bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis of fecal neutral steroids and bile acids in humans on constant fat diet
Authors: Mitchell W. D. , Diver M. J. 
Published: November 2006

AbstractA method is described for the separation and quantification of fecal neutral steroids and fecal bile acids. The fecal extract is separated into the neutral steroid fraction and bile acid fraction with ionexchange resin columns. The principal neutral steroids and bile acids are then separated and quantitated by thin‐layer chromatography. Values for the fecal neutral steroids, cholesterol, coprostanol and coprostanone and fecal bile acids, deoxycholic acid and lithocholic acid of 5 subjects on a constant fat diet for a 3‐week period are presented.
(S)‐1,2‐diacyl‐3‐acetins: Optically active triglycerides fromEuonymus verrucosus seed oil
Authors: Kleiman R. , Miller R. W. , Earle F. R. , Wolff I. A. 
Published: November 2006

AbstractThe seed oil ofEuonymus verrucosus Scop., family Celastraceae, contains more than 90% 1,2‐diacyl‐3‐acetins (monoacetotriglycerides). The constituent triglyceride acids, other than acetic, are the usual long‐chain fatty acids.Thin‐layer chromatography (TLC), infrared (IR) and hydrolysis with pancreatic lipase indicate that the acetic acid is esterified exclusively on the outer glycerol carbon atoms. The isolated mixed monoacetotriglycerides exhibit optical rotation caused by asymmetry of the central glycerol carbon atom. Comparison with synthetic products of known configuration shows that the natural material is essentially all (S)‐1,2‐diacyl‐3‐acetin.IR, TLC and GLC analyses indicate the presence of monoacetotriglycerides in seven other species of Celastraceae and five species in three other plant families in amounts from 13 to 98%.
Brain cholesterol. XII. The incorporation of 1‐14C‐acetate into baboon sterol
Authors: Kabara Jon J. , Werthessen N. T. 
Published: November 2006

AbstractThe incorporation of 1‐14C‐Acetate into tissue cholesterol of the baboon was measured. Using this indicator gray matter of the cerebrum indicated greater metabolic activity than did white matter.Other tissues besides neural tissue were examined. The peak of radioactivity occurred between 3 and 4 hr. The highest incorporation of radioactivity was measured in the adrenal gland. Liver, spleen and kidney values were of intermediate order.
Maternal diet and brain fatty acids in young rats
Authors: Walker Brian L. 
Published: November 2006

AbstractIn 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

AbstractThis 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

AbstractThe 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

AbstractTrans 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

AbstractLipids 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

AbstractResults 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

AbstractThe 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

AbstractThe 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

AbstractThe 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

AbstractAeration 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

AbstractThe 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

AbstractThe 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

AbstractHeating 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

AbstractThe 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

AbstractCryptococcus 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.
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

AbstractThe 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

AbstractWe 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

AbstractThe 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

AbstractEmbryos 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

AbstractAn 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

AbstractOuricuri 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

AbstractFive 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.