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1.
Characterization of polar and nonpolar seed lipid classes from highly saturated fatty acid sunflower mutants 总被引:4,自引:0,他引:4
Rosario Álvarez-Ortega Sara Cantisán Enrique Martínez-Force Rafael Garcés 《Lipids》1997,32(8):833-837
The seed lipids from five sunflower mutants, two with high palmitic acid contents, one of them in high oleic background, and
three with high stearic acid contents, have been characterized. All lipid classes of these mutant seeds have increased saturated
fatty acid content although triacylglycerols had the highest levels. The increase in saturated fatty acids was mainly at the
expense of oleic acid while linoleic acid levels remained unchanged. No difference between mutants and standard sunflower
lines used as controls was found in minor fatty acids: linolenic, arachidic, and behenic. In the high-palmitic mutants palmitoleic
acid (16∶1n−7) and some palmitolinoleic acid (16∶2n−7, 16∶2n−4) also appeared. Phosphatidylinositol, the lipid with the highest
palmitic acid content in controls, also had the highest content of palmitic or stearic acids, depending on the mutant type,
suggesting that saturated fatty acids are needed for its physiological function. Positional analysis showed that mutant oils
have very low content of saturated fatty acids in the sn-2 position of triacylglycerols, between the content of olive oil and cocoa butter. 相似文献
2.
Milk fat globules: Fatty acid composition,size and in vivo regulation of fat liquidity 总被引:3,自引:0,他引:3
Populations of large and small milk fat globules were isolated and analyzed to determine differences in fatty acid composition.
Globule samples were obtained by centrifugation from milks of a herd and of individual animals produced under both pasture
and barn feeding. Triacylglycerols of total globule lipids were prepared by thin layer chromatography and analyzed for fatty
acid composition by gas chromatography. Using content of the acids in large globules as 100%, small globules contained fewer
short-chain acids, −5.9%, less stearic acid, −22.7%, and more oleic acids, +4.6%, mean values for five trials. These differences
are consistent with alternative use of short-chain acids or oleic acid converted from stearic acid to maintain liquidity at
body temperature of milk fat globules and their precursors, intracellular lipid droplets. Stearyl-CoA desaturase (EC 1.14.99.5),
which maintains fluidity of cellular endoplasmic reticulum membrane, is suggested to play a key role in regulating globule
fat liquidity. Possible origins of differences between individual globules in fatty acid composition of their triacylglycerols
are discussed. 相似文献
3.
M. L. Gaspar R. J. Pollero M. N. Cabello 《Journal of the American Oil Chemists' Society》1994,71(4):449-452
Lipids and fatty acids of spores of the vesicular-arbuscular mycorrhizal fungusGlomus versiforme were identified and quantitatively determined at different times of germination. Triacylglycerols were, by far, the most
abundant lipid (38% on a wet-weight basis). Phosphatidylethanolamine, together with minor quantities of other phospholipids,
was the main polar lipid. Palmitoleic, palmitic and oleic acids were quantitatively the most important fatty acids in total
lipids, and even more so in the triacylglycerol fraction. Minor percentages of fatty acids, identified as ω3 and ω6 polyunsaturated,
completed the fatty acid spectra. Germination ofG. versiforme spores evokes a continuous decrease of triacylglycerols and an increase of phospholipids. The balance of fatty acids during
germination suggests either a degradation or a transference of fatty acids from triacylglycerols to phospholipids. 相似文献
4.
J. P. Beilby 《Lipids》1980,15(11):949-952
The fatty acids and sterols of ungerminated chlamydospores of the vesicular-arbuscular (VA) endophyteAcaulospora laevis were examined by gas chromatography and mass spectrometry. The total lipid content of the spores was 45.5% of the spore dry
weight. Predominant fatty acids were palmitoleic (52.5%), palmitic (25.5%) and oleic (7.4%). Minor fatty acids consisted of
a range of (n−3) and (n−6) polyunsaturated acids. The occurrence of (n−3) polyunsaturated fatty acids is rare in fungi of
the order Mucorales. Three sterols were identified as 24-ethylcholesterol (79.9%), cholesterol (11.0%) and 24-methylcholesterol
(9.2%). No ergosterol was detected. Lipids of the chlamydospores ofA. laevis are compared with those ofGlomus caledonius. 相似文献
5.
The fatty acid composition of milk fat is known to be affected by dietary and genetic differences, while the milk triacylglycerol
structure is believed to be attuned to the needs of the subsequent lipolysis during gastrointestinal passage. The availability
of milk samples from eight species of prosimian primates, whose milk triacylglycerol structure had not been analyzed, offered
an opportunity to further assess these ideas. The milk samples were collected by manual expression and the lipids extracted
with chloroform/methanol (2∶1, vol/vol). The lipid classes were resolved by thin-layer chromatography, and the neutral lipids
subjected to detailed analyses by capillary gas-liquid chromatography of fatty acids and molecular species of triacylglycerols
using nonpolar and polarizable liquid phases. The milk samples were found to differ greatly in total fat content (4–73%) and
in the composition of the neutral liqid classes and molecular species. The concentration of triacylglycerols ranged from 88–95%,
free fatty acids from 0.5–10%, alkyldiacylglycerols from 0.5–5.0%, and diacylglycerols, monoacylglycerols and free and esterified
cholesterol made up the remainder. The fatty acid chain length ranged from C8−C24, with palmitic (16–31%) and oleic (13–40%) acids being the major components in most of the species. In all instances, the
molecular association of the fatty acids differed from random distribution by a higher proportion of the monoacid (trioleoyl)
and diacid (dipalmitoyloleoyl) glycerols. The phylogenetic influences on neutral milk lipid composition, however, remained
unclear, as some of the differences between closely related species were greater than those between more distantly related
ones.
Triacylglycerol structures are abbreviated by listing their three constituent fatty acids in sequence, e.g., PPP, LaOL. 相似文献
6.
Dibutyrate derivatives of monoacylglycerols of oleic, petroselinic, and cis-vaccenic acids were prepared by diesterification of monoacylglycerols with n-butyryl chloride. The resulting triacylglycerols were analyzed by gas chromatography (GC) with a 65% phenyl methyl silicone
capillary column and separated on the basis of both fatty acid composition and regiospecific position. The petroselinic acid
derivatives eluted first, followed sequentially by the oleic and cis-vaccenic acid derivatives, with the sn−2 positional isomer eluting before the sn−1(3) isomer in each case. Separation of the peaks was almost baseline between petroselinic and oleic acids as well as between
oleic and cis-vaccenic acids. To assess the accuracy of the method, mixtures of triolein, tripetroselinin, and tri-cis-vaccenin in various known proportions were partially deacylated with the use of ethyl magnesium bromide and derivatized and
analyzed as above. The results showed that this method compares favorably to the existing methods for analysis of oleic, petroselinic,
and cis-vaccenic fatty acids by GC with respect to peak separation and accuracy, and it also provides information on the regiospecific
distribution of the fatty acids. The method was applied to basil (Ocimum basilicum) and coriander (Coriandrum sativum) seed oils. cis-Vaccenic, oleic, and linoleic acids were mainly distributed at the sn−2 position in basil seed oil, and higher proportions of linolenic, palmitic, and stearic acids were distributed at the sn−1(3) position than at the sn−2 position. In coriander seed oil, petroselinic acid was mainly distributed at the sn−1(3) position, and both oleic and linoleic acids were mostly located at the sn−2 position, whereas palmitic, stearic, and cis-vaccenic acids were located only at the sn−1(3) position. 相似文献
7.
Kumar D. Mukherjee 《Lipids》1986,21(5):347-352
Lipids in developing seeds ofSinapis alba contain appreciable proportions of (n−7)octadecenoic (vaccenic) acid besides its (n−9) isomer (oleic acid), whereas the constituent
very long chain (>C18) monounsaturated fatty acids of these lipids are overwhelmingly composed of the (n−9) isomers. Cotyledons of developingSinapis alba seed use [1-14C]acetate, [1-14C]malonate or [1,3-14C]malonyl-CoA for de novo synthesis of palmitic, stearic and oleic acids and for elongation of preformed oleic, vaccenic and
stearic acids to their higher (n−9), (n−7) and saturated homologs, respectively. Moreover, elongation of preformed (n−7)palmitoleic
acid to vaccenic acid is observed. Stepwise C2-additions to preformed oleoyl-CoA by acetyl-CoA or malonyl-CoA yielding (n−9)icosenoyl-CoA, (n−9)docosenoyl-CoA and (n−9)tetracosenoyl-CoA
are by far the most predominant reactions catalyzed by the elongase system, which seems to have a preference for oleoyl-CoA
over vaccenoyl-CoA as the primer. The pattern of14C-labeling of the very long chain fatty acids formed from either acetate or malonate shows a close analogy in the mode of
elongation of monounsaturated and saturated fatty acids. 相似文献
8.
The positional distribution of fatty acids has been determined for the milk triacylglycerols of the Antarctic fur seal,Arctocephalus gazella. Of particular interest was the positional distribution of the polyunsaturated n−3 fatty acids in milk triacylglycerols (TG).
In adipocytes of pinnipeds, TG are synthesized with the n−3 fatty acids primarily in thesn-1,3 positions. To determine the positional distribution, extracts of enzymatically digested lipids were separated by thin-layer
chromatography, and the constituent fatty acids were separated and quantified by gas-liquid chromatography. Monoenoic and
saturated fatty acids comprised over 75% of the total, the ratio of monoenoic to saturated fatty acids being 2∶1. The percent
content of the long-chain n−3 fatty acids, 20∶5, 22∶5 and 22∶6, ranged between 15–20%. The positional analyses revealed that
at thesn-2 position of milk TG, saturated fatty acids were in excess (57%), and the content of n−3 fatty acids was less than 5%. More
than 80% of the n−3 fatty acids in milk were located in thesn-1,3 positions. The data indicate that in pinnipeds TG are synthesized in the mammary gland and adipose tissue with fatty
acids having similar positional distributions. 相似文献
9.
Dexamethasone depresses Δ6 and Δ5 and increases Δ9 desaturase and synthase activities. Therefore, we investigated the effect
on the fatty acid composition of microsomal liver lipids and phosphatidylcholine (PtdCho) molecular species. After 15 d of
treatment we found a notable decrease in arachidonic acid, a small decrease in stearic acid, and increases of linoleic, oleic,
palmitoleic, and palmitic acids in liver microsomal total lipids and PtdCho. The study of the distribution of the PtdCho molecular
species indicated that 18∶0/20∶4n−6, 16∶0/20∶4n−6, and 16∶0/18∶2n−6 predominated in the control animals. Dexamethasone, as
expected because of its depressing effect on arachidonic acid synthesis and activation of oleic and palmitic acid synthesis,
evoked a very significant decrease in 18∶0/20∶4n−6 PtdCho (P<0.001) and an important increase in 16∶0/18∶2n−6. The invariability of 16∶0/20∶4n−6 PtdCho could be related to the antagonistic
effect of arachidonic and palmitic acid synthesis. PtdCho species containing oleic acid were not significant. The bulk fluidity
and dynamic properties of the microsomal lipid bilayer measured by fluorometry using the probes 1,6-diphenyl-1,3,5-hexatriene
and 4-trimethylammonium-phenyl-6-phenyl-1,3,5-hexatriene showed no significant modification, probably owing to a compensatory
effect of the different molecular species, but changes of particular domains not detected by this technique are possible.
However, the extremely sensitive Laurdan detected increased lipid packing in the less-fluid domains of the polar-nonpolar
interphase of the bilayer, possibly evoked by the change of molecular species and cholesterol/phospholipid ratio. The most
important effect found is the decrease of arachidonic acid pools in liver phospholipids as one of the corresponding causes
of dexamethasone-dependent pharmacological effects. 相似文献
10.
The present study was designed to investigate the metabolism of the n−3 olyunsaturated fatty acids (PUFA) in adipose tissue
and its dependence upon dietary factors. Changes in the positional distribution of the fatty acids in triacylglycerols from
retroperitoneal adipose tissue were studied as a function of time on rats fed for 4 wk a diet enriched with fish oil. The
stereospecific analysis of triacylglycerols was based on random formation ofrac-1,2-diacylglycerols by Grignard degradation. This was followed by synthesis ofrac-phosphatidic acids and treatment with phospholipase A2. In the triacylglycerols of the fish oil diet, 57% of the total n−3 fatty acids were in position 3,i.e., two-thirds of 22∶5n−3 and 22∶5n−3 were esterified insn-3 position, whereas 22∶6n−3 was equally distributed in positions 2 and 3. After 4 wk of feeding fish oil, the fatty acid
composition of adipose tissue triacylglycerols reached a steady state. Half of the n−3 fatty acids were found in position
3, namely 75% of 22∶5n−3, 50% of 20∶5n−3 and 18∶4n−3 and 45% of 22∶6n−3, the latter being equally distributed in positions
2 and 3. This pattern of distribution resembled that found in triacylglycerols of the fish oil diet, except for a higher proportion
of 20∶5n−3 in adipose tissue in position 1 at the expense of position 3. Throughout the 4-wk period of fish oil feeding, the
distribution pattern of minor n−3 fatty acids (18∶4n−3 and 22∶5n−3) in adipose tissue triacylglycerols remained unchanged.
On the other hand, at the onset of fish oil feeding, 20∶5n−3 and 22∶6n−3 became concentrated in position 3, but thereafter
20∶5n−3 was progressively incorporated into position 1 and 22∶6n−3 into position 2. We thus conclude that n−3 fatty acids
are differentially esterified in triacylglycerols of white adipose tissue. Despite the complex sequence of hydrolysis and
acylation steps involved, the positional distribution of n−3 fatty acids was found to be similar in both the fish oil diet
and the stored fat, in contrast to what was observed for nonessential fatty acids. 相似文献
11.
Relative fatty acid composition of plasma and red blood cell (RBC) choline phosphoglycerides (CPG), and RBC ethanolamine phosphoglycerides
(EPG) of pregnant (n=40) and nonpregnant, nonlactating (n=40), healthy Korean women was compared. The two groups were of the same ethnic origin and comparable in age and parity. Levels
of arachidonic (AA) and docosahexaenoic (DHA) acids were lower (P<0.05) and palmitic and oleic acids higher (P<0.0001) in plasma CPG of the pregnant women. Similarly, the RBC CPG and EPG of the pregnant women had lower AA and DHA (P<0.05) and higher palmitic and oleic acids (P<0.01). The reduction in DHA and total n−3 fatty acids in plasma CPG of the pregnant women was paralleled by an increase in
docosatetraenoic (DTA) and docosapentaenoic (DPA) acids of the n−6 series and in DPA/DTA ratio. In the RBC phospholipids (CPG
and EPG) of the pregnant women, DTA and DPA acids of the n−6 series and DPA/DTA ratio did not increase with the decrease of
the n−3 metabolites (eicosapentaenoic acid, DPA, and DHA) and total n−3. Since pregnancy was the main identifiable variable
between the two groups, the lower levels of AA and DHA in RBC CPG and EPG of the pregnant women suggest that the mothers were
mobilizing membrane AA and DHA to meet the high fetal requirement for these nutrients. It may also suggest that RBC play a
role as a potential store of AA and DHA and as a vehicle for the transport of these fatty acids from maternal circulation
to the placenta to be utilized by the developing fetus. 相似文献
12.
The fatty acid composition of erythrocytes, platelets, and serum lipids was compared between subjects who had been eating
a strict uncooked vegan diet (“living food”) for years and omnivore controls. The vegan diet contains equal amounts of fat
but more monounsaturated and polyunsaturated and less saturated fatty acids than the mixed diet of the control group. In vegans,
the proportion of linoleic acid was greater in all lipid fractions studied. Also, the levels of other n−6 fatty acids were
greater, with the exception of arachidonic acid levels, which were similar in most fractions. In erythrocytes, platelets and
serum phospholipid fractions, this increase was mainly at the expense of the n−3 fatty acids. The proportions of eicosapentaenoic
and docosahexaenoic acid were only 29–36% and 49–52% of those in controls, respectively. In vegans the ratio of n−3 to n−6
fatty acids was only about half that in omnivores. In addition to the lower levels of n−3 fatty acids, the proportions of
palmitic and stearic acids were lower in serum cholesteryl esters, triglycerides and free fatty acids of vegans. The proportion
of oleic acid was slightly lower only in serum cholesteryl esters and erythrocyte phosphatidylserine. The results show that,
in the long term, the vegan diet has little effect on the proportions of oleic and arachidonic acids, whereas the levels of
n−3 fatty acids are depressed to very low levels with prolonged consumption of the high linoleic and oleic acid components
of this diet. 相似文献
13.
Uptake and metabolism of saturated (16∶0, 18∶0) and unsaturated [18∶1(n−9), 18∶2(n−6), 18∶3(n−3)] fatty acids by cultured
epimastigotes ofTrypanosoma cruzi were studied. Between 17.5 and 33.5% of the total radioactivity of [1-14C]labeled fatty acids initially added to the culture medium was incorporated into the lipids ofT. cruzi and mostly choline and ethanolamine phospholipids. As demonstrated by argentation thin layer chromatography, gas liquid chromatography
and ozonolysis of the fatty acids synthesized, exogenous palmitic acid was elongated to stearic acid, and the latter was desaturated
to oleic acid and 18∶2 fatty acid. The 18∶2 fatty acid was tentatively identified as linoleic acid with the first bond in
the Δ9 position and the second bond toward the terminal methyl end. Exogenous stearic acid was also desaturated to oleic and
18∶2 fatty acid, while oleic acid was only converted into 18∶2. All of the saturated and unsaturated fatty acids investigated
were also converted to a small extent (2–4%) into polyunsaturated fatty acids. No radioactive aldehyde methyl ester fragments
of less than nine carbon atoms were detected after ozonolysis of any of the fatty acids studied. These results demonstrate
the existence of Δ9 and either Δ12 or Δ15 desaturases, or both, inT. cruzi and suggest that Δ6 desaturase or other desaturases of the animal type are likely absent in cultured forms of this organism. 相似文献
14.
Uptake and incorporation of long-chain fatty acids were studied in a human colorectal cancer cell line (HT29/219) grown in
culture medium supplemented with either fetal calf serum (FSC) or horse serum (HS). The cells were grown for 120 h with no
change of medium; the two major cellular lipid classes, the phospholipids and the triacylglycerols, were analyzed at regular
time-points. We observed significant changes in the concentration of most fatty acids throughout culture, and differences
in their composition when different sera were used to supplement the medium. Minimal levels of free fatty acids were found
in the cells, indicating a very small “free fatty acid pool”. A major difference between the cells grown in media supplemented
with different sera was the changes observed in concentrations of cellular polyunsaturated fatty acids during growth. In cells
grown with FCS (in which 20∶4n−6 is present), the levels of this acid in the phsopholipid and triacylglycerol fractions declined
rapidly during cell growth, suggesting further metabolism. In cells grown in medium supplemented with HS, 18∶2n−6 was the
major polyunsaturated acid present. There was clear evidence that this acid accumulated in the cellular triacylglycerol and
phospholipid fractions. Furthermore, its concentration did not decline during growth in culture, suggesting minimal conversion
to other polyunsaturated n−6 acids. Our results suggest that fatty acids from additional sources in the medium, for example
triacylglycerols and phospholipids associated with the lipoproteins, are taken up by the cells. There is also indication of
cellular fatty acid synthesis, particularly of monounsaturated and saturated acids during the culture period. HT29/219 cells
were shown to take up and incorporate radioactivity when trace amounts of [1-14C]-labeled arachidonic, linoleic or oleic acids were added to the culture medium. Most (80%) of the label was detected in
cellular phospholipids and triacylglycerols, although the specific activities of these various fatty acids were different
in the two lipid fractions. 相似文献
15.
In this study we determined in rats the complete 24-h lymphatic fatty acid profile after administration of either rapeseed
oil (RO) or rapeseed oil interesterified with 10∶0 (RO/C10) with special emphasis on the transition from absorptive to postabsorptive phase. Rats were subjected to cannulation of the
main mesenteric lymph duct and the next day oils were administered through a gastric feeding tube. Lymph was collected in
1-h fractions for the following 24 h. The time for maximum lymphatic transport of fatty acids was at 4 h with fast changes
in fatty acid composition from the fatty acids of endogenous origin to those of the administered oils. Seven to eight hours
after administration the transport was significantly lower than maximum, indicating the change from absorptive to postabsorptive
phase. At 24 h after administration of either oil the transport of total fatty acids, palmitic acid (16∶0), and linoleic acid
(18∶2n−6) together with oleic acid (18∶1n−9) after RO had not returned to the transport at baseline. In contrast, the transport
of decanoic acid (10∶0) and α-linolenic acid (18∶3n−3) returned to baseline values between 12 and 15 h. This indicated that
the absorption of purely exogenous fatty acids (illustrated by 10∶0 and 18∶3n−3) was complete at 15 h and that the fatty acids
transported between 15 and 24 h were derived mostly from endogenous stores. 相似文献
16.
Fukushima M Ohhashi T Ohno S Saitoh H Sonoyama K Shimada K Sekikawa M Nakano M 《Lipids》2001,36(3):261-266
Hypocholesterolemic effects in older animals after long-term feeding are unknown. Therefore, aged rats (24 wk of age) fed
a conventional diet were shifted to diets containing 10% perilla oil [PEO; oleic acid+linoleic acid+α-linolenic acid; n−6/n−3,
0.3; polyunsaturated fatty acid/saturated fatty acid (P/S), 9.6], borage oil [oleic acid+linoleic acid+α-linolenic acid; n−6/n−3,
15.1; P/S, 5.3], evening primrose oil (FPO; linoleic acid+γ-linolenic acid; P/S, 10.5), mixed oil (MIO; oleic acid+linoleic
acid+γ-linolenic acid+α-linolenic acid; n−6/n−3, 1.7; P/S, 6.7), or palm oil (PLO; palmitic acid+oleic acid+linoleic acid;
n−6/n−3, 25.3; P/S, 0.2) with 0.5% cholesterol for 15 wk in this experiment. There were no significant differences in the
food intake and body weight gain among the groups. The liver weight in the PEO (n−6/n−3, 0.3) group was significantly higher
than those of other groups in aged rats. The serum total cholesterol and very low density lipoprotein (VLDL) +intermediate
density lipoprotein (IDL)+low density lipoprotein (LDL)-cholesterol concentrations of the PLO (25.3) group were consistently
higher than those in the other groups. The serum high density lipoprotein cholesterol concentrations of the PEO (0.3) and
EPO groups were significantly lower than in the other groups at the end of the 15-wk feeding period. The liver cholesterol
concentration of the PLO (25.3) group was significantly higher than those of other groups. There were no significant differences
in the hepatic LDL receptor mRNA level among the groups. Hepatic apolipoprotein (apo) B mRNA levels were not affected by the
experimental conditions. The fecal neutral steroid excretion of the PLO (25.3) group tended to be low compared to the other
groups. The results of this study demonstrate that both n\t-6 fatty acid and n\t-3 fatty acids such as \gg-linolenic acid
and \ga-linolenic acid inhibit the increase of serum total cholesterol and VLDL+IDL+LDL-cholesterol concentrations of aged
rats in the presence of excess cholesterol in the diet compared with dietary saturated fatty acid. 相似文献
17.
The use of a capillary column coated with 100% cyanopropyl polysiloxane (CPTMSil 88) allows the separation of several fatty acids associated with fat deficiency. Starting with liver mitochondrial phospholipids
of weanling rats fed a fat-free diet, an unusual fatty acid was isolated, along with 20∶4n−6, by thin-layer chromatography
on AgNO3-impregnated silica gel plates. After partial hydrazine reduction of these acids, the resulting monoenes were isolated and
subjected to ozonolysis in BF3/methanol. The resulting monomethyl and dimethyl esters were identified by gas chromatography/mass spectrometry. Our data
indicate that the unusual component corresponds to 20∶4n−7. Based on published biochemical and analytical studies and on our
own chromatographic retention data, some of the other unusual fatty acids were tentatively identified as 18∶2n−7, 20∶2n−7
and 20∶3n−7. The CPTMSil 88 column appears to be a simple and useful tool for the separation of fatty acids of the palmitoleate series. 相似文献
18.
Ikuo Ikeda Jun Murakami Takayuki Oka Michihiro Sugano Hideaki Yamada Sakayu Shimizu Hiroshi Kawashima Yoshifumi Shinmen Teruo Amachi 《Lipids》1991,26(1):27-30
The effects of perfused oleic (18∶1n−9), arachidonic (20∶4n−6) and 5,8,11,14-nonadecatetraenoic (19∶4n−5) acids on triglyceride
and cholesterol secretion and ketone body production were studied in isolated rat liver. As compared to oleic and 19∶4n−5
acids, both ketone body production and triglyceride secretion were significantly lowered when arachidonic acid was perfused.
The concentration of triglyceride in the post-perfused liver was lower upon perfusion with arachidonic acid than upon perfusion
with oleic acid or 19∶4n−5 acid. Cholesterol secretion in the liver perfused with arachidonic acid or 19∶4n−5 acid was significantly
higher than with oleic acid. The concentration of cholesterol in the post-perfused liver was slightly but significantly higher
with 19∶4n−5 acid than with the other fatty acids. The results suggest that 19∶4n−5 acid when compared with arachidonic acid
affects lipid metabolism in liver differently. 相似文献
19.
Muscle tissue from the common two-banded sea bream Diplodus vulgaris L. originating from the Adriatic Sea, Croatia, was analyzed. The FA composition of neutral (TAG) and polar (PE, PC, PI/PS)
lipid classes was determined, as well as the lipid and water contents during winter and summer periods. Both the total lipid
and water contents were higher in the winter period. We identified 16 different FA. The major constituents of the total FA
in both seasons were saturates: palmitic (16∶0) and stearic acids (18∶0); monoenes: oleic (18∶1n−9) and palmitoleic acids
(16∶1n−7); and polyunsaturates: arachidonic acid (20∶4n−6), EPA (20∶5n−3), and DHA (22∶6n−3), but their amounts and ratios
differed significantly between the two seasons and between lipid fractions. The FA composition showed a noticeable pattern
of seasonality that reflected fluctuations mainly in TAG. The diminution of the monounsaturated FA content in the summer was
clearly followed by an increase in PUFA content. Diplodus vulgaris is a good source of natural n−3 PUFA and would therefore be suitable for inclusion in highly unsaturated low-fat diets. 相似文献
20.
Lipids of canola seedcoats (Brassica napus L. andB. rapa L.) were prepared by surface washing and by complete extraction of seed coats with toluene. The major fatty acyl-containing
triacylglycerols, wax esters and free fatty acids were separated by thin-layer chromatography prior to transesterification
and analysis by gas-liquid chromatography. The proportion of C18∶1n−7 to C18∶1n−9 was higher in the extracted lipids than
in the surface-washed lipids for all three classes. 相似文献