bluuebunny/crossref_metadata_2025_split huggingface dataset:
Phospholipid studies of marine organisms: III. New phospholipid fatty acids fromPetrosia ficiformis
Authors: Ayanoglu Eser , Walkup Robert D. , Sica Donato , Djerassi Carl 
Published: December 2006

AbstractThe fatty acyl components of the phospholipids from the spongePetrosia ficiformis consisted predominantly of branched, especially iso and anteiso acids. The two major components of the complex mixture are the hitherto unknown Z,Z‐25‐methyl‐5,9‐hexacosadienoic and Z,Z‐24‐methyl‐5,9‐hexacosadienoic acids. Other unknown acids are: 7,13,16‐docosatrienoic acid, 15‐methyldocosanoic acid, 15‐methyltricosanoic acid and 24‐methyl‐5,9‐pentacosadienoic acid. Short branched‐chain fatty acids, presumably of bacterial origin, are considered to be the possible bioprecursors of these novel phospholipid constituents. The major phospholipids were PE, PC, PG, PS and PI. The distribution of fatty acids among the phospholipid classes was also studied.
Isolation and determination of cholesterol glucuronide in human liver
Authors: Hara Atsushi , Taketomi Tamotsu 
Published: December 2006

AbstractSeparation of the acidic lipid fraction from human liver led to the identification of cholesterol‐β‐glucuronide for the first time from this organ. Cholesterol glucuronide was purified by DEAE‐Sephadex column chromatography and preparative silica gel thin‐layer chromatography. The content in normal human liver was about 33 nmol/g wet tissue. It must be emphasized that cholesterol glucuronide cannot be distinguished readily from ganglioside GM4 by thin‐layer chromatography.
Uptake and metabolism of free fatty acids by the morris 7777 hepatoma and host rat liver
Authors: Morton Richard E. , Waite Moseley , Lynn King V. , Morris Harold P. 
Published: December 2006

AbstractThe relative capacity of Morris 7777 hepatomas and livers of tumor‐bearing rats to take up and subsequently metabolize intravenously injected radiolabeled free fatty acids was investigated. The objective was to determine differences in lipid metabolism which may affect the lipid composition previously observed in this tumor. Both tissues demonstrated comparable selectivity in the uptake of palmitate, linoleate and arachidonate from blood, although the hepatoma took up one‐tenth as much free fatty acid per g wet wt as liver. A much greater percentage of fatty acid taken up by the hepatoma was converted to aqueous soluble radioactivity, perhaps the result of oxidation. In the hepatoma, palmitate was incorporated into phospholipid molecular species in a pattern similar to that observed for diglyceride, which suggested that phospholipid synthesis occurred predominantly de novo. On the other hand, in liver, a large percentage of palmitate was incorporated into polyunsaturated phospholipid molecular species that were not present in the diglyceride pool, which suggested significant incorporation by the acylation of monoacyl phosphoglycerides. These studies indicate that the specificity for the uptake of fatty acids was not different in the two tissues; however, the subsequent metabolic processes are markedly different.
13C nuclear magnetic resonance spectroscopic analysis of seed oils containing conjugated unsaturated acids
Authors: Tulloch A. P. 
Published: December 2006

Abstract13C Nuclear magnetic resonance spectroscopy has been used in a nondestructive investigation of conjugated unsaturated acids in seed oil triacylglycerols. Spectra of seven seed oils, fromPunica granatum, Cucurbita palmata, Jacaranda mimosifolia, Centranthus ruber, Catalpa bignonioides, Chilopsis linearis andCalendula officinalis, containing among them six isomeric trienoic acids,cis,trans,cis‐ andtrans,trans,cis‐8,10,12‐,cis,trans,cis‐, cis,trans,trans‐, trans,trans,cis‐ andtrans,trans,trans‐9,11,13‐octadecatrienoic acids, and of the oil ofImpatiens balsamina containingcis,trans,trans,cis‐9,11,13,15‐octadecatetraenoic acid, have been examined. Structures of component acids were derived from shifts of double bond carbons and of carbons close to the double bond systems. Compositions of the oils were obtained from signal intensities. Results were similar to those obtained by older methods. Only oil ofCentranthus ruber contained more than one major conjugated acid; bothcis,trans,trans‐ andtrans,trans,trans‐9,11,13‐octadecatrienoic acids were found. The latter acid is now thought to occur naturally.
Enzymatic hydrolysis of fractionated products from oils thermally oxidized in the laboratory
Authors: Yoshida Hiromi , Alexander J. C. 
Published: December 2006

AbstractEnzymatic hydrolysis of the acylglycerol products obtained from thermally oxidized vegetable oils was studied. Corn, sunflower and soybean oils were heated in the laboratory at 180 C for 50, 70 and 100 hr with aeration and directly fractionated by silicic acid column chromatography. By successive elution with 20%, then 60% isopropyl ether inn‐hexane, and diethyl ether, the thermally oxidized oils were separated into three fractions: the nonpolar fraction (monomeric compounds), slightly polar fraction (dimeric compounds), and polar fraction comprising oligomeric compounds. Enzymatic hydrolysis with pancreatic lipase showed that the monomers were hydrolyzed as rapidly as the corresponding unheated oils, the dimers much more slowly, and the oligomeric compounds barely at all. Overall, the hydrolysis of the dimers was less than 23% of that for the monomers, with small differences among the oils. Longer heating periods resulted in greater reductions in hydrolysis of the dimeric compounds. These results suggest that the degree of enzymatic hydrolysis of the fractionated acylglycerol compounds is related to differences in the thermal oxidative deterioration, and amounts of polar compounds in the products.
Metabolism of sterols by anaerobicSaccharomyces cerevisiae
Authors: Sekula Bernard C. , Nes William R. 
Published: December 2006

AbstractAnaerobically grownSaccharomyces cerevisiae retained the ability to transfer a C1‐group to the C‐24 position of a Δ24(25)‐sterol and to reduce the Δ24(28)‐bond of a 24‐methylenesterol. Both desmosterol and 24‐methylenecholesterol yielded 24β‐methylcholesterol. However, when the substituent at C‐24 was enlarged to a 24‐ethylidene group (fucosterol), reduction of the Δ24(28)‐bond did not occur. In no cases was a Δ7 a Δ22‐bond introduced. Because the Δ24(28)‐bond was, reduced in the absence of the Δ22‐bond the Δ22 is not an obligatory requirement for reduction.
Suppression of hepatocyte fatty acid synthesis by albumin‐bound linoleate involves depolymerization of acetyl‐CoA carboxylase filaments
Authors: Clarke Steven D. , Hillard Bruce L. 
Published: December 2006

AbstractDigitonin treatment of chick liver cells in monolayer culture results in plasma membrane perforations due to digitonin removal of membrane cholesterol. The amount and rate of acetyl‐CoA carboxylase activity that escapes from the hepatocyte during digitonin treatment is positively related to the amount of protomeric carboxylase in the cells. Incubation of chick liver cells in culture with albuminbound linoleate (60 min) caused a 3‐fold increase in the amount of carboxylase activity released during exposure of cells to digitonin. Concomitant with the enhanced release of carboxylase activity was an 85% reduction in fatty acid synthesis induced by linoleate. Apparently, acute suppression of hepatocyte fatty acid synthesis by media free fatty acids resulted, in part, from a change in carboxylase conformation from the active polymeric state to the inactive protomeric form.
Interrelationship between the dietary regulation of fatty acid synthesis and the fatty acyl‐CoA desaturases
Authors: Jeffcoat R. , James A. T. 
Published: December 2006

AbstractIn this paper we present further evidence for the close control of fatty acid synthetase and stearoyl‐CoA desaturase. Furthermore, we have established that whereas dietary palmitic acid may influence the activity of this desaturase but not of fatty acid synthetase, dietary linoleic acid appears to control both these enzymes. Finally, we have studied the influence of dietary fat and carbohydrate on the activities of the Δ6 and Δ5 desaturases. The former is only slightly affected by these dietary components. The Δ5 desaturase activity is stimulated as the dietary fat content rises but is un‐affected by dietary carbohydrate. The control of these enzymes is therefore independent of the control of fatty acid synthetase and stearoyl‐CoA desaturase. From the data presented, the magnitude of the controlling effect of polyunsaturated fatty acids on fatty acid synthetase and stearoyl‐CoA desaturase activity is determined and its relevance to lipogenesis in man based on daily intake of carbohydrate and linoleic acid is discussed.
Analysis of oleate and linoleate hydroperoxides in oxidized ester mixtures
Authors: Wong Wing‐sum Dominic , Hammond E. G. 
Published: December 2006

AbstractThe hydroperoxides in oxidized mixtures of methyl oleate and linoleate were reduced to the corresponding hydroxyesters, which were separated from unoxidized esters by thin layer chromatography on silica gel. The hydroxyesters from oleate and linoleate were converted to trimethylsilyl ethers and separated by gas chromatography on OV 225. The results suggest that methyl linoleate oxidizes about ten times faster than methyl oleate, but oleate hydroperoxides are formed in appreciable amounts, even in mixtures containing 87% methyl linoleate.
Studies on the inhibition of the desaturases by cyclopropenoid fatty acids
Authors: Jeffcoat R. , Pollard M. R. 
Published: December 2006

AbstractUnwashed rat liver microsomes were used to study the inhibition of the Δ6 and Δ9 desaturases by cyclopropenoid fatty acids with the ring structure about the 9,10 or 6,7 carbon atoms. The 9,10 cyclopropenoid acid (sterculic acid) is shown to be an effective inhibitor of only Δ9 desaturase and then only in the presence of MgCl2 and coenzyme A (prepresence of MgCl2 and coenzyme A (presumably due to the formation of sterculoyl‐CoA). Two 6,7 cyclopropenoid acids of different chain lengths showed no marked inhibition of either the Δ6 or Δ9 desaturase. By the use of [3H]‐sterculic acid, it has been shown that under conditions of high inhibition of the Δ9 desaturase the inhibitor is not covalently attached to the enzyme at any point. This disproves older ideas on the mechanism of inhibition that assumed reaction between the cyclopropenoid ring and sulphydryl groups on the enzymes.
The effect of various dietary factors on the size distribution of lymph fat particles in rat
Authors: Boquillon Micheline , Paris Roger , Clement Jacqueline 
Published: December 2006

AbstractBy means of cellulose acetate electrophoresis and measurement of radioactivity, lipoproteins (d≤1,006) of lymph collected from rats fed a diet containing fats added to labeled fatty acids for 20–24 hr, have been separated into two kinds differing in their size. Fats with different saturated and unsaturated fatty acid content were tested: corn oil, lard, mutton tallow, tripalmitin, corn oil‐lard mixture, and randomized palmitic‐linoleic triglycerides. Factors studied were: (a) increased amounts of these fats given alone or included in a test meal; (b) added amounts of nutrients (other than fats) in the test meal; (c) adaptation to a diet containing 20% fat for 10 days. The major part of the labeled lymph lipid was always transported by the smaller particles. Size distribution of lymph fat particles was influenced by some of the factors studied. Generally, unsaturated fats produced higher amounts of larger particles.
Thiobarbituric acid reaction of methyl arachidonate monohydroperoxide isomers
Authors: Terao J. , Matsushita S. 
Published: December 2006

AbstractMethyl ester of monohydroperoxy eicosatetraenoic acid (MeHPETE) was prepared from methylene blue sensitized photooxidation products of methyl arachidonate. The thiobarbituric acid (TBA) value of MeHPETE was increased by adding ferrous sulfate to the reaction mixture. A linear relationship existed betweent he TBA value and the concentration of MeHPETE when ferrous sulfate was added. By using high performance liquid chromatography, MeHPETE was separated into 5 fractions whose isomeric compositions were determined by gas chromatography‐mass spectrometry. The results of the TBA test for each fraction suggest that all of the MeHPETE isomers are positive to the TBA test. It is concluded that each isomer of HPETE formed by peroxidation of arachidonic acid in a biological system can yield TBA‐reacting materials during the test reaction.
The effect of different proportions of casein in semipurified diets on the concentration of serum cholesterol and the lipoprotein composition in rabbits
Authors: Terpstra A. H. M. , Harkes L. , van der Veen F. H. 
Published: December 2006

AbstractThe effect of different proportions of casein in semipurified diets on the concentation of serum cholesterol and the lipoprotein composition was studied in rabbits. Low‐casein diets (10% w/w) resulted in serum cholesterol levels and growth rates that were lower than high‐casein diets (40%). An intermediate proportion of casein (20%) produced intermediate concentrations ofserum cholesterol, but only minor differences in food intake and weight gain, compared with the high‐casein group. In the animals with the highest values of total serum cholesterol (the 40% casein group), most of the serum cholesterol was transported in the very low density lipoproteins, whereas with moderate hypercholesterolemia (the 20% casein group), the low density lipoproteins were the main carriers of cholesterol. Elevation in lipoprotein cholesterol was associated in all groups with an increased ratio of cholesterol to protein, suggesting the formation of particles relatively rich in cholesterol. When the rabbits on the diet containing 10% casein were subsequently transferred to the 40% casein diet, a steep increase in the level of serum cholesterol occurred. Conversely, switching the rabbits on the 40% casein diet to the 10% casein diet resulted in a decrease in the level of serum cholesterol.
A lysosomal enzyme involved in diphosphatidylglycerol degradation
Authors: Werchola George Michael , Mellors Alan 
Published: December 2006

AbstractA soluble lysosomal phosphodiesterase in rat liver that hydrolyzes monoacyglycerophosphoryl‐glycerophosphorylglycerol (AGPGPGase) was shown to be distinct from a lysosomal acid phosphodiesterase IV (PDase IV) which catalyzes the hydrolysis of bis(p‐nitrophenyl) phosphate. The criteria used to distinguish lysosomal AGPGPGase from PDase IV were: separation on ion exchange celluloses, dissimilar inhibition patterns and different rates of inactivation on concentration. The lysosomal PDase IV activity was competitively inhibited by inorganic phosphate with a Ki value of 0.33 mM phosphate and was inhibited by a number of organophosphoryl compounds including AGPGPG, phosphatidylcholine, phosphatidylinositol, ATP and 4‐methylum belliferylpyrophosphate.
Stereospecific analysis of fatty acid esters of chloropropanediol isolated from fresh goat milk
Authors: Myher J. J. , Kuksis A. , Marai L. , Cerbulis J. 
Published: December 2006

AbstractThe fatty acid esters of chloropropanediol isolated from goat milk fat in small quantities were subjected to a stereospecific analysis via phospholipase C and phosphocholine esters as intermediates. Synthetic rac‐1‐chloro‐2,3‐dioleoyl‐propanediol was prepared by standard methods and was used as a control. The stereospecific analyses were performed following a release of the fatty acids from the primary positions of each chloropropanediol diester with pancreatic lipase. The resulting X‐1‐chloro‐2‐acylpropanediols were then converted into the corresponding phosphocholine derivatives by a stepwise reaction with phosphorus oxychloride and choline chloride. The X‐1‐chloro‐2‐acyl‐3‐phosphocholinepropanediols were subjected to hydrolysis with phospholipase C (C. perfringens), which hydrolyzed 50% of the phosphatide within two min and the rest of it in two hr. From previous experience with glycerol esters, it was assumed that the more rapidly hydrolyzed molecules were the sn‐1‐chloro‐2‐acyl‐propanediol derivatives and the more slowly hydrolyzed ones the sn‐2‐acyl‐3‐chloropropanediol derivatives. A hydrolysis with phospholipase A2 (Crotalus adamanteus) released 50% of the total fatty acid along with the corresponding lyso compound within 10 min, after which there was no further reaction. The hydrolysis products were assayed directly by gas liquid chromatography (GLC) or were isolated by thin layer chromatography (TLC) prior to quantitation by GLC. Both naturally occurring and synthetic chloropropanediol diesters behaved similarly on stereospecific analysis and were therefore concluded to be racemic.
Influence of dietary fiber on lipids and aortic composition of vervet monkeys
Authors: Kritchevsky David , Davison Larry M. , Goodman Gordon T. , Tepper Shirley A. , Mendelsohn Dennis 
Published: December 2006

AbstractA semipurified, cholesterol‐free diet containing 40% carbohydrate can produce aortic sudanophilia or aortic atherosclerosis in vervet monkeys (Ceroopithecus aethiops pygerethrus) depending on the particular carbohydrate fed. Four groups of vervet monkeys (three males and three females per group) were fed semipurified diets containing lactose. Two of the groups were also fed 15% cellulose (C) or 15% cellulose plus 0.1% cholesterol (CC); the two other groups were fed 15% pectin (P) or 15% pectin plus 0.1% cholesterol (PC). The average serum total cholesterol and low density lipoprotein cholesterol levels over the entire feeding period (mg/dl±SEM) were, for C, 156±14 and 95±5; for P, 173±15 and 112±8; for CC, 187±27 and 122±21; and for PC, 155±11 and 108±7. Cholesterol levels at autopsy (mg/dl±SEM) were, for C, 103±6; for P, 108±16; for CC, 92±9; and for PC, 106±7. Aortic sudanophilia (percentage of area) was, for C, 5.9±2.7; for P, 13.5±9.4; for CC, 5.3±2.1; and for PC, 21.6±10.3. Dietary pectin led to more severe sudanophilia (increased by 129% in the absence of cholesterol and by 308% in its presence) than did cellulose. Analysis of aortic glycosaminoglycans (GAG) revealed that dermatan sulfate levels fell in both cholesterol‐fed groups, and chondroitin sulfate fell in aortas of group CC. Heparan sulfate levels were unaffected by cholesterol feeding. Hexuronic acid, galactosamine and hexosamine levels were elevated in the pectin‐fed monkeys, but levels were unaffected by dietary cholesterol. Pectin may contribute galactosamine and glucuronic acid towards aortic GAG.
Lipid content of swine influenza and other vaccines
Authors: Leskawa Kenneth C. , Hogan Edward L. , Dasgupta Somsankar , Chien Jaw‐Long , Erwin Robert E. , Brostoff Steven W. 
Published: December 2006

AbstractAn analysis of the lipids in swine influenza vaccines was performed, comparing six different lots of swine influenza, other influenza and noninfluenza vaccines. Cholesterol content and phospholipid content varied greatly, but there were no major differences between the types of vaccines. Appreciable amounts of phosphatidylethanolamine were found in only one swine influenza vaccine. The major phospholipids of influenza vaccines were phosphatidylcholine, sphingomyelin and phosphatidic acid. A detectable amount of phosphatidylserine was not found in any swine influenza vaccine, but was present in two of three nonswine influenza vaccines. Only two of six swine influenza vaccines showed trace amounts (less than 0.5 μg/ml) of ganglioside (GM3). However, larger quantities of galactocerebroside were found (2.24–6.43 μg/ml) in all influenza vaccines examined, including swine influenza vaccines.
Quantitation of dolichyl phosphate and dolichol in major organs of the rat as a function of age
Authors: Kennedy Keller R. , Nellis Steven W. 
Published: December 2006

AbstractPrevious studies in mice and humans have shown age‐related increases in the levels of dolichol in all organs investigated. In the present study, the levels of dolichyl phosphate, the physiologically active form of dolichol, as well as dolichol and cholesterol were determined in five major organs of the rat from 4 to 14 wk of age. As observed for mice and humans, the levels of dolichol increased in all tissues examined, especially testis where an eightfold increase was found. Cholesterol levels remained relatively constant in all tissues examined except brain, where a threefold increase was observed. Hepatic dolichyl phosphate levels decreased slightly during growth while nonhepatic tissues showed moderate (1.2–1.7‐fold) increases. It is proposed that steady‐state levels of hepatic dolichyl phosphate are maintained in the face of constant de novo synthesis by a combination of two pathways: export, either via the circulation or the previously demonstrated fecal route (Connelly and Keller [1984]bioscience Reports 4, 771–776) and conversion to dolichol with subsequent accumulation.
Dietary lipid modulation of immune responsiveness
Authors: Erickson Kent L. , Adams Dorothy A. , McNeill Carla J. 
Published: December 2006

AbstractThe influence of dietary fat concentration and saturation on blastogenesis, cytotoxicity, antibody response and fatty acid composition of murine splenic lymphocytes was studied. Blastogenesis of lymphocytes from dietarily manipulated mice in response to alloantigens from control mice was significantly greater for those mice fed a diet containing minimal essential fatty acids (EFA) as the only fat source (EFA control) than those fed an EFA‐deficient diet. When the dietary fat concentration was increased, blastogenic responses decreased compared to the EFA control diet. Lymphocyte‐mediated cytotoxicity against allogeneic melanoma cells was greater for mice receiving diets with EFA only than for those deficient in EFA. However, cytotoxicity responses of mice fed additional polyunsaturated fat (PUF) decreased as concentration increased, whereas responses of mice fed the saturated fat (SF) diets decreased only when the dietary fat concentration was greater than 8%. As compared to diets with EFA control, direct plaqueforming cell (PFC) response was decreased for mice fed high levels of PUF and increased for mice fed high levels of SF; however, no difference in the percentage of IgM‐positive cells was observed. These changes in PFC response were inversely related to the levels of linoleic acid in the lymphocyte. Thus, high levels of dietary fat, and particularly PUF, suppress lymphocyte functions when EFA requirements are met, whereas low levels (EFA control) intensify these responses. EFA deficiency, however, suppresses some lymphocyte responses. Thus, dietary lipids differentially modulate the levels of T‐ and B‐cell responsiveness.