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1.
Production of triglycerides enriched in long-chain n-3 polyunsaturated fatty acids from fish oil 总被引:1,自引:0,他引:1
Stephen R. Moore Gerald P. McNeill 《Journal of the American Oil Chemists' Society》1996,73(11):1409-1414
Processes that combine enzymic and physical techniques have been studied for concentrating and separating eicosapentaenoic
acid (EPA) and docosahexaenoic acid (DHA) from fish oil.Candida rugosa lipase was used in hydrolysis reactions to concentrate these acids in the glyceride fraction. By controlling the degree of
hydrolysis, two products have been obtained, one enriched in total n-3(∼50%), the other enriched in DHA and depleted in EPA
(DHA∼40%, EPA∼7%). The glyceride fraction from these reactions was recovered by evaporation and converted back to triglycerides
by partial enzymic hydrolysis, followed by enzymic esterification. Both reactions were carried out withRhizomucor miehei lipase. DHA-depleted free fatty acids from aC. rugosa hydrolysis were fractionated to increase the EPA level (∼30%) and re-esterified to triglycerides by reaction with glycerol
andR. miehei. 相似文献
2.
Gerald P. McNeill Robert G. Ackman Stephen R. Moore 《Journal of the American Oil Chemists' Society》1996,73(11):1403-1407
Lipase hydrolysis was evaluated as a means of selectively enriching long-chain ω3 fatty acids in fish oil. Several lipases
were screened for their ability to enrich total ω-3 acids or selectively enrich either docosahexaenoic acid (DHA) or eicosapentaenoic
acid (EPA). The effect of enzyme concentration, degree of hydrolysis, and fatty acid composition of the feed oil was studied.
Because the materials that were enriched in long-chain ω3 acids were either partial glycerides or free fatty acids, enzymatic
reesterification of these materials to triglycerides by lipase catalysis was also investigated. Hydrolysis of fish oil by
eitherCandida rugosa orGeotrichum candidum lipases resulted in an increase in the content of total ω3 acids from about 30% in the feed oil to 45% in the partial glycerides.
The lipase fromC. rugosa was effective in selectively enriching either DHA or EPA, resulting in a change of either the DHA/EPA ratio or the EPA/DHA
ratio from approximately 1:1 to 5:1. Nonselective reesterification of free fatty acids or partial glycerides that contained
ω3 fatty acids could be achieved at high efficiency (approximately 95% triglycerides in the product) by using immobilizedRhizomucor miehei lipase with continuous removal of water. 相似文献
3.
The intake of fat, saturated and monounsaturated FA (SFA and MUFA), and omega-6 and omega-3 PUFA has been estimated in 641
Belgian women (age 18-39 y). Their food intake was recorded using a 2-d food diary. The PUFA included were linoleic (LA),
alpha-linolenic (LNA), arachidonic (AA), eicosapentaeonoic (EPA), docosapentaenoic (DPA) and docosahexaenoic (DHA) acids.
The mean total fat intake corresponded to 34.3% of total energy intake (E). The mean intake of the FA groups corresponded
to 13.7%, 13.1%, and 6.0% of E, for SFA, MUFA, and PUFA, respectively. The mean intake of LA was 5.3% of E and of LNA was
0.6% of E, with a mean LA/LNA ratio of 8.7. The mean intake of AA was 0.03% of E. The mean intake of EPA, DPA, and DHA was
0.4%, 0.01%, and 0.06% of E, respectively. According to the Belgian recommendations, the total fat and SFA intake was too
high for about three-quarters of the population. The mean LA and overall n-6 PUFA intake corresponded with the recommendation,
with part of the population exceeding the upper level. Conversely, the population showed a large deficit for LNA and n-3 PUFA.
The major food source for LA and LNA was fats and oils, followed by cereal products. The main sources of long-chain PUFA were
fish and seafood, and meat, poultry, and eggs. From a public health perspective, it seems desirable to tackle the problem
of low n-3 PUFA intake. 相似文献
4.
The ratio of n-6 to n-3 polyunsaturated fatty acids in the rat diet alters serum lipid levels and lymphocyte functions 总被引:3,自引:0,他引:3
N. M. Jeffery P. Sanderson E. J. Sherrington E. A. Newsholme P. C. Calder 《Lipids》1996,31(7):737-745
Previous studies have reported that feeding rats diets rich in fish oils, which contain high proportions of the n-3 polyunsaturated
fatty acids (PUFA) eicosapentaenoic and docosahexaenoic acids, results in lowering of blood lipid levels and suppression of
lymphocyte functions testedex vivo andin vivo. The effects of other n-3 PUFA, such as α-linolenic acid, which is found in high proportions in linseed oil, are not as well
documented. Therefore, in the present study, weanling male rats were fed for six weeks on one of five high-fat (20% by weight)
diets made by mixing together sunflower and linseed oils; the resulting blends had n-6/n-3 PUFA ratios of 112.5:1 (pure sunflower
oil), 14.8:1, 6.5:1, 0.8:1, and 0.33:1 (pure linseed oil); the levels of all other components in the diet were identical.
The final body weight and total dissectable fat were lowest in rats fed the pure linseed oil diet. Serum cholesterol, triacylglycerol
and nonesterified fatty acid concentrations decreased as the n-6/n-3 PUFA ratio of the diet decreased. The fatty acid composition
of the serum and of spleen lymphocytes was influenced by the diet fed-there was a progressive decrease in the proportions
of linoleic and arachidonic acids and a progressive increase in the proportion of α-linolenic acid as the n-6/n-3 PUFA ratio
of the diet decreased. Eicosapentaenoic and docosahexaenoic acids were detected in the serum but not in spleen lymphocytes.
Inclusion of α-linolenic acid in the diet resulted in significant suppression of spleen lymphocyte proliferation in response
to the T-cell mitogen concanavalin A and in spleen lymphocyte natural killer cell activity, both measuredex vivo. The localized graft vs. host response, a measure of cellmediated immunityin vivo, progressively decreased as the n-6/n-3 PUFA ratio of the diet decreased. Thus, this study shows that dietary α-linolenic
acid results in lowered blood lipid levels and suppressed lymphocyte functionsex vivo andin vivo. With respect to these effects, α-linolenic acid is as potent as dietary fish oil. 相似文献
5.
A. Grandgirard J. M. Bourre F. Julliard P. Homayoun O. Dumont M. Piciotti J. L. Sebedio 《Lipids》1994,29(4):251-258
During heat treatment, polyunsaturated fatty acids and specifically 18∶3n−3 can undergo geometrical isomerization. In rat
tissues, 18∶3 Δ9c, 12c, 15t, one of thetrans isomers of linolenic acid, can be desaturated and elongated to givetrans isomers of eicosapentaenoic and docosahexaenoic acids. The present study was undertaken to determine whether such compounds
are incorporated into brain structures that are rich in n−3 long-chain polyunsaturated fatty acids. Two fractions enriched
intrans isomers of α-linolenic acid were prepared and fed to female adult rats during gestation and lactation. The pups were killed
at weaning. Synaptosomes, brain microvessees and retina were shown to contain the highest levels (about 0.5% of total fatty
acids) of thetrans isomer of docosahexaenoic acid (22∶6 Δ4c, 7c, 10c, 13c, 16c, 19t). This compound was also observed in myelin and sciatic nerve, but to a lesser extent (0.1% of total fatty acids). However,
the ratios of 22∶6trans to 22∶6cis were similar in all the tissues studied. When the diet was deficient in α-linolenic acid, the incorporation oftrans isomers was apparently doubled. However, comparison of the ratios oftrans 18∶3n−3 tocis 18∶3n−3 in the diet revealed that thecis n−3 fatty acids were more easily desaturated and elongated to 22∶6n−3 than the correspondingtrans n−3 fatty acids. An increase in 22∶5n−6 was thus observed, as has previously been described in n−3 fatty acid deficiency.
These results encourage further studies to determine whether or not incorporations of suchtrans isomers into tissues may have physiological implications.
Presented in part at the 32nd International Conference on the Biochemistry of Lipids, 1991, Granada, Spain.
Delta nomenclature (Δ) is used fortrans polyunsaturated fatty acids to specify the position and geometry of ethylenic bonds. Polyunsaturated fatty acids containingtrans double bonds are abbreviated giving the locations of thetrans double bonds only; e.g., 20∶5 Δ17t 20∶5 Δ5c,8c,11c,14c,17t; 22∶5 Δ19t, 22∶5 Δ7c,10c,13c,16c,19t; 22∶6 Δ19t 22∶6 Δ4c,7c,10c,13c,16c,19t. 相似文献
6.
Preparation of phospholipids highly enriched with n-3 polyunsaturated fatty acids by lipase 总被引:3,自引:0,他引:3
Gudmundur G. Haraldsson Atli Thorarensen 《Journal of the American Oil Chemists' Society》1999,76(10):1143-1149
The immobilized 1,3-regiospecific Rhizomucor miehei lipase (Lipozyme™) was employed to catalyze the transesterification reaction (acidolysis) of 1,2-diacyl-sn-glycero-3-phosphatidylcholine with n-3 polyunsaturated fatty acids under nonaqueous solvent-free conditions. With a concentrate
of 55% eicosapentaenoic acid (EPA) and 30% docosahexaenoic acid (DHA) and pure phosphatidylcholine from egg yolk, phospholipids
of 32% EPA and 16% DHA content were obtained, presumably as a mixture of phosphatidylcholine and lysophosphatidylcholine.
31P nuclear magnetic resonance (NMR) analysis turned out to be a valuable technique to study the details of the reactions involved.
It revealed that when 1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine was transesterified with 98% pure EPA, a substantial amount of hydrolysis side reaction took
place (39%), leading to a product mixture of 39% phosphatidylcholine, 44% lysophosphatidylcholine, and 17% sn-glycerol-3-phosphatidylcholine. The lysophosphatidylcholine constituent comprised 70% EPA, whereas the phosphatidylcholine
component contained 58% EPA. The 31P NMR technique provided valid information about the mechanism of the reaction. It became evident that a high dosage of lipase
containing 5% water afforded optimal conditions for the optimal extent of EPA incorporation into the phospholipids, under
which the extent of hydrolysis side reaction remained relatively high. 相似文献
7.
3-Hydroxy-3-methylglutaryl (HMG)-CoA reductase, the rate-limiting enzyme in cholesterol biosynthesis, catalyzes the formation
of mevalonate which is also required for cell proliferation. Changes in HMG-CoA reductase may mediate the differential effects
of n-3 and n-6 polyunsaturated fatty acids (PUFA) on experimental mammary tumorigenesis, but the mechanisms by which these
fatty acids regulate HMG-CoA reductase are unclear. To determine whether the low density lipoprotein receptor (LDL-R) is required
for this regulation, groups of female LDL-R knockout (−/−) and wild-type (+/+) mice were fed 7% fat diets rich in either n-3
(menhaden oil) or n-6 (safflower oil) PUFA for 1 wk. Dietary PUFA and deletion of the LDL-R had independent effects on HMG-CoA
reductase and serum lipids, and a significant diet-gene interaction was observed. The effects of PUFA on HMG-CoA reductase
in the mammary gland, but not the liver, were mediated by the LDL-R. We also observed that differences in HMG-CoA reductase
and serum LDL-cholesterol, high density lipoprotein cholesterol, and triglycerides between −/− and +/+ mice were dependent
on whether the mice were fed n-3 or n-6 PUFA. Differences between −/− and +/+ mice were much greater when animals were fed
n-6 PUFA rather than n-3 PUFA. These results show that the LDL-R mediates the effects of PUFA on HMG-CoA reductase in the
mammary gland but not the liver. Furthermore, the composition of dietary PUFA profoundly influences the effects of deleting
the LDL-R on HMG-CoA reductase and serum lipids and suggests that diet may influence the phenotype of other knockout or transgenic
animals.
This work was presented in part at the Third Congress of the International Society for the Study of Fatty Acids and Lipids,
June 1–5, 1998, Lyon, France. 相似文献
8.
Enzymatic modification of trilinolein: Incorporation of n-3 polyunsaturated fatty acids 总被引:2,自引:0,他引:2
Casimir C. Akoh Brenda H. Jennings Dorris A. Lillard 《Journal of the American Oil Chemists' Society》1995,72(11):1317-1321
Two immobilized lipases, IM60 fromMucor miehei and SP435 fromCandida antarctica, were used as biocatalysts for the modification of trilinolein with n-3 polyunsaturated fatty acids (PUFA), such as eicosapentaenoic
acid (EPA) and docosahexaenoic acid (DHA), by using their ethyl esters as acyl donors (EEPA and EDHA, respectively). Transesterification
(ester-ester interchange) reactions were carried out in organic solvent. The products were analyzed according to their equivalent
carbon number and polarity by reverse-phase high-performance liquid chromatography, and the fatty acid profiles were determined
by gas-liquid chromatography. Modified triacylglycerol products contained 1 or 2 molecules of n-3 PUFA. With EEPA as the acyl
donor, the total EPA product yields with IM60 and SP435 as biocatalysts were 79.6 and 81.4%, respectively. However, with EDHA
as the acyl donor and IM60 and SP435 as biocatalysts, the total DHA product yields were 70.5 and 79.7%, respectively. Effects
of reaction parameters, such as type of solvent, enzyme load, time course, and molar ratio of substrates on the n-3 PUFA incorporation,
were followed with SP435 as the biocatalyst. High yields were obtained, even in the absence of organic solvent. These lipids
do hold promise for specialty nutrition and other therapeutic uses. 相似文献
9.
Angélica Ganga Susana Nieto Julio Sanhuez Claudio Romo Hernán Speisky Alfonso Valenzuela 《Journal of the American Oil Chemists' Society》1998,75(6):733-736
A simple and relatively inexpensive procedure to obtain 90% eicosapentaenoic acid + docosahexaenoic acid concentrates from
sardine oil involved a two-step winterization of the oil (10 and 4°C), followed by saponification and selective precipitation
of saturated and less unsaturated free fatty acids by an ethanolic solution of urea. Antioxidant effects of butylated hydroxytoluene,
dl-α-tocopherol, and two natural antioxidants, quercetin and boldine, added to the concentrate (0.5% wt/vol), were compared
in the Rancimat at 60°C. dl-α-Tocopherol was unable to inhibit concentrate oxidation. Butylated hydroxyanisole and butylated hydroxytoluene had induction
periods of 1.7–1.8 h compared to the control (1.0 h). A mixture of quercetin + boldine (2:1 w/w) significantly increased the
induction period to 4.5 h. 相似文献
10.
Six oils of marine, algal, and microbial origin were analyzed for stereospecific distribution of component fatty acids. The
general procedure involved preparation ofsn-1,2-(2,3)-diacylglycerols by partial deacylation with ethylmagnesium bromide or pancreatic lipase, separation of X-1,3- andsn-1,2(2,3)-diacylglycerols by borate thin-layer chromatography, resolution of thesn-1,2- andsn-2,3-enantiomers by chiral phase high-performance liquid chromatography following preparation of dinitrophenylurethane derivatives,
and determination of the fatty acid composition by gas chromatography. Unexpected complications arose during a stereospecific
analysis of triacylglycerols containing over 33% of either 20∶4 or 22∶6 fatty acids. Thesn-1,2(2,3)-diacylglycerols made up of two long-chain polyunsaturated acids migrated with the X-1,3-diacylglycerols and required
separate chiral phase resolution. Furthermore, the enzymatic method yieldedsn-1,2(2,3)-diacylglycerols, overrepresenting the polyenoic species due to their relative resistance to lipolysis, but prolonged
digestion yielded correct composition for the 2-monoacylglycerols. The final positional distribution of the fatty acids was
established by pooling and normalizing the data from subfractions obtained by norman- and chiral-phase separation of diacylglycerols.
The molecular species of X-1,3-,sn-1,2- andsn-2,3-diacylglycerol dinitrophenylurethanes were identified by chiral-phase liquid chromatography/mass spectrometry with electrospray
ionization, which demonstrated a preferential association of the paired long-chain acids with thesn-1,2- andsn-2,3-diacylglycerol isomers. 相似文献
11.
Lipase-assisted concentration of n-3 polyunsaturated fatty acids in acylglycerols from marine oils 总被引:1,自引:0,他引:1
Udaya N. Wanasundara Fereidoon Shahidi 《Journal of the American Oil Chemists' Society》1998,75(8):945-951
Preparation of n-3 polyunsaturated fatty acid (PUFA) concentrates from seal blubber oil (SBO) and menhaden oil (MHO) in the
form of acylglycerols was carried out by hydrolysis with a number of commercial microbial lipases. The lipases tested were
Aspergillus niger, Candida cylindracea (CC), Chromobacterium viscosum, Geotrichum candidum, Mucor miehei, Pseudomonas sp., Rhizopus oryzae, and Rhizopus niveus. After lipase-assisted hydrolysis of oils, free fatty acids were removed, and fatty acid composition of the mixture containing
mono-, di-, and triacylglycerols was determined. All lipases were effective in increasing the n-3 PUFA content of the remaining
acylglycerols of both SBO and MHO. The highest concentration of n-3 PUFA was provided by CC lipase; 43.5% in SBO [9.75% eicosapentaenoic
acid (EPA), 8.61% docosapentaenoic acid (DPA), and 24.0% docosahexaenoic acid (DHA)] and 44.1% in MHO (18.5% EPA, 3.62% DPA,
and 17.3% DHA) after 40 h of hydrolysis. Thus, CC lipase appears to be most suitable for preparation of n-3 PUFA in the acylglycerol
form from marine oils. 相似文献
12.
Enrichment of eggs with n-3 polyunsaturated fatty acids: effects of vitamin E supplementation 总被引:1,自引:0,他引:1
Eggs enriched with n−3 polyunsaturated fatty acids (PUFA) could contribute to dietary intake of these healthful fatty acids
(FA). Because n−3 PUFA are highly susceptible to peroxidation, a first part of the study with Leghorn laying hens was carried
out to investigate the influence of different levels of fish oil (0, 0.7, 1.4, 2.8, or 5.6%, respectively) in the diet on
n−3 PUFA, cholesterol, vitamin E, and lipid peroxidation product contents in eggs. Addition of fish oil to a complete diet
based on wheat, rye, tapioca, and soybean constituents containing 11 IU vitamin E/kg resulted in increased n−3 PUFA content
in egg yolk, mainly due to accumulation of docosahexaenoic acid. Cholesterol was not altered up to 2.8% fish oil in the diet.
The vitamin E content of the yolk was insufficient for the protection of PUFA from peroxidation. Addition of up to 2.8% fish
oil to laying hen diets increased the n−3 PUFA content of yolks with a concomitant imbalance between vitamin E and PUFA, leading
to increased levels of cytotoxic aldehydic lipid peroxidation products such as malondialdehyde (MDA). In a second part of
the studies, the balance between vitamin E, PUFA, and lipid peroxidation was analyzed during the period of storage of n−3
PUFA-enriched eggs produced after feeding the laying hens with 1.5% fish oil diets with different concentrations of vitamin
E (0, 5, 10, 20, 40, 80, 160 IU/kg). Storage of eggs resulted in a marked loss of vitamin E in yolk. In stored eggs, the cytotoxic
lipid peroxidation products MDA, 4-hydroxynonenal, and 4-hydroxyhexenal were reduced in response to vitamin E supplementation.
To prevent the increase of cytotoxic aldehydic lipid peroxidation during production and storage of n−3 PUFA-enriched eggs,
a high vitamin E supplementation with at least 80 IU vitamin E/kg is needed. 相似文献
13.
The dietary intake of EFA and long-chain PUFA (LCPUFA) by women with (n=14) and without (n=31) gestational diabetes mellitus (GDM) was determined by repeated 24-h recalls. Women with GDM consumed significantly more
energy as fat compared with women who had uncomplicated pregnancies; absolute dietary fat did not differ. Dietary n−3 LCPUFA
was substantially lower than the current recommendation for pregnancy, whereas intake of saturated FA (SFA) exceeded it. We
conclude that replacing dietary sources of SFA with those of EFA and LCPUFA, especially n−3 LCPUFA, would benefit the dietary
fat profiles of all pregnant women. 相似文献
14.
Long-chain polyunsaturated fatty acids (LCPUFA) are important for normal visual and cortical development. In a previous study
of the effects of LCPUFA on cognitive function of term infants at the age of 3 mon, we indicated that infants with evidence
of reduced growth parameters at birth and impaired attention control as manifested by a late peak fixation during infant habituation
assessment may benefit from LCPUFA supplementation. The aim of this prospective study was to determine whether LCPUFA supplementation
and late peak fixation are related to means-end problem-solving ability in these same infants at the age of 9 mon. Term infants
(58) were randomized to one of two formulas containing either LCPUFA or no LCPUFA and completed 4 mon of feeding with their
formula. Cognitive function was assessed at 3 mon of age by measures of infant habituation. Infants (20 LCPUFA and 20 no-LCPUFA)
completed the problem-solving assessment at 9 mon. The no-LCPUFA group had lower scores on both measures of intention and
number of solutions, but neither of these differences was significant. Analysis of covariance for the effects of group and
peak fixation, covaried with gestation and birth weight, showed that the number of solutions was significantly reduced in
the late peak-fixation infants receiving no LCPUFA (P<0.02). Intention scores tended to be reduced in this group (P<0.06). The late peak-fixation infants who received LCPUFA had solution and intention scores similar to early peak-fixation
infants receiving LCPUFA or no LCPUFA. These findings suggest that in term infants who have reduced growth parameters at birth
and who show evidence of impaired attention control, information processing and problem-solving ability in infancy may be
enhanced by LCPUFA supplementation.
Based on a presentation at the AOCS Meeting on PUFA in Infant Nutrition: Consensus and Controversies, Barcelona, November
7–9, 1996. 相似文献
15.
The presence oftrans fatty acids in human milk may be a concern because of their possible adverse nutritional and physiological effects on the
recipient infant. The mother's diet is the source of human milktrans fatty acids, and since these fatty acids are prevalent in many common foods of the Canadian diet, thetrans fatty acid content and the fatty acid composition of Canadian human milk were measured by gas-liquid chromatography coupled
with silver nitrate-thin layer chromatography. In samples obtained from 198 lactating mothers across Canada, the average percentage
of totaltrans (sum oft18∶1,t18∶2, andt18∶3) was 7.2% of breast milk fatty acids with a range of 0.1–17.2%. Analysis oft18∶1 isomer distribution indicated that partially hydrogenated vegetable oils are the major source of thesetrans fatty acids in human milk, whereas contribution from dairy products appeared to be relatively minor. Linoleci and α-linolenic
acid levels were inversely related to the totaltrans fatty acids, indicating that the elevation oftrans fatty acids in Canadian human milk is at the expense of n-3 and n-6 essential fatty acids. Levels of arachidonic and docosahexaenoic
acids did not correlate with their parent fatty acids, indicating that it might be difficult to elevate the levels of n-6
and n-3 C20–22 polyunsaturated fatty acids in breast milk by increasing levels of linoleic and α-linolenic acids in the mother's diet. 相似文献
16.
For determination of the double-bond position in polyunsaturated C24–30 fatty acids from marine organisms, methoxy derivatives were prepared. Diagnostic mass spectral fragment as well as molecular
ion intensities were obtained by adjusting the ion source optics in the presence of ammonia at a lower source pressure than
used conventionally. A lower detection limit was observed compared to conventional methane chemical ionization, which is a
more favorable condition for capillary gas chromatography. Analysis of fatty acids from the spongeCalyx niceaensis showed the double-bond position of 8 unsaturated fatty acids, including two new ones. In addition, structural proof is provided
for the presence of a new cyclopropane-containing fatty acid: 19,20-methylene-hexacosanoic acid.
“Mass Spectrometry in Structural and Stereochemical Problems 262.” For preceding paper in this series, see Patterson, D.G.,
Haley, M.J., Midgley, J., and Djerassi, C., Org. Mass. Spectrom., submitted for publication.
Recipient of a travel grant from the Queen Wilhelmina Fund, The Netherlands Cancer Foundation 相似文献
17.
Mechanisms for the antiarrhythmic effect of n−3 polyunsaturated fatty acids (PUFA) are currently being investigated using isolated cardiac myocytes. It is still not known whether the incorporation of n−3 PUFA into membrane phospholipids is a prerequisite for its protective action or if n−3 PUFA exert antiarrhythmic effects in their nonesterified form as demonstrated by recent studies. Adult porcine cardiomyocytes were grown in media supplemented with arachidonic acid (AA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). After 24 h, analysis of total lipids showed that the myocytes were enriched with the respective fatty acids compared to control cells. Large proportions of all three fatty acids supplemented (69% AA, 72% DHA, and 66% EPA) remained unesterified. Fatty acid analysis of total phospholipids (PL) revealed that the incorporation of EPA and DHA, though small, was significantly different (P<0.05) from that of the control cells. The PL fraction was further separated into phosphatidylinositol (Pl), phosphatidylethanolamine, phosphatidylcholine, and phosphatidylserine to study the pattern of incorporation of the fatty acids in these fractions. It became apparent that EPA and DHA were selectively incorporated into the Pl fraction. This study demonstrates that in adult porcine cardiomyocytes, the n−3 PUFA supplementation selectively modulates two important lipid fractions, nonesterified fatty acid and Pl, which were implicated in the mechanisms of prevention of cardiac arrhythmias. 相似文献
18.
Progress toward the production of long-chain polyunsaturated fatty acids in transgenic plants 总被引:2,自引:2,他引:0
Long-chain PUFA such as eicosapentaenoic and docosahexaenoic acids are prevalent in fish oils, and these compounds have been
demonstrated to play important roles in human health and nutrition. In particular, these n−3/omega-3 long-chain PUFA provide
protection from cardiovascular disease and a collection of symptoms (termed metabolic syndrome) associated with progression
toward type 2 diabetes and obesity. Within Western populations, a large increase in the occurrence of these conditions represents
a major public health concern. Unfortunately, both marine fish stocks and (consequentially) consumption of fish oils are in
steep decline, limiting the protective role of long-chain PUFA in human health. One alternative approach to the provision
of these health-beneficial FA is via their synthesis in transgenic plants. This review will describe recent advances in the production of transgenic plant oils
nutritionally enhanced to produce long-chain PUFA. 相似文献
19.
Four sources of long-chain polyunsaturated fatty acids (LCP) differing in their chemical structure (triglycerides or phospholipids)
and in their origin (tuna triglycerides, fungal triglycerides, egg phospholipids, and pig brain phospholipids) were analyzed
to determine the distribution of the component fatty acids within the molecule. Lipase and phospholipase A2 hydrolysis was performed to obtain 2-monoacylglycerols and lysophospholipids, respectively, which allowed us to determine
the distribution of fatty acids between the sn-2 and sn-1,3 positions of triglycerides or between the sn-1 and sn-2 position of phospholipids. Fatty acids in the LCP sources analyzed were not randomly distributed. In tuna triglycerides,
half of the total amount of 22∶6n−3 was located at the sn-2 position (49.52%). In fungal triglycerides, 16∶0 and 18∶0 were esterified to the sn-1,3 (92.22% and 91.91%, respectively) 18∶1 and 18∶2 to the sn-2 position (59.77% and 62.62%, respectively), and 45% of 20∶3n−6 and only 21.64% of 20∶4n−6 were found at the sn-2 position. In the lipid sources containing phospholipids, LCP were mainly esterified to the phosphatidylethanolamine fraction.
In egg phospholipids, most of 20∶4n−6 (5.50%, sn-2 vs. 0.91%, sn-1) and 22∶6n−3 (2.89 vs. 0.28%) were located at the sn-2 position. In pig brain phospholipids, 22∶6n−3 was also esterified to the sn-2 (13.20 vs. 0.27%), whereas 20∶4n−6 was distributed between the two positions (12.35 vs. 5.86%). These results show a different
fatty acid composition and distribution of dietary LCP sources, which may affect the absorption, distribution, and tissue
uptake of LCP, and should be taken into account when supplementing infant formulas. 相似文献
20.
Gruppo Italiano per lo Studio della Sopravvivenza nell'Infarto Miocardio (GISSI)-Prevenzione was conceived as a population, pragmatic trial on patients with recent myocardial infarctions conducted in the framework of the Italian public health system. In GISSI-Prevenzione, patients were invited to follow Mediterranean dietary habits, and were treated with up-to-date preventive pharmacological interventions. Long-term n-3 PUFA (1 g daily) but not vitamin E (300 mg daily), was beneficial for death and for combined death, nonfatal myocardial infarction, and stroke. All the benefit, however, was attributable to the decrease in risk for overall, cardiovascular, cardiac, coronary, and sudden death.At variance with the orientation of a scientific scenario largely dominated by the “cholesterol-heart hypothesis”, GISSI-Prevenzione results indicate n-3 PUFA (virtually devoid of any cholesterol-lowering effect) as a relevant pharmacological treatment for secondary prevention after myocardial infarction.As to the relevance and comparability of GISSI-Prevenzione results, up to 5.7 lives could be saved every 1000 patients with previous myocardial infarction treated with n-3 PUFA (1 g daily) per year. Such a result is comparable to that observed in the Long-Term Intervention with Pravastatin in Ischaemic Disease (LIPID) trial, where 5.2 lives could be saved per 1000 hypercholesterolemic, coronary heart disease patients treated with pravastatin for 1 yr.The choice of a relatively low-dose regimen (1-g capsule daily) more acceptable for long-term treatment in a population of patients following Mediterranean dietary habits, and the pattern of effects seen in GISSI-Prevenzione (namely, reduction of overall mortality with no decrease in the rate of nonfatal myocardial infarction) all strongly suggest that n-3 PUFA treatment should be considered a recommended new component of secondary prevention. The importance of this combined/additive effect is further suggested by the analyses of the interplay between diet and n-3 PUFA: There is an interesting direct correlation between size of the effect and “correctness” of background diets. It can be anticipated that a conceptual barrier must be overcome: A “dietary drug” should be added to “dietary advice”, which remains fundamental to allow this statement to become true in clinical practice. 相似文献