bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stereospecific analysis of hepatoma, host liver, and normal rat liver triglycerides from animals on chow and fat free diets
Authors: Wood Randall 
Published: November 2006

AbstractTriglycerides from normal liver, host liver, and hepatoma of rats maintained on chow and fat‐free diets were subjected to stereospecific analysis. Normal and host liver triglycerides from animals on the same diet did not exhibit significant differences. Fat‐free diet reduced polyunsaturated fatty acids in normal and host liver triglycerides, but had no effect upon hepatoma triglycerides. Each position of hepatoma and liver triglyceride glycerol exhibited a characteristic fatty acid composition. Palmitate concentrations were reduced dramatically and stearate levels were increased significantly at the 1 position of hepatoma triglycerides, relative to the corresponding position of liver triglycerides which were affected little by diet or tumor. Except for higher percentages of C‐20 and higher fatty acids, common to all three positions, the composition of hepatoma triglycerides at the 2 position appeared normal. The 3 position of hepatoma triglycerides contained significantly higher percentages of stearate than liver. Data obtained previously for Ehrlich ascites cell triglycerides were in good agreement with this hepatoma. Data from these two neoplasms suggest that the metabolic system that regulates or controls the fatty acid composition at the 1 and 3 positions of normal tissue triglycerides does not function normally in neoplasms.
Phosphatidylkojibiosyl diglyceride: Metabolism and function as an anchor in bacterial cell membranes
Authors: Pieringer Ronald A. , Ganfield Mong‐Ching W. 
Published: November 2006

AbstractThe recently discovered phosphoglycolipid, phosphatidylkojibiosyl diglyceride (PKD), was first observed as a biosynthetic by‐product of glucosyl diglyceride metabolism inStreptococcus faecalis (faecium) ATCC 9790. Its structure is 1,2‐diacyl‐3‐O(2′‐O‐α‐D‐glucopyranosyl‐6′‐O‐phosphoryl‐[1″,2″‐diacyl‐3″‐O‐sn‐glycerol]‐α‐D‐glucopyranosyl)‐sn‐glycerol. The biosynthesis of phosphatidylkojibiosyl diglyceride occurs by a novel transphosphatidylation reaction in which a phosphatidyl group is transferred from diphosphatidyl glycerol to the primary alcohol function at the 6 position of the internal glucose of kojibiosyl diglyceride. The reaction is catalyzed by a membrane‐derived enzyme. Phosphatidylkojibiosyl diglyceride is bound covalently through a phosphodiester bond to the polyglycerol phosphate moiety of membrane lipoteichoic acid fromS. faecalis. Phosphatidylkojibosyl diglyceride has four nonpolar long chain fatty acyl groups and appears to have the necessary physico‐chemical properties to anchor the long hydrophilic glycerol phosphate polymer of lipoteichoic acid to the hydrophobic environment of the membrane ofS. faecalis and probably other gram‐positive bacteria as well.
Dietary and hormonal effects upon activity of “soluble” protein and particulate fraction of fatty acid desaturation system of rat liver microsomes
Authors: Nervi Aníbal M. , Catala Angel , Brenner Rodolfo R. , Peluffo Raúl O. 
Published: November 2006

AbstractRat liver microsomes were extracted with a buffered 0.15 M KCl and 0.25 M sucrose solution and fractionated by centrifugation into a particulate component and a supernatant containing a protein factor necessary for fatty acid desaturation. The Δ6 fatty acid desaturation activity of the extracted microsomes was reduced significantly, and the readdition of the supernatant restored the enzymatic activity to the original value of the whole microsomes. A protein diet or a fat‐free diet increased the Δ6 desaturation activity of the whole microsomes. The activating effect was evoked upon the particulate components of the enzymatic desaturation system and not upon the protein factor present in the supernatant. Fasting, refeeding, and refeeding plus glucagon and theophylline treatments of rats also modified the Δ6 desaturation activity of whole liver microsomes. The effect also was evoked on the Δ6 desaturation system tightly bound to the microsomal membrane but not on the protein factor of the supernatant. Accordingly, the protein factor of the supernatant is considered to be different from the cyanide sensitive factor and the desaturase.
GLC and TLC analysis of isopropylidene derivatives of isomeric polyhydroxy acids derived from positional and geometrical isomers of unsaturated fatty acids
Authors: Wood Randall 
Published: November 2006

AbstractGas‐liquid chromatography (GLC) and thin‐layer chromatography (TLC) were used to investigate the isomeric positional geometrical isopropylidene derivatives of nine isomeric dihydroxy esters, four isomeric methyl 9,10‐12‐trihydroxystearates, and eight isomeric methyl 9,10‐12,13‐tetrahydroxystearates prepared from unsaturated fatty acids. The isopropylidenes derived fromcis andtrans monounsaturated fatty acids were easily separated on both polar and nonpolar columns. Positional isopropylidenes derived from positional isomers of monounsaturated fatty acids were not separated on either liquid phase but were resolved by TLC.Four of the eight isomeric isopropylidenes derived from the four geometrical isomers of linoleic acid were resolved on the polar column; the other four isomers eluted as a single peak. The four isomeric isopropylidene‐trifluoroacetate derivatives derived from ricinoleic and ricinelaidic acids were also resolved on the polar column. GLC analyses were carried out with liquid phases of ethylene glycol succinate methyl silicone polymer (EGSS‐X) and methyl silicone polymer (SE‐30) packed columns. Isopropylidenes, in addition to their applicability for the resolution of polyhydroxy acid mixtures, are particularly useful for the determination of double bond positions and geometrical configurations of fatty acids without cleavage.
Relationship between erucic acid and myocardial changes in male rats
Authors: Hulan H. W. , Kramer J. K. G. , Mahadevan S. , Sauer F. D. , Corner A. H. 
Published: November 2006

AbstractThe back and belly fat of pigs fed a diet containing 20% by wt rapeseed oil (22% erucic acid) for 16 weeks was rendered into oil. This rendered pig fat, which contained 5.6% erucic acid, was fed to male rats in three separate experiments at 20% by wt of the diet for 16 weeks. In experiment I rendered pig fat was compared only toBrassica campestris var. Span rapeseed oil containing 4.8% erucic acid. In experiments II and III, rendered pig fat was compared to commerical lard containing 0.2% docosenoic acid, commercial lard to which 5.4% free erucic acid was added, and Span rapessed oil. There was no significant (P<0.01) differences observed in the level of erucic acid in the hearts of rats fed diets of rendered pig fat, Span rapeseed oil, or commercial lard plus erucic acid. However, the incidence (P<0.001) and severity (P<0.01) of cardiac lesions were significantly higher in Span rapeseed oil fed rats compared to rats fed control diets. The number of rats affected or the severity of lesions in the rendered pig fat fed group was not significantly different from controls. The results of this study indicate that the myocardial lesions associated with feeding 20% rapeseed oil diets are not related to the content of erucic acid per se. The possible reasons why rapeseed oil causes cardiac lesions in rats are discussed. It is suggested that a triglyceride imbalance in the oil might play an important role in causing these lesions in rats.
Effect of dietary fat supplementation on the composition and positional distribution of fatty acids in ruminant and porcine glycerides
Authors: Mills S. C. , Cook L. J. , Scott T. W. , Nestel P. J. 
Published: November 2006

AbstractDietary fats which were protected from ruminal metabolism were fed to ruminants, and the constituent fatty acids subsequently appeared in the glycerides of tissues and secretory products. These dietary fat induced alterations in tissue lipid composition were particularly apparent when the fat source was enriched with linoleic acid. Similarly, when pigs were fed linoleic‐enriched fats, the linoleic acid was incorporated into the adipose tissue triglycerides. Stereospecific analyses were carried out on triglycerides from various tissues and secretory products obtained from animals fed control or linoleate‐enriched diets. The analysis of adipose tissue triglycerides showed that linoleate and oleate were preferentially esterified to positions 2 and 3 (cattle and sheep), and positions 1 and 3 (pigs). Of the other major adipose tissue fatty acids, palmitate was preferentially esterified at position 1 (ruminants) and position 2 (pigs), and stearate was preferentially esterified at positions 1 and 3 (ruminants), and position 1 (pigs). Stereospecific analysis of high mol wt milk triglycerides showed that linoleate was either evenly distributed on all three positions (goats), or predominantly on position 3 (cows). Furthermore, the incorporation of this linoleate did not markedly alter the positional specificity of the other major milk triglyceride fatty acids. Of these fatty acids, the short and medium chain length acids (butyratelaurate) were mainly on position 3, myristate and palmitate on positions 1 and 2, and stearate and oleate evenly distributed. Thoracic duct lymph triglycerides from sheep tended to show preferential incorporation of linoleate at position 3, palmitate at position 2, and stearate at position 1 and 3; oleate, on the other hand, tended to be evenly distributed on all three positions of the lymph triglyceride. The stereospecific arrangement of fatty acids in sheep liver triglycerides was similar to that of lymph triglycerides, and this may reflect the uptake of intact or partially hydrolysed chylomicron and/or very low density lipoprotein triglycerides by the liver. There were also some analogies in the stereospecific arrangement of fatty acids on ruminant lymph and milk triglycerides and this may reflect an incomplete hydrolysis of chylomicron and/or very low density lipoprotein triglycerides prior to uptake by the mammary gland. An unusual feature of lymph from sheep fed linoleate was the presence of phospholipids which contained large amounts of linoleate in ca. equal proportion at both positions 1 and 2 of the phospholipid molecule.
Acid lipase of the castor bean
Authors: Ory Robert L. 
Published: November 2006

AbstractThe acid lipase of the castor bean is present in the dormant seed. It is extracted from the fat pad obtained by centrifuging a macerate of the seed in pH 7.0 buffer containing cysteine and ethylene diaminetetraacetic acid. The pH optimum of the enzyme is 4.2; it is rather heat‐stable, and is inhibited by mercurials and sulfhydryl reagents. Maximum hydrolysis of saturated triglycerides occurs with fatty acids of chain length C4 to C8; unsaturated C18 triglycerides are hydrolyzed at a slightly lower rate.This lipase is a three‐component system consisting of the apoenzyme, a lipid cofactor (a cyclic tetramer of ricinoleic acid), and a protein activator (a small, heat‐stable glycoprotein which appears to be related to some of the castor allergens). Maximum lipolysis requires all three components. Lipase activity is associated with the spherosomes, the subcellular site of oil storage in the endosperm.
Configuration at C‐24 of 24‐methyl and 24‐ethylcholesterol in tracheophytes
Authors: Nes William R. , Krevitz Kenneth , Behzadan Shamideh 
Published: November 2006

Abstract24‐Ethylcholesterol was shown by proton magnetic resonance spectroscopy to have only the α‐configuration in a series of tracheophytes ranging through the evolutionary hierarchy from ferns through gymnosperms and primitive angiosperms to climax angiosperms. 24‐Methylcholesterol, however, was consistently an epimeric mixture, with the 24α‐epimer present in about twice the concentration of the 24β‐epimer. 24‐Methylcholesterol was always present in smaller amount than the 24‐ethylcholesterol.
Effect of transplanted human ovarian cancer tissue on liver lipid metabolism of nude mice
Authors: Nakazawa Ichiro , Mead James F. 
Published: November 2006

AbstractThe changes in the lipids of liver tissues of nude mice with and without transplanted human cancerous tissues were studied to clarify the effect of transplanted human tumor tissues on host liver lipid metabolism. The total lipid was extracted and separated into phospholipid, triglyceride, and other fractions by thin layer chromatography. The amounts of methyl esters of fatty acids of each lipid fraction were measured by quantitative gas liquid chromatography after each lipid fraction had been subjected to methanolysis by 5% HCl‐methanol. The phospholipid content of liver tissues of six tumor bearing nude mice was increased and the triglyceride content decreased in comparison with these fractions in three control nude mice. The ratio of the phospholipid fatty acid content to the triglyceride fatty acid content (phospholipid∶triglyceride [PL∶TG]) of six tumor bearing nude mice was distributed between 7.6 and 33.5, whereas PL∶TG ratios of three control nude mice were distributed between 1.7 and 3.8. This result was similar to that reported for human liver tissues of patients with malignant neoplastic disease, indicating that nude mice with transplanted human cancer may be useful for clarifying the mechanisms of the lipid‐chemical changes of liver tissues of patients with malignancies.
Methodology for separation of gangliosides from potential water‐soluble precursors
Authors: Carter T. P. , Kanfer J. 
Published: November 2006

AbstractThe following methods were examined for their ability to remove labeled nucleotide sugars and other water‐soluble precursors from ganglioside preparations: enzymatic digestion of nucleotide sugars followed by dialysis; silicic acid and Sephadx G‐25 column chromatography; ascending paper chromatography; high voltage paper electrophoresis; thin layer chromatography; co‐precipitation of gangliosides and bovine serum albumin with trichloroacetic acid. A procedure was developed which allows these complex glycosphingolipids to remain in the chloroform‐rich lower phase during conventional Folch partitioning.
Inhibition of staphylococcus aureus lipase activity by alcohol
Authors: Mates A. 
Published: November 2006

AbstractA series of saturatedn‐primary alcohols has been examined for its inhibitory effect on staphylococcal lipase. The efficiency of the inhibition of hydrolysis of the triglycerides increased with the chain length of the alcohol and reached a maximum of seven carbon atoms. Further increases in the chain length caused a decrease in the inhibitory ability of the alochol. However the efficiency of the inhibitory effect on Tween 80 hydrolysis increased with the chain length up to 12 carbon atoms. The degree of inhibition caused with the removal of the hydroxyl group away from the end of the chain. The similar keto compounds were more effective than were the alochol compounds. The effect of the alcohols on the enzyme activity could be overcome by addition of more substrate. Evidence is presented that shows that the inhibiting activity of the alcohol is due to its adsorption onto the substrate, thus blocking the enzyme from the substrate.
Biological effects of autoxidized safflower oils
Authors: Nakamura M. , Tanaka H. , Hattori Y. , Watanabe M. 
Published: November 2006

AbstractStudies on the biological effects of autoxidized safflower oil are reported. Autoxidized safflower oil (peroxide value 465 me/kg) was administered daily by intubation in doses of 1 ml to weanling male rats of the Sprague‐Dawley strain. Groups of rats were killed at 3 days, 3 weeks and 3 months after starting the daily doses. The growth curves, weights of organs, light and electron microscopic examinations, chemical analysis of blood and liver, and the in vitro conversion of 1‐14C‐sodium acetate to CO2, cholesterol and fatty acids in liver slices were studied. Growth was suppressed and the weights of the livers were increased by administration of the autoxidized safflower oil. Light microcopic examination revealed no significant changes in the liver, but marked changes in the endoplasmic reticulum and an increase in the number of microbodies in liver cells of the animals after 3 days and accumulation of lipofuscin‐like substances in liver cells of animals after 3 months were demonstrated by electron microscopy. Serum glutamic oxaloacetic transaminase and serum glutamic pyruvic transaminase increased in animals of the treated groups. Although triglyceride, cholesterol and phospholipid in the plasma did not show any specific changes, triglyceride increased in the livers of the animals after 3 days but markedly decreased in the animals after 3 months. There was no marked effect on the14C incorporation into CO2, but decreased incorporations into cholesterol were demonstrated in the treated animals. The incorporation of14C into fatty acid was increased by the liver slices of rat after 3 days, but was decreased in the liver slices of animals after 3 weeks and 3 months. These results suggest that the marked decrease in triglyceride in the liver of the 3 month group of animals was partly due to a decreased capacity to synthesize fatty acid in the liver.
Specificity of digestive lipases in hydrolysis of wax esters and triglycerides studied in anchovy and other selected fish
Authors: Patton J. S. , Nevenzel J. C. , Benson A. A. 
Published: November 2006

AbstractThe physiological specificity of fat digestion in several species of marine fish was studied by incubating a variety of synthetic and natural lipid substrates in fish intestinal fluid. Wax ester and triglyceride hydrolyses were studied in vivo and in vitro. In vivo feeding studies showed triglyceride hydrolyses and reesterification in the gut occurred 4 times faster than wax ester metabolism. In vitro comparisons of wax and triglyceride lipolysis always showed triglycerides to be hydrolyzed faster than wax esters; however, wide variation in the ratio occurred among different batches of intestinal juice. Ca. 50% of the 2‐monoglycerides formed in the lipolytic sequence were hydrolyzed. Esters of lipase resistant fatty acids (20∶4 and 20∶5) were cleaved faster than normal fatty acid esters (18∶2 and 18∶3). Two of the species studied, the northern anchovy,Engraulis mordax and the jack mackerel,Trachurus symmetricus, empty lipase(s) into their gall bladders and produce phospholipid‐free bile.
Positional specificity of γ‐ketol formation from linoleic acid hydroperoxides by a corn germ enzyme
Authors: Gardner H. W. , Kleiman R. , Christianson D. D. , Weisleder D. 
Published: November 2006

AbstractWe have shown unequivocally that the positional specificity of γ‐ketol formation by a corn germ enzyme was different from that observed previously by others with an alfalfa seedling enzyme. When the pure positional isomers of linoleic acid hydroperoxide served as substrates, the corn germ enzyme formed one of two γ‐ketols: 12‐oxo‐9‐hydroxy‐trans‐10‐octadecenoic acid from 13‐hydroperoxy‐cis‐9,trans‐11‐octadecadienoic acid (99+% pure) and 10‐oxo‐13‐hydroxy‐trans‐11‐octadecenoic acid from 9‐hydroperoxy‐trans‐10,cis‐12‐octadecadienoic acid (96% pure). Also isolated from these reactions was one of two α‐ketols commonly found as a result of catalysis by linoleic acid hydroperoxide isomerase: 12‐oxo‐13‐hydroxy‐cis‐9‐octadecenoic acid from the 13‐hydroperoxide and 10‐oxo‐9‐hydroxy‐cis‐12‐octadecenoic acid from the 9‐hydroperoxide. Evidence is offered that γ‐ketol formation is catalyzed by linoleic acid hydroperoxide isomerase, the same enzyme responsible for α‐ketol production.
Phosphatidyl choline: Donor of 18‐carbon unsaturated fatty acids for glycerolipid biosynthesis
Authors: Roughan P. G. 
Published: November 2006

AbstractKinetics of radiocarbon incorporation into the phosphatidyl choline of pumpkin leaf fed 1‐14C‐acetate at low light intensity were strongly suggestive of lipid bound fatty acids acting as substrates for desaturase enzymes. After pulse labeling in direct sunlight with the same precursor, phosphatidyl choline and phosphatidyl glycerol contained up to 90% of total glycerolipid radiocarbon at the shortest sampling times. Subsequent loss of radiocarbon from phosphatidyl choline and a corresponding gain in other glycerolipids is taken to indicate a net flow of long chain fatty acids through phosphatidyl choline and into other lipids. It is proposed that there may be 2 separate synthetases in leaf tissue, one producing oleic and the other palmitic acids as their end products. Oleic acid is transferred almost exclusively to phosphatidyl choline, where it is further desaturated to linoleic and linolenic acids before being made available for the biosynthesis of other lipids. Palmitic acid is transferred mainly to phosphatidyl glycerol, where it is desaturated totrans‐Δ3‐hexadecenoic acid.
Analysis of methylsterol fractions from twenty vegetable oils
Authors: Jeong T. M. , Itoh T. , Tamura T. , Matsumoto T. 
Published: November 2006

AbstractThe 4‐monomethylsterol and 4,4‐dimethylsterol fractions were separated from the unsaponifiables of 20 vegetable oils by preparative thin layer chromatography, and their compositions were determined by gas liquid chromatography. Tentative identification of the individual components of these fractions was carried out by gas liquid chromatography and combined gas liquid chromatographymass spectrometry. Among 4‐monomethylsterols, obtusifoliol, gramisterol, and citrostadienol occur abundantly in most of the oils. Cycloeucalenol also occurs in some of the oils as a major component of 4‐monomethylsterols. Other 4‐monomethylsterols tentatively identified are: lophenol, 31‐norlanosterol, 31‐norcycloartenol, and 31‐norlanostenol and/or 4α‐methylzymostenol. Among 4,4‐dimethylsterols, cycloartenol and 24‐methylenecycloartanol followed by β‐amyrin and cycloartanol are common to most of the oils. Butyrospermol, α‐amyrin, lupeol, and cyclobranol together with a 4,4‐dimethylsterol, presumably lanostenol, occur in some of the oils. Cyclolaudenol is present in poppy seed oil. Besides these compounds, each of the oils contains some unidentified members of 4‐monomethylsterols and 4,4‐dimethylsterols. The methylsterol fraction of capsicum seed oil as compared with that of the other oils is characterized by its very high content of lophenol and cycloartanol together with three other members, presumably 31‐norlanostenol, 4α‐methylzymostenol, and lanostenol.
Changes with diet in the composition of phosphatidyl choline of sheep bile
Authors: Christie W. W. , Moore J. H. , Noble R. C. , Vernon R. G. 
Published: November 2006

AbstractBile phosphatidyl choline from sheep, in contrast to that from nonruminants, contains low levels of the normal range of polyunsaturated fatty acids. A comparison has been made of the composition of bile phosphatidyl cholines from sheep receiving either a control diet, a control diet supplemented with unprotected maize oil, or a control diet supplemented with soybean oil or tallow that had been protected against hydrolysis and hydrogenation in the rumen. The composition of bile phosphatidyl choline from sheep receiving protected soybean oil supplement was virtually indistinguishable from that from nonruminants.