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1.
Randall Wood 《Lipids》1979,14(12):975-982
The percentage distribution of the geometrical and positional isomers in the hexadecenoates and octadecenoates isolated from
triglycerides, phosphatidylcholines, and phosphatidylethanolamines of brain, heart, kidney, liver, lung, muscle, spleen, and
adipose tissues from rats maintained four weeks on a semipurified diet supplemented with 15% partially hydrogenated safflower
fatty acids, has been determined. Except for brain, octadecenoate percentages were increased in each of the lipid classes
of all the tissues by the dietary fat. Although the diet did not contain detectable hexadecenoates, the 16∶1 fraction from
the lipid classes of all the tissues was composed of 10–70% of thetrans isomers, indicating chain shortening of the dietary octadecenotes. Distribution ofcis andtrans positional isomers in triglyceride hexadecenoates was approximately the same in all tissues. Relatively high percentages
of the Δ9, Δ10, and Δ11 isomers were observed, but the Δ8 was the predominatingtrans hexadecenoate isomer, indicating preferential chain shortening of thetrans δ10 octadecenoate.Trans octadecenoates were found in all tissues, but concentrations were dependent on tissue and lipid class. The distribution of
thecis andtrans octadecenoate isomers was similar in all the tissue triglycerides, with the distribution of thetrans isomers resembling the diet. In contrast, the percentage distribution of thetrans octadecenoates in the phospholipid classes differed dramatically from the diet, and the distribution was dependent on both
the tissue and lipid class. The Δ12, Δ13, and Δ14trans octadiet, suggesting an accumulation of these isomers. Although thecis Δ10 octadecenoate was a significant dietary component, this isomer was not incorporated significantly into any lipid class
of any tissue. The metabolic fate of this isomer remains unknown. 相似文献
2.
The effect of dietary cyclopropene fatty acids on the concentration of octadecenoate chain positional isomers in individual
lipid classes of normal liver, host liver, and hepatoma 7288CTC has been determined. The data revealed the following: (a)
Saturated and monoene fatty acid percentages of liver phosphatidylcholines and phosphatidylethanolamines werenot affected, but the percentage of saturated fatty acids of the triglycerides and cholesteryl esters was increased while the
monoene percentages decreased. (b) Oleate to vaccenate percentage ratios, previously shown to be characteristic of individual
lipid classes, were completely disrupted. (c) Oleate concentrations of the two major liver phospholipids were elevated, and
vaccenate levels were dramatically reduced. (d) Cyclopropene fatty acids appear to inhibit monoene elongation. (e) The elevated
concentrations of oleate indicate that an alternate route of oleate biosynthesis must exist if the Δ9 desaturation is inhibited
by cyclopropene fatty acids as reported previously. (f) In contrast to liver, oleate and vaccenate concentrations in hepatoma
were not affected by the dietary cyclopropene fatty acids. 相似文献
3.
Enzymatic synthesis of high-purity structured lipids with caprylic acid at 1,3-positions and polyunsaturated fatty acid at 2-position 总被引:2,自引:0,他引:2
Akiko Kawashima Yuji Shimada Miwa Yamamoto Akio Sugihara Toshihiro Nagao Sadao Komemushi Yoshio Tominaga 《Journal of the American Oil Chemists' Society》2001,78(6):611-616
We attempted to synthesize high-purity structured triacylglycerols (TAG) with caprylic acid (CA) at the 1,3-positions and
a polyunsaturated fatty acid (PUFA) at the 2-position by a two-step enzymatic method. The first step was synthesis of TAG
of PUFA (TriP), and the second step was acidolysis of TriP with CA. Candida antarctica lipase was effective for the first reaction. When a reaction medium of PUFA/glycerol (3∶1, mol/mol) and 5% immobilized Candida lipase was mixed for 24 h at 40°C and 15 mm Hg, syntheses of TAG of γ-linolenic, arachidonic, eicosapentaenoic, and docosahexaenoic
acids reached 89, 89, 88, and 83%, respectively. In these reactions, the lipase could be used for at least 10 cycles without
significant loss of activity. In the second step, the resulting trieicosapentaenoin was acidolyzed at 30°C for 48h with 15
mol parts CA using 7% of immobilized Rhizopus delemar lipase. The CA content in the acylglycerol fraction reached 40 mol%. To increase the content further, the acylglycerols were
extracted from the reaction mixture with n-hexane and were allowed to react again with CA under conditions similar to those of the first acidolysis. After three successive
acidolysis reactions, the CA content reached 66 mol%. The content of dicapryloyl-eicosapentaenoyl-glycerol reached 86 wt%
of acylglycerols, and the ratio of 1,3-dicapryloyl-2-eicosapentaenoyl-glycerol to 1(3),2-dicapryloyl-3(1)-eicosapentaenoyl-glycerol
was 98∶2 (w/w). In this reaction, the lipase could be used for at least 20 cycles without significant loss of activity. Repeated
acidolysis of the other TriP with CA under similar conditions synthesized 1,3-dicapryloyl-2-γ-linolenoyl-glycerol, 1,3-dicapryloyl-2-arachidonoyl-glycerol,
and 1,3-dicapryloyl-2-docosahexaenoyl-glycerol in yields of 58, 87, and 19 wt%, respectively. 相似文献
4.
P. Van Der Plank 《Journal of the American Oil Chemists' Society》1972,49(8):489-493
A simple method is described to evaluate gas chromatograms of mixtures containing aldehydes and aldehydic esters obtained
by ozonolysis of mixtures of positional isomers of methyl octadecenoate. The evaluation is based on the assumption that the
process of ozonolysis and the subsequent reduction of the ozonides is independent of the double bond position. This implies
the formation of equivalent amounts of aldehydes and aldehydic esters, which results in certain ratios between the values
of gas chromatographic peak areas of degradation products from the same molecule. These ratios can be calculated for a flame-ionization
detector. Peak area values of partly or completely fused peaks can then easily be corrected. 相似文献
5.
采用气相色谱法对1-(2-溴乙氧基)-4-硝基苯异构体混合物进行分离和测定,比较了4种不同固定液毛细管柱的分离效果,发现该类异构体在非极性色谱柱上分离度较好,达到基线分离;采用峰面积归一化法定量,相对标准偏差在0.46%-1.13%。 相似文献
6.
The effects of dietary cis and trans α-linolenic acid (18∶3n−3) on the FA composition of plasma, red blood cell, and liver phospholipids were studied in newborn
piglets. Animals were fed for 14 d with one of three diets: a control diet (group A) containing cis 18∶3n−3 at a level of 2.0% of total FA, a diet (group B) in which a part of the 18∶3n−3 acid was isomerized (1.3% of cis 18∶3n−3 and 0.7% of trans 18∶3n−3), or a diet (group C) with 2.0% cis 18∶3n−3 and 0.7% trans 18∶3n−3. Feeding animals with diets containing trans 18∶3n−3 resulted in the presence of trans isomers of 18∶3n−3, trans isomers of EPA, and trans isomers of DHA in phospholipids; however, the level of total trans n−3 PUFA in tissues was less than 0.3% of total tissue FA. In group B, the reduction of dietary amounts of cis 18∶3n−3 was associated with a decrease in individual and total cis n−3 PUFA. In contrast, in group C there was no decrease in tissue n−3 PUFA despite the increased dietary level of trans 18∶3n−3. These results suggest that the isomerization of a part of dietary n−3 PUFA, leading to the reduction of their levels
in the diet, could induce a decrease in n−3 PUFA in phospholipids. The physiological effects of trans PUFA are not known and should be considered in future studies. 相似文献
7.
The activity of Δ9 desaturase was determined in the microsomal fraction of normal mouse liver and hepatoma SS1K in the presence
of the 105,000 × g supernatant. Neither hepatic nor hepatoma soluble fractions were able to modify the low desaturating capacity.
Two enzymes from the microsomal electron transport chain associated with Δ9 desaturase, namely NADH-cytochrom b5 reductase and NADH-cytochrome C reductase were also measured. The results indicate that the low Δ9 desaturase activity in
hepatoma SS1K could be related to the reduced amount of desaturase. 相似文献
8.
以吡咯为原料,经Vilsmeier—Haeeh反应合成2-乙酰基吡咯,再用碘甲烷进行甲基化得到1-甲基-2-乙酰基吡咯。所得产物的化学结构经红外光谱,核磁共振氢谱得到了证实。此合成方法操作简便,收率较高。 相似文献
9.
Under similar hydrothermal synthetic conditions using a novel flexible ligand 2-(3-(pyridin-2-yl)-1H-pyrazol-1-yl)acetonitrile (PPAN), benzenedicarboxylate isomers (H2pa = phthalate, H2ip = isophthalate, and H2tp = terephthalate) and Cadmium(II) acetate, three novel mixed-ligand Cd(II) coordination polymers {[Cd2(PPAA)2(μ-pa)(H2O)]·2H2O}n (1), {[Cd4(PPAA)4 (μ4-ip)2]·2H2O}n (2) and {[Cd2(PPAA)2(μ-tp)]·2H2O}n (3) (PPAA− = 2-(3-(pyridin-2-yl)-1H-pyrazol-1-yl) acetate) have been isolated, in 1–3 PPAN, and are also hydrolyzed into a novel PPAA− ligand. Complex 1 is a 1D coordination polymer in which the tetra-nuclear [Cd4(PPAA)4]4 + structural units are extended by tri-dentate μ-pa2 − ligands. Complex 2 contains binuclear [Cd2(PPAA)2]4 + structural units, which are extended by four tetra-dentate μ4-ip2 − ligands to link eight neighboring binuclear [Cd2(PPAA)2]4 + units ultimately forming a 2D layered framework, while complex 3 contains 1D double chain containing [Cd(PPAA)]n cation structural units, which are further extended by tetradentate μ-tp2 − ligands to form a new 2D layered framework. All the complexes have been investigated by elemental analysis, FT-IR, thermal analysis and fluorescence characterization. The flexible coordination modes of PPAA− are also briefly analyzed. The flexible coordination modes of PPAA− and benzenedicarboxylate isomers also reveal great potential in the construction of these novel mixed-ligand luminescent frameworks with diverse structural motifs and unique functional properties. 相似文献
10.
L. Ulmann J. P. Blond C. Maniongui J. P. Poisson G. Durand J. Bézard G. Pascal 《Lipids》1991,26(2):127-133
The combined effects of age and dietary n−6 and n−3 fatty acids were studied in 3-, 6- and 9-month-old rats. At each age,
two groups were fed diets containing 5% (w/w) of vegetable oils rich in either 18∶3n−6 (borage group) or 18∶3n−6 plus 18∶4n−3
(black currant group), for a period increasing with age. A control group was fed the essential fatty acids 18∶2n−6 and 18∶3n−3
only. For each group, Δ6, Δ5 and δ9 desaturase activities were measured in liver microsomes, and fatty acid composition was
determined in microsomal phospholipids. Desaturase activity varied as a function of age and dietary lipids. Δ6 Desaturation
of 18∶3n−3 was more sensitive to these factors while Δ6 desaturation of 18∶2n−6 and Δ9 desaturation were more dependent on
season than the other two. Desaturase activity was influenced more by the black currant than by the borage diet, especially
at 6 and 9 months of age. A large proportion of arachidonic acid was maintained in the microsomes independent of the diet.
Changes in the fatty acid composition did not strictly reflect the differences in desaturase activities. The effects of the
two factors (age and diet) on the activities of the desaturases are complex, suggesting that the enzymes are susceptible to
other factors as well. 相似文献
11.
12.
Endometria from nonpregnant and 6-day pregnant rabbits and from humans in the proliferative and secretory phases were incubated
with 1-14C-acetate.14CO2 was collected, and subsequently the amounts, specific radioactivities, and in some cases the fatty acid compositions of the
isolated phospholipids were determined. Phosphatidyl choline was the phospholipid present in highest amount in endometria
from both nonpregnant and pregnant rabbits, and in human endometria; this phospholipid also showed the highest degree of incorporation
of14C-acetate. Pregnancy in the rabbit seemed to decrease the incorporation of14C-acetate into most of the endometrial phospholipid classes. In humans, the incorporation of acetate into phosphatidyl choline
and phosphatidyl ethanolamine was lower in the secretory than the proliferative endometria.
Of the fatty acids, linoleic acid in phosphatidyl choline and phosphatidyl ethanolamine of the rabbit endometria showed a
significant relative increase during pregnancy and palmitoleic acid showed a decrease.
This investigation was supported by a grant from the Ford Foundation. 相似文献
13.
14.
Human serum lipid and lipoprotein concentrations and compositions were compared in ten healthy middle-aged men consuming phospholipids
from egg or from soybean or triacylglycerol mixtures with fatty acid compositions similar to those of the phospholipids. All
subjects followed each of the four treatments: egg phospholipids (EP), soybean phospholipids (SP), an oil of fatty acid composition
similar to that of EP, and an oil similar in fatty acid composition to SP for six weeks with “wash-out” periods of similar
duration between treatment periods. The phospholipids, 15 g/d, and the oils, 12 g/d, which contained approximately equivalent
quantities of fatty acids were provided to the subjects in gelatin capsules and were taken before meals. Diet intake was monitored
by three-day food records. Serum lipoproteins (Lp) were separated by ultracentrifugation into very low density lipoproteins, low density lipoproteins (LDL), high density lipoproteins
(HDL)2 and HDL3. Lp fractions and whole serum were analyzed for triacylglycerols, cholesterol (CH), phospholipids (PL), and protein. HDL cholesterol
was determined in while serum. Cholesteryl esters were determined in some Lp fractions. Lipid compositions of Lp were expressed in mmol/g protein. Apoprotein B was measured in whole serum and in LDL; apoprotein A-I in whole serum and
in HDL3. In whole serum, CH and PL were significantly lower after the SP compared to EP treatment periods. CH, but not PL, was lower
after SPTG compared to EP. CH in HDL2 was significantly higher after SP compared to SPTG. Also, PL in HDL2 were significantly higher after SP compared to all other treatments and to baseline. Although human serum lipid responses
to dietary phospholipids were generally the same as responses to ingested oils of comparable fatty acid composition, the data
suggest the possibility that SP selectively increase HDL2 cholesterol and phospholipids. 相似文献
15.
The online version of the original article can be found at 相似文献
16.
The aim of the study was to determine major triacylglycerols (TG), and sn-1(3) and sn-2 isomers of butyryl and caproyl TG in butteroil (BO) and interesterified butteroil (IBO) by gas-liquid chromatography (GLC) and silver ion column chromatography. Altogether, 112 molecular species of TG were synthesized by interesterification and their retention indices were determined. Molar empirical correction factors for TG were determined using linear calibration. Retention indices showed that sn-1(3) and sn-2 isomers of the TG containing one short-chain acyl (butyrate, caproate) and two long-chain acyls (lauroate, myristate, palmitate, stearate, and oleate) were separated on a phenyl (65%) methylsilicone column. The difference between retention indices of 1(3)- and 2-short-chain acyl isomers ranged from 14 to 19, and from 9 to 16 for butyrates and caproates, respectively. The proportion of sn-2 isomers of butyrates averaged 1.4%, but only traces of sn-2 isomers of caproates were detected in butteroil. The ratio of sn-1(3)- to sn-2-butyrates and caproates in interesterified butteroil averaged 2.0:1. The most abundant molecular species of mono-short-chain TG in butteroil were BPP + BMS (5.6 mol%), BPO + BSPo (4.8 mol%), BMP + BLaS (3.4 mol%), BMO + BPPo (2.7 mol%), BPS (2.5 mol%), and CoPP + CoMS (2.3 mol%). 相似文献
17.
H. V. Tumer R. O. Feuge T. L. Ward E. R. Cousins 《Journal of the American Oil Chemists' Society》1964,41(6):413-415
Olive oil was hydrogenated to an iodine value (I.V.) of ca. 50 under widely differeing operating conditions. Three types of
catalyst were employed. Each catalyst was used at the lowest possible operating temp and at 170C. The hydrogenated samples
were subjected to lipase hydrolysis to remove a portion of the acyl groups in the 1,3-positions, and the fractions obtained,
as well as the unhydrolyzed samples, were analyzed for fatty acid composition and content oftrans mononenes. From these data it was concluded that the position of the oleoyl group in the triglyceride molecule is not a factor
in the rate of hydrogenation or isomerization.
A laboratory of So. Utiliz. Res. and Dev. Div., ARS, USDA. 相似文献
18.
The lipid fatty acid pattern of normal liver, host liver, and Novikoff hepatoma was determined by gas liquid chromatography,
and Δ6-desaturase activity for linoleic acid was measured in the microsomal fractions. The results showed that, in Novikoff
hepatoma, there is a correlation between the low content of arachidonic acid and the low activity of Δ6-desaturase, a key
enzyme in the biosynthetic pathway of this acid. 相似文献
19.
20.
Geometric and positional isomers of [1-14C] octadecenoic acids have been synthesized by modifications of published procedures. Positional isomers of octadecynoic acids
also have been synthesized to obtain the geometric and positional isomers of the unlabeled octadecenoic acid analogs. The
syntheses were accomplished by coupling a haloalkyl compound with a substituted acetylene using n-butyl lithium in hexamethylphosphoramide.
The coupled product, either a 17-or 18-carbon acetylenic alcohol, could be semihydrogenated and chain extended to afford a
carboxy labeled derivative, could be partially hydrogenated and chain extended to afford a carboxyl labeledcis-ortrans-octadecenoic acid in the former case. In the latter case, octadecynoic,cis-octadecenoic ortrans-octadecenoic acids could be obtained by the appropriate reactions. The methods used in this study enabled the synthesis of14C-labeled fatty acids in generally higher yields and by simpler reactions than were previously possible. 相似文献