bluuebunny/crossref_metadata_2025 huggingface dataset:
Maternal diet and brain fatty acids in young rats
Authors: Walker Brian L.
Published: November 2006

In order to determine to what extent maternal diet influenced the brain lipids of young rats, female rats were maintained on diets differing in fatty acid composition. Fatty acid determinations on the total brain lipids of the young from these dams indicated that the maternal dietary lipids influence the polyunsaturated fatty acid composition of these animals. A maternal diet with a high linoleic‐linolenic acid ratio (corn oil) resulted in lower levels of 22∶6ω3 and higher levels of 22∶5ω6 than one with a low linoleic‐linolenic acid ratio (grain). Transfer of young rats at birth to a foster mother, which was fed a diet differing from that of the natural dam, resulted in brain polyunsaturated fatty acid patterns at weaning similar to those of the natural young, and suckling, of the foster mother, thus indicating that the maternal diet in the immediate postnatal period can modify the brain lipids of young rats prior to weaning. The brain lipids of young rats from dams which were fed corn oil exhibited a marked tendency to incorporate 22∶6ω3 in the immediate postnatal period in spite of a relatively high linoleic‐linolenic acid ratio in the milk.
Physical studies of lipid‐lipid and lipid‐protein interactions
Authors: Chapman Dennis
Published: November 2006

This is a review of studies of lipid‐lipid and lipid‐protein interactions conducted in the author's laboratory. Studies of the thermotropic mesomorphism of phospholipids and effects due to the presence of water are described. The relevance of these thermal transitions to monolayer, bilayer and membrane systems is discussed. Studies on the interactions of phospholipids and cholesterol are reviewed. Finally, lipid‐protein interactions under various conditions are discussed with special attention being given to serum lipoproteins and natural membranes.
Studies on positional specificity of the castor bean acid lipase
Authors: Ory Robert L. , Kiser James , Pradel Paul A.
Published: November 2006

The acid lipase of castor bean endosperm catalyzed the hydrolysis of fatty acids from the 1 and 3 positions of synthetic glycerides immediately after achieving proper reaction conditions, but fatty acids from the 2 position were not detected in the reaction products until 7 to 10 min later. Results obtained with 2,3‐butane dioleate, n‐hexyl oleate and 2‐hexyl oleate showed that the castor lipase does not cleave secondary ester linkages. These findings suggest that the acid lipase of the castor bean may catalyze hydrolysis of fatty acids from the 1 and 3 positions of triglycerides only; the steady appearance of 2 position fatty acids in the reaction products during lipolysis is probably the result of an apparent isomerization reaction.
Cis‐Trans isomerization of unsaturated fatty acid methyl esters without double bond migration
Authors: Sgoutas D. S. , Kummerow F. A.
Published: November 2006

Trans isomerization of monoenoic and dienoic fatty acid methyl esters has been carried out with thiols and diphenylphosphine in the presence of azobisisobutylnitrile. The equilibrium mixture contained 75–80%trans double bonds and there was no migration of the double bonds.
Triglyceride sub‐classes of dog plasma and organs
Authors: Gold Martin
Published: November 2006

Lipids were extracted from liver, kidney, myocardium, skeletal muscle, arterial and femoral venous plasma. Triglycerides were purified by thin layer chromatography and the double bond subclasses separated by silver nitrate silica gel H thin layer plates. Gas chromatography was used to delineate the fatty acid composition of each sub‐class as well as the carbon number of the purified triglyceride from each site. The major double bond sub‐class was O11 (O,saturated fatty acid; 1,one double bond; 2,two double bonds). The plasma values were highest in 001 and 002. All sites had quite uniform 112 while plasma had the lowest 012. The percentage of all saturated fatty acids in a band was summed and equated to 100% and the fatty acid percentage recalculated on this basis. The saturated fatty acid distribution in myocardium and skeletal muscle was highest in myristate in the third 001 sub‐class and liver and plasma had the highest stearate in the second 001 band. The palmitate was similar in most bands. Every sample, except the subcutaneous adipose tissue, had a maximum triglyceride content of carbon number 52 (the carbon number represented the sum of all carbon atoms in the fatty acids present in a molecule). The liver and subcutaneous adipose tissue triglyceride carbon number 52 and 54 were approximately equal. The liver exhibited the largest 56.
The relation of carnitine to the formation of phosphatidyl‐β‐methylcholine byTenebrio molitor L. Larvae
Authors: Bieber L. L. , Monroe R. E.
Published: November 2006

Results demonstrate thatTenebrio molitor larvae can incorporate β‐methylcholine into their phospholipids and that β‐methylcholine spares larval choline. Phosphatidyl‐β‐methylcholine is detected when larvae are reared on a diet in which choline is replaced by β‐methylcholine. Results indicate that, in contrast to housefly and blowfly larvae,Tenebrio larvae do not metabolize carnitine to β‐methylcholine. The same phospholipids were found with all rearing conditions. They were lecithin, sphingomyelin, phosphatidylethanolamine, phosphatidylserine and two others tentatively identified as cardiolipin and phosphatidylinositol. The ratio of lecithin to sphingomyelin and to the combined other phospholipids did not vary significantly, regardless of the rearing conditions. Larvae reared on diets lacking either choline or carnitine contained more lipid phosphorus per gram of tissue than those reared on a complete diet. The fatty acid composition of the neutral lipids was similar regardless of the rearing conditions. Oleic acid represented greater than 55% of the total fatty acids, and unsaturated fatty acids comprised 75–80% of the total. Palmitic acid was the predominant saturated fatty acid.
Succinate dehydrogenase: III. Stability and interaction with phosphatides
Authors: Cerletti P. , Caiafa P. , Giordano M. G. , Testolin G.
Published: November 2006

The stability of soluble succinate dehydrogenase and the effect of phosphatides on dehydrogenase activity were studied. Phosphatides stabilize dehydrogenase preparations solubilized in the presence of succinate but do not affect the dehydrogenase prepared in the absence of succinate, which stabilizes the enzyme independent of the action of phospholipids. Phospholipids stabilize the flavoprotein under the same conditions they need to affect succinate dehydrogenase activity. These effects probably derive from a similar interaction of phosphatides with the flavoprotein.
Absorption and metabolism of 1‐14C‐hydroxy octadecadienoate in the rat
Authors: Reber R. J. , Draper H. H.
Published: November 2006

The metabolism of 1‐14C‐9(13)‐hydroxy octadecadienoic acid methyl ester (1‐14C‐HAME) by the rat was investigated in vivo and in liver slices. A 1.5 mg dose of 1‐14C‐HAME administered by stomach tube was efficiently hydrolyzed and absorbed from the intestinal tract. In comparison with 1‐14C‐methyl linoleate (1‐14C‐ML), 1‐14C‐HMAE was more extensively oxidized to14CO2 in vivo and in vitro. After 1‐14C‐HAME administration as much as 50% of the radioactivity in the adipose tissue triglycerides was associated with14C‐hydroxy fatty acids. The remaining activity was present in randomly labeled normal fatty acids. No evidence was obtained for the incorporation of14C‐hydroxy acids into liver lipids; most of the radioactivity from 1‐14C‐HAME in this organ was recovered in saturated and monoenoic fatty acids. About 10% of the radioactivity 24 hr after 1‐14C‐HAME administration was associated with triglyceride trienoic acids, indicating that at least a portion of this acid was dehydrated in the liver. An unidentified polar acid was detected in the urine of the 1‐14C‐HAME‐treated animals.
Stereochemical course of diacylglycerol formation in rat intestine
Authors: Breckenridge W. C. , Kuksis A.
Published: November 2006

The biosynthesis of diacylglycerols from 2‐monoacylglycerols and free fatty acids was examined in evert sacs of rat intestinal mucosa. By means of alternate labeling of the monoacylglycerols and fatty acids, and conventional stereo‐specific analysis, it was shown that the main products of synthesis were thesn‐1,2‐diacylglycerols (53–63%), butsn‐2,3‐diacylglycerols (37–47%) were also formed in significant amounts. The total yield and proportions of the isomeric diacylglycerols recovered appeared to vary with the nature of the monoacylglycerol and the complexity of the free fatty acid mixture supplied.
Effects of acyl chain hydroxyl groups and increasing unsaturation on the autoxidation of cholesteryl esters in aqueous colloidal suspension
Authors: Norcia L. N. , Mahadevan V.
Published: November 2006

Aeration in aqueous collodial suspension results in oxidation of the sterol moiety of cholesteryl linoleate, linolenate, arachidonate and O‐tetrahydropyranylricinoleate. The extent of such oxidation is different for each compound, and the O‐tetrahydropyranylricinoleate ester oxidizes relatively slowly. Cholesteryl 12‐hydroxystearate and ricinoleate are resistant to this oxidation. Factors that may contribute to autoxidative susceptibility of cholesteryl esters are discussed briefly.
Effects of parathion on lipolysis in isolated rat adipose tissue cells
Authors: Caley Richard M. , Jensen Robert G.
Published: November 2006

The effects of the pesticide, Parathion (0,0‐diethyl 0‐p‐nitrophenyl thiophosphate) and various lipolytic and antilipolytic agents on lipolysis in adipose tissue were studied with isolated fat cells from rat epididymal fat pads. Lipolysis was measured as the release of free fatty acids into an albumin‐bicarbonate medium. Parathion depressed lipolysis in a linear manner at concentrations ranging from 10−9 to 10−3M. At a concentration of 10−5M, Parathion depressed the lipolytic response to epinephrine (0.15 μg/ml) and slightly to cyclic 3′,5′‐adenosine monophosphate (10−3 M) and enhanced the antilipolytic response to nicotinic acid (33 μM). It is possible that Parathion may interfere with adenyl cyclase activity.
Autoxidation of fatty acid esters in the presence of a heavy metal catalyst “Salcomine” (Co[II]‐bissalicylalethylenedi‐imine): II. Formation of a reaction product from a peroxy radical and salcomine
Authors: Jarvi Pentti K.
Published: November 2006

The formation of ionic Co(II)‐bis‐salicylalaethylenedi‐imine complexes of peroxy radicals of methyl esters of fatty acids was followed by means of UV spectra. Typical compounds were isolated and purified, and analyzed for Co content. IR spectra were determined. The mechanism of the autoxidation of fatty acid methyl esters in the presence of “Salcomine” (Co[II]‐bissalicylalethylene‐di‐imine) has been outlined, and its effect is explained as an oxidative addition reaction, resulting from coordinative unsaturation.
Evidence for singlet oxygen in the air oxidation of surface adsorbed 2,5‐diphenylfuran
Authors: Slawson Vida , Adamson Arthur W. , Stein Robert A.
Published: November 2006

Heating 2,5‐diphenylfuran on a silicon or titanium dioxide surface results in its conversion tocis‐dibenzoylethylene. This is considered an indication of singlet oxygen intermediacy. No significant reaction occurs with the solid or in solvents other than acetone. A singlet oxygen quencher inhibits the reaction, and a free radical scavenger has little effect. The differences between the surface reaction and lack of reactivity in solution may arise from several causes. These include local forces involved in adsorption, topographical and geometric effects, and metal catalysis. Knowledge of factors influencing singlet oxygen formation under nonphotochemical conditions has potential practical application.
Sorbic acid containing triglycerides in aphids and their fractionation by high pressure liquid chromatography
Authors: Fallon W. E. , Shimizu Y.
Published: November 2006

The sorbic acid containing triglycerides found in various aphid species have been fractionated by high pressure liquid chromatography. Mass spectral analysis afforded identification of three isolates as 2‐trans, trans‐sorbo‐1, 3 dimyristin; 2‐trans, trans‐sorbo‐1,3 myristopalmitin; and 2‐trans, trans‐sorbo‐1,3 dipalmitin. No evidence of asymmetry was found by circular dichroism. The composition and proportions of these triglycerides was found to be species variable.
Thein vivo incorporation of [32P]‐labeled orthophosphate into pyrophosphatidic acid and other phospholipids ofCryptococcus neoformans through cell growth
Authors: Itoh Toshihiro , Kaneko Hiroshi
Published: November 2006

Cryptococcus neoformans was cultured in a liquid medium containing [32P]‐orthophosphate and harvested at various stages of cell growth. An aliquot of the [32P]‐labeled cells was transferred to a nonradioactive medium, and the culture was continued again for some hours. The [32P]‐radioactivity composition and the phosphorus composition of individual phospholipids relative to the total phospholipid through the incubation periods were estimated. Although levels of major phospholipids remained constant throughout the cell growth, the distribution pattern of the [32P]‐radioactivity of individual phospholipids changed remarkably along with the progress of cell growth. The changing patterns of the specific radioactivities of individual phospholipids through the growth phase demonstrated that phosphatidic acid was one of the most active metabolites in phospholipids and that pyrophosphatidic acid was also metabolically active.
A mass spectrometric survey of some biologically important lipids
Authors: Natale Nicholas
Published: November 2006

The mass spectra of lipids are reviewed with emphasis on characteristic fragmentation patterns of each general class of compounds. Recent developments in the area of field ionization and field desorption mass spectrometry are discussed relative to each class of lipids.
Studies on the hydrogen belts of membranes: I. Diester, diether, and dialkyl phosphatidylcholines and polyoxyethylene glycerides in monolayers with cholesterol
Authors: Fong Jones W. , Tirri Lawrence J. , Deshmukh Diwakar S. , Brockerhoff Hans
Published: November 2006

The hydrogen belts of membranes are defined as the regions consisting of hydrogen bond acceptors, i.e., the C=O groups of glycero‐ and sphingolipids, and hydrogen bond donors, i.e., cholesterol‐OH, sphingolipid‐OH, proteins, and water. Lipid‐lipid hydrogen bonding in these belts has been suggested. The connection of such hypothetical bonding with the condensation effect, i.e., the apparent reduction of surface area occupied by phospholipids in mixed monolayers with cholesterol, has been tested with lipids possessing and lacking C=O groups: diester, diether, and dialkyl phosphatidylcholine, and analogous polyoxyethylene diglycerides. Condensation by cholesterol was observed for all lipids. Consequently, the hypothetical lipid‐C=O‐cholesterol hydrogen bonding is not a prerequisite for the condensation effect.
Studies on the hydrogen belts of membranes: II. Non‐electrolyte permeability of liposomes of diester, diether, and dialkyl phosphatidylcholine and cholesterol
Authors: Tirri Lawrence J. , Schmidt Perla C. , Pullarkat Raju K. , Brockerhoff Hans
Published: November 2006

We have postulated the existence of lipid‐lipid and protein‐lipid hydrogen bonding in the hydrogen belts of membranes, i.e., the regions of hydrogen bond acceptors (carbonyl oxygens of esters and amides) and hydrogen bond donors (hydroxyls of cholesterol, sphingosine, proteins, water). To assess the possible effects of modifications of the hydrogen belts on membrane permeability, we prepared a diester phosphatidylcholine and two analogs lacking carbonyl oxygens, a diether and a dialkyl phosphatidylcholine, care being taken to synthesize lipids of identical efficient hydrophobic chain length. Relative permeation rates for glycerol and urea were determined by osmotic swelling of liposomes containing the phospholipids alone or with an equimolar quantity of cholesterol, with 4 mole % of dioleylphosphate added. The permeation rates of both solutes were similar for all three lipids, with Arrhenius activation energies ΔE* around 16 kcal/mole. Cholesterol reduced the permeability of all three membranes. The activation energy ΔE* of permeation did not change for diester and dialkyl phosphatidylcholine with cholesterol, but was lower by about 5 kcal/mole for the diether lipid with cholesterol. This corresponds to a reduction in the entropy of activation ΔΔS*∼‐16 cal/mole/degree. We interpret the results as supporting the hypothesis of interaction between cholesterol hydroxyl and phospholipid carbonyl.
A new rotifer‐based assay for tocopherol
Authors: Kabay Michel E. , Gilbert John J.
Published: November 2006

The body‐wall‐outgrowth response of the rotiferAsplanchna sieboldi to tocopherol has been developed into a new bioassay which can estimate tocopherol titres more than 106 times more dilute than the detection limits of previously reported bioassays, and which is more sensitive and permits greaters qualitative discrimination than any fluorometric assay. this rotifer bioassay may prove especially useful in determining biological activities of tocopherol compounds and in estimating total tocopherol activity in biological material of very limited size or tocopherol content. It may also be used to analyze and describe the effects of environmental, genetic, and pharmacological factors on the body‐wall‐out‐growth responses ofAsplanchna to given doses of tocopherol in terms of regression equations or equivalent changes in inducing tocopherol concentrations.
Lipid metabolism in early development using labeled precursors incorporated during oogenesis and in cell‐free embryo homogenates
Authors: Pechèn Ana M. , Bazàn Nicolàs G.
Published: November 2006

Embryos of the toad,Bufo arenarum, Hensel, taken during early stages of development were used to survey the [U‐14C] glycerol and32P lipid labeling. When precursors were supplied at the time of oogenesis, large differences in specific activities of phospholipid were observed. Using32P, a steep rise as a function of development was evidenced. Triglycerides contained much higher proportions of [U‐14C] glycerol than phospholipids when administered to the female toad along with a pituitary homogenate. However, lack of [U‐14C] glycerol uptake into lipids was observed when cell‐free homogenates of eggs at different stages of development ranging from unfertilized oocyte to midgastrula were incubated in unsupplemented amphibian Ringer. At the later stage, significant de novo biosynthesis of lipids from glycerol began to be measurable, whereas during cell cleavage intracellular redistribution of preformed phosphoglycerides was used for membrane assembly.
A comparative in vivo study of intestinal absorption of biliary phosphatidylcholines and micellar phosphatidylcholines in the rat
Authors: Nalbone G. , Lajron D. , Lafont H. , Amic J. , Domingo N. , Hauton J. C.
Published: November 2006

An in vivo study was performed using rats with the purpose of comparing the absorption of native biliary and purified phosphatidylcholines. The latter were purified from bile and solubilized in the form of mixed micelles of bile saltsphosphatidylcholines‐cholesterol. The animals all bore bile duct diversions, and were divided into two groups: one had a normal pancreatic secretion while in the other group the pancreatic duct was ligated. Animals with normal pancreatic secretion showed comparable rates of absorption of micellar and biliary phosphatidylcholines. In the absence of normal pancreatic secretion, the rate of absorption of biliary phosphatidylcholines was unchanged, whereas that of micellar phosphatidylcholines markedly decreased. The results are consistent with the concept that some billary phosphatidylcholines are absorbed independently of pancreatic secretion in an unhydrolyzed form.
The triterpenes of ouricuri wax
Authors: Tulloch A. P.
Published: November 2006

Ouricuri was contains lupeyl acetate (3.9%), taraxerone (1.3%), lupenone (1.2%), simiarenol (0.09%), and taraxeryl acetate (0.03%). The triterpenes can be readily isolated from the wax by hexane extraction. Gas liquid chromatographic analysis shows that lupeyl acetate is the principal single component of the wax.
Absence of eicosatrienoic acid in plasma of sheep parenterally infused with a high glucose fat‐free solution
Authors: Palmquist D. L. , Mattos W. , Stone R. L.
Published: November 2006

Five yearling wether sheep were maintained on total intravenous, fat‐free feeding for periods in excess of 4 weeks. Analysis of plasma total lipid, neutral lipid, and phospholipid fatty acid patterns showed a decrease in linoleic acid during the first week, after which levels tended to stabilize. Rate of decrease in linoleic acid content of plasma phospholipids of two sheep was different. Changes in nonessential fatty acids were variable. 5,8,11‐ and 8,11,14‐Eicosatrienoic acids were not detected in any of the sheep.
A simple method for the preparation of cholesteryl esters
Authors: Prabhudesai A. V.
Published: November 2006

A simple and convenient procedure for the synthesis of cholesterol esters of long chain saturated and unsaturated fatty acids is presented. Condensation is achieved with thionyl chloride as a catalyst.
Analysis of autoxidized fats by gas chromatography‐mass spectrometry: I. Methyl oleate
Authors: Frankel E. N. , Neff W. E. , Rohwedder W. K. , Khambay B. P. S. , Garwood R. F. , Weedon B. C. L.
Published: November 2006

A structural investigation of autoxidation products of methyl oleate was carried out by gas chromatography‐mass spectrometry (GC‐MS) of trimethylsilyl (TMS) ether derivatives. GC‐MS using computer plots of selected masses afforded structural assignments of GC peaks due to incompletely resolved mixtures. This method provided evidence of epoxy and keto esters which are not completely separated from the main components consisting of the TMS derivatives of the allylic hydroxy esters. Use of an MS‐computer system also showed that the hydroxyoctadecanoate TMS ethers were partially separated by GC. The use of synthetic hydroxyoctadecanoates for the first time enabled us to demonstrate the quantitative reliability of a GC‐MS computer summation approach to analyze the isomeric composition of oleate hydroperoxides (as the saturated TMS ether derivatives). Consistently higher concentrations were found of the 8‐ and 11‐hydroperoxides than of the 9‐ and 10‐hydroperoxides. Minor products of autoxidation identified by GC‐MS include allylic enones, isomeric epoxyoctadecanoates, dihydroxyctadecenoates, and dihydroxyoctadecanoates.
Analysis of autoxidized fats by gas chromatography‐mass spectrometry: II. Methyl linoleate
Authors: Frankel E. N. , Neff W. E. , Rohwedder W. K. , Khambay B. P. S. , Garwood R. F. , Weedon B. C. L.
Published: November 2006

The gas chromatography‐mass spectrometry (GC‐MS) approach developed in the preceding paper was applied for qualitative and quantitative investigations of autoxidation products of methyl linoleate. A GC‐MS computer summation method was standardized with synthetic 9‐ and 13‐hydroxyoctadecanoate. Equal amounts of 9‐ and 13‐hydroperoxides were found in all samples of linoleate autoxidized at different temperatures and peroxide levels. The results are consistent with the classical free radical mechanism of autoxidation involving a pentadiene intermediate having equivalent sites for oxygen attack at carbon‐9 and carbon‐13. Minor oxygenated products of autoxidation indicated by GC‐MS include keto dienes, epoxyhydroxy monoenes di‐ and tri‐hydroxy monoenes. These hydroxy compounds are presumed to be present in the form of hydroperoxides. The quantitative GC‐MS method was found suitable for the analysis of autoxidized mixtures of oleate and linoleate. By this method, it is possible to determine the origin of the hydroperoxides formed in mixtures of these fatty esters.
Spectrofluorescent detection of malonaldehyde as a measure of lipid free radical damage in response to ethanol potentiation of spinal cord trauma
Authors: Seligman Myron L. , Flamm Eugene S. , Goldstein Bernard D. , Poser Richard G. , Demopoulos Harry B. , Ransohoff Joseph
Published: November 2006

Studies of the role of free radical damage to the spinal cord following a 400 g‐cm impact have suggested an increase in at least one free radical product, malonaldehyde, 24–36 hr post injury. To investigate further the role of free radical lipid peroxidation in degeneration of the spinal cord following injury, a study of specific lipid fluorescence (SLF) indicative of the double Schiff‐base adduct formed by a reaction between malonaldehyde and cellular components was carried out in the presence of ethanol, a known potentiator of free radical lipid peroxidation. The study was carried out in cats who received a 200 g‐cm impact 3 hr to 23 days prior to sacrifice. Half of the impacted animals received ethanol, 5 ml/kg, prior to injury. These animals were rendered paraplegic, whereas the nonethanol treated animals were neurologically intact. Controls consisting of laminectomies alone or laminectomies with ethanol but without injury were also studied. Spinal cord segments at the impact or laminectomy site were minced and extracted with chloroform‐methanol, cleared by centrifugation, and examined in a scanning fluorometer with excitation maximum at 360 nm and emission maxima at 420, 440, 450, and 460 nm. SLF was minimal in cats 3 hr and 1 day post injury, but markedly increased at 3 days. By 5 days, background levels were again found in all groups. SLF in the alcohol‐pretreated impact animals rose to a peak at 7 days, followed by a decline to background by 10 days. The presence of SLF supports a role for free radical lipid peroxidation in the degenerative changes in the spinal cord following injury. The findings of two peaks of SLF activity suggest two different sites of damage. One site, found acutely after injury, appears in all groups and was associated with reversible changes, while the other site is associated with later changes and chronic paraplegia only. The two sites could be the gray and white matter.
Phytyl esters in a marine dinoflagellate
Authors: Withers Nancy W. , Nevenzel Judd C.
Published: November 2006

The first naturally occurring phytyl esters from a marine alga were isolated from a dinoflagellate,Peridinium foliaceum (Stein) Biecheler, cultured photosynthetically and harvested at stationary phase of growth. At this stage, phytyl esters were the major wax esters present, constituting 5% of the total lipid, and may be present largely in the “eyespot” structure. The fatty acids esterified to the phytol were predominantly polyunsaturated: 16∶3 n−3 (15%), 18∶5 n−3 (6%), 20∶5 n−3 (36%), and 22∶6 n−3 (17%).
Glyceride structure variation in soybean varieties: II. Silver ion chromatographic analysis
Authors: Fatemi S. H. , Hammond E. G.
Published: November 2006

The glyceride structures of 20 soybean varieties were determined by silver ion chromatography. Plots of the percentage of each triglyceride vs. the percentage of its constitutent fatty acids revealed no genetic variants that had not been found previously by stereospecific analysis. The results deviated significantly from the amounts predicted by the 1‐random‐2‐random‐3‐random hypothesis of glyceride distribution. This deviation can be explained by a noncoincidence of the peak biosynthesis of oleic and linoleic acids during maturation of the beans.
Lipid composition and erucic acid in rat liver cells in culture
Authors: Rogers C. G.
Published: November 2006

Erucic acid (Δ13‐docosenoic acid) was added to fetal calf serum, then fed to rat liver epithelial cells in culture, and uptake measured at intervals over 24 hr. During the first 6 hr. of incubation, uptake of the docosenoic acid was 21 nmoles/hr/mg protein in 7‐day cells, and 15 mmoles/hr/mg protein in 14‐day cells. Of14C‐labeled erucic acid taken up by the cells in 24 hr, radioactivity measurements showed 60% of the total lipid14C activity derived from [1‐14C] 22∶1 in neutral lipid (NL) and 40% in phospholipid (PL); whereas 55% of lipid14C activity was in NL and 45% in PL when the substrate was [14‐14C] 22∶1. Within the NL fraction, 75% of14C activity derived from [1‐14C] 22∶1 was in triglyceride (TG) and 11% in cholesterol (CHL), while 79% was in TG and 6.5% in CHL when the substrate was [14‐14C] 22∶1. Triglycerides and cholesteryl esters accumulated in the cells during incubation with erucic acid. Among phospholipids separated by thin layer chromatography, 75% of14C activity was in lecithin (PC), 10% in phosphatidylethanolamine (PE), 5% in sphingomyelin (SPH), and 1% or less in cardiolipin (DPG). The highest specific activity (SA) was in PC, followed by SPH and PE. Incubation with erucic acid altered fatty acid composition of PC, PE, and SPH, although amounts of phospholipids were unaffected. Gas liquid chromatography analyses detected 18% erucic acid in PC, 2% in PE, and 4–5% in SPH.
Alveolar lavage and lavaged lung tissue phosphatidylcholine composition during fetal rabbit development
Authors: Rooney Seamus A. , Gobran Laurice I.
Published: November 2006

Pulmonary surfactant, the major surface‐active component of which in the adult is dipalmitoylglycerophosphocholine, can be obtained by lavaging lungs with physiological saline. We have previously shown that there is an increase in the amount of phosphatidylcholine in fetal rabbit lung lavage during the latter part of gestation. We have now measured the amount of disaturated phosphatidylcholine as well as the fatty acid composition of phosphatidylcholine in lung lavage from fetal rabbits during the period 27 days' gestation to full term (31 days). There was no developmental change in the amount of disaturated phosphatidylcholine during the period examined. About 50% of the total phosphatidylcholine was disaturated which is approximately the same as in adult rabbit lung lavage. The fatty acid composition, however, did change. There was an increase in the amount of 16∶0 from about 20% of the total fatty acids in phosphatidylcholine at 27–28 days to about 60% at full term, after birth, and in the adults. There was a corresponding decrease in the amounts of 14∶0, 18∶0, and longer chain fatty acids, most of which were saturated. In the lavaged lung tissue, there was a 2.6‐fold increase in the percentage of phosphatidylcholine which was disaturated during the period 27–31 days' gestation. It had not decrease to the adult value 24 hr after birth.
Fatty acid and sterol synthesis by rat small intestine in vitro
Authors: Miguel S. G.
Published: November 2006

Slices of rat jejunum were incubated with [2‐14C]pyruvate, [1‐14C]acetate, or [3H]H2O to determine lipogenic activity. Under all conditions studied, pyruvate acted as a better precursor than acetate for fatty acid synthesis but not for the synthesis of sterol. Exogenous glucose significantly (P≤0.05) increased the conversion of both pyruvate and acetate to fatty acids. By contrast, fasting resulted in a decrease (p≤0.05) in lipogenic activity. The highest levels of lipogenesis were observed when [3H]H2O + glucose at a concentration of 20 mM was used. From such experiments, the absolute rate of fatty acid synthesis in the tissue preparation was calculated: 734±54 nmoles acetyl units incorporated into fatty acids/g tissue/hr.
Action of three bile acids on hepatic and intestinal cholesterogenesis in the rat
Authors: Reynier M. O. , Marteau CH. , Vigne J. L. , Mule A. , Crotte C. , Gerolami A.
Published: November 2006

Incorporation of [114−C] acetate into cholesterol by subcellular particles from the liver and the small intestine of rats with a biliary diversion and a duodenal perfusion of sodium taurocholate, taurochenodeoxycholate or taurodehydrocholate, was studied in vitro. In the liver, taurochenodeoxycholate prevented the increase of cholesterol synthesis induced by biliary drainage. Taurocholate had no action on cholesterol synthesis at any time, day or night. Intestinal synthesis of cholesterol was reduced by taurocholate and taurochenodeoxycholate but was not modified by taurodehydrocholate infusion.
Serum and liver lipid responses to 3‐hydroxy‐3‐methylglutaric acid in rats on different carbohydrate diets
Authors: Yousufzai S. Y. K. , Siddiqi Majid
Published: November 2006

Groups of male adult albino rats were administered 3‐hydroxy‐3‐methylglutaric acid (HMG) intraperitoneally along with six diets differing only in the type of carbohydrate used. Groups not treated with HMG served as controls. HMG showed a significant cholesterol‐ and triglyceride‐lowering effect in the whole serum, serum β‐lipoproteins, and liver of animals on all types of dietary carbohydrates. The effect was more marked in glucose, fructose, sucrose, and lactose. The phospholipid levels in whole serum, serum β‐lipoproteins, as well as in liver were also significantly lowered on all types of carbohydrates except dextrin and starch fed animals, where it had no effect on liver levels. The lipid‐lowering effect of HMG seems to be independent of the type of carbohydrate in diet.
Titration of sterol double bonds with dibromopyridine sulfate
Authors: Rosenstein Fumiko U. , Caruso Ramon , Kircher Henry W.
Published: November 2006

Cis andtrans‐22‐dehydrocholesteryl acetates andcis andtrans‐22‐cholesten‐3β‐yl acetates were prepared and compared to Δ22‐phytosteryl acetates by titration with dibromopyridine sulfate. The cholesterol derivatives absorbed close to the theoretical quantity of bromine (1 Br2 per double bond), whereas the Δ22‐C24‐alkylated sterols consumed 0.14 to 0.23 Br2 in excess of the calculated values. This excess is attributed to the formation of additional unsaturation during bromination. Δ7 and Δ8(14)‐sterols consume more than 2 and 3 moles Br2, respectively, which indicates that at least one or two new double bonds are formed in these molecules during the bromination step.
Identification of the free and conjugated sterol in a non‐photosynthetic diatom,Nitzschia alba, as 24‐methylene cholesterol
Authors: Kates M. , Tremblay P. , Anderson R. , Volcani B. E.
Published: November 2006

Previous studies on the sterol fraction of the nonphotosynthetic marine diatom,Nitszchia alba, indicated the major sterol to be either brassicasterol (24R‐methylcholesta‐5,22‐dien‐3β‐ol) or 22‐dehydrocampesterol (24S‐methylcholesta‐5,22‐dien‐3β‐ol) on the basis only of gas chromatographymass spectral analysis. The present studies using nuclear magnetic resonance, infrared, and gas chromatography‐mass spectrometry on the free and bound sterol fractions isolated by preparative thin layer chromatography showed the presence in both fractions of a single sterol, with spectral and chromatographic properties identical with those reported for 24‐methylenecholesterol (ergosta‐5,24(28)‐dien‐3β‐ol). This sterol may be the precursor of 24‐methyl sterols found in diatoms. The bound sterol fraction was found to consist of a single compound identified as 24‐methylenecholesterol sulfate. No sterol esters or sterol glycosides were detected.
Studies on lipid biosynthesis and cholesterol content of liver and serum lipoproteins in rats fed various phthalate esters
Authors: Bell F. P. , Patt C. S. , Brundage B. , Gillies P. J. , Phillips W. A.
Published: November 2006

The effect of various phthalate ester plasticizers on lipid metabolism in rats was studied in vivo and in vitro. Di‐2‐ethylhexyl phthalate (DEHP) and di‐n‐butyl phthalate (DBP) inhibited (30–70%) hepatic sterologenesis from14C‐acetate and14C‐mevalonate in liver minces from rats fed the phthalates at a level of 2.5 mmoles/100 g of chow diet for 21 days; inhibition of14C‐acetate incorporation into phospholipids, triglycerides, and steryl esters was reduced (35–70%) by DEHP and DBP feeding. In addition, serum cholesterol was lowered ca. 14 mg/dl with dietary DEHP or DBP but not with dimethyl phthalate (DMP). Hepatic total cholesterol levels were reduced significantly (31%, P<0.001) by DMP but not by DBP or DEHP. In other studies with DEHP fed at the 0.5% level in chow diets (1.3 mmoles/100 g), the incorporation (esterification) of3H‐oleate into di‐ and triglycerides was reduced ca. 40%. Furthermore, the addition of DEHP (2%, 5 mmoles/100 g) to a semisynthetic diet containing 10% fat (hydrogenated coconut oil) resulted in changes in serum lipoprotein composition. The percentage of serum cholesterol in LDL rose from 22% to 34% while that in HDL fell from 78% to 66%; these changes occurred without net changes in serum cholesterol levels. Possible mechanisms for the inhibitory effect of phthalates on hepatic lipid biosynthesis are discussed.
Distribution of dietary octadecenoate isomers at the 1‐ and 2‐positions of hepatoma and liver phospholipids
Authors: Wood Randall , Chumbler Fred
Published: November 2006

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.
Incorporation and metabolic conversion of erucic acid in various tissues of the rat in short term experiments
Authors: Ong Nelly , Bezard Jean , Lecerf Jean
Published: November 2006

Rats were intravenously injected with a mixture of free (14‐14C) erucic acid (22∶1) and (9–103H) oleic acid (18∶1). After 2, 4, 8, 16, and 30 min, radioactivity was examined in blood, liver, heart, kidneys, and spleen. Free (14C) 22∶1 disappeared from the blood more rapidly than free (14C) 18∶1 between 0 and 8 min. Incorporation of label into triglycerides only appeared after 16 min and at 30 min they represented 4% of the injected radioactivity. In this fraction, 63% of14C radioactivity was present as 18∶1 and not as the original 22∶1, while almost all3H radioactivity was recovered as unchanged 18∶1. At all times studied, the majority of radioactivity was found in the liver, primarily as triglycerides (60% of radioactivity in total lipids) and as phospholipids (20–30%).14C was present in nearly the same proportion as3H (13% of injected radioactivity after only 2 min, 11% at 30 min).14C radioactivity was contained in 18∶1 in higher proportion than 22∶1 (45% in triglycerides, 65% in phospholipids). Since labeled triglycerides of blood, rich in (14C) 18∶1, mainly originate from the liver triglycerides, it appears that 18∶1 is the major form of utilization of 22∶1 in the tissues after its conversion in liver. In the other organs tested, radioactivity was found 10–15 times lower than in liver. In the heart,14C was 3 to 4 times higher than3H. More than 80% was recovered as 22∶1 in triglycerides. In spleen and kidneys, the14C:3H ratio was particularly high in free fatty acids and monoglycerides. In kidneys, 60% of14C was present as nervonic acid (24∶1) in monoglycerides and 40% in phospholipids, suggesting that the mononervonin formed was used for phospholipid biosynthesis.
Type and amount of dietary fat affect relative concentration of cholesterol in blood and other tissues of calves
Authors: Wiggers Kenneth D. , Richard Marlene J. , Stewart Jeanne W. , Jacobson Norman L. , Berger P. Jeffrey
Published: November 2006

Sixteen male Holstein calves consumed by nipple a reconstituted milk containing nonfat dry milk and either soybean oil or tallow for 24 weeks. Calves fed milk in this manner (with no dry feed) are functionally nonruminants because the milk bypasses the ruminoreticulum. The fat in these diets contributed about 30% of total dietary calories. The calves consuming soybean oil milk had significantly greater amounts of cholesterol in blood plasma and adipose tissue than did the calves consuming tallow milk.
Biosynthesis of prostaglandins
Authors: Hemler Martin E. , Lands William E. M.
Published: November 2006

Highly purified cyclooxygenase from sheep vesicular glands is stimulated by the presence of protoporphyrin IX compounds. This stimulation may be due to the conversion of an apoenzyme to the holoenzyme, and full activity is achieved when half of the enzyme subunits (70,000 daltons) bind heme. Also, one‐half of the subunits appear to contain non‐heme iron. The apparent molecular weight of the holoenzyme is approximately 300,000 daltons and is compatible with a complex of four 70,000 dalton subunits. Thus, we suggest that heme and non‐heme iron may be attached to different 70,000 daltons subunits that make up an A2B2‐type of peptide chain arrangement.
The effect of long‐chain monoenes on prostaglandin E2 synthesis by rat skin
Authors: Hulan H. W. , Kramer J. K. G.
Published: November 2006

In order to ascertain whether the dermal lesions observed in male rats fed rapeseed oils are due to impaired prostaglandin biosynthesis, endogenous levels of prostaglandin E2 (PGE2) in skin and the capacity of this tissue to synthesize PGE2 from arachidonic acid was investigated. Male Sprague‐Dawley rats were fed from weaning for 8 weeks either a standard rat diet (chow) or semisynthetic diets containing 20% by weight of the following fat sources: corn oil; commercial lard; commercial lard to which was added 5.4% free erucic acid; rendered pig fat; or the following rapeseed oils:Brassica napus var. Zephyr;B. campestris var. Span;B. campestris var. Arlo (15%) and var. Echo (85%) designated HEAR (high erucic acid rapeseed). The long‐chain monoene content (18∶1, 20∶1, and 22∶1) of the diets fed ranged from 30 to 71 mole % and that of skin from 27 to 74 mole %. A significant (P<0.01) correlation was found between the level of 18∶2n−6 in the diet and the endogenous PGE2 levels in skin and the capacity of this tissue to synthesize PGE2. No relationship was found between these two PGE2 parameters and the level of erucic acid in the diet. The rate of turnover of PGE2 appeared to be lower in rats fed rapeseed oil as evidenced by the relatively high endogenous PGE2 levels when these oils were fed (96 to 105 μg/g). On the other hand, the lowest capacity for PGE2 synthesis was found with skin from rats fed Zephyr rapeseed oil, rats which also had the most severe incidence of hair loss and dermal lesions. Significant (P<0.01) negative correlations were observed between the level of monoenes and specifically the level of oleic (18∶1n−9) acid in the diets and PGE2 synthesis capacity of skin, possibly confirming the known inhibitory effect of 18∶1n−9 on the prostaglandin synthesizing enzyme system.
Alchornea cordifolia seed oil: A rich source of a new C20 epoxide, (+)cis‐14,15‐epoxy‐cis‐11‐eicosenoic acid
Authors: Kleiman R. , Plattner R. D. , Spencer G. F.
Published: November 2006

A C20 homolog of vernolic acid has been found at the 50% level inAlchornea cordifolia, Euphorbiaceae, seed oil. This new acid, (+)cis‐14,15‐epoxy‐cis‐11‐eicosenoic (alchornoic) acid, was isolated by high‐pressure liquid chromotography and characterized by mass spectrometry, nuclear magnetic resonance and infrared spectroscopy, optical rotary dispersion, and ozonolysis‐gas‐chromotography.
Further studies of the saturated methyl branched fatty acids ofVernix caseosa lipid
Authors: Nicolaides N. , Apon J. M. B. , Wong David H.
Published: November 2006

By the method of capillary gas chromatography‐mass spectrometry, we have identified 35 monomethyl and 46 dimethyl branched acids in the saturated acids of vernix caseosa lipid with chain lengths ranging from C11 to C18. Many other mono‐, di‐, and trimethyl branched acids have been partially identified. All methyl branches were found to be on the even numbered C‐atoms except for some terminal iso methyl groups. Three types of dimethyl branched acids were found: those with a terminal iso structure, those with a terminal anteiso structure, and those with neither iso nor anteiso structures. The 4‐methyl branch predominated for all types of branched acids. Equivalent chain length data for di‐ and trimethyl branched acids were determined on a Pentasil (nonpolar) wall coated capillary column and checked by calculation from monomethyl branched acid data. Mass spectral identification was performed with and without the aid of a data system. A possible mode of formation of these acids is discussed.
High pressure reverse phase liquid chromatography of fatty acidp‐bromophenacyl esters
Authors: Pel P. T. S. , Kossa W. C. , Ramachandran S. , Henly R. S.
Published: November 2006

High pressure reverse phase liquid chromatography has been employed to rapidly separate saturated and unsaturated fatty acids as the correspondingp‐bromophenacyl esters. Through the use of a highly efficient C18 reverse phase column packing, it has also been possible to distinguish among geometrical and positional isomers of the unsaturated acids. The use of ultroviolet‐sensitive esters has permitted the detection of low (nanogram range) concentrations of fatty acids. The time required for analysis has been further reduced by employing a novel and rapid method for the preparation of the esters.