共查询到20条相似文献,搜索用时 15 毫秒
1.
Triacylglycerols of Finnish winter butterfat containing one saturated and two monoenoic fatty acyl residues were studied.
With silver ion high-performance liquid chromatography (HPLC), molecules were separated according to the difference in the
configuration of one fatty acyl moiety. The distribution of the saturatedcis,trans-dimonoenoic and saturatedcis,cis-dimonoenoic triacylglycerols according to their acyl carbon numbers was compared by means of reversed-phase HPLC and tandem
mass spectrometry. Furthermore, two examples of the fatty acid composition of a specified molecular weight species were shown.
The fatty acid compositions of corresponding saturatedcis,trans-dimonoenoic and saturatedcis,cis-dimonoenoic triacylglycerols were similar; however, there may be differences in the proportions of different fatty acid combinations
or in the distribution of fatty acids between primary and secondary glycerol positions. 相似文献
2.
The triacylglycerols of winter butterfat were fractionated according to the type and degree of unsaturation into six fractions
by silver ion high-performance liquid chromatography (Ag-HPLC). The acyl carbon number distribution of the triacylglycerols
in each fraction was elucidated by reversed-phase HPLC and mass spectrometry (MS). The MS analysis of each fraction gave deprotonated
triacylglycerol [M - H]− ions which were produced by chemical ionization with ammonia. The daughter spectrum of each of the [M - H]− ions provided information on its fatty acid constituents. Successful fractionation of triacylglycerols differing in the configuration
of one fatty acyl residue by Ag-HPLC was important because geometrical isomers could not be distinguished by the MS system
used. In addition to the fatty acid compositions, reversed-phase HPLC analysis demonstrated the purity of the collected fractions:
molecules having acis-trans difference were separated nearly to the baseline. Triacylglycerols differing in the configuration of one fatty acyl residue
were not equally distributed in relation to their acyl carbon numbers. This indicates that during the biosynthesis of triacylglycerols,cis- andtrans-fatty acids are processed differently. Although the fatty acid compositions of the corresponding molecular weight species
of disaturatedtrans- and disaturatedcis-monoenoic triacylglycerols were similar, there may be differences in the amounts of different fatty acid combinations or
in the distribution of fatty acids between the primary and secondary glycerol positions. In addition to the main components,
it was possible to analyze minor triacylglycerols, such as molecules containing one odd-chain fatty acid, by the MS system
used. 相似文献
3.
A. B. Imbs N. V. Nevshupova L. Q. Pham 《Journal of the American Oil Chemists' Society》1998,75(7):865-870
The triacylglycerol (TG) composition of Pinus koraiensis seed oil, which contains Δ5 nonmethylene-interrupted (NMI) fatty acids (FA) (the main acid is pinolenic, 18:3 Δ5, 9, 12),
was determined. TG were preliminarily separated by argentation thin-layer chromatography (TLC), and the obtained fractions
were analyzed by high-temperature gas chromatography (GC) on a capillary column with methyl phenyl silicone phase. Additionally,
high-performance liquid chromatography (HPLC) of TG was applied. The FA composition of all TG fractions was identified. The
identification of TG was carried out by combining TLC, GC, HPLC, and calculated equivalent carbon numbers of TG standards.
The TG species identification was confirmed by comparison of the theoretical recalculated and directly analyzed FA compositions
of all TLC fractions of TG. Species of TG with unsaturation degrees of 1 to 7 and trace amounts of saturated and octaenoic
TG species were found. Except for minor compounds, 26 TG molecular species of 32 main components were quantitatively determined.
The main species were oleoyl dilinoleoylglycerol (14.7%), dilinoleoyl pinolenoylglycerol (10.7%), palmitoyl oleoyl linoleoylglycerol
(8.3%), triolein (7.6%), and dioleoyl, linoleoylglycerol (7.4%). Seven TG species contained Δ5 NMI acyl groups. Of these,
the major were dilinoleoyl pinolenoyglycerol (10.7%), stearoyl linoleoyl pinolenoylglycerol (6.5%) dioleoyl, pinolenoylglycerol
(5.4%), and palmitoyl linoleoyl pinolenoyl-glycerol (5.5%). TG species with two or three NMI acyl groups were not detected. 相似文献
4.
Päivi Laakso 《Journal of the American Oil Chemists' Society》1997,74(10):1291-1300
Triacylglycerols of oils rich in α- and/or γ-linolenic acids were analyzed by reversed-phase high-performance liquid chromatography
(HPLC) coupled with atmospheric pressure chemical ionization mass spectrometry [(APCI)MS]. The (APCI)MS spectra of most triacylglycerols
exhibited [M + H]+ and [M - RCOO]+ ions, which defined the molecular weight and the molecular association of fatty acyl residues, respectively. Reversed-phase
HPLC resulted in, at least, partial separation of triacylglycerols containing α- and/or γ-linolenic acid moieties. Molecules
containing α-linolenic acid residues exhibited a relatively weaker retention by the stationary phase than the corresponding
molecules containing γ-linolenic acid residues. Good separation of triacylglycerols of cloudberry seed oil, evening primrose
oil, borage oil, and black-currant seed oil was achieved. The molecular species identification of separated components was
based on the (APCI)MS data as well as on the elution properties of triacylglycerols on reversed-phase HPLC. This study demonstrated
the efficiency of HPLC-(APCI)MS in determining the molecular species compositions of triacylglycerols in complex natural mixtures.
Good quality mass spectra could be extracted even from minor chromatographic peaks representing 0.2% or less of the total
triacylglycerols. 相似文献
5.
Jeung Hee Lee Kerby C. Jones Thomas A. Foglia Alberto Nuñez Jong Ho Lee Yu Mi Kim Phuong-Lan Vu Ki-Teak Lee 《Journal of the American Oil Chemists' Society》2007,84(3):211-217
Using a 1,3-regioselective lipase as a catalyst, soybean oil and olive oil were interesterified with the short-chain triacylglycerol
tributyrin (1,2,3-tributyrylglycerol) to produce mixtures of structured triacylglycerols (SL-TAG). The SL-TAG were purified
by column chromatography and analyzed by both normal-phase (silica column; NPSIL) and reversed-phase [octadecyl silane (ODS) column] high-performance liquid chromatography (HPLC). Individual SL-TAG molecular
species were detected by evaporative light-scattering detection, and characterized by mass spectrometry. NPSIL HPLC successfully separated the newly synthesized SL-TAG into two groups of TAG: one composed of one butyryl group and two
long-chain fatty acyl groups (from soybean or olive oil); the second was composed of two butyryl groups and one long-chain
fatty acyl group. The SL-TAG species were further analyzed by reversed-phase HPLC which gave a more detailed separation of
the TAG species present in the two SL-TAG. 相似文献
6.
Boryana Nikolova-Damyanova William W. Christie Bengt Herslof 《Journal of the American Oil Chemists' Society》1990,67(8):503-507
The triacylglycerols of meadowfoam oil have been resolved by HPLC in the silver ion and reversed-phase modes, and by the two
techniques used in a complementary fashion. The fractions obtained were collected and quantified by gas chromatography of
their methyl esters in the presence of an internal standard. Silver ion chromatography gave a distinctive resolution in which
fractions differing solely in the position and chain-length of a single monoenoic fatty acyl group were resolved, the order
of elution being 11−20∶1, 5−20∶1, 13−22∶1, 5−18∶1 and 9−18∶1. Reversed-phase chromatography also gave fractions containing
single positional isomers, (11−20∶1<5−20∶1<13−22∶1<5−22∶1), but the pattern was more difficult to discern since fractions
containing 22∶2 tended to overlap with those containing 20∶1. The species (5−20∶1)(5−20∶1)(22∶2), (5−20∶1)(5−20∶1)(5−20∶1)
and (5−20∶1)(5−20∶1)(13−20∶1) were found to be the most abundant, and together comprised 67% of the total. A small but significant
trilinolein fraction was detected and its presence may have biosynthetic implications. 相似文献
7.
Triacylglycerols from Atlantic herring (Clupea harengus), sandeel (Ammodytes sp.) and Baltic herring (Clupea harengus membras) have been fractionated by silver ion high-performance liquid chromatography. An ion exchange column loaded with silver ions
was the stationary phase, and a gradient in the mobile phase from 1,2-dichloroethane/dichloromethane (1∶1, v/v) to acetone
and then to acetone/acetonitrile (2∶1, v/v) was used to effect the separation with light-scattering (i.e., mass) detection.
Fractions were collected via a streamsplitter, and fatty acid methyl esters were prepared by transesterification in the presence
of an internal standard for identification and quantification by gas liquid chromatography. Triacylglycerols were separated
according to the number of double bonds in the fatty acyl residues. Resolution was excellent at first, when the least unsaturated
molecules eluted (trisaturated to dimonoene-monodiene fractions). Base-line resolution could no longer be achieved when molecules
containing trienoic or more highly-unsaturated fatty acids began to elute because of overlapping components. Nonetheless,
some valuable separations of species containing two saturated and/or monoenoic fatty acids and one polyenoic fatty acid were
achieved. Double bond indices (average number of double bonds in each triacylglycerol molecule) were calculated to estimate
the separations possible. Fractions containing at least 11–14 double bonds per molecule were obtained. 相似文献
8.
Yong-Goe Joh Elizabeth Y. Brechany William W. Christie 《Journal of the American Oil Chemists' Society》1995,72(6):707-713
The wax esters of the roe oil of the amber fish,Seriola aureovittata, have been resolved by high-performance liquid chromatography (HPLC) in the silver-ion mode. Each of the fractions collected
was transmethylated, and the fatty acids and alcohols were identified by gas chromatography/mass spectrometry (GC/MS) as the
picolinyl esters and nicotinates, respectively. Their compositions were determined by GC. The fatty acid composition is complex,
and the main components are C18:1n-9 (35.5 mol%), C22:6n-3 (20.3 mol%), and C16:1n-7 (10.7 mol%), while fatty alcohols are
limited to saturated (C16:0, 60.3 mol%; C18:0, 15.3 mol%; C14:0, 5.1 mol%) and monoenoic alcohols (C18:1n-9, 6.5 mol%; C16:1n-7,
4.5 mol%) with traces (<0.1 mol%) of polyunsaturated fatty alcohols such as C20:3n-3, C20:4n-6, C20:5n-3, and C22:5n-3. Silver-ion
HPLC exhibited excellent resolution in which fractions were resolved on the basis of the number and configuration of double
bonds as well as the distribution pattern between the acid and alcohol moieties of the molecules with a given number of double
bonds. The main wax ester fraction are those of monoenoic acid-saturated alcohol species, hexaenoic acid/saturated alcohol
species, and pentaenoic acid/saturated alcohol species. Appreciable specificity was observed in the esterification of fatty
acids with alcohols, and surprisingly, no saturated acid-monoenoic alcohol species were detected. 相似文献
9.
Two approaches to the high pressure liquid chromatography (HPLC) isolation of intact plasmalogens were investigated. The first
used reversed-phase HPLC and sought to take advantage of subtle differences in the hydrophobicity of the alk-1-enyl chain
from the acyl counterpart. On a C-18 column, bovine heart phosphatidylcholine (PC), which was 47% plasmalogen, was separated
into a number of fractions that differed in their molecular species composition. One combination of fractions amounted to
a 26% yield of PC enriched to 82% plasmalogen. The second approach sought to take advantage of the uniquely electron-rich
functionality of the plasmalogens, the alk-1-enyl ether double bond, and its potential to coordinate with heavy metal ions.
Specificially, bovine heart PC was applied to a cation-exchange type HPLC column in the silver ion mode. Although complete
exchange of all the active sites of the column with silver ion led to complete retention of PC, partial activation with silver
ion resulted in the separation of the PC into fractions, according to the degree of unsaturation. Plasmalogen-rich fractions
eluted last and remained intact during the process. One combination of these fractions amounted to a 49% yield of PC enriched
to 72% plasmalogen. Use of a cation-exchange system in the mercuric ion mode led to on-column hydrolysis of the plasmalogen;
with palladium ion, the metallic species was stripped from the column by the eluting lipid. 相似文献
10.
Afaf Kamal-Eldin Lars Åke Appelqvist 《Journal of the American Oil Chemists' Society》1994,71(2):135-139
Seeds from different collections of cultivatedSesamum indicum Linn. and three related wild species [specifically,S. alatum Thonn.,S. radiatum Schum and Thonn. andS. angustifolium (Oliv.) Engl.] were studied for their oil content and fatty acid composition of the total lipids. The wild seeds contained
less oil (ca. 30%) than the cultivated seeds (ca. 50%). Lipids from all four species were comparable in their total fatty acid composition, with palmitic (8.2–12.7%), stearic
(5.6–9.1%), oleic (33.4–46.9%) and linoleic acid (33.2–48.4%) as the major acids. The total lipids from selected samples were
fractionated by thin-layer chromatography into five fractions: triacylglycerols (TAG; 80.3–88.9%), diacylglycerols (DAG; 6.5–10.4%),
free fatty acids (FFA; 1.2–5.1%), polar lipids (PL; 2.3–3.5%) and steryl esters (SE; 0.3–0.6%). Compared to the TAG, the four
other fractions (viz, DAG, FFA, PL and SE) were generally characterized by higher percentages of saturated acids, notably palmitic and stearic
acids, and lower percentages of linoleic and oleic acids in all species. Slightly higher percentages of long-chain fatty acids
(20∶0, 20∶1, 22∶0 and 24∶0) were observed for lipid classes other than TAG in all four species. Based on the fatty acid composition
of the total lipids and of the different acyl lipid classes, it seems thatS. radiatum andS. angustifolium are more related to each other than they are to the other two species. 相似文献
11.
Identification of milk fat triacylglycerols was accomplished by capillary supercritical fluid chromatography (SFC) combined
with atmospheric pressure chemical ionization mass spectrometry [(APCI)MS]. Supercritical carbon dioxide was the carrier fluid
in SFC. Ionization was achieved by introducing vapor of ammonia in methanol into the ionization chamber, which resulted in
the formation of abundant [M+18]+ and [M-RCOO]+ ions of triacylglycerols. These ions defined both the molecular weight and the fatty acid constituents of a triacylglycerol,
respectively. SFC on a nonpolar stationary phase provided an efficient separation of triacylglycerols according to the combined
number of carbon atoms in the acyl chains of a molecule. In addition to the identification of the major chromatographic peaks
representing molecules with 26–54 acyl carbons, minor peaks representing triacylglycerols with an odd number of acyl carbons
were separated and identified. Furthermore, compositional information on partially separated isobaric triacylglycerols, which
differed substantially in the chain length of the fatty acyl residues, was achieved within some of the peaks. A new finding
of the present study was the formation of abundant [M+18]+ ions of saturated triacylglycerols in addition to diagnostic fragment ions, being of primary importance in structure elucidation.
This extends the applicability of capillary SFC-(APCI)MS in the analysis of both saturated and unsaturated triacylglycerols. 相似文献
12.
Identification of the less common isologous short-chain triacylglycerols in the most volatile 2.5% molecular distillate of butter oil 总被引:6,自引:0,他引:6
The isologous short-chain triacylglycerols of the most volatile 2.5% distillate of butter oil were resolved by reversed-phase
high-performance liquid chromatography (HPLC) with mass spectrometry. The molecular species were identified by means of the
[MH]+ and the [MH-RCOOH]+ ions in positive chemical ionization mode. A set of empirically determined incremental elution factors was found that could
be used to calculate the accurate elution order of natural butterfat triacylglycerols when analyzed by reversed-phase HPLC.
The triacylglycerols were also resolved by temperature-programmed gas-liquid chromatography on capillary columns coated with
polar liquid phases. The high polarity of the columns provided separation of triacylglycerols on the basis of the degree of
unsaturation, as well as on the nature of the shortest acyl chain, with the isologous species having the shortest chainlength
eluting last. Both saturated and unsaturated triacylglycerols containing normal and branched-chain odd-carbon fatty acids
in combination with short-chain acids were identified, and over 150 molecular species were quantitated. 相似文献
13.
Koretaro Takahashi Tsugihiko Hirano Makoto Egi Mutsuo Hatano Koichi Zama 《Journal of the American Oil Chemists' Society》1986,63(12):1543-1546
The matrix model that has been expressed as linear relationship between the logarithm of the relative retention time of a
molecular species of a triglyceride versus total acyl carbon number or total double bonds when only one acyl group differs
in carbon number or number of double bonds was reviewed. A similar linear relationship was observed when the fatty acid residues
were substituted in the triglyceride molecule. This relationship was demonstrated by introducing the theory of partition chromatography
presented by A.J.P. Martin. 相似文献
14.
Two petroleum residues from European crudes have been fractionated using solvent (heptane) separation and column chromatography. The residues and the separated fractions have been characterised by size exclusion chromatography (SEC) and by UV-fluorescence spectroscopy (UV-F). Matrix assisted laser desorption/ionisation-mass spectrometry of the whole residues and the heptane insoluble fractions indicated that the bulk of the residues covered the mass range m/z 300-2000, while the heptane insolubles (1-2% of the whole) contained material in the mass range from about m/z 300 to 10?000. The upper mass ranges indicated by SEC using polystyrene standards were higher; the earliest eluting material from both distillation residues eluted at times corresponding to polystyrene standards of MMs above 1.85 million u. Possible reasons for the different observations are given. Data from UV-F suggests that the heptane solubility separation method was the most successful for the separation of the largest molecular mass and also probably the most polar materials in these residues. However, all three fractionation methods produced similar trends, showing greater polarity of the fractions to correlate with increasing molecular mass. The shift of maximum intensity of fluorescence towards longer wavelengths (in UV-fluorescence) with increasing molecular size, as indicated by SEC, strongly suggests that the fluorescing molecules are large rather than aggregates of small molecules. Differences in comparison with American petroleum residues can be observed. 相似文献
15.
Ulrich Stoll 《European Journal of Lipid Science and Technology》1996,98(5):178-182
Identification of Molecular Species of Phospholipids from Pig Heart by Combining Chromatographic Techniques. Glycero-phospholipids from subcellular organelles and membranes from pig heart were divided into subclasses. The molecular species within the main subclasses were analyzed. The phosphorus moiety had been removed by phospholipase-C and the acetylated molecules were separated in diacyl-, alkylacyl- and alkenylacyl-glycerols by thin-layer chromatography (TLC). For further identification the subclasses from the first fractionation by TLC were separated by silver ion chromatography according to their polarity. A small portion of the acetylated diradyl-species was transesterified so that the fatty acid composition could be assessed as methyl esters. The acetylated molecular species derived from glycerophospholipids were chromatographed on WCOT fused silica columns with TAP as stationary phase according to molecular weight and unsaturation. Gaschromatography (GC) of fatty acid methyl esters and dimethylacetals from plasmalogens was executed on DEGS-columns or on WCOT fused silica columns with CP-Sil 88 as stationary phase. The distribution of molecular species within a phospholipid class (PC or PE) was rather similar for the diacyl-and the alkenylacyl molecules. But the latter are more volatile. In the case of phosphati-dylcholine the composition of C16-C18-:1; C16-C18:2 and C18-C18:2 was predominant for diacyl- as well as alkenylacyl-species. In the case of phosphatidylethanolamine the fatty acid composition of C18-C20:4 and C18-C18:2 were the most important species. The composition of fatty acids in diacyl-and alkenylacyl-species is of special interest as the metabolism of diacyl-glycerophospholipids is quite different from alkenylacyl-glycerophospholipids. 相似文献
16.
The utility of reverse-phase high-performance liquid chromatography (HPLC), desorption chemical-ionization mass spectrometry
(DCI-MS) and tandem mass spectrometry (MS/MS) for the characterization of triacylglycerols in complex mixtures has been further
explored. Triacylglycerols of anhydrous bovine milk fat were separated by using two reversephase C18 HPLC columns, and eluents were monitored with an evaporative light-scattering detector. Fifty-eight fractions were resolved
and analyzed by positive ion isobutane DCI-MS. The formation of protonated molecules and of major fragments corresponding
to the random loss of any one of the constituent fatty acids readily identified acyl carbon numbers and the number of double
bonds within each fatty acid. MS/MS was only required when the original mass spectra indicated the presence of more than one
triacylglycerol or of impurities in a fraction. Protonated molecules produced by DCI were fragmented using high energy collisional
activation, and the resulting ions were detected by MS/MS. Odd-chain triacylglycerols were also readily distinguished using
this methodology. The positive ion DCI and MS/MS techniques described here demonstrate the usefulness of this approach for
the characterization of triacylglycerols in complex mixtures. 相似文献
17.
Miguel Á. Rincón‐Cervera José L. Guil‐Guerrero 《European Journal of Lipid Science and Technology》2010,112(2):227-232
HPLC analysis of Echium plantagineum seed oil shows a complex triacylglycerol (TAG) profile. TAG species were separated on an analytical scale by HPLC and their fatty acid (FA) composition is reported. GLC analyses showed that some TAG fractions reached a stearidonic acid (SDA, 18:4n‐3) percentage significantly higher than that in the original oil. TAG separation on a bigger scale was also essayed, by means of a gravimetric normal‐phase chromatographic column, using silver ion‐silica gel as stationary phase. Gradient elution with solvents of increasing polarity was applied, allowing the separation of valuable TAG species containing γ‐linolenic acid (GLA, 18:3n‐6), α‐linolenic acid (ALA, 18:3n‐3) and SDA as the main constituents (more than 85% of the total FA). An enzymatic hydrolysis reaction showed the distribution of FA in the isolated species of TAG. SDA was the major FA in the sn‐2 position (more than 50% of total FA), followed by ALA (19%) and GLA (18.5%). 相似文献
18.
An analysis of monoacetyldiglyceride was performed by gas chromatographymass spectrometry for the purpose of determining the
molecular species of ovolecithin. Separation of monoacetyldiglycerides was made according to the degree of unsaturation and
to the sum of the carbon numbers of fatty acyl residues. Fragments of monoacetyldiglyceride were analyzed and interpreted
in relation to the molecular structure in a similar manner to that of triglyceride. 相似文献
19.
A method employing reversed-phase high performance liquid chromatography (HPLC) has been developed for the analysis of molecular
species of underivatized cerebrosides. By using a high carbon (20%) C18-silica bead column, monohexosylceramides isolated
from bovine brain and Japanese quail intestine could each be separated into 42 and 56 peaks, respectively, and could subsequently
be recovered. Under our analytical conditions, underivatized cerebrosides with 24∶1 and 22∶0 fatty acids were completely separated
by single step HPLC. Each of the molecular species was then analyzed by high performance thin layer chromatography and gas
chromatography-mass spectrometry (or fast atom bombardment mass spectrometry). This analytical method permits the complete
identification of molecular species of glycosphingo-lipids. 相似文献
20.
Subcellular fractions of nuclei, mitochondria, endoplasmic reticulum, plasma membrane and cytosol were prepared from liver
and hepatoma 72288CTC. Marker enzyme activities, biochemical compositions and electron microscopy were used to establish purity.
Hepatoma NADH: cytochrome C reductase and 5′-nucleotidase exhibited abnormal subcellular distributions.
The lipids from the subcellular fractions were examined in detail. Mitochondria and plasma membranes were characterized by
elevated percentages of diphosphatidylglycrerol and sphingomyelin, respectively, in both tissues. All hepatoma subcellular
fractions contained dramatically elevated levels of sphingomyelin and cholesterol, two components that form preferential strong
complexes in vitro. The fatty acid composition of hepatoma sphingomyelin differed markedlg from liver and, unlike liver, did
not exhibit organelle specific compositions. Some hepatoma lipid classes contained reduced percentages of palmitate while
others contained higher levels. Hepatoma phosphatidylcholine and phosphatidylethanolamine from organelles contained lower
percentages of long chain polyunsaturated fatty acids than liver. Generally, unique fatty acid profiles exhibited by individual
phospholipid classes of liver subcellular fractions were absent or much reduced in the hepatoma. The ratios of oleate to vaccenate
were near one for most of the phospholipid classes of most liver fractions, but all hepatoma classes, with few exceptions,
contained a much higher percentage of oleate in all subcellular fractions. The hypothesis is proposed that the origin of some
acyl moieties for the biosynthesis of various hepatome lipid classes differs from liver sources. The possible changes in acyl
pools, sources and compartments for complex lipid biosynthesis could result in change in the quantities of molecular species
that could contribute to the abnormal properties of the hepatoma membranes. 相似文献