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1.
Stereospecific analysis of soybeans and related species showed that there was little palmitic or stearic acid on thesn-2-position, and thesn-1-position is consistently richer in palmitic, stearic, and linolenic acids than thesn-3-position. Thesn-3-position is enriched in oleic acid and thesn-2-position with linoleic. Plots of the percentage of fatty acids on the glycerol positions vs. the percentage in the whole
oil revealed a soybean variety that had a deviant distribution that is probably genetically controlled.
Journal Paper No. J-8837 of the Iowa Agriculture and Home Economics Experiment Station, Ames IA. Project No. 2143. 相似文献
2.
Pancreatic lipase hydrolyzed fatty acids in equimolar quantities from thesn-1- and 3-positions of three synthetic enantiomeric triglycerides, two of which could make a racemic pair. The monoglycerides
from digestions of five enantiomeric triglycerides were at least 99% representative of the 2-position. The data confirm that
pancreatic lipase did not distinguish between thesn-1- and 3-positions and that with these triglycerides pancreatic lipolysis can be used to help establish structure.
Scientific contribution No. 419 Agricultural Experiment Station, University of Connecticut, Storrs. 相似文献
3.
W. Van Pee J. Van Hee L. Boni A. Hendrikx 《Journal of the American Oil Chemists' Society》1979,56(10):901-903
The distribution of fatty acids between the sn-1-, sn-2- and sn-3-positions of the triglycerides from the oils of eight African
peanut varieties has been determined. The saturated fatty acids and eicosenoic acid occur almost exclusively at the sn-1-
and sn-3-positions. The sn-1-position contained slightly more palmitic acid than the sn-3-position. The fatty acids with a
chain length exceeding 18 carbons were preferentially incorporated in the sn-3-position. Linoleic acid was preferentially
esterified at the sn-2-position, whereas oleic acid was equally distributed among the three positions. The amount of the saturated
fatty acids, i.e., palmitic and stearic acid, and of oleic acid and linoleic acid incorporated in the sn-1-, sn-2-and sn-3-position,
were each linearly related to their respective content in the triglycerides. 相似文献
4.
Soybeans of the Hawkeye variety were picked at eleven periods from 30 to 111 days after flowering and extracted with chloroform-methanol.
The triglyceride fraction of five pickings, selected 35 to 91 days after flowering (when synthesis of lipid was most active),
were isolated by silicic acid thin layer chromatography (TLC) and species composition determined using argentation TLC and
lipase hydrolysis. The triglyceride content of the total lipid increased from 6.5% at 30 days after flowering to 85% in the
mature bean (111 days). The major changes in fatty acid composition of the triglycerides occurred during the first 52 days
after flowering. During this period linolenic acid decreased from 34.2% to 11.7%, the percentages of linoleic and oleic acids
increased, stearic remained fairly constant and palmitic decreased slightly. Large quantitative changes occurred in the molecular
species of the triglycerides of the bean during maturation; some triglycerides containing linolenic acid could not be detected
approximately 66 days after flowering. Although changes occurred in the percentage and amount of each triglyceride species,
the positional distribution of fatty acids remained virtually unchanged throughout maturation. Linolenic acid was distributed
fairly uniformly between the β-position and the α-positions, linoleate favored esterification in the β-position, and oleate
the α-positions. Most of the stearic and palmitic acids were esterified in the α-positions. The consistency of the positional
arrangement of the fatty acids indicated that the mode of glyceride synthesis was established very early during maturation
and molecular species composition was controlled by the fatty acids available for synthesis. 相似文献
5.
H. S. Murali M. S. Mohan K. S. Manja R. Sankaran 《Journal of the American Oil Chemists' Society》1993,70(10):1039-1041
A few species ofFusarium have been evaluated for their potential to produce lipids. The isolates under investigation exhibited wide variation with
respect to the mycelial weight, total lipid content and percentage composition of polar and nonpolar lipids in which triglycerides
were the major components (81–90%). Palmitic, stearic, oleic and linoleic acids were the major fatty acids in both the fractions.
The polar lipids contained higher levels of linoleic acid, whereas nonpolar lipids contained oleic acid as the predominant
acid. Nonpolar lipids were more saturated than polar lipids. 相似文献
6.
Detailed investigation was made of the triacylglycerol structure of three varieties of peanut oils of varying atherogenic
activity. By means of chromatographic and stereospecific analyses, it was shown that all the oils had markedly nonrandom enantiomeric
structures with the long chain saturated fatty acids (C20−C24) confined exclusively to thesn-3-position, whereas the palmitic and oleic acids were distributed about equally between thesn-1-andsn-3-positions, with the linoleic acid being found preferentially in thesn-2-position. On the basis of detailed studies of the molecular species of the separatesn-1,2-,sn-2,3- andsn-1,3-diacylglycerol moieties, it was concluded that the fatty acids in the three positions of the glycerol molecule are combined
with each other solely on the basis of their relative molar concentrations. As a result, it was possible to calculate the
composition of the molecular species of the peanut oil triacylglycerols (including the content of the enantiomers and the
reverse isomers) by means of the 1-random 2-random 3-random distribution. In general, the three peanut oils possessed triacylglycerol
structures which where closely similar to that derived earlier for a commercial peanut oil of North American origin. Since
their oil has exhibited a high degree of atherogenic potential, it was anticipated that the present oils would likewise be
atherogenic, which has been confirmed by biological testing. However, there are certain differences in the triacylglycerol
structures among these oils, which can be correlated with the variations in their atherogenic activity. The major differences
reside in the linoleic/oleic acid ratios in the triacylglycerols, especially in thesn-2-position, and in the proportions in which these acids are combined with the long chain fatty acids. On the basis of the
characteristic structures identified in the earlier analyzed atherogenic peanut oil, the peanut oil of South American origin
would be judged to possess the greatest atherogenic potential and this has been borne out by biological testing. 相似文献
7.
The pattern of accumulation of triacylglycerols, their fatty acid compositions and the positional distribution of the fatty
acids at thesn-2- andsn-1,3-positions of the triacylglycerol molecules at progressive stages of oil palm fruit development were determined. There
was an exponential rate of increase of triacylglycerols and their fatty acids toward the end of fruit development. The fatty
acid composition of the triacylglycerols in the early stages of development, prior to active accumulation, was more or less
similar, but differed appreciably from the later stages, and the transition of fatty acid composition toward that of normal
palm oil occurred at around 16 wk after anthesis (WAA) and stabilized at 20 WAA. All fatty acids increased in terms of absolute
quantity. There was an overall consistency in fatty acid positional distribution, irrespective of development stage. More
saturated fatty acids were found to be esterified at thesn-1,3-positions and more unsaturated fatty acids at thesn-2-position of triacylglycerol. Higher rate of incorporation of 16:0 at the 1,3-positions during the active phase of triacylglycerol
synthesis was observed, while 18:1 acid exhibited a reverse trend. 相似文献
8.
Phosphatidylcholines and phosphatidylethanolamines were isolated from hepatoma 7288CTC, normal liver, and host liver of rats
fed one of the following diets: fat-free diet; fat-free diet supplemented with safflower oil, safflower oil fatty acids, or
partially hydrogenated safflower oil fatty acids; and commercial chow. Thecis andtrans octadecenoate fatty acids were isolated from the 1- and 2-positions of both phosphoglycerides and analyzed quantitatively
for chain positional isomers. Octadecenoates from hepatoma and liver phosphoglycerides of animals fed fat-free or natural
fatsupplemented diets contained almost exclusively twocis isomers: oleic and vaccenic acids. Oleic acid predominated in the 2-position octadecenoates of both phosphoglycerides from
hepatoma and liver. In contrast, vaccenic acid predominated in the 1-position of normal liver phosphatidylcholine and, to
a lesser extent, phosphatidylethanolamine. Host liver and hepatoma exhibited a shift to a higher percentage of oleic acid
at the 1-position. Dietarytrans fatty acids were incorporated predominately in the 1-position of both phosphoglycerides of hepatoma and liver. Except for
thecis Δ10 octadecenoate isomer, all of the unnatural dietarycis isomers between Δ8 and Δ14 were incorporated into the 1-position of the phospholipids, while the unnaturalcis octadecenoates at the 2-position consisted primarily of the Δ12 isomer. Hepatoma phosphoglycerides contained higher percentages
of thetrans Δ10 isomer that was nearly excluded from the 1-position of the two liver phosphoglycerides. All the othertrans octadecenoate isomers were incorporated into the 1-position of both phosphoglycerides, but the small amount oftrans fatty acids incorporated into the 2-position of liver and hepatoma phosphatidylcholine consisted of four isomers, Δ9 to Δ12,
including the Δ10 isomer. Phosphatidylethanolamine exhibited a similar distribution, except for the presence of the Δ13 and
Δ14 isomers at the 2-position. A combination of evidence suggests that the 1-position fatty acids in phosphatidylcholine and
phosphatidylethanolamine are of similar origin. The octadecenoates at the 2-position of these two phosphoglycerides appear
to be of the same origin in hepatoma but not in liver. It was also revealed that the 2-position of hepatoma phosphatidylcholine
contained much higher percentages of palmitate than liver. 相似文献
9.
Milk triglycerides from the platypus were subjected to fatty acid and stereospecific analysis to determine the positional
distribution of fatty acids in the triglycerides. Of the major fatty acids, 12∶0 was preferentially esterified at thesn-3 position, 14∶0 and 16∶0 were selectively associated with thesn-2 position, and 18∶0 was located predominantly at thesn-1 position. The unsaturated fatty acids, 14∶1, 16∶1, 18∶1, 18∶2 and 18∶3, were preferentially esterified at thesn-3 position. The fatty acid distribution pattern of the platypus, a monotreme, is similar to that of marsupials and eutherians
but is in contrast to the only other extant monotreme, the echidna. 相似文献
10.
Total triglycerides in medium (MEAR) and low (LEAR) erucic acid cultivars of rapeseed were fractionated by argentation chromatography
into twelve and ten fractions, respectively. Gas liquid chromatography of the fatty acids in the triglyceride fractions and
their 2-monoglycerides was used to evaluate the structural characteristics of the individual fractions. Fractionation occurred
on the basis of degree of unsaturation, molecular weight and positional characteristics. The most mobile fractions contained
34–50% of saturated fatty acids while the less mobile had 59–65% of polyunsaturated fatty acids. In the medium erucic acid
oil, long chain fatty acids (C20–C22) were found in all fractions, but four fractions of low erucic acid oil were essentially
free of long chain acids. Two of these fractions in the latter oil, which represented 44% of the total triglycerides, were
glycerol trioleate and dioleoyllinoleoylglycerol. The majority of the 2-positions were occupied by unsaturated C18 fatty acids,
generally in the order of linoleic ≥linolenic> oleic acids. The saturated and long chain fatty acids occurred predominantly
in the 1-and 3-positions. The various fractions of medium and low erucic acid oils were similar in structural composition
except that eicosenoic and erucic acids substituted for oleic acid in some external positions. Erucic acid did not appear
to substitute directly for oleic acid in the 2-position. 相似文献
11.
Mohamed M. Soumanou Uwe T. Bornscheuer Rolf D. Schmid 《Journal of the American Oil Chemists' Society》1998,75(6):703-710
Structured triacylglycerides with medium-chain fatty acids (caprylic acid) in sn1- and sn3-positions and a long-chain unsaturated fatty acid (oleic or linoleic acid) in the sn2-position of glycerol (MLM) were synthesized by lipase catalysis in a two-step process. First, pure 2-monoacylglycerides
(2-MG) were synthesized by alcoholysis of triacylglycerides (triolein, trilinolein, or peanut oil) in organic solvents with
1,3-regiospecific lipases (from Rhizomucor miehei, Rhizopus delemar, and Rhizopus javanicus). The 2-MG were purified by crystallization and obtained in up to 71.8% yield. These 2-MG were esterified in a second reaction
with caprylic acid in n-hexane to form almost pure MLM. For 2-MG obtained from peanut oil, the final product contained more than 90% caprylic acid
in the sn1- and sn3-positions, whereas the sn2-position was composed of 98.5% unsaturated long-chain fatty acids. Reaction conditions for both steps were optimized with
respect to source and immobilization of lipase, water activity, and solvent. 相似文献
12.
Suspension cell cultures of cocoa bean rapidly incorporated palmitic, stearic, oleic and linoleic acids into cellular lipids.
Thus, 75 and 20% of [1-14C] palmitic acid was incorporated into polar lipids and triglycerides, respectively, after 48 hr. When [1-14C] oleic and [1-14C] linoleic acid were added separately, polar lipids consistently contained most of the radioactive fatty acids. Ca. 60% of
the stearic acid accumulated as unesterified fatty acid in the cells. Palmitic and stearic acid were not desaturated, but
oleic acid and linoleic acid were further desaturated. The kinetics of conversion of oleic acid and linoleic acid suggested
a sequential desaturation pathway of 18∶1→18∶2→18∶3 in cocoa bean cell suspensions. 相似文献
13.
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
14.
M. A. Ali M. A. Gafur M. S. Rahman G. M. Ahmed 《Journal of the American Oil Chemists' Society》1985,62(3):520-523
The kernels of 10 different mango varieties were extracted. The physico-chemical characteristics and lipid class composition
of fats were studied. The fat content of mango kernels grown under the soil and climatic conditions of Bangladesh varied from
7.1% to 10%, depending on the variety. The total lipid extracts were fractionated into lipid classes by a combination of column
and thin layer chromatography (TLC). The hydrocarbon and sterol esters varied from 0.3% to 0.7%, triglycerides from 55.6%
to 91.5%, partial glycerides from 2.3% to 4% and free sterol from 0.3% to 0.6%. Free fatty acids amounted to 3.0–37% as oleic;
glycolipids were 0.6–1.2% and phospholipids 0.11–0.8%. The fatty acid composition of triglyceride (TG) fractions was analyzed
by gas liquid chromatography (GLC). Palmitic acid varied from 7.9 molar % to 10.0 molar %, stearic from 38.2% to 40.2%, oleic
from 41.1% to 43.8%, linoleic from 6.0% to 7.6%, linolenic from 0.6% to 1.0% and arachidic acid from 1.7% to 2.6%. TLC revealed
the presence of lyso-phosphatidylcholine, phosphatidylcholine, phosphatidylinositol, phosphatidylethanolamine and phosphatidic
acid in the phospholipid fraction. 相似文献
15.
D. C. Wright W. D. Park N. R. Leopold P. M. Hasegawa J. Janick 《Journal of the American Oil Chemists' Society》1982,59(11):475-479
Developing embryos ofTheobroma cacao ranging in weight from 0.01–2.2 g dry weight, equivalent to 100–180 days postpollination, were analyzed for lipids, alkaloids,
proteins, and anthocyanins. Total lipid, fatty acid, triglyceride, alkaloid, and anthocyanin accumulation increased linearly
after an initial lag with embryo dry weight. Palmitic, stearic, arachidic, and oleic acids had constant rates of accumulation
per micromole of total fatty acid (0.29, 0.27, 0.38, and 0.01, respectively); however, linoleic and linolenic acid accumulation
decreased from 0.2 and 0.02 below 0.2 g dry weight to 0.035 and 0.0035 above 0.2 g dry weight, respectively. Monounsaturated
triglycerides [palmito-oleo-stearin (POS), oleo-distearin (SOS), and oleo-dipalmitin (POP)] continued to accumulate as dry
weight increased but polyunsaturated triglycerides [palmito-diolein (POO), stearo-diolein (SOO), linoleo-dipalmitin (PLP),
and palmito-linoleo-olein (PLO)] ceased to accumulate at about 0.4 g dry weight. Theobromine accumulation increased linearly
with dry weight after an initial lag but the rate differed with cultivar. Caffeine accumulation was low until the final stages
of development. The protein pattern became dominated by 4 protein species with apparent molecular weights of 43, 34, 22, and
14 kDa as embryos matured. 相似文献
16.
Triacylglycerol structure of human colostrum and mature milk 总被引:2,自引:0,他引:2
Jean-Charles Martin Philippe Bougnoux Jean-Michel Antoine Monique Lanson Charles Couet 《Lipids》1993,28(7):637-643
Because triacylglycerol (TAG) structure influences the metabolic fate of its component fatty acids, we have examined human
colostrum and mature milk TAG with particular attention to the location of the very long chain polyunsaturated fatty acid
on the glycerol backbone. The analysis was based on the formation of various diacylglycerol species from human milk TAG upon
chemical (Grignard degradation) or enzymatic degradation. The structure of the TAG was subsequently deduced from data obtained
by gas chromatographic analysis of the fatty acid methyl esters in the diacylglycerol subfractions. The highly specific TAG
structure observed was identical in mature milk and colostrum. The three major fatty acids (oleic, palmitic and linoleic acids)
each showed a specific preference for a particular position within milk TAG: oleic acid for thesn-1 position, palmitic acid for thesn-2 position and linoleic acid for thesn-3 position. Linoleic and α-linolenic acids exhibited the same pattern of distribution and they were both found primarily
in thesn-3 (50%) andsn-1 (30%) positions. Their longer chain analogs, arachidonic and docosahexaenoic acids, were located in thesn-2 andsn-3 positions. These results show that polyunsaturated fatty acids are distributed within the TAG molecule of human milk in
a highly specific fashion, and that in the first month of lactation the maturation of the mammary gland does not affect the
milk TAG structure. 相似文献
17.
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
18.
The lipids of the common house cricket,Acheta domesticus L., have been examined with the following results. The fatty acids associated with the lipid extracts do not change significantly
from the third through the eleventh week of the crickets' postembryonic life. The major fatty acids are linoleic (30–40%),
oleic (23–27%), palmitic (24–30%), and stearic acids (7–11%). There are smaller amounts of palmitoleic (3–4%), myristic (∼1%),
and linolenic acids (<1%). The fatty acid composition of the cricket lipids reflects but is not identical to the fatty acids
of the dietary lipids: linoleic (53%), oleic (24%), palmitic (15%), stearic (3%), myristic (2%), and linolenic acid (2%).
The amount of triglycerides present in the crickets increases steadily from the second through the seventh or eighth week
of postembryonic life, then drops sharply. Other lipid classes, such as hydrocarbons, simple esters, diglycerides, monoglycerides,
sterols, and free fatty acids remain about constant. The composition of the fatty acids associated with the tri-, di-, and
monoglycerides and the free fatty acid fraction are all about the same. The fatty acids associated with the simple esters
are high in stearic acid.
Postdoctoral Research Associate, Department of Chemistry, University of Michigan, 1965–1967. 相似文献
19.
Mohammad R. Sabzalian Ghodratollah Saeidi Aghafakhr Mirlohi 《Journal of the American Oil Chemists' Society》2008,85(8):717-721
Seeds of six safflower (C. tinctorius L.) genotypes and 19 accessions of two wild species were analyzed for oil and fatty acid composition. Oil content ranged
from 29.20 to 34.00, 20.04 to 30.80 and 15.30 to 20.80% in C. tinctorius, C. oxyacantha Bieb. and C. lanatus L., respectively. The main fatty acids of oleic, linoleic, palmitic and stearic acids composed 96–99% of the total fatty acids
in all species. The sum of myristic, palmitoleic, arachidic, and behenic fatty acids in oil of the species ranged from 0.43
to 0.57%. The oleic acid in seed oil of C. tinctorius, C. oxyacantha and C. lanatus ranged from 12.24 to 15.43, 14.11 to 19.28 and 16.70 to 19.77%, respectively. The corresponding ranges for linoleic acid
were 71.05 to 76.12, 63.90 to 75.43 and 62.47 to 71.08%. Palmitic acid in seed oil varied from 5.48 to 7.59% in C. tinctorius, 6.09 to 8.33% in C. oxyacantha and 7.44 to 8.78% in C. lanatus. The stearic acid of the seed oil showed a variation of 1.72 to 2.86, 2.50 to 4.87 and 3.14 to 4.79% in genotypes of these
species, respectively. The fatty acids composition of oil among the cultivated and wild species were not considerably different,
indicating that seed oil of the wild safflower is possibly suitable for human consumption and industrial purposes. 相似文献
20.
Fatty acid composition of Iranian citrus seed oils 总被引:1,自引:0,他引:1
Fatty acid compositions of seed oils from eight Iranian citrus fruits were determined. The ranges of values for major fatty
acids were 21.8–29.4% palmitic, 3.1–7.60% stearic, 0.3–1.3% palmitoleic, 23.5–32.3% oleic, 33.5–39.8% linoleic, and 3.1–7.6%
linolenic. Low amounts (up to 0.1%) of myristic and arachidic acids and traces of a few unidentified ones constituted minor
fatty acids. 相似文献