Ethanolamine Phosphatides Research Articles

The effect of silicon compounds on hematological indicators and content of lipids in blood of rabbits

The aim of the study was to find out the effect of casting of citrate nanosіlicon absorption and metasilicate sodium on the hematological parameters and lipid content and their fractional composition in blood plasma preparatory period 10 days prior to insemination and 20 days of lactation. The research was carried out on 60 rabbits of the Hyla hybrid, divided into three groups (control and two experimental), with 20 animals in each. The control animals were fed without limitation full-grain granulated feed with free access to water. Animals of the first experimental group (E-I) fed the diet of the control group and during the course of the day poured out the silicon citrate obtained using the nanotechnology method, 50 mkg Si/kg body weight with water. Samples of the second experimental group (E-II) feed the diet of the control group and set the sodium metasilicate (Na2SiO3H2O) 2.5 mg Si/kg body weight with water. The trial lasted 95 days, including the preparatory period of 10 days, the trial – 85 days. In the preparatory period of 10 days from the beginning of the study and in a trial of 20 days of lactation (65 days of supplements) in the rabbits, samples of blood from the marginal ear vein were taken. Hematologic studies were performed using the automatic hematologic analyzer “Orphee Mythic 18”, in the blood plasma, the content of total lipids and their fractional composition were determined. It was established that the number of erythrocytes and hemoglobin concentration in the blood of the rabbits of experimental group, which were given silicon citrate, were respectively higher by 15.2% (P < 0.05) and 12.0% (P < 0.01) by 20 days lactation versus control. This may indicate a more pronounced effect of the organic compound of silicon on the hematopoietic function of the body of the rabbits. According to white blood, the differences from control were found during the presentation of supplements with higher (P < 0.05) changes in 20 days of lactation in animal blood and experimental group. It was noted that the content of triacylglycerols in plasma of blood of groups I and II was lower by 31.2 and 32.8%, respectively (P < 0.05) compared to control. In blood plasma of animals in experimental groups an increase in the fractions of phosphatidylcholine, sphingomyelin and lysolecetin was observed compared to control. Such a redistribution was due to the reduction of the fractions of phosphatidic acid, phosphatidyl ethanolamine and phosphatidylinositol, and apparently, is associated with changes in the activity of the enzymes concerned. Hematological studies and determination of the fractional composition of lipids and phospholipids of blood plasma of the rabbits show positive changes that contribute to the metabolic accumulation of energy and plastic components of their organism.

Phospholipids in guinea pig spermatozoa before and after capacitation in vitro.

Phospholipids of guinea pigs spermatozoa were examined using high performance liquid chromatography (HPLC) and thin layer chromatography (TLC). Two types of spermatozoa were compared: fresh epididymal (uncapacitated) spermatozoa and epididymal spermatozoa preincubated in Ca2+-free medium for 17-18 hr (capacitated spermatozoa). Determination of lipid phosphorus revealed that the total phospholipid content of spermatozoa did not change significantly during capacitation of spermatozoa. HPLC analyses of choline and ethanolamine phosphatides, lysophosphatides, and sphingomyelin revealed that the relative amounts of these phospholipids remained unchanged during capacitation. In contrast to spermatozoa, phospholipids in the medium surrounding spermatozoa reduced by 20% during capacitation of spermatozoa, suggesting that spermatozoa may utilize extracellular phospholipids as possible energy sources during their capacitation.

Clinical relevance of multiple antibody specificity testing in anti-phospholipid syndrome and recurrent pregnancy loss

We wanted to evaluate whether testing for anti-phosholipid antibodies other than anti-cardiolipin (aCL) and anti-beta-2 glycoprotein I (abeta2GPI) immunoglobulin (Ig)G and IgM identifies patients with recurrent pregnancy loss (RPL) who may be positive for anti-phospholipid syndrome (APS). In a cross-sectional study comprising 62 patients with APS, 66 women with RPL, 50 healthy blood donors and 24 women with a history of successful pregnancies, we tested IgM and IgG antibodies to phosphatidic acid, phosphatidyl choline, phosphatidyl ethanolamine, phosphatidyl glycerol, phosphatidyl inositol and phosphatidyl serine with and without beta-2 glycoprotein I (beta2GPI) from a single manufacturer as well as aCL and abeta2GPI antibodies. Diagnostic accuracies of individual and combined anti-phospholipid (aPL) assays were assessed by computing sensitivities, specificities, positive predictive values and negative predictive values together with their 95% confidence intervals. There was a general trend for increased sensitivities in the presence of beta2GPI co-factor with significant effect for certain specificities. The overall combined sensitivity of the non-recommended aPL assays was not significantly higher than that of the aCL and aB2GPI tests. Multiple aPL specificities in RPL group is not significantly different from controls and therefore of no clinical significance.

Comparative study of lipid composition of two halotolerant alga, Dunaliella bardawil and Dunaliella salina

The composition of polar, neutral and glycolipid fractions of two halotolerant algae, Dunaliella salina and Dunaliella bardawil, which are exclusively used for the production of β-carotene was determined in modified medium. In D. salina the glycolipid fraction accounted to 28%, in comparison with 40% of D. bardawil. However, in D. salina the polar lipid was 42% compared with D. bardawil at 24%. The glycolipid fraction of D. bardawil was rich in linolenic acid (81%). In both the species we could find elongation in the fatty acids from C16 to C20 to C22 and the percentage was higher than the earlier reports (>3%). The polar lipid fraction was composed of (in descending order) phosphatidyl glycerol, phosphatidic acid, phosphatidic ethanolamine, phosphatidyl choline and phosphatidyl glycerol and the neutral lipid fraction, which was rich in monoglycerides and diglycerides and diacylglycero-trimethylhomoserine.

Metabolism of Exogenous Palmitic and Oleic Acids by Preimplantation Mouse Embryos.

In the present study, the oxidation of palmitic acid to carbon dioxide and the difference of incorporation rate of the same and oleic acid into embryo lipids were examined. To test the exact role of fatty acids for energy production, the oxidative rates of exogenous palmitic were assessed in M16 medium with and without carbohydrate substrates. The oxidation of palmitic acid in the medium with carbohydrates was lower than that without carbohydrates in the blastocyst stage. Incorporation rates of both palmitic and oleic acids into embryo lipids increased significantly from the 2-cell to the blastocyst stage (P<0.05), whereas the incorporation rates of palmitic acid were significantly higher than those of oleic acid at most of the cell stages except for the blastocyst stage (P<0.05). In the neutral lipid fraction, 3H-palmitic acid was predominately distributed in triacylglycerol species and a little in the other glycerides (P<0.05). However, higher percentages of 14C-oleic acid were recovered in fatty alcohols, diacylglycerols and monoacylglycerols. In the polar lipid fraction, the percentages of 3H-palmitic acid in choline and ethanolamine phosphatides were significantly higher than those of oleic acid among all cell stages except the 2-cell stage (P<0.05), whereas the percentages of 14C-oleic acid in inositol and serine phosphatides were significantly higher than those of 3H-palmitic acid during preimplantation development (P<0.05). According to the comparison of incorporations into the embryo lipids and distributions in individual lipid classes between palmitic and oleic acids, it could be inferred that exogenous oleic acid is not a main energy substrate but a major intermediate for synthesis of various embryo lipids.

Incorporation and Distribution of Both 3H-Palmitic and 14C-Oleic Acids in Lipids by Preimplantation Mouse Embryos.

Both 3H-palmitic and 14C-oleic acids were simultaneously incorporated into mouse embryo lipids from the 1-cell to the blastocyst stage. Rates of incorporation of the two fatty acids into the embryo lipids increased and differed from each other significantly after 8-cell stage (P<0.05). That of palmitic acid into the polar lipid fraction was significantly higher than that of oleic acid at all corresponding cell stages, but that of palmitic acid into the neutral lipids was significantly higher than that of oleic acid at the morula and blastocyst stages (P<0.05). In the neutral lipid fraction, the radioactivity of 3H-palmitic acid distributed in triacylglycerols, monoakyldiglycerols and diacylglycerols were significantly higher than that of 14C-oleic acid at most corresponding cell stages with the exception of high monoacyldiglycerol content in 14C-oleic acid at the 2-cell stage (P<0.05). But that of 3H-palmitic acid in fatty alcohols and monoacylglycerols was significantly lower than that of 14C-oleic acid at the most corresponding cell stages (P<0.05). In the polar lipid fraction, the amounts of 3H-palmitic acid distributed in choline phosphatides, ethanolamine phosphatides and sphingomyelins were significantly greater at most corresponding cell stages than that of 14C-oleic acid (P<0.05) but the radioactivity of 14C-oleic acid recovered in inositol or serine phosphatides, lysophosphatidylcholines, monoglycosylglycerides was significantly higher than that of 3H-palmitic acid at almost every corresponding cell stage (P<0.05). These results demonstrated that the patterns of incorporation and distribution of double fatty acids in various lipid species were significantly different from those of the same single fatty acids in our previous report.

Determination of lipid ester ozonides and core aldehydes by high-performance liquid chromatography with on-line mass spectrometry

Unsaturated triacylglycerols (TG) and choline (PC) and ethanolamine (PE) phosphatides of known structure were subjected to ozonization and reduction with triphenylphosphine to yield the corresponding lipid ester core aldehydes. Mono- and di-C 9 aldehyde palmitoylglycerols were prepared from oleoyldipalmitoyl and oleoyllinoleoylpalmitoyl glycerols, respectively, while egg yolk PC and PE provided the mono-C 5 and mono-C 9 aldehydes of palmitoyl-and stearoyl glycerophospholipids. The aldehydes were isolated in the free form and as the dinitrophenylhydrazone (DNPH) derivatives by thin-layer chromatography (TLC). The intermediate ozonides, free aldehydes and hydrazones were identified by reversed phase high performance liquid chromatography (HPLC) with on-line negative ion thermospray and normal phase HPLC with on-line positive ion electrospray mass spectrometry (LC-MS). The synthetic aldehydes were used as carriers during isolation from natural sources and as reference compounds in quantitative analyses

Phospholipid analysis of mammalian optic nerve tissue: a 31P nuclear magnetic resonance spectroscopic study.

Phospholipids of optic nerve (n = 30) from 5.6-kg rabbits were analyzed by 31P nuclear magnetic resonance (NMR) spectroscopy. Phospholipid metabolites detected were as follows (mol %): phosphatidylcholine (PC; 25.82 +/- 0.12), PC plasmalogen/alkylacyl PC (2.07 +/- 0.13), sphingosylphosphorycholine (1.12 +/- 0.20), phosphatidylinositol (PI; 2.17 +/- 0.21), lyso PC (0.85 +/- 0.06), sphingomyelin (12.52 +/- 0.10); phosphatidylserine (PS; 14.38 +/- 0.11), phosphatidylethanolamine (8.98 +/- 0.11), ethanolamine plasmalogen (28.99 +/- 0.30), unidentified phospholipid (1.10 +/- 0.01), phosphatidic acid (PA; 1.72 +/- 0.06), and lyso PS (0.28 +/- 0.10). The bulk of the ethanolamine phosphatide is in the form of its plasmalogen, which is the major phospholipid detected. The choline plasmalogen, or a reduced derivative thereof, also is present; thus, a significant phospholipid biosynthetic pathway for optic nerve tissue involves the plasmalogen route, which is a pathway distinct from the PA route responsible for the synthesis of PS, PI, and PC. This new 31P NMR lipid analytical technique offers potential for studying optic nerve phospholipid metabolism and degenerating optic nerve tissue, since the technique can accurately quantitate (1) both plasmalogen and nonplasmalogen phospholipids, (2) minor phospholipid components, and (3) previously undetected phospholipids.

Effect of Phospholipase A2 on Temperature-Induced High-Affinity (3H)Tryptamine Binding Sites in Rat Brain.

To investigate a link between membrane phospholipids and tryptamine binding molecules, we examined the effects of phospholipases A2 and D on the temperature-sensitive high-affinity [3H]tryptamine binding sites in rat brain. When the phospholipase A2-treated membranes were exposed to 1% bovine serum albumin (BSA) before assaying for [3H]tryptamine binding, a complete dose-dependent inhibition curve was observed. At a concentration of 0.03 U, the action of phospholipase A2 resulted in the splitting of phosphatidylserine (PS), choline phosphatides (PC) and ethanolamine phosphatides (PE) by about 32, 34 and 65%, respectively, and reduced [3H]ligand binding by about 32%. On the contrary, in the case of phospholipase D (500 U), PS and PC decreased by about 8% and 33% and PE by about 29% with no significant alteration in the binding capacity. Moreover, Scatchard analysis of the [3H]tryptamine binding showed that phospholipase A2 drastically increased only the KD value of the high affinity sites, and this was accompanied by a decrement of the Bmax values of both the high and low affinity binding sites. From these results, it is inferred that certain lipids (PS) may be a modulator for the function of the temperature-induced high-affinity [3H]tryptamine binding molecules.

Adaptations to temperature in the cellular membranes of crustacea: membrane structure and metabolism

1. 1.|Acute changes in environmental temperature have deleterious effects on the structure and function of cellular membranes of crustaceans, as well as other poikilothermic animals. Low temperature increases membrane order, and decreases “fluidity”, in addition to influencing the activity of membrane-bound enzymes. 2. 2.|Crustaceans adapt to prolonged exposure to low temperatures by increasing the fluidity of membrane lipids, which serves to restore membrane function. 3. 3.|Membrane fluidity is regulated by changing the proportions of saturated and unsaturated fatty acids on membrane phosphatides at different temperatures. Unsaturation increases at low temperatures. 4. 4.|The proportion of different phospholipid head groups also changes in response to temperature, particularly among winter-active crustaceans. Ethanolamine phosphatides increase at the expense of choline phosphatides at low temperatures. 5. 5.|The experimental evidence for various metabolic mechanisms of membrane restructuring in crustaceans is discussed.

Lipid synthesis by oligodendrocytes from adult pig brain maintained in long-term culture

Oligodendrocytes were isolated from adult pig brain and cultivated for 18–24 days. [ 14C]acetate, [ 3H]galactose or [ 35S]sulfate were added to the medium for an additional 24 h. Lipids were extracted and separated by high-performance thin-layer chromatography. The labeled lipids were studied by fluorography and scintillation counting. [ 14C]acetate was incorporated in decreasing order into neutral lipids, phosphatidylcholine, ethanolamine phosphatides, galactocerebrosides, phosphatidylinositol, phosphatidylserine, sulfatides and sphingomyelin. From the [ 14C]acetate incorporated into ethanolamine and choline phosphatides, 71.6 and 14.8%, respectively, were found in plasmalogens. Among neutral lipids, [ 14C]acetate labeled not only cholesterol but also large amounts of triglycerides. No cholesterol esters were synthesized. [ 3H]galactose primarily labeled galactocerebrosides, sulfatides, and monogalactosyl diglyceride. [ 35S]sulfate incorporation was restricted to sulfatides. Together with our previous results concerning proteins, these data show that: (1) oligodendrocytes remain highly differentiated in long-term cultures; (2) they are able to synthesize the major components of myelin; (3) they synthesize surprisingly high amounts of triglycerides and of monogalactosyl diglyceride, a marker for myelination.

The properties of brain galactocerebroside monolayers

Using a Langmuir film balance we have compared the properties of films of the brain galactocerebrosides at 37°C. There are two types of cerebroside in brain, those with an α-hydroxy substituent on the acyl chain (HFA) and those without (NFA). At equivalent pressures the areas of both cerebroside films are significantly less than the areas of films of the brain glycerolipids, the choline and ethanolamine phosphatides. The isotherm of NFA galactocerebrosides has two discontinuities, one at low and one at high film pressure, while the isotherm of HFA galactocerebrosides is a smooth curve at all film pressures. Below the high-pressure transition the area of the NFA film is significantly larger than the area of the HFA film. When compressed beyond the high-pressure transition there is a marked hysteresis between compression and expansion isotherms of the NFA galactocerebrosides. The pressures of both films continue to rise steeply when they are compressed into areas which are too small for them to exist as simple monolayers. We conclude that under compression cerebroside films form bilayer structures; that bilayer formation starts at low pressure and occurs progressively as the HFA cerebroside monolayer is compressed, but occurs more abruptly in the NFA cerebroside monolayer at the high-pressure-transition region of the isotherm. A study of pure cerebrosides with a single defined acyl chain shows that there is a correlation between the relative volumes of the hydrophobic and hydrophilic parts of the molecule and the ease of bilayer formation. The larger the relative volume of the hydrophilic group the more readily the cerebroside forms a bilayer film. Other brain lipids added to cerebroside monolayers have sharply differing effects on their areas. The areas of films containing cholesterol are less than the areas calculated by adding the areas of the pure components multiplied by their mole fractions. On the other hand, the area of phosphatidylcholine-containing films is much larger than calculated.

Isolation of purified brush-border membranes from rat jejunum containing a Ca 2+-independent phospholipase A 2 activity

A novel phospholipase activity was recognized in intact, rat jejunal brush-border membranes and its effect on membrane lipid composition was evaluated following various incubation protocols. Brush-border membranes were isolated from mucosal scrapings by a combination of existing techniques. A brush-border plus nuclei fraction was first prepared by homogenization and low-speed centrifugation in isotonic mannitol, in the presence of 5 mM EDTA. Brush-border membrane vesicles were isolated from this fraction by homogenization, followed by precipitation of the remaining undesired membranes with 10 mM CaCl 2. Membranes were judged to be highly purified by marker enzyme content, protein profile, and electron microscopy. In total lipid extracts, prepared immediately following membrane isolation, the ethanolamine phosphatides were found to be the major phospholipid class, accounting for nearly 45% of the total lipid phosphorus. Storage of the intact membranes, at either room temperature or at −20° C, but not at −70° C, resulted in a gradual and progressive hydrolysis of phosphatidylethanolamine to lysophosphatidylethanolamine. Over 60% of the total ethanolamine phospholipid was converted to the lyso form during a 2 week storage period. Incubation of the intact membranes at 37° C produced a similar effect in one hour. Only small amounts of other glycerophospholipids were degraded under these conditions. Hydrolysis was specific for the sn-2 position as more than 80% of the fatty acids in the lysophosphatidylethanolamine were found to be saturated. Substitution of MgCl 2 for CaCl 2 in the precipitation step did not bblock the hydrolysis. It was concluded that rat brush-border membranes contain a Ca 2+-independent phospholipase A 2 with a high substrate preference for phosphatidylethanolamine. The physiological significance of this enzyme is not known.

Opsonization with antimyelin antibody increases the uptake and intracellular metabolism of myelin in inflammatory macrophages.

In most demyelinating diseases, macrophages are believed to be active agents of myelin destruction. In experimental encephalomyelitis, these cells appear to strip off and ingest the myelin lamellae, and myelin debris has been observed within the cell body. We show here in vitro conditions in which rat peritoneal macrophages phagocytose and metabolize CNS myelin lipids. Purified rat myelin, prelabeled in vivo with [14C]acetate, was incubated with preimmune serum or rabbit antiserum to rat CNS myelin and added to macrophage monolayers. Myelin opsonized with antimyelin antibodies was more readily phagocytosed and metabolized by cultured macrophages than untreated myelin or that preincubated with preimmune serum. In the presence of macrophages, levels of myelin polar lipids and cholesterol decreased, whereas radioactive cholesterol ester and triglyceride accumulated. Up to five times as much radioactive cholesterol ester and about twice as much triglyceride accumulated in macrophage cultures containing antibody-treated myelin as in cultures fed preimmune serum-treated myelin or in those incubated with untreated myelin. Both the fatty acid and the cholesterol from cholesterol ester contained radioactive label; therefore, both were derived at least partly from the radioactive myelin lipid. Antiserum to myelin purified from peripheral nerve was almost as effective as that to CNS myelin in stimulating cholesterol metabolism, whereas antiserum to galactocerebroside was about 70% as active. Antiserum to basic protein had less effect, whereas antiserum to the myelin-associated glycoprotein and proteolipid protein was inactive. Of the polar lipids, ethanolamine phosphatide was most degraded in both the antiserum- and preimmune serum-treated myelin, with the diacyl form and plasmalogen form degraded about equally. These experiments indicate that myelin-specific antibodies in inflammatory CNS lesions may participate in and stimulate macrophage-mediated demyelination.

Plasma membrane lipids of bovine adrenal chromaffin cells.

The lipid composition of plasma membranes isolated from bovine adrenal chromaffin cells has been determined. Choline and ethanolamine phosphatides were predominant; the level of lyso compounds was very low. The amount of cholesterol and the cholesterol/phospholipid molar ratio was low compared to those of the other subcellular fractions of chromaffin cells. A complex pattern of neutral glycolipids was observed in contrast to that of gangliosides.

The role of phospholipases from inflammatory macrophages in demyelination.

Activated macrophages harvested from rat peritoneum were shown to contain phospholipase A1, A2 and lysophospholipase activities which were defined on a series of radiolabelled phospholipid substrates. During in vitro culture of these elicited macrophage populations, phospholipase enzymes were secreted into the culture medium. Radiolabelled myelin, prepared from young rats after intracerebral injection of 14C acetate, was used as a substrate to analyze the susceptibility of central nervous system (CNS) myelin to attack by cell-associated and secreted macrophage enzymes. Homogenates of peritoneal macrophages degraded the myelin lipids at acid pH; phosphatidyl choline (PC) and ethanolamine phosphatide (EP) were both degraded with liberation of free fatty acid and small amounts of lysolipids. The ethanolamine lipids were most vulnerable; up to 20% of this fraction was degraded in six hours. Selected batches of macrophage culture supernatant similarly degraded the myelin EP at acid pH. These results suggest that phospholipase enzymes, released from activated macrophages in close proximity to the myelin sheath, may participate in primary demyelination in inflammatory CNS lesions.

Shiverer and normal peripheral myelin compared: basic protein localization, membrane interactions, and lipid composition.

We have correlated membrane structure and interactions in shiverer sciatic nerve myelin with its biochemical composition. Analysis of x-ray diffraction data from shiverer myelin swollen in water substantiates our previous localization of an electron density deficit in the cytoplasmic half of the membrane. The density loss correlates with the absence of the major myelin basic proteins and indicates that in normal myelin, the basic protein is localized to the cytoplasmic apposition. As in normal peripheral myelin, hypotonic swelling in the shiverer membrane arrays occurs in the extracellular space between membranes; the cytoplasmic surfaces remain closely apposed notwithstanding the absence of basic protein from this region. Surprisingly, we found that the interaction at the extracellular apposition of shiverer membranes is altered. The extracellular space swells to a greater extent than normal when nerves are incubated in distilled water, treated at a reduced ionic strength of 0.06 in the range of pH 4-9, or treated at constant pH (4 or 7) in the range of ionic strengths 0.02-0.20. To examine the biochemical basis of this difference in swelling, we compared the lipid composition of shiverer and normal myelin. We find that sulfatides, hydroxycerebroside, and phosphatidylcholine are 20-30% higher than normal; nonhydroxycerebroside and sphingomyelin are 15-20% lower than normal; and ethanolamine phosphatides, phosphatidylserine, and cholesterol show little or no change. A higher concentration of negatively charged sulfatides at the extracellular surface likely contributes to an increased electrostatic repulsion and greater swelling in shiverer. The cytoplasmic surfaces of the apposed membranes of normal and shiverer myelins did not swell apart appreciably in the pH and ionic strength ranges expected to produce electrostatic repulsion. This stability, then, clearly does not depend on basic protein. We propose that P0 glycoprotein molecules form the stable link between apposed cytoplasmic membrane surfaces in peripheral myelin.

The effects of temperature- and oxygen-acclimation on phospholipids of goldfish (Carassius auratus L.) brain microsomes.

Brain microsome phospholipids and their acyl groups, from temperature and oxygen acclimated goldfish, were investigated. At the lower acclimation temperature (5C) the proportion of ethanolamine- to choline-glycerophosphatides (GPE/GPC) was increased, and the proportion of phosphatidal ethanolamine value decreased. A rise in the n-6/n-3 fatty acyl group also occurred in cold acclimation. Irrespective of acclimation temperature, 25 degrees C or 5 degrees C, a partial replacement of GPC by GPE occurred when the concentration of oxygen was increased; conversely the GPE/GPC ratio decreased at the hypoxic level. The plasmalogen GPE content increased as the oxygen concentration was raised. A rise in the n-6/n-3 ratio, for ethanolamine glycerophosphatides and phosphatidyl choline, occurred when the oxygen concentration was increased (hypoxia to hyperoxia). It is concluded that the lipid alterations associated with thermal acclimation are, in part, attributable to the concomitant change in oxygen concentration.

Biosynthesis of sex pheromone components and glycerolipid precursors from sodium [1-14C]acetate in redbanded leafroller moth

Sodium [1-(14)C]acetate in water-dimethyl sulfoxide (1∶1) was applied topically to sex pheromone glands ofArgyrolaenia velutinana. Radiolabel was incorporated into the pheromone components (Z)-11-tetradecenyl acetate and (E)-11-tetradecenyl acetate, and also into triacylglycerols, diacylglycerols, ethanolamine phosphatides, and choline phosphatides. In the triacylglycerols, radiolabel appeared in (Z)-11-tetradecenoate, (E)-11-tetradecenoate, tetradecanoate, hexadecanoate, and octadecanoate. In the choline phosphatides, the same acyl moieties incorporated radiolabel but at lower levels. In the diacylglycerols and ethanolamine phosphatides, only the radiolabel in hexadecanoate and octadecanoate was above the limit of detection. At different times following application of sodium [1-(14)C]acetate, the relative proportions of labeled (Z)-11-tetradecenyl acetate and (E)-11-tetradecenyl acetate changed very little, but the relative proportions of labeled fatty acyl moieties in the triacylglycerols and choline phosphatides changed markedly. After 8 min, triacylglycerols had incorporated about equal amounts of radiolabel into (Z)-11-tetradecenoate, (E)-11-tetradecenoate, and tetradecanoate. As the incubation time was increased, triacylglycerols accumulated proportionately more radiolabeled (E)-11-tetradecenoate than (Z)-11-tetradecenoate, and accumulated proportionately less radiolabeled tetradecanoate. In the choline phosphatides, at all times of incubation the amount of radiolabel incorporated into (Z)-11-tetradecenoate was small but above the limit of detection, and the amounts of radiolabel in (E)-11-tetradecenoate and tetradecanoate were smaller and often below the limit of detection. In both the triacylglycerols and the choline phosphatides, the relative proportion of radiolabeled hexadecanoate decreased with time, and that of octadecanoate increased.

Sex pheromone biosynthetic precursors in Bombyx mori

In addition to the sex pheromone components (E,Z)-10,12- hexadecadienol , (E,E)-10,12- hexadecadienol , and (E,Z)-10,12- hexadecadienal , the sex pheromone gland of Bombyx mori produces glycerolipids containing (E,Z)-10,12- hexadecadienoate and (E,E)-10,12- hexadecadienoate . The methyl esters of these fatty acyl groups were identified on the basis of mass spectra, ozonolysis and comparison of gas-liquid chromatographic retention times with those of the corresponding synthetic compounds. (Z)-11- hexadecenoate was also present, in addition to the more common fatty acyl groups hexadecanoate, (Z)-9- hexadecenoate , octadecanoate, (Z)-9- octadecenoate , (Z,Z)-9,12- octadecadienoate and (Z,Z,Z)-9,12,15- octadecatrienoate . (E,Z)-10,12- hexadecadienoate and (Z)-11- hexadecenoate were the most abundant fatty acyl groups in the triacylglycerols, were less abundant in the choline phosphatides and ethanolamine phosphatides and were virtually absent from the diacylglycerols. Base methanolysis was used to convert fatty acyl groups to the corresponding methyl esters for identification. It was observed that acid methanolysis destroyed fatty acyl groups with conjugated double bonds, as well as the corresponding pheromone components. Non-conjugated fatty acyl groups in the gland formed methyl esters equally well by base methanolysis or acid methanolysis.