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1.
Inhibition of cholesterol biosynthesis by organosulfur compounds derived from garlic 总被引:3,自引:0,他引:3
The study was undertaken to test the inhibitory potential on cholesterogenesis of organosulfur compounds derived from garlic.
The primary rat hepatocytes maintained in Dulbecco's modified Eagle's medium were treated with [2-14C]-acetate as substrate for cholesterol synthesis in the presence or absence of test compounds at 0.05 to 4.0 mmol/L. Eleven
watersoluble and six lipid-soluble compounds of garlic were tested. Among water-soluble compounds,S-allyl cysteine (SAC),S-ethyl cysteine (SEC), andS-propyl cysteine (SPC) inhibited [2-14C]acetate incorporation into cholesterol in a concentration-dependnet manner, achieving 42 to 55% maximal inhibition. γ-Glutamyl-S-allyl cysteine, γ-glutamyl-S-methyl cysteine, and γ-glutamyl-S-propyl cysteine were less potent, exerting only 16 to 29% maximal inhibitions. Alliin,S-allyl-N-acetyl cysteine,S-allylsulfonyl alanine, andS-methyl cysteine had no effect on cholesterol synthesis. Of the lipid-soluble compounds, diallyl disulfide (DADS), diallyl
trisulfide (DATS), and dipropyl disulfide (DPDS) depressed cholesterol synthesis by 10 to 25% at low concentrations (0.5 mmol/L),
and abolished the synthesis at high concentrations (1.0 mmol/L). Diallyl sulfide, dipropyl sulfide, and methyl allyl sulfide
slightly inhibited [2-14C]acetate incorporation into cholesterol only at high concentrations. The complete depression of cholesterol synthesis by
DADS, DATS, and DPDS was associated with cytotoxicity as indicated by marked increase in cellular LDH release. There was no
apparent increase in LDH secretion by water-soluble compounds exceptS-allyl mercaptocysteine, which also abolished cholesterol synthesis. Judging from maximal inhibition and IC50 (concentration required for 50% of maximal inhibition), SAC, SEC, and SPC are equally potent in inhibiting cholesterol synthesis. 相似文献
2.
Garlic reduces plasma lipids by inhibiting hepatic cholesterol and triacylglycerol synthesis 总被引:3,自引:0,他引:3
Prompted by the reported hypolipidemic activity of garlic, the present study was undertaken to elucidate the mechanism(s)
underlying the cholesterol-lowering effects of garlic. Rat hepatocytes in primary culture were used to determine the short-term
effects of garlic preparations on [1-14C]acetate and [2-3H]glycerol incorporation into cholesterol, fatty acids and glycerol lipids. When compared with the control group, cells treated
with a high concentration of garlic extracts [i.e., petroleum ether- (PEF), methanol- (MEF) and water-extractable (WEF) fractions
from fresh garlic] showed decreased rates of [1-14C]acetate incorporation into cholesterol (by 37–64%) and into fatty acids (by 28–64%). Kyolic containingS-allyl cysteine and organosulfur compounds inhibited cholesterogenesis in a concentration dependent manner with a maximum
inhibition of 87% at 0.4 mM. At this concentration, Kyolic decreased [1-14C]acetate incorporation into fatty acids by 67%.S-allyl cysteine at 2.0 and 4.0 mM inhibited cholesterogenesis by 20–25%. PEF, MEF and WEF depressed the rates of [2-3H]glycerol incorporation into triacylglycerol, diacylglycerol and phospholipids in the presence of acetate, but not in the
presence of oleate. The results suggest that the hypocholesterolemic effect of garlic stems, in part, from decreased hepatic
cholesterogenesis, whereas the triacylglycerol-lowering effect appears to be due to inhibition of fatty acid synthesis. Primary
hepatocyte cultures as used in the present study have been proven useful as tools for screening the anticholesterogenic properties
of garlic principles. 相似文献
3.
The effects of various unsaturated fatty acids such as oleic (18∶1n−9), linoleic (18∶2n−6) and arachidonic (20∶4n−6) on the
activities of fatty acid synthetase (FAS), malic enzyme (ME), glucose-6-phosphate dehydrogenase (G6PDH) and 6-phosphogluconate
dehydrogenase (6PGDH) all were determined in primary cultures of mouse hepatocytes. Activities of FAS and ME were found to
decrease with time in culture regardless of whether hepatocyte donors were fed diets containing polyunsaturated fatty acid-free
hydrogenated cottonseed oil (HCTO) or corn oil (CO). On the other hand, while G6PDH activity also declined in cultured hepatocytes
obtained from HCTO-fed mice, the activity of this enzyme increased in cells cultured from CO-fed mice. 6PGDH activity was
found to increase in hepatocytes obtained from both diet groups. Neither 18∶2 nor 20∶4 when added to media could alter FAS
or ME activities compared with those observed with either 18∶1-containing or fatty acid-free media. Since lactic dehydrogenase
activity and the rate of incorporation of [3H] leucine into FAS protein were unaltered with time in hepatocyte cultures, the decreased activities of FAS and ME cannot
be attributed to a loss in cell viability during culture but rather appear to be specific for those enzymes which respond
to diet hormones in vivo. Examination of the fatty acid contents of the cells after the culture period showed that the values
for the ratios of 16∶0/16∶1 and of 18∶0/18∶1 were elevated when either 18∶2 or 20∶4 was added to the medium even though there
was no evidence for elongation of the added 18∶2 or for 20∶4 being converted to 22∶4. This result suggest that Δ9-desaturase
activity was inhibited by these polyunsaturated fatty acids and that conversion of 18∶2 to 20∶4 was not required for such
action.
The rate of synthesis determined by the relative rate of incorporation of [3H]leucine into FAS was two to five times higher in hepatocytes prepared from mice fed the HCTO diet than in hepatocytes from
mice fed the CO diet. We have concluded that the mechanisms for long-term regulation may not be contained entirely within
the liver. 相似文献
4.
Ricarda Freke Dr. Björn Heinemann Samuel Edward Hakim Prof. Dr. Claus-Peter Witte Dr. Marco Herde Prof. Dr. Tatjana M. Hildebrandt Prof. Dr. Jakob Franke 《Chembiochem : a European journal of chemical biology》2023,24(10):e202300056
Plants of the genus Allium such as chives, onions or garlic produce S-alk(en)yl cysteine sulfoxides as flavor precursors. Two major representatives are S-propenyl cysteine sulfoxide (isoalliin) and S-propyl cysteine sulfoxide (propiin), which only differ by a double bond in the C3 side chain. The propenyl group of isoalliin is derived from the amino acid valine, but the source of the propyl group of propiin remains unclear. Here, we present an untargeted metabolomics approach in seedlings of chives (Allium schoenoprasum) to track mass features containing sulfur and/or 13C from labeling experiments with valine-13C5 guided by their isotope signatures. Our data show that propiin and related propyl-bearing metabolites incorporate carbon derived from valine-13C5, but to a much lesser extent than isoalliin and related propenyl compounds. Our findings provide new insights into the biosynthetic pathways of flavor precursors in Allium species and open new avenues for future untargeted labeling experiments. 相似文献
5.
The effect of eicosapentaenoic acid (EPA) on fatty acid oxidation and on key enzymes of triglyceride metabolism and lipogenesis
was investigated in the liver of rats. Repeated administration of EPA to normolipidemic rats resulted in a time-dependent
decrease in plasma triglycerides, phospholipids and cholesterol. The triglyceride-lowering effect was observed after one day
of feeding whereas lowering of plasma cholesterol and phospholipids was observed after five days of treatment. The triglyceride
content of liver was reduced after two-day treatment. At that time, increased mitochondrial fatty acid oxidation occurred
whereas mitochondrial and microsomal glycerophosphate acyltransferase was inhibited. The phosphatidate phosphohydrolase activity
was unchanged. Adenosine triphosphate:citrate lyase, acetyl-CoA carboxylase, fatty acid synthetase and glucose-6-phosphate
dehydrogenase were inhibited during the 15 d of EPA treatment whereas peroxisomal β-oxidation was increased. At one day of
feeding, however, when the hypotriglyceridemic effect was established, the lipogenic enzyme activities were reduced to the
same extent in palmitic acid-treated animals as in EPA-treated rats. In cultured rat hepatocytes, the oxidation of [14C]palmitic acid to carbon dioxide and acid-soluble products was stimulated in the presence of EPA. These results suggest that
the instant hypolipidemia in rats given EPA could be explained at least in part by a sudden increase in mitochondrial fatty
acid oxidation, thereby reducing the availability of fatty acids for lipid synthesis in the liver for export,e.g., in the form of very low density lipoproteins, even before EPA induced peroxisomal fatty acid oxidation, reduced triglyceride
biosynthesis and diminished lipogenesis. 相似文献
6.
Schizochytrium sp. is a marine microalga that has been developed as a commercial source for docosahexaenoic acid (DHA, C22∶6 ω−3), enriched
biomass, and oil. Previous work suggested that the DHA, as well as docosapentaenoic acid (DPA, C22∶5 ω−6), that accumulate
in Schizochytrium are products of a multi-subunit polyunsaturated fatty acid (PUFA) synthase (1). Here we show data to support this view and
also provide information of other aspects of fatty acid synthesis in this organism. Three genes encoding subunits of the PUFA
synthase were isolated from genomic DNA and expressed in E. coli along with an essential accessory gene encoding a phosphopantetheinyl transferase (PPTase). The resulting transformants accumulated
both DHA and DPA. The ratio of DHA to DPA was approximately the same as that observed in Schizochytrium. Treatment of Schizochytrium cells with certain levels of cerulenin resulted in inhibition of 14C acetate incorporation into short chain fatty acids without affecting labeling of PUFAs, indicating distinct biosynthetic
pathways. A single large gene encoding the presumed short chain fatty acid synthase (FAS) was cloned and sequenced. Based
on sequence homology and domain organization, the Schizochytrium FAS resembles a fusion of fungal FAS β and α subunits. 相似文献
7.
The suppression of plasma very low density lipoprotein (VLDL) triglyceride levels by dietary fish oils rich in polyunsaturated
n−3 fatty acids has been attributed to decreased hepatic VLDL secretion. To investigate the effect of n−3 fatty acids on lipid
metabolism and VLDL secretion in a tissue culture system, we incubated rabbit hepatocytes with oleic acid and eicosapentaenoic
acid (EPA) and examined [3H]glycerol and [14C]fatty acid incorporation into hepatocyte triglyceride and phospholipid and into media VLDL. Glycerol incorporation studies
showed that EPA failed to stimulate VLDL triglyceride secretion from hepatocytes as occurred with oleic acid (P<0.05). Oleic
acid preferentially enhanced hepatocyte triglyceride synthesis while EPA stimulated significantly phospholipid synthesis (P<0.01).
Varying the relative concentrations of oleic acid and EPA at a constant total fatty acid concentration corroborated preferential
triglyceride synthesis from oleic acid. Synthesis shifted predominantly to phospholipids with increasing concentrations of
EPA and lower levels of oleic acid. Incorporation of the [14C]fatty acids (800 μM) followed similar patterns: 87% of [14C]oleic acid was incorporated into hepatocyte triglyceride and 44% of [14C]EPA was assimilated in hepatocyte phospholipid (p<0.001). Fatty acids at trace concentrations (53 nM) showed a more divergent
pattern of lipid incorporation: 60% of [14C]oleic acid was incorporated into triglyceride while 91% of [14CEPA was incorporated into phospholipid (p<0.001). We conclude that in primary rabbit hepatocyte culture, which appears to
be a useful model to study lipid metabolism and VLDL secretion, EPA is avidly incorporated into phospholipid while oleic acid
predominantly becomes esterified in triglyceride. In addition, EPA, unlike oleic acid, fails to stimulate hepatocyte VLDL
secretion. These divergent effects on hepatocyte lipid metabolism are, at least in part, likely to be responsible for fish
oil induced suppression of plasma triglycerides. 相似文献
8.
The mechanisms behind the hypolipidemic effect of two sulfur-substituted fatty acid analogues, 3-thiadicarboxylic acid and
tetradecylthioacetic acid, have been investigated in cultured hepatocytes. There was a dose-dependent reduction in incorporation
of [3H]water into triacylglycerol and diacylglycerol when tetradecylthioacetic acid was added to rat hepatocytes cultured in the
presence of 200 μM oleic acid. Tetradecylthioacetic acid also increased the oxidation of [14C]palmitic acid compared to oleic acid, inhibited the incorporation of radiolabeled precursors into diacylglycerol to a greater
extent than into triacylglycerol, and reduced the secretion of triacylglycerol more than its synthesis. A stimulation, rather
than a reduction, in glycerolipid synthesis and secretion by tetradecylthioacetic acid was observed when oleic acid was omitted
from the culture medium. When 3-thiadicarboxylic acid was added to cultured hepatocytes, the effects on glycerolipid synthesis
were generally similar to those observed with tetradecylthioacetic acid, but 3-thiadicarboxylic acid did not increase the
oxidation of [14C]palmitic acid. The two fatty acid analogues also had different effects on the synthesis and secretion of cholesterol and
cholesteryl esters—3-thiadicarboxylic acid reduced the incorporation of [3H]water into synthesized and secreted cholesterol and cholesteryl esters, whereas tetradecylthioacetic acid only reduced the
secretion of cholesteryl esters without affecting its synthesis. It is concluded that tetradecylthioacetic acid increases
the oxidation of fatty acids and reduces the synthesis and secretion of glycerolipids. 3-Thiadicarboxylic acid reduces the
synthesis and secretion of both glycerolipids and cholesterol to approximately the same extent without a concomitant increase
in the oxidation of fatty acids. 相似文献
9.
S. C. Cunnane G. Moine S. S. Likhodii J. Vogt T. N. Corso J. T. Brenna H. Demmelmair B. Koletzko K. -H. Tovar G. Kohn G. Sawatzki R. Muggli 《Lipids》1997,32(2):211-217
Our objective was to develop a suitable probe to study metabolism of polyunsaturated fatty acids by 13C nuclear magnetic resonance (NMR) in the suckling rat pup. [3-13C] γ-Linolenic acid was chemically synthesized, and a 20 mg (Experiment 1) or 5 mg (Experiment 2) dose was injected into the
stomachs of 6–10-day-old suckling rat pups that were then killed over a 192 h (8 d) time course. 13C NMR showed that 13C in γ-linolenate peaked in liver total lipids by 12-h post-dosing and that [5-13C]-arachidonic acid peaked in both brain and liver total lipids 48–96 h post-dosing. 13C enrichment in brain γ-linolenic acid was not detected by NMR, but gas chromatography-combustion-isotope ratio mass spectrometry
showed that its mass enrichment in brain phospholipids at 48–96 h post-dosing was 1–2% of that in brain arachidonic acid.
13C was present in liver and brain cholesterol and in perchloric acid-extractable water-soluble metabolites in the brain, liver
and carcass. We conclude that low but measurable amounts of exogenous γ-linolenic acid do access the suckling rat brain in vivo. The slow time course of [5-13C] arachidonic acid appearance in the brain suggests most of it was probably transported there after synthesis elsewhere,
probably in the liver. Some carbon from γ-linolenic acid is also incorporated into lipid products other than n−6 long-chain
polyunsaturated fatty acids. 相似文献
10.
Radioactivity from orally administered radiolabeled dihomo-γ-linolenic acid (20∶3ω6) was recovered from the liver, plasma
and brain lipid fractions. After administration the fatty acid was metabolized to arachidonic acid, the 22 carbon chain length
fatty acid, and was also β-oxidized. However, 22 hr after administration of [1-14C]20∶3 between one-third and one-half of the recovered radioactivity was still associated with dihomo-γ-linolenic acid in
the liver and plasma lipid fractions. Orally administered dihomo-γ-linolenic acid is incorporated into lipid fractions and
is, therefore, available in the metabolic pool for PGE1 synthesis. 相似文献
11.
In vitro cultivated Atlantic salmon (Salmo salar L.), hepatocytes were incubated without or with a mixture of sesamin and episesamin in order to test for possible effects
on lipid metabolism. Sesamin/episesamin exposure (0.05 mM, final concentration) led to increased elongation and desaturation
of 14C 18:3n-3 to docosahexaenoic acid (14C 22:6n-3, DHA, P < 0.01) and down regulated gene expression of Δ6 and Δ5 desaturases compared to control treatment. Sesamin/episesamin further
increased the hepatocytes capacity for fatty acid β-oxidation of 14C 18:3n-3 (P < 0.01) to the 14C acid soluble products, acetate, malate and oxaloacetate, in agreement with an increased gene expression of carnitine palmitoyltransferase
I. Also the gene expression of cluster of differentiation 36 was upregulated and the expression of scavenger receptor type
B, peroxisome proliferator-activated receptors α and γ were downregulated. The amount of triacylglycerols secreted by the
cells tended to be lower in the sesamin/episesamin incubated hepatocytes than the control cells. This study shows that sesamin
has favourable effects on lipid metabolism leading to increased level of DHA, which may be of interest for aquaculture use. 相似文献
12.
目的探讨碳水化合物反应元件结合蛋白(Carbohydrate response element binding protein,ChREBP)在高糖诱导肝细胞脂变中的作用。方法分别以18和25 mmol/L葡萄糖培养L02细胞,以11 mmol/L葡萄糖培养L02细胞作为对照,甘油三酯(TG)含量测定及油红O染色观察细胞脂变程度;免疫荧光观察细胞ChREBP的核转位情况;RT-PCR检测细胞肝型丙酮酸激酶(Liver pyruvate kinase,LPK)基因mRNA的表达水平,Western blot分析细胞脂肪酸合成酶(Fatty acid synthase,FAS)蛋白的表达水平。结果与对照组比较,高糖可使L02细胞内甘油三酯和脂滴含量增加,刺激ChREBP核转位,上调LPK基因mRNA和FAS蛋白的表达水平。结论葡萄糖可能通过其代谢产物经ChREBP-LPK-FAS途径诱导肝细胞脂肪变性。 相似文献
13.
Fatty acid esterification by cell free preparations of bovine mammary tissue was investigated to determine if the type of
long chain fatty acid supplied might influence the rate of triglyceride synthesis by that tissue. Homogenates of lactating
bovine mammary tissue esterified14C-fatty acids into glycerides at rates dependent upon chain length and degree of unsaturation. Palmitic, stearic, oleic and
linoleic acids were esterified at rates consistent with their concentration in milk fat. A comparison of free fatty acid concentrations
of mammary tissue with levels saturating esterification suggested that supply of fatty acids does not limit glyceride synthesis.
Certain combinations of fatty acids were facilitory, competitive or inhibitory to esterification. Stearic acid complimented
esterification of palmitic and oleic acids. Unlabeledtrans-11-octadecenoic acid did not compete with14C-palmitate as efficiently in the esterification process as did unlabeledcis-9-octadecenoic acid, indicating that the mammary gland may preferentially esterify thecis-isomer of C-18∶1. Linoleic acid inhibited esterification of palmitic, stearic and oleic acids.
Michigan Agricultural Experiment Station Journal Article No. 5100. 相似文献
14.
Linoleate is oxygenated by manganese-lipoxygenase (Mn-LO) to 11S-hydroperoxylinoleic acid and 13R-hydroperoxyoctadeca-9Z,11E-dienoic acid, whereas linoleate diol synthase (LDS) converts linoleate sequentially to 8R-hydroperoxylinoleate, through an 8-dioxygenase by insertion of molecular oxygen, and to 7S,8S-dihydroxylinoleate, through a hydroperoxide isomerase by intramolecular oxygen transfer. We have used liquid chromatography-mass
spectrometry (LC-MS) with an ion trap mass spectrometer to study the MSn mass spectra of the main metabolites of oleic, linoleic, α-linolenic and γ-linolenic acids, which are formed by Mn-LO and
by LDS. The enzymes were purified from the culture broth (Mn-LO) and mycelium (LDS) of the fungus Gaeumannomyces graminis. MS3 analysis of hydroperoxides and MS2 analysis of dihydroxy- and monohydroxy metabolites yielded many fragments with information on the position of oxygenated
carbons. Mn-LO oxygenated C-11 and C-13 of 18∶2n−6, 18∶3n−3, and 18∶3n−6 in a ratio of ∼1∶1–3 at high substrate concentrations.
8-Hydroxy-9(10)expoxystearate was identified as a novel metabolite of LDS and oleic acid by LC-MS and by gas chromatography-MS.
We conclude that LC-MS with MSn is a convenient tool for detection and identification of hydroperoxy fatty acids and other metabolites of these enzymes. 相似文献
15.
The ciliate,Tetrahymena, was provided a supplement of the fatty acid [1-14C] 18∶2Δ6,9. After a period of growth the cells were claimed, the lipids extracted, the polar lipids recovered and the mild
alkali-labile fatty acid methyl esters generated. The fatty acids were resolved by high pressure liquid chromatography (HPLC),
the 18∶3Δ6,9,12 (γ-linolenic acid) was recovered and its identity verified by high pressure liquid chromatography (HPLC),
gas liquid chromatography (GLC), hydrogenation and oxidation. Fifty-three percent of the cell-associated label was found in
γ-linolenic acid; thus, a Δ12 fatty acid desaturase converts the 6,9 octadecadienoic acid to the 6,9,12 derivative. No carboxyl
or methyl terminus restriction appears on Δ9 monoenoic or dienoic fatty acid desaturation in this cell as is found in higher
plants and animals. 相似文献
16.
Fei Zhao Ping Xie Jiali Jiang Lingqiang Zhang Wei An Yutao Zhan 《International journal of molecular sciences》2014,15(3):4019-4030
The aim of this study was to determine the effect and mechanism of tamoxifen (TAM)-induced steatosis in vitro. HepG 2 (Human hepatocellular liver carcinoma cell line) cells were treated with different concentrations of TAM for 72 h. Steatosis of hepatocytes was determined after Oil Red O staining and measurement of triglyceride (TG) concentration. The expressions of genes in the TG homeostasis pathway, including sterol regulatory element-binding protein-1c (SREBP-1c), peroxisome proliferator-activated receptor γ (PPARγ), CCAAT/enhancer-binding protein α (C/EBPα), fatty acid synthase (FAS), acetyl-CoA carboxylase (ACC), stearoyl-CoA desaturase (SCD), carnitine palmitoyltransferase 1 (CPT1) and microsomal triglyceride transfer protein (MTP), were examined using quantitative real-time PCR and Western blot analysis. Cell proliferation was examined using the cell counting kit-8 (CCK-8) assay. We found that hepatocytes treated with TAM had: (1) induced hepatocyte steatosis and increased hepatocyte TG; (2) upregulation of SREBP-1c, FAS, ACC, SCD and MTP mRNA expressions (300%, 600%, 70%, 130% and 160%, respectively); (3) corresponding upregulation of protein expression; and (4) no difference in HepG 2 cell proliferation. Our results suggest that TAM can induce hepatocyte steatosis in vitro and that the enhancement of fatty acid synthesis through the upregulations of SREBP-1c and its downstream target genes (FAS, ACC and SCD) may be the key mechanism of TAM-induced hepatocyte steatosis. 相似文献
17.
Highly selective asymmetric synthesis of 2-hydroxy fatty acid methyl esters has been accomplioshed through chiral imide enolates.
Five chiral oleic acid imides were prepared by reaction of oleioc acid with pivaloyl chloride followed by reaction with five
different lithiated chiral oxazolidinones including (R)-(+)-4-benzyl-2-, (S)-(-)-4-benzyl-2-, (4R,5S)-(+)-4-methyl-5-phenyl-2-, (4S,5R)-(-)-4-methyl-5-phenyl-2-, and (R)-(+)-4-isopropyl-2-oxazolidinones in 88–92% yileds. The chiral imides were reacted with NaN(Me3Si)2 at −78°C to give enolates, which subsequently reacted with 2-(phenylsulfonyl)-3-phenyloxaziridine to give hydroxylated products
in 78–83% yields. Methanolysis of the hydroxylated products with magnesium methoxide gave methyl 2-hydroxyoleate. Enantiomeric
excesses (ee) of the products were determined to be very high (98–99% ee) by 1H nuclear magnetic resonance study after esterification of the hydroxy group with (S)-(+)-O-acetylmandelic acid. Enantioselective hydroxylation of other fatty acids including elaidic, petroselinic, vaccenic, and linoleic
was evaluated under the similar conditions using (4R, 5S)-(+)-4-methyl-5-phenyl-2-oxazolidinone as a chiral auxiliary to give 98% ee values for all cases. 相似文献
18.
The effect of the γ-linolenic acid (18:3n-6) residue on the elution of triacylglycerols on a 25% cyanopropyl-25% phenyl-50%
methylpolysiloxane stationary phase was confirmed by using capillary supercritical fluid chromatography-atmospheric pressure
chemical ionization mass spectrometry [cSFC-(APCI)MS]. The general elution rule on this stationary phase is that triacylglycerols
having the same ACN+2n value coeluted (ACN-acyl carbon number and n=combined number of double bonds in the acyl chains). The different effect of γ- and α-linolenic acid residues on the retention
of triacylglycerols and the use of cSFC-(APCI)MS allowed the study of the number of different linolenic acid residue isomer
combinations in triacylglycerols with an identical ACN and degree of unsaturation. Stearidonic acid (18:4n-3) residue was
found to have a similar effect on the retention behavior of triacylglycerols as that of γ-linolenic acid residue. The abundance
of the [M-RCOO]+ ion, formed by the loss of one fatty acid moiety of a triacylglycerol, was found to be clearly higher in the case of γ-isomer
of the linolenic acid than that of α-isomer in the identical regiospecific position. This indicates that the distance of the
double bonds from the glycerol backbone in the acyl chain affects the stability of a triacylglycerol molecule in the (APCI)MS
system. The triacylglycerol composition and the fatty acid combinations of triacylglycerols were found to be almost identical
in black currant (Ribes nigrum) and alpine currant (R. alpinum) seed oils. 相似文献
19.
γ-Linolenic acid containing oils have been found in seed lipids of a number of plants, but are restricted to certain genera
and families,e.g., the Boraginaceae. Some of these oils have found considerable interest for pharmaceutical and dietary use,e.g., borage oil and evening primrose oil in treatment of essential fatty acid and Δ6 desaturase deficiency. Our investigation
of the seed lipids of certain Mongolian and other Ranunculaceae has now shown the presnce of unusual fatty acids, including
considerable amounts (up to 20%) ofγ-linolenic acid in certain species ofAnemone, whereas this acid was found to be absent in other species ofAnemone. A number of other unusual fatty acids are present inA. rivularis but have not yet been identified. The significance of the presence ofγ-linolenic acid, a Δ6 acid, is discussed in relation to δ5 fatty acids that had been reported to occur in the same plant family. 相似文献
20.
Ikuo Ikeda Takayuki Oka Kazunori Koba Michihiro Sugano Marcel S. F. Lie Ken Jie 《Lipids》1992,27(7):500-504
The effects of 5c, 11c, 14c-eicosatrienoic acid (20∶3BSO) and 5c, 11c, 14c, 17c-eicosatetraenoic acid (20∶4BSO), polyunsaturated fatty acids (PUFA) contained inBiota orientalis seed oil (BSO), on lipid metabolism in rats were compared to the effects of fats rich in linoleic acid (LA) or α-linolenic
acid (ALA) under similar conditions. The potential effect of ethyl 20∶4BSO as an essential fatty acid also was examined in
comparison with the ethyl esters of LA. ALA and γ-linolenic acid (GLA). BSO- and ALA-rich fat decreased the concentration
of plasma total cholesterol, high density lipoprotein cholesterol, triglyceride and phospholipid as compared to LA-rich fat.
BSO was more effective in reducing plasma cholesterol concentrations than was the ALA-rich fat. Dietary BSO markedly decreased
the hepatic triglyceride concentration as compared to the LA-rich or ALA-rich fats. Aortic production of prostaglandin I2 tended to decrease in rats fed BSO or ALA-rich fat compared to those fed the LA-rich fat. Adenosine diphosphate-induced platelet
aggregation was similar in the three groups. The proportion of arachidonic acid (AA) in liver phosphatidylcholine (PC) of
rats fed BSO was lowest compared to that of rats fed ALA-rich or LA-rich fats. Administration of 20∶4BSO, ALA or GLA to essential
fatty acid-deficient rats decreased the ratio of 20∶3n−9 to AA in liver PC to the same extent; administration of LA was more
effective. The results indicate that the effects of specific PUFA contained in BSO on lipid metabolism are different from
those of LA and ALA. It is also suggested that 20∶4BSO may exhibit some essential fatty acid effects. 相似文献