 0.02N NaOH decreased as the amount of acetic acid in the solvent used to prepare each meal increased.
Other aspects of using acidified hexane are described.
A preliminary report was presented at the AOCS Meeting in New Orleans, April 1973.
ARS, USDA. 相似文献
13.
M. Cartens E. Molina Grima A. Robles Medina A. Giménez Giménez J. Ibáñez González 《Journal of the American Oil Chemists' Society》1996,73(8):1025-1031
Eicosapentaenoic acid (EPA, 20∶5n-3) was obtained from the marine microalgaePhaeodactylum tricornutum by a three-step process: fatty acid extraction by direct saponification of biomass, polyunsaturated fatty acid (PUFA) concentration
by formation of urea inclusion compounds, and EPA isolation by semipreparative high-performance liquid chromatography (HPLC).
Alternatively, EPA was obtained by a similar two-step process without the PUFA concentration step by the urea method. Direct
saponification of biomass was carried out with two solvents that contained KOH for lipid saponification. An increase in yield
was obtained because the problems associated with emulsion formation were avoided by separating the biomass from the soap
solution before adding hexane for extraction of insaponifiables. The most efficient solvent, ethanol (96%) at 60°C for 1 h,
extracted 98.3% of EPA. PUFA were concentrated by the urea method with a urea/fatty acid ratio of 4∶1 at a crystallization
temperature of 28°C and by using methanol and ethanol as urea solvents. An EPA concentration ratio of 1.73 (55.2∶31.9) and
a recover yield of 78.6% were obtained with methanol as the urea solvent. This PUFA concentrate was used to obtain 93.4% pure
EPA by semipreparative HPLC with a reverse-phase, C18, 10 mm i.d.×25-cm column and methanol/water (1% acetic acid), 80∶20 w/w, as the mobile phase. Eighty-five percent of EPA
loaded was recovered, and 65.7% of EPA present inP. tricornutum biomass was recovered in highly pure form by this three-step downstream process. Alternatively, 93.6% pure EPA was isolated
from the fatty acid extract (without the PUFA concentration step) with 100% EPA recovery yield. This two-step process increases
the overall EPA yield to 98.3%, but it is only possible to obtain 20% as much EPA as that obtained by three-step downstream
processing. 相似文献
14.
W. McLean Grogan 《Lipids》1981,16(12):940-942
Fatty acid composition of phospholipid (PL) classes was measured in mouse testis. Among the long-chain polyenoic acids (LCPA),
22∶6 was found in highest concentration in phosphatidylethanolamine (PE), whereas percentages of 20∶4 and 22∶5 were not different
in PE than in phosphatidylcholine. Each PL class had a unique fatty acid composition which was also different from that of
triglycerides and cholesteryl esters. Differential metabolisms of 22∶5 and 22∶6 suggest different roles for these fatty acids
in mouse testis. Tissue-specific functions of LCPA in mouse spermatogenesis may be divided between 22∶5 and 22∶6. 相似文献
15.
This study examined the effect on the plasma lipids and plasma phospholipid and cholesteryl ester fatty acids of changing
from a typical western diet to a very low fat (VLF) vegetarian diet containing one egg/day. The effect of the addition of
saturated, monounsaturated or polyunsaturated fat (PUFA) to the VLF diet was also examined. Three groups of 10 subjects (6
women, 4 men) were fed the VLF diet (10% energy as fat) for two weeks, and then in the next two weeks the dietary fat in each
group was increased by 10% energy/week using butter, olive oil or safflower oil. The fat replaced dietary carbohydrate. The
VLF diet reduced both the low density lipoprotein (LDL)-and high density lipoprotein (HDL)-cholesterol levels; addition of
the monounsaturated fats and PUFA increased the HDL-cholesterol levels, whereas butter increased the cholesterol levels in
both the LDL- and HDL-fractions. The VLF diet led to significant reductions in the proportion of linoleic acid (18∶2ω6) and
eicosapentaenoic acid (20∶5ω3) and to increases in palmitoleic (16∶1), eicosatrienoic (20∶3ω6) and arachidonic acids (20∶4ω6)
in both phospholipids and cholesteryl esters. Addition of butter reversed the changes seen on the VLF diet, with the exception
of 16∶1, which remained elevated. Addition of olive oil resulted in a significant rise in the proportion of 18∶1 and significant
decreases in all ω3 PUFA except 22∶6 compared with the usual diet. The addition of safflower oil resulted in significant increases
in 18∶2 and 20∶4ω6 and significant decreases in 18∶1, 20∶5ω3 and 22∶5ω3. These results indicate that the reduction of saturated
fat content of the diet (<6% dietary energy), either by reducing the total fat content of the diet or by exchanging saturated
fat with unsaturated fat, reduced the total plasma cholesterol levels by approximately 12% in normocholesterolemic subjects.
Although the VLF vegetarian diet reduced both LDL- and HDL-cholesterol levels, the long-term effects of VLF diets are unlikely
to be deteterious since populations which habitually consume these diets have low rates of coronary heart disease. The addition
of safflower oil or olive oil to a VLF diet produced favorable changes in the lipoprotein lipid profile compared with the
addition of butter. The VLF diets and diets rich in butter, olive oil or safflower oil had different effects on the 20 carbon
eicosanoid precursor fatty acids in the plasma. This suggests that advice on plasma lipid lowering should also take into account
the effect of the diet on the fatty acid profile of the plasma lipids. 相似文献
16.
Mesenteric fat tissue obtained at autopsy from 6 patients with mesenteric panniculitis (MP) were found to contain significant
amounts of cholesteryl esters (CE). In addition, samples from 3 of these cases were found to contain 0.5–1.3% free cholesterol,
0.9–1.9% free fatty acids (FFA), 0.6–2.5% 1-alkyl glyceryl ether diesters and small amounts of squalene. Two of these tissues
also contained alk-1-enyl glyceryl ether diesters. The fatty acid compositions of the CE, FFA, triacylglycerides and glyceryl
ether diesters (GEDE) were determined and oleic acid (18∶1) was found to be the major fatty acid. The alkyl group composition
of the GEDE consisted essentially of 16∶0 and 18∶0 and 18∶1 carbon atoms in both types of ethers. 相似文献
17.
Substitution of palmolein (POL) for groundnut oil (GNO) doubles saturated fatty acids and decreases by half the linoleic acid
(18∶2n−6) content of Indian diets. The effects of this substitution on selected parameters of cardiovascular risk and membrane
functions were studied in middle-aged subjects. Both metabolic (short-term) and “in-home” (long-term) studies were conducted,
and the subjects were crossed over from GNO to POL or vice versa. During both studies and in both sexes, blood pressure, plasma
levels of total cholesterol and triglycerides and their distributions in various lipoprotein fractions were not altered. The
lower 18∶2n−6 and higher 16∶0 intakes were reflected in fatty acid compositions of cholesteryl esters and triglycerides. However,
the plasma and platelet phospholipid fatty acid patterns did not shift toward saturation. The observation that the levels
of long-chain polyunsaturated fatty acids in phospholipids were similar at the end of GNO and POL regimens indicates that
18∶2n−6 furnished during POL regimen may be sufficient to maintain the levels of arachidonic acid in cell membranes. Platelet
aggregation, erythrocyte membrane fluidity, and activity of Na+,K+ ATPase, a membrane-bound enzyme, were essentially similar at the end of the two oil regimens. These results indicate that
POL is comparable to GNO and may not induce hypercholesterolemia in Indian subjects consuming cereal-based diets containing
30% total fat calories and low cholesterol.
Based on a paper presented at the PORIM International Palm Oil Congress (PIPOC) held in Kuala Lumpur, Malaysia, September
1993. 相似文献
18.
The emperor penguin (Aptenodytes forsteri) is an Antarctic seabird feeding mainly on fish and therefore has a high dietary intake of n-3 polyunsaturated fatty acids.
The yolk is accumulated in the developing oocyte while the females are fasting, and a large proportion of the fatty acid components
of the yolk lipids are derived by mobilization from the female's adipose tissue. The fatty acid composition of the total lipid
of the yolk was characterized by high levels of n-3 polyunsaturated fatty acids. However, it differed in several respects
from that of the maternal adipose tissue. For example, the proportions of 14∶0, 16∶1n−7, 20∶1n−9, 22∶1n−9, 20∶5n−3, and 22∶6n−3
were significantly greater in adipose tissue than in yolk. Thus adipose tissue lipids contained 7.6±0.3% and 8.0±0.3% (wt%
of total fatty acids; mean ±SE; n=5) of 20∶5n−3 and 22∶6n−3, respectively, whereas the yolk total lipid contained 1.6±0.1 and 5.5±0.3% of these respective
fatty acids. The proportions of 16∶0, 18∶0, 18∶1n−9, 18∶2n−6, and 20∶4n−6 were significantly lower in the adipose tissue than
in the yolk lipids. The proportions of triacylglycerol, phospholipid, free cholesterol, and cholesteryl ester in the yolk
lipid were, respectively, 67.0±0.2, 25.4±0.3, 5.3±0.2, and 1.8±0.2% (wt% of total yolk lipid). The proportions of 20∶4n−6,
20∶5n−3, 22∶5n−3, and 22∶6n−3 were, respectively, 5.7±0.3, 2.8±0.2, 1.4±0.1, and 11.7±0.5% in phospholipid and 0.4±0.0, 1.2±0.1,
0.8±0.1 and 3.6±0.3% in triacylglycerol. About 95% of the total vitamin E in the yolks was in the form of α-tocopherol with
γ-tocopherol forming the remainder. Two species of carotenoids, one identified as lutein, were present. 相似文献
19.
Trans, trans-linoleate at 50 and 100% of dietary fat decreased kidney size and altered its composition.Trans, trans-linoleate as the sole source of dietary fat imparied growth and caused more severe symptoms of essential fatty acid deficiency
than was observed with hydrogenated coconut oil (HCO). The concentration of renal cholesterol, phospholipids (PL), triglycerides
(TG) and cholesteryl esters (CE) were also decreased. Linoleic (18∶2), homo-γ-linolenic acid (20∶3n6) and arachidonic acid
(20∶4n6) were significantly depressed in lipid classes, especially in PL and CE, by dietarytrans, trans-linoleate. The increase in eicosatrienoate (20∶3n9), especially in PL and CE of kidneys of rats fed HCO (essential fatty
acid deficient), was slight in rats fed 100%trans, trans-linoleate, indicating that thetrans, trans acid probably inhibited acyl elongation and desaturation. 相似文献
20.
The effect of essential fatty acid (EFA) deficiency on the lipid composition of basolateral plasma membranes (BPM) from intestinal
mucosal cells was investigated in weaning pigs fed control or EFA-deficient diets for 12 weeks. The phospholipid and cholesterol
contents relative to protein were similar in both groups, showing a cholesterol/phospholipid molar ratio of 0.6. The distribution
of phospholipid classes was also unaffected by the diet. In contrast, fatty acid profiles of the two phospholipid main classes,
phosphatidylcholine and phosphatidylethanolamine were altered by EFA deficiency. Linoleic acid (18∶2n−6) was largely reduced,
whereas arachidonic acid (20∶4n−6) only slightly decreased in EFA-deficient pigs. The unsaturation index was essentially maintained
by high levels of oleic acid (18∶1n−9) and by conversion of oleic acid to 5,8,11-eicosatrienoic acid (20∶3n−9). Finally, during
the period of EFA deficiency, the lipid composition of BPM of the intestinal mucosal cells was little affected, suggesting
a preferential uptake of 20∶4n−6 and (or) precursor mobilized from other tissues. However, an effect of dietary treatment
on the function of membrane-associated proteins cannot be ruled out. 相似文献