bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterization of two steroidal olefins in nonfat dry milk
Authors: Flanagan Vincent P. , Ferretti Aldo , Ruth John M.
Published: December 2006

Two steroidal olefins were isolated from the hydrocarbon fraction of a n‐hexane extract of nonfat dry milk. They were characterized as 24‐methyl‐Δ2‐cholestene (Δ2‐campestene) and 24‐ethyl‐Δ2‐cholestene (Δ2‐sitostene) by gas chromatography, mass spectrometry, and synthesis.
Brain cholesterol: XVI. Incorporation of different precursors into baboon tissue sterol
Authors: Kabara Jon J.
Published: December 2006

The relative order of incorporation of 1‐C14‐acetate and 2‐3H‐acetate into tissue cholesterol was similar. Short term fasting tended to decrease incorporation of acetate into liver and adrenal sterol. Other tissues, particularly neural, had the same or showed an increased incorporation. This relative order of incorporation found for acetate was different when U‐14C‐glucose was used. Cholesterol values from neural tissue after glucose were greater than non‐neural sterol values.
The structures of the principal glycerolipids of pig liver
Authors: Hunter M. L. , Christie W. W. , Moore J. H.
Published: December 2006

The lipid composition of pig liver has been determined. The principal glycerolipids, i.e., triglycerides, phosphatdyl choline, phosphatidyl ethanolamine and phosphatidyl inositol, were isolated and the positional distribution of fatty acids in each determined by stereospecific analysis procedures. Previous results for the triglycerides were confirmed, while the phospholipids were similar in structure to those found in most other animal livers. The triglycerides were separated into simpler molecular species by combinations of silver nitrate thin layer chromatography and high temperature gas liquid chromatography, but the proportions found did not agree well with those calculated assuming a 1‐random, 2‐random, 3‐random arrangement. The phospholipids were hydrolyzed with phospholipase C and converted to diglyceride acetates that were fractionated into simpler molecular species by the same procedures as were used with triglycerides. Highly specific fatty acid combinations were found in molecular species, and these specificities were very similar to those reported in similar lipids from the livers of such disparate species as the rat and chicken.
Identification of 18‐oxo‐9,10‐epoxystearic acid, a novel compound in the cutin of young apple fruits
Authors: Kolattukudy P. E.
Published: December 2006

18‐Oxo‐9,10‐epoxystearic acid was identified in the cutin of young apple fruits by hydrogenolysis with LiAlH4, deuterolysis with LiAlD4, CrO3 oxidation of deuterated product followed by reduction with LiAlH4 and mass spectrometry of the products.
Prostaglandins in swine testes
Authors: Michael C. M.
Published: December 2006

The prostaglandin content of swine testes was investigated. It was found that PGE1, PGE2, PGF1 and PGF2 were present, and the amount of total PGE's and PGF's was determined.
Characterization of plasma lipoproteins in swine with different propensities for obesity
Authors: Etherton Terry D. , Kris‐Etherton P. M.
Published: December 2006

Yorkshire (lean) and Ossabaw (obese) swine ca. one year of age were used to characterize the quantity and composition of plasma lipoproteins in animals with markedly different adiposity. While lean swine weighed more (175 vs 88 kg for obese), they had less backfat than obese swine (2.64 vs 5.97 cm; P<0.05). Fasting plasma triacylglycerol (Tg) and cholesterol (CH) levels were elevated in obese swine. Swine plasma lipoproteins were fractionated into very low density lipoprotein (VLDL; d<1.006), low density lipoprotein1 (LDL1; d=1.019–1.063), low density lipoprotein2 (LDL2; d=1.063–1.09), and high density lipoprotein (HDL; d=1.09–1.21) by density ultracentrifugation. Obese VLDL‐Tg, CH and protein (Pr) were elevated more than 2‐fold. VLDL from obese swine were 2‐fold larger than VLDL from lean swine. No alterations in LDL1 or LDL2 composition were observed. HDL‐Tg, CH, Pr and phospholipid levels were significantly higher in obese swine. Plasma and VLDL‐Tg levels were highly correlated with backfat thickness (r=0.67 and r=0.73, respectively). These was a positive correlation between adiposity and HDL‐CH as well as VLDL‐Tg and HDL‐CH. These data indicate that (a) there are marked alterations in swine plasma lipoprotein composition between lean and obese swine; (b) that swine plasma lipoprotein levels may be useful parameters in estimating body composition; and (c) that HDL‐CH is positively correlated with adiposity in swine.
Selectivity in incorporation, utilization and retention of oleic and linoleic acids by human skin fibroblasts
Authors: Rosenthal Miriam D.
Published: December 2006

Fetal human fibroblasts were grown in culture medium containing 10% fetal bovine serum supplemented with [1‐14C] linoleate or [1‐14C] oleate. At all concentrations of exogenous fatty acids, the incorporation of oleate was greater than that of linoleate. With increased medium fatty acid concentrations, linoleate in triacylglycerol (TAG) could be increased from 13 to 75% of the total incorporated; at each concentration, relatively more linoleate than oleate was in TAG. When the cells were exposed to exogenous oleate/linoleate mixtures, the composition of the mixture determined the extent of incorporation of both fatty acids. When the mixture was primarily linoleate, scarce oleate was used preferentially for phospholipids (PL); no such specificity for scarce linoleate was observed. Addition of exogenous fatty acids resulted in a shift of previously incorporated14C fatty acids from phospholipid into TAG; retention of oleate in PL was greater than that of linoleate. Incorporation of oleate into phospholipids was also higher than that of linoleate from exogenous fatty acid mixtures which were 80% saturated. It is suggested that normal human fibroblasts have adapted to the low levels of exogenous polyunsaturated fatty acids in culture media by increased use of oleate in phospholipid. Even when the cells aresupplemented with linoleate, the preferential use of oleate in phospholipid groups is retained.
Origins of the cholesterol in milk
Authors: Long Carol A. , Patton Stuart , McCarthy Robert D.
Published: December 2006

Studies were conducted to investigate the origin of milk cholesterol in the ruminant. In the first experiment, [1‐14C] sodium acetate was infused into one side of the udder of a lactating goat via the teat canal whereas in the second, [1,2‐3H] cholesterol was injected intravenously and concurrently with a [14C] acetate intrammamary infusion. In both experiments, blood and milk samples were collected at intervals for 6 days postinjection. Maximum unesterified cholesterol specific activity (sp act) in whole milk appeared at 78 hr after intravenous injections of3H cholesterol and within 3–7 hr after infusion of [14C]acetate. Virtually all the tritium in milk was associated with unesterified cholesterol. The sp act of14C‐labeled cholesterol was only 20% of gland‐synthesized decanoic acid. Decanoic acid is known to be completely synthesized in the mammary gland, and, like cholesterol, acetate is its precursor. The results indicate that, although some milk cholesterol is synthesized in the mammary gland, it is derived principally from serum cholesterol. The data show also that serum cholesterol equilibrates with membrane cholesterol of the lactating cell prior to its secretion in milk.
Distribution of deuterium‐labeledcis‐andtrans‐12‐octadecenoic acids in human plasma and lipoprotein lipids
Authors: Emken E. A. , Dutton H. J. , Rohwedder W. K. , Rakoff Henry , Adlof R. O. , Gulley R. M. , Canary J. J.
Published: December 2006

Triglycerides containingcis‐ andtrans‐12‐octadecenoic acid (12c‐18∶1 and 12t‐18∶1) andcis‐9‐octadecenoic acid (9c‐18∶1) labeled with deuterium were fed to 2 young adult male subjects. These fatty isomers each contained a different number of deuterium labels, which allowed mass spectrometric analysis to distinguish among them after they were fed as a mixture. This approach results in a direct comparison of the absorption and distribution of these 3 monoenoic acids into blood plasma and lipoprotein lipids. Plasma lipid data indicated that all phospholipid fractions selectively incorporate 12c‐18∶1 and 12t‐18∶1 in preference to 9c‐18∶1. Discrimination against 12c‐18∶1 and 12t‐18∶1 compared to 9c‐18∶1 was found in the plasma neutral lipids, with a strong discrimination against 12t‐18∶1 incorporation into the cholesteryl ester fraction. Considerable reduction in the percentage of linoleic and arachidonic acid was observed when 12–18∶1 isomers were incorporated in plasma triglyceride, phosphatidylcholine and sphingomyelin samples. Chylomicron lipid analyses indicated that all isomers were well absorbed. Variation was observed in the relative distribution of 12c‐18∶1, 12t‐18∶1 and 9c‐18∶1 between the very low density, low density and high density lipoprotein lipid classes. No desaturation of 12c‐18∶1 to linoleic acid was detected.
Incorporation of fatty acids into phospholipids in L cells stimulated by antibody
Authors: Shearer William T. , Ulrich Robert G.
Published: December 2006

Binding antibodies to surface membranes stimulated incorporation of fatty acids (FA) into phospholipids of L cells. Antibodies stimulated at least a 3.4‐fold greater incorporation of arachidonic acid into phosphatidylinositol than into any other class of phospholipid when compared on a molar basis (p<0.003). This enhanced incorpoation was selective, depending on the character of the FA, because antibodies stimulated the incorporation of arachidonic acid at least 2.4‐fold more than oleic acid, palmitic acid or stearic acid (p<0.001). Surprisingly, an antibody‐stimulated incorporation of palmitic acid into sphingomyelin (SM) was at least 2.2‐fold greater than that into any other class of phospholipid (p<0.001) and the antibody‐stimulated incorporation of palmitic acid into SM was at least 60‐fold greater than that of arachidonic acid, stearic or oleic acid (p<0.001). Nontoxic doses of ethylenediamine tetraacetic acid (EDTA), dexamethasone, 4‐bromophenacylbromide and indomethacin inhibited the antibody‐stimulated incorporation of arachidonic acid into cellular phospholipids, principally phosphatidylinositol (PI), and similarly inhibited the antibody stimulation of DNA synthesis. We conclude that when antibody binds to surface antigens on L cells, a rapid and selective incorporation of fatty acids into certain cellular phospholipids occurs, possibly mediated by calcium‐dependent phospholipases. Degradation products of arachidonic acid, i.e., prostaglandins, may be important in these antibody stimulation events, as well. These early changes in phospholipid metabolism may serve as an important signal or mechanism for the subsequent stimulation of DNA synthesis in L cells.
Linoleate hydroperoxides are cleaved heterolytically into aldehydes by a Lewis acid in aprotic solvent
Authors: Gardner H. W. , Plattner R. D.
Published: December 2006

Treatment of isomeric methyl linoleate hydroperoxides with a Lewis acid, BF3, in anhydrous ether led to a carbon‐to‐oxygen rearrangement that caused cleavage into shorter‐chain aldehydes. Methyl (9Z,11E)‐13‐hydroperoxy‐9,11‐octadecadienoate afforded mainly hexanal and methyl (E)‐12‐oxo‐10‐dodecenoate, whereas methyl (10E,12Z)‐9‐hydroperoxy‐10,12‐octadecadienoate cleaved into 2‐nonenal and methyl 9‐oxononanoate. The 2 aldehydes obtained from each hydroperoxide isomer were uncharacteristic of the complex volatile profile usually obtained by β‐scission of oxy radicals derived from homolysis of the hydroperoxide group. Rather, the reaction resembled the one catalyzed by the plant enzyme, hydroperoxide lyase.
Urinary prostaglandin E2 and vasopressin excretion in essential fatty acid‐deficient rats: Effect of linolenic acid supplementation
Authors: Hansen Harald S. , Jensen Benny
Published: December 2006

Three groups of weanling male rats were fed on a fat‐free diet for 13 weeks. One group received only the fat‐free diet (FF rats), the other 2 groups received the fat‐free diet and a daily supplement of 2 energy% ethyl linoleate ([n−6] rats), or 2 energy% ethyl linolenate ([n−3] rats). Urinary excretion of prostaglandin E2 (PGE2), immunoreactive arginine vasopressin (iA VP), and kallikrein were determined. PGE2 was quantitated with a radioimmunoassay having 4.9% cross‐reactivity with prostaglandin E3 (PGE3). After 4 weeks on the diet, water consumption and urinary iAVP excretion increased significantly in the FF rats and the (n−3) rats compared with the (n−6) rats. Urinary PGE2 excretion was the same for all 3 groups during the first 10 weeks; thereafter it decreased in FF rats and (n−3) rats compared with the (n−6) rats. There was no difference in urinary PGE2 excretion between the FF rats and the (n−3) rats, even though large differences were found in the percentage of arachidonic acid (20∶4[n−6]), icosapentaenoic acid (20∶5[n−3]), and icosatrienoic acid (20∶3[n−9]) of total kidney fatty acids as well as of kidney phosphatidylinositol fatty acids. Fractionation of urine extracts on high performance liquid chromatography with radioimmunoassay detection indicated that (n−3) rats excreted very little PGE3, if any. Urine output followed the same pattern, as did urinary PGE2 excretion. Urinary kallikrein was estimated at week 12 only. It was found to be significantly lower in FF rats and (n−3) rats. Increased water consumption and increased urinary iAVP excretion seem to be early symptoms (after 4 weeks) of EFA deficiency, whereas decreased urine output and decreased urinary PGE2 excretion occur much later (after 10 weeks). Two energy% linolenate supplementation to a fat‐free diet did not change the appearance of any of the measured EFA‐deficiency symptoms except for a slightly improved growth rate. There was no evidence of a significant urinary PGE3 excretion in spite of an extreme enrichment of kidney lipids with 20∶5(n−3). It is suggested that urinary PGE2 is derived from precursors delivered from an arachidonic acid pool, which is rather resistant to restriction in dietary linoleate.
Changes in renal phospholipid fatty acids in diabetes mellitus: Correlation with changes in adenylate cyclase activity
Authors: Clark Daniel L. , Hamel F. G. , Queener Sherry F.
Published: December 2006

Male Sprague‐Dawley rats made diabetic with alloxan (37.5 mg/kg) or streptozotocin (65 mg/kg) were killed after 3–6 weeks of disease; renal tissues were studied for phospholipid content and for fatty acid composition of the phospholipids. No consistent change was noted in total phospholipid content nor in the proportion of various phospholipids in diabetics. However, diabetic animals showed a consistent reduction of arachidonic acid content in phosphatidylcholine (PC) and phosphatidylethanolamine in whole renal cortex, plasma membranes purified from renal cortex, and in isolated glomeruli. Associated with the fall in arachidonic acid was a rise in linoleic acid in the samples studied. Insulin therapy returned the fatty acid profiles to normal. These results are similar to patterns observed in other diabetic tissues and suggest that diabetes is associated with generalized changes in cell membranes. That these structural changes may have functional significance is suggested by demonstrated alterations in the temperature‐dependence of adenylate cyclase in renal plasma membranes of diabetic animals. Adenylate cyclase is thought to be intimately associated with PC in plasma membranes, a phospholipid showing significant changes in fatty acid content in diabetes (unsaturation index 165±2 for normals, 147±5 for diabetics). Na+,K au+‐ATPase which is thought to be primarily associated in vivo with phosphatidylinositol (PI), shows no change in apparent energy of activation in diabetes. The fatty acid content of PI is minimally altered in diabetes, and the unsaturation index is unchanged.
Autoxidation of phenyl linoleate and phenyl oleate: HPLC analysis of the major and minor monohydroperoxides as phenyl hydroxystearates
Authors: Haslbeck Franz , Grosch Werner
Published: December 2006

Phenyl linoleate was oxidized under different conditions. The monohydroperoxide products were isolated and subsequently hydrogenated. The isomers of phenyl hydroxysterate obtained were separated by high pressure liquid chromatography. On the basis of cochromatography with reference materials and mass spectroscopy, it was shown that the mixture was composed mainly (96%) of phenyl 9‐hydroxy‐ and phenyl 13‐hydroxysterates (9‐ and 13‐HOPh) with 8‐, 10‐, 12‐ and 14‐HOPh as minor compounds (4%). In the minor fraction, the 8‐ and 14‐HOPh predominated in comparison to the 10‐ and 12‐HOPh. The presence of α‐tocopherol in the autoxidation experiment changed the proportion of the phenyl hydroxystearate isomers: the proportion of the 9‐ and 13‐HOPh increased and those of the 8‐ and 14‐HOPh decreased. After addition of 0.05% or higher concentrations of α‐tocopherol, the minor fraction comprised approximately equal amounts of 8‐, 10‐, 12‐ and 14‐HOPh. Autoxidation of phenyl oleate followed by hydrogenation of the monohydroperoxides resulted in the formation of a mixture of phenyl hydroxystearates containing approximately equal amounts of 8‐, 9‐, 10‐ and 11‐HOPh.
(n−3) and (n−6) polyunsaturated fatty acids in the phosphoglycerides of salt‐secreting epithelia from two marine fish species
Authors: Bell Michael V. , Simpson Catriona M. F. , Sargent John R.
Published: December 2006

Fatty acid analyses were carried out on phosphoglycerides isolated from microsomal fractions of the rectal gland of the dogfish,Scyliorthinus canicula, and gills of the cod,Gadus morhua. Ratios of (n−3)/(n−6) polyunsaturated fatty acids were ca. 10 for phosphatidylcholine, (PC), phosphatidylethanolamine (PE) and phosphatidylserine (PS) from cod gills, reflecting high concentrations of 20∶5 (n−3) and 22∶6(n−3). The ratio for phosphatidylinositol (PI) from cod gills was 1.3, reflecting high concentrations of 20∶4(n−6) as well as (n−3) polyunsaturates. PC, PE and PS from rectal glands all had much lower (n−3)/(n−6) ratios than in cod gills, reflecting higher concentrations of 20∶4(n−6), but the lowest ratio was again present in PI. The latter phospholipid had high concentrations of 18∶0 in both tissues. The relative constancy of the fatty acid composition of PI in the two salt‐secreting tissues and its similarity to mammalian phospholipids is considered to reflect its specialized role in biomembranes.
Lipid deterioration: β‐Carotene destruction and oxygen evolution in a system containing lactoperoxidase, hydrogen peroxide and halides
Authors: Kanner Joseph , Kinsella John E.
Published: December 2006

A model system containing lactoperoxidase/H2O2/halide decomposed β‐carotene in a reaction greatly affected by the concentration of H2O2. The optimal concentrations of H2O2 for activation of iodide and bromide were 2 mM and 10 μM, respectively. The oxidation of chloride by a lactoperoxidase, using β‐carotene destruction as a sensitive method to determine the activity of the enzyme, is reported herein. In the presence of optimal amounts of H2O2, the rate of β‐carotene destruction increases slowly until a critical concentration of the halides, followed by a rapid increase in the rate when halide concentrations were furthere increased. A lactoperoxidase/H2O2/iodide and/or bromide system generates oxygen in the presence of high H2O2 and halide concentrations. β‐Carotene inhibited the evolution of oxygen. A possible mechanism of β‐carotene destruction and triplet unexcited oxygen evolution by a lactoperoxidase/H2O2/halide system are proposed.
Polycyclic hydrocarbon and polychlorinated biphenyl solubilization in aqueous solutions of mixed micelles
Authors: Laher J. M. , Barrowman J. A.
Published: December 2006

To determine the physiochemical behavior of xenobiotic hydrocarbons in simulated intestinal content, we examined the partition of 7,12‐dimethylbenzanthracene (DMBA), 3‐methyl cholanthrene (MC), benzo(a)pyrene, and a polychlorinated biphenyl compound (PCB, Aroclor 1242) between an emulsified oil phase and a mixed micellar solution. In a mixed lipid‐bile salt system, negligible amounts of hydrocarbon were present in aqueous solution below the critical micellar concentration (CMC) of sodium taurocholate. Once the CMC was obtained, the 4 hydrocarbons exhibited nearly identical partitions from the lipid into the micellar system which was enhanced by increased concentrations of bile salt, reduction of triglyceride concentration and the formation of mixed rather than pure bile salt micelles. The partition of DMBA and MC into micelles was optimized by long‐chain monounsaturated oleic acid and monooleoylglycerol as compared to their octanoic or linoleic counterparts. Linoleic acid and monolinoleoylglycerol maximized the partition of PCB from the oil into the micellar phase. In a mixed micellar system excluding an oil phase and an excess of DMBA, a molar saturation ratio (mol hydrocarbon:mol bile salt) was calculated by regression analysis to be 0.162. This indicates that more than one molecule of hydrocarbon is solubilized per mixed micelle and that the aqueous solubilization of hydrocarbon may be attributed to true micellar solubilization.
Relative contribution of the main tissues and organs to body fatty acid synthesis in the rat
Authors: Gandemer G. , Durand G. , Pascal G.
Published: December 2006

Tritiated water was used to measure the rate of fatty acid synthesis in the main tissues and organs of 7‐week old wistar male rats in order to determine the relative contribution of each tissue to body fatty acid synthesis. We reached the following conclusions: (a) the liver is the main site of fatty acid synthesis, it alone synthesizes 42% of the newly synthesized fatty acids in the body. (b) The dissectable white adipose tissues synthesize 27% of the fatty acids in the body. This group of tissues is heterogeneous because the mesenteric adipose tissue alone contains 40% of the labeled fatty acids present in the white adipose tissues. (c) Besides the intestines, organs other than the liver play a negligible role (2% of the total) in fatty acid synthesis. (d) The skin contributes 7% of the body fatty acid synthesis. (e) The rest of the carcass, essentially composed of the musculature and the skeleton, contributes 18% of body fatty acid synthesis and accounts for 33% of the extrahepatic tissue fatty acid synthesis.
Determination of lycopene, α‐ and β‐carotene and retinyl esters in human serum by reversed‐phase high performance liquid chromatography
Authors: Broich Carla R. , Gerber Leonard E. , Erdman John W.
Published: December 2006

A rapid specific, microdetermination of the major human blood carotenoids by high performance liquid chromatography (HPLC) separation and quantitation at 466 nm is detailed in this paper. Serum retinyl esters can also be quantified utilizing the same separation procedure but detected at 325 nm. One hundred microliters of deproteinated serum were extracted with chloroform and injected on a reverse‐phase column. Separation occurred within 16 min for all compounds of interest employing a mobile solvent of MeOH/AcN/CHCl3 (47∶47∶6). All compounds were quantified at the wavelengths cited by integrated peak areas using retinyl acetate as a daily standard. Analysis of serum from a hypercarotenemic anorexia nervosa patient and a person suffering from hypervitaminosis A are presented as examples of the clinical application of this procedure.
Effect of antioxidants on the photooxidation of fatty acids
Authors: Logani M. K. , Shah B. , Davies R. E.
Published: December 2006

The effect of butylated hydroxytoluene (BHT), butylated hydroxy anisole (BHA) and tocopherol acetate on photooxidation of the fatty acids was studied. A marked increase in the photooxidation was observed in the presence of BHT, and this effect was further potentiated by hexabromobiphenyls. Conversely, BHA and tocopherol acetate as such did not show any significant effect, but greatly enhanced the photooxidation when hexabromobiphenyls were also present. Hexabromobiphenyls by themselves did not show any notable effect on the photooxidation.
Desmosterol in human milk
Authors: Clark Richard M. , Fey Mark B. , Jensen Robert G. , Hill Dennis W.
Published: December 2006

Milk samples were collected from mothers at 2,6, 12 and 16 weeks postpartum. Desmosterol was found to be present in all the milk samples. Identification of desmosterol was based on retention times with two gas liquid chromatography (GLC) columns and verified by GC‐m ass spectrometry. The concentration of desmosterol in breast milk increased significantly (P<0.5) from 0.6 mg/100 ml at 2 weeks to 1.3 mg/100 ml at 16 weeks postpartum. Desmosterol was not significantly correlated with total lipid, total cholesterol or free cholesterol in the milk.
Double‐bond location in long‐chain polyunsaturated fatty acids by chemical lonization‐mass spectrometry
Authors: Lankelma Jan , Ayanoglu Eser , Djerassi Carl
Published: December 2006

For determination of the double‐bond position in polyunsaturated C24–30 fatty acids from marine organisms, methoxy derivatives were prepared. Diagnostic mass spectral fragment as well as molecular ion intensities were obtained by adjusting the ion source optics in the presence of ammonia at a lower source pressure than used conventionally. A lower detection limit was observed compared to conventional methane chemical ionization, which is a more favorable condition for capillary gas chromatography. Analysis of fatty acids from the spongeCalyx niceaensis showed the double‐bond position of 8 unsaturated fatty acids, including two new ones. In addition, structural proof is provided for the presence of a new cyclopropane‐containing fatty acid: 19,20‐methylene‐hexacosanoic acid.
Stereospecific analysis of triglycerides ofGlycine max, Glycine soya, Avena sativa andAvena sterilis strains
Authors: Pan W. P. , Hammond E. G.
Published: December 2006

A rapid method for the stereospecific analysis of triglycerides based on enzymatic hydrolysis on thin layer plates was applied to a number ofGlycine max, Glycine soya, Avena sativa andAvena sterilis strains. The percentage of each fatty acid on thesn‐1,sn‐2‐ andsn‐3‐positions was linearly related to the total percentage of the fatty acid in the triglyceride. Large deviations from the common triglyceride pattern were not found.
Ceramides from the spongeDysidea etheria
Authors: Grode Stephen H. , Cardellina John H.
Published: December 2006

Ceramides have been isolated from the polar organic extracts of the spongeDysidea etheria. The ceramides proved to be amides of sphingosine with either normal, saturated fatty acids or saturated α‐hydroxy fatty acids. Sphingosine was identified by isolation from the hydrolysis reaction mixture, acetylation and comparison of its physical and spectral properties with those reported for authentic sphingosine triacetate. The acids were identified by gas chromatography‐mass spectrometry analysis of their respective methyl esters.
Occurrence of long‐chain alkan‐diols and alkan‐15‐one‐1‐ols in a quaternary sapropel from the Eastern Mediterranean
Authors: Smith Dedric J. , Eglinton Geoffrey , Morris Robert J.
Published: December 2006

C28−C32 alkandiols and keto‐ols are reported in an S1 sapropel from the Eastern Mediterranean. Mediterranean. Their occurrence in this sediment and in certain other sedimentary environments may provide a clue to their source which is thought to be a specific marine organism or group of marine organisms.
Characteristics of the formation of the platelet lipoxygenase product from endogenous arachidonic acid
Authors: Hwang Daniel H.
Published: December 2006

The concentration of 12‐hydroxyeicosatetraenoic acid (12‐HETE) formed in rat platelets aggregated by collagen suspension increased continuously during a 115‐min incubation period, whereas the concentration of TXB2 or PGF2α reached the maximum within 3 min and stayed at the plateau for the remaining incubation period. These data indicate that platelet lipoxygenase is not completely inactivated as is cyclooxygenase by the oxidizing agent. Platelets of essential fatty acid deficient (EFAD) rats resuspended in plasma of control rats produced more 12‐HETE than platelet‐rich plasma (PRP) of EFAD rats, whereas platelets of control rats resuspended in plasma of EFAD rats formed less 12‐HETE than PRP of control rats. However, the concentration of TXB2 or PGF2α produced was not changed in both cases implying that platelet cyclooxygenase preferentially utilizes arachidonic acid (AA) derived from platelet lipids. Radioactivity of phosphatidylcholine (2‐arachidonyl‐1‐14C) suspended in the plasma of PRP was incorporated into 12‐HETE but not to TXB2, indicating again that only lipoxygenase can utilize AA derived from plasma phospholipids. The significance of this observation is that the effects of platelet lipoxygenase products, although their physiological roles are not known, would be much more persistent than cyclooxygenase products after platelets are stimulated or aggregated in vivo.
Phosphatidate phosphatase of dermatophytes
Authors: Kasinathan C. , Chopra A. , Khuller G. K.
Published: December 2006

Phosphatidate phosphatase (EC 3.1.3.4) was detected in filamentous pathogenic fungi. In both dermatophytes,Microsporum gypseum andEpidermophyton floccosum, the enzyme was located in the mitochondrial and microsomal subcellular fractions with a pH optimum of 6.0. TheE. floccosum enzyme was more active than that ofM. gypseum. Although the enzyme in both fractions of the dermatophytes was susceptible to inhibition by Fe2+, Mn2+, Cu2+, Ba2+ and Hg2+, theE. floccosum microsomal enzyme was completely inhibited by Mn2+ and Fe2+. The enzyme ofM. gypseum as well as ofE. floccosum exhibited a Mg2+ dependency in presence of EDTA. Sulphydryl reagents did not inhibit either the mitochondrial or the microsomal enzyme of these fungi. Phosphorylcholine and lysophosphatidylcholine markedly inhibited the enzyme in the two dermatophytes; however, the inhibition was less pronounced with phosphatidylcholine.
Fatty acid specificity in the inhibition of cell proliferation and its relationship to lipid peroxidation and prostaglandin biosynthesis
Authors: Morisaki N. , Sprecher H. , Milo G. E. , Cornwell D. G.
Published: December 2006

Primary cultures of smooth muscle cells were established from the medial layer of guinea pig aorta. Cells at passage level 4 were treated with different series of fatty acids belonging to the n‐9, n‐6 and n‐3 families. Lipid peroxidation was measured by the thiobarbituric acid assay and prostaglandin biosynthesis was measured by the radioimmunoassay of PGE and 6‐keto‐PGF1α. Cell proliferation was estimated from the total cell number of cultures seeded at low density. 18∶1(n‐9) did not form lipid peroxides and this fatty acid stimulated cell proliferation. All fatty acids which generated lipid peroxides inhibited cell proliferation, but inhibition was correlated with the degree of lipid peroxidation only in the n‐9 fatty acid family. 22∶4(n‐6) and 22∶6(n‐3) inhibited prostaglandin biosynthesis. 18∶2(n‐6), 18∶2(n‐9), 18∶3(n‐3), 20∶2(n‐9), 20∶3(n‐3) and 20∶5(n‐3) had no effect on prostaglandin biosynthesis. 18∶3(n‐6), 20∶3(n‐6) and 20∶4(n‐6) generated prostaglandins. 20∶3(n‐9) generated metabolites with prostaglandin immunoreactivity. The inhibition of cell proliferation did not correlate with enhanced or inhibited prostaglandin synthesis. The inhibition of cell proliferation was related to the structures of the different polyunsaturated fatty acid families decreasing in the order n‐9>n‐6>n‐3. Eicosatrienoic acids were the most effective inhibitors of cell proliferation in each fatty acid family and 20∶3(n‐9) was the most potent eicosatrienoic acid. These data show that specific as yet unrecognized products of fatty acid metabolism are responsible for the inhibition of cell proliferation.
Fatty acid and phospholipid composition ofBacillus megaterium spores with altered germination properties
Authors: Skomurski J. F. , Vary J. C.
Published: December 2006

The ability of spores to trigger germination was altered by growing spores at either a suboptimal temperature or in a rich medium modified by substituting L‐isoleucine for D‐glucose. Compared to the control, spores grown in the presence of isoleucine germinated more readily between 20 and 28 C, while spores grown at 20 C germinated slower than the control at any temperature tested. Analysis of the composition of these spores indicated that spores grown in the presence of isoleucine had much higher levels of anteiso‐C15 fatty acids than the control, while the phospholipid composition and the phospholipid to protein ratio were unchanged. The fatty acid composition for spores grown at 20 C was comparable to that of the control spores, but the levels of diphosphatidylglycerol and phosphatidylglycerol were altered as well as the ratio of phospholipid to protein. Steady‐state fluorescent anisotropy measurements were made with 1,6‐diphenyl‐1,3,5‐hexatriene incorporated into membrane isolated from these spores. The membranes from spores grown in the presence of isoleucine were more “fluid” between 10 and 20 C than membranes from the control spores. Membranes from 20 C grown spores were less “fluid” between 10 and 38 C than membranes from the control spores. These results show that triggering of spore germination was altered by growing spores under conditions that altered the composition of spore membranes.
Nonspecific lipid transfer proteins as probes of membrane structure and function
Authors: Crain Richard C.
Published: December 2006

A protein that accelerates transfer of phospholipids of varying head group and fatty acid composition has been purified from bovine liver. As previously found for other phospholipid transfer proteins, “nonspecific lipid transfer protein” stimulates a kinetically biphasic transfer of radioactively labeled phospholipid from small unilamellar vesicles to unlabeled multilamellar vesicles. The kinetics are consistent with rapid transfer of phospholipid from the outer monalyer and slow transfer of that localized in the inner monolayer (half‐times greater than 3 days for phosphatidylcholine, phosphatidylethanolamine, and phosphatidylinositol). Protein catalyzed transfer is inhibited by high ionic strength and has an activation energy of 35 kJ/mol. The broad lipid specificity and ease of large‐scale purification make these proteins candidates for membrane phospholipid compositional modification. The compositions of rat liver mitochondrial and microsomal membranes and Morris hepatoma 7288c mitochondrial membranes were altered by incubation with lipid vesicles and nonspecific lipid transfer protein. Incubation with phosphatidylcholine vesicles led to increased levels of phosphatidylcholine and decreased levels of other transferrable lipids (phosphatidylethanolamine, phosphatidylinositol, and cholesterol) unless the latter were included in the vesicles. When vesicles containing dipalmitoylphosphatidylcholine were incubated with microsomal membranes, a large increase in disaturated phosphatidylcholine was also observed. These changes in composition were correlated with activities of membrane enzymes. It appears that microsomal glucose‐6‐phosphatase is inhibited by increased phosphatidylcholine saturation. Moreover, this enzyme is also inhibited by decreases in the phosphatidylethanolamine/phosphatidylcholine ratio whereas NADPH cytochrome c reductase is not. Likewise, decreased cholesterol to phospholipid ratios did not greatly affect the abnormally low levels of hepatoma succinate cytochrome c reductase activity.
Changes in the activities of lipoprotein lipase and the lipogenic enzymes in tumor‐bearing rats
Authors: Lanza‐Jacoby Susan , Miller Elizabeth E. , Rosato Francis E.
Published: December 2006

The effects of tumor growth on lipid metabolism were investigated by evaluating serum lipids, lipoprotein lipase activity (LPLA), the lipogenic enzymes, urinary catecholamines along with serum insulin and glucagon levels. We injected 1.5×106 cells of rat mammary tumor, AC33, and killed the rats on the 18th day. Serum triglycerides and free fatty acids of the tumor‐bearing (TB) rats increased 4 and 5 times, respectively, more than the control (C) rats. Total liver lipids were not significantly different between the two groups. Tumor growth produced a 70% decrease in total epididymal fat pad LPLA; there were no changes in soleus muscle LPLA. Serum insulin levels of the TB rats were 49% less than the C rats. The TB rats had significantly lighter epididymal fat pads and lower activities of adipose fatty acid synthetase and citrate cleavage enzyme. Urinary catecholamines of the TB rats were reduced over 30% compared with the C rats. These results show that the hypertriglyceridemia of the TB rats may be due, in part, to a deficiency of adipose tissue LPLA. The data also suggest that the effects of the tumor on lipid metabolism may be mediated through insulin.
Effects of different fractions of the barley kernel on the hepatic lipid metabolism of chickens,
Authors: Burger Warren C. , Qureshi Asaf A. , Prentice Neville , Elson Charles E.
Published: December 2006

Various physical fractions of the barley kernel were fed to one‐day‐old female and male chickens to determine their effect on hepatic β‐hydroxy‐β‐methylglutaryl coenzyme A (HMG‐CoA) reductase, cholesterol 7α‐hydroxylase and the lipogenic enzymes, acetyl‐CoA carboxylase (ACX), malic enzyme (ME), citrate‐cleavage enzyme (CCE) and fatty acid synthetase (FAS) at the subcellular level. Significant inhibition (p<0.01) of cholesterol biosynthesis accompanied by significant decreases in plasma cholesterol concentrations and induction of fatty acid synthesis were found in diets based on pearled barley, barley pearlings and a high‐protein barley flour (HPBF: aleurone and subaleurone layers of barley endosperm) separated from the pearlings when compared to corn. Lower weight gains in 1‐ to 4‐week‐old birds fed the high‐protein barley flour were found to be the result of lower feed consumption; pair feeding of 12‐week‐old birds with diets based on corn and high‐protein barley flour produced equal weight gains in both treatments and significant reductions in hepatic HMG‐CoA reductase, plasma cholesterol and induction in several lipogenic enzymes in birds fed the high‐protein barley flour. Substitutions of 5–20% high‐protein barley flour for corn in a corn‐based diet produced significant weight gains (p<0.01) of 10 to 20% in 2‐week‐old chickens, inhibited cholesterol biosynthesis by 45–65% and produced a 3‐fold increase in a fatty acid synthetase. The results indicate that HPBF contains an inhibitor(s) of cholesterol biosynthesis and a growth factor(s) when compared to a corn‐based diet.
Synthesis of deuterium labeled cholesterol and steroids and their use for metabolic studies
Authors: Goad L. J. , Breen M. A. , Rendell N. B. , Rose M. E. , Duncan J. N. , Wade A. P.
Published: December 2006

A simple method is described for the preparation of [6,7,7−2H3] sterols and steroids. The synthesis starts with a Δ5‐sterol or steroid and involves preparation of the 6‐oxo‐3α,5α‐cyclosteroid, base exchange in the presence of deuterium oxide to introduce two deuteriums at the C‐7 position and sodium borodeuteride reduction of the 6‐oxo group to introduce the third deuterium atom at C‐6. Rearrangement of the [6,7,7−2H3]6α‐hydroxy‐3α,5α‐cyclosteroid then gives the desired [6,7,7‐2H3]‐Δ5 sterol or steroid. [6,7,7−2H3]Cholesterol, [6,7,7−2H3]pregnenolone and [6,7,7−2H3]3β‐hydroxyandrost‐5‐en‐17‐one were synthesized in this fashion and [6,7,7−2H3]progesterone was prepared from the [6,7,7−2H3]pregnenolone. Three examples of the use of these deuchromatography‐mass spectrometry. The chrysophyte alga,Ochromonas malhamensis, was shown to be capable of introducing an extra methyl or ethyl group at C‐24 of the side chain of [6,7,7−2H3]cholesterol to yield brassicasterol and poriferasterol, respectively. The ovary of the echinoderm,Asterias rubens, was demonstrated to metabolize [6,7,7−2H3]progesterone to yield mainly the 5α‐isomers of pregnane‐3,20‐dione and 3β‐hydroxypregnan‐20‐one. However, the 5β‐isomers of these compounds were also detected as minor products for the first time as progesterone metabolites in this animal. Isolated oocytes of the frog,Xenopus laevis, produced a number of metabolites of [6,7,7−2H3]progesterone. In this report, two of them were shown to be 17α‐hydroxy‐pregn‐4‐en‐3,20‐dione and 20α‐hydroxypregn‐4‐en‐3‐one.
Anesthetics may restructure the hydrogen belts of membranes
Authors: Brockerhoff H.
Published: December 2006

Anesthetic molecules can form hydrogen bonds or organize hydrogen‐bond networks. It is argued that they affect the neuronal cell membrane not by an amorphous fluidization of the hyprophobic core of the lipid bilayer but by a restructuring of its hydrogen belts, i.e., the regions occupied by the CO and OH groups of the membrane lipids. The structured disturbance of the hydrogen‐bond network is translated latitudinally to hydrogen‐bonding sites of the proteins of the membrane, causing allosteric changes of ion channels that result in neuronal blocking.
The effect of embryological development on phosphatidylethanolamine methyltransferase, phosphatidyldimethylethanolamine methyltransferase and choline phosphotransferase of rabbit liver microsomes
Authors: Cornatzer W. E. , Hoffman Dennis R. , Haning Judy A.
Published: December 2006

The effect of embryological development on the two biosynthetic enzymes involved in phosphatidylcholine biosynthesis in liver microsomes of −12, −9, 0, +4, +14, +36 day old rabbits has been determined. The specific activity (pmol phosphatidylcholine formed/min/mg microsomal protein) of the phosphatidyletanolamine methyltransferase in the liver microsomes is very low before birth and a 33% increase at birth occurs when compared to the‐12 day old fetal livers. The pmol of phosphatidylcholine formed/min/mg protein by the choline phosphotransferase pathway in fetal liver microsomes is 5, 10, 73, 199, 107 and 307 times greater than by the phosphatidylethanolamine methyltransferase pathway for −12, −9, 0, +4, +14, +36 day old rabbits, respectively. The specific activities of the choline phosphotransferase in the liver microsomes increased from the −12 day old fetal livers to 1.6, 19, 73, 39, 27 times for the −9, 0, +4, +14 and +36 day old animals, respectively. The choline phosphotransferase pathway in comparison to the phosphatidylethanolamine methyltransferase pathway is providing the major phosphatidylcholines in the membranes of the endoplasmic reticulum before birth and early fetal development of the rabbit.
Effect of dietary animal and vegetable protein on gallstone formation and biliary constituents in the hamster
Authors: Mahfouz‐Cercone Susan , Johnson James E. , Liepa George U.
Published: December 2006

A gallstone‐inducing diet was utilized to examine the effect of dietary proteins (casein, soybean and cottonseed) on gallstone formation. Casein produced gallstones in 100% of the animals; however, soybean or cottonseed proteins reduced gallstone incidence to 32% and 0%, respectively. In an effort to ascertain the mechanisms responsible for gallstone formation, serum cholesterol and the 3 primary biliary constituents (bile acids, phospholipids and cholesterol) were measured. Casein produced a 4‐fold increase in biliary cholesterol, whereas soybean and cottonseed yielded a 3‐and 2‐fold increase, respectively, when compared to a commercial diet (Purina, no. 5001). Serum cholesterol was reduced by substituting dietary vegetable protein for animal protein. This study suggests that substitution of vegetable for animal protein in the diet can decrease gallstone formation in hamsters. It is proposed that this reduced gallstone formation is due to the decreased concentrations of biliary cholesterol induced by dietary modification.
Lipoxygenase inhibition by naturally occurring monoenoic fatty acids
Authors: St. Angelo A. J. , Ory R. L.
Published: December 2006

Lipoxygenase activity was not detected in preparations from several varieties of rapessed. Erucic acid, one of the main components of rapessed oil, competitively inhibited both soybean and peanut lipoxygenases. Various other long‐chain monoenoic fatty acids were assayed for their effects on lipoxygenase activity with linoleic acid as substrate. Fatty acid chain length, from C16, to C24, was not a significant factor, but position of the point of unsaturation did affect enzyme activity. The position of the double bond from the carboxyl group seemed to be more significant than the distance between the point of unsaturation and the methyl terminal group in terms of inhibition.
The dietary regulation of acyltransferase and desaturase activities in microsomal membranes of rat liver
Authors: Pugh E. L. , Kates M.
Published: December 2006

Dietary manipulation produces marked alterations in desaturase activities of rat liver microsomes with no concomitant changes in acyltransferase activities. Desaturation of stearoyl‐CoA (Δ9‐desaturase), linoleoyl‐CoA (Δ6‐desaturase), eicosatrienoyl‐CoA (Δ5‐desaturase) and eicosatrienoyl‐phosphatidylcholine (Δ5‐desaturase) was elevated in animals fed a corn oil diet and lowered in those fed a coconut oil diet compared to control animals. The Δ5‐desaturase activities were also lowered in starved animals and elevated in starved animals refed a fat‐free diet. However, no changes in acyl‐CoA:1‐acylsn‐glycero‐3‐phosphocholine acyltransferase activity were observed in the membranes of animals maintained on any of the dietary regimens studied. These observations suggest that the desaturases of rat liver microsomes are regulated independently of the acyltransferases and that desaturation of eicosatrienoyl‐phosphatidylcholine is regulated at the level of the desaturase itself and not by availability of the phospholipid substrate.
Lipids of liver, kidney, spleen and muscle in a case of generalized deficiency of cytochrome b5 reductase in congenital methemoglobinemia with mental retardation
Authors: Hirono Haruko
Published: December 2006

The lipid compositions of liver, kidney, spleen and muscle in a case of generalized deficiency of cytochrome b5 reductase in congenital methemoglobinemia with mental retardation were analyzed and compared with age‐matched controls. The contents of cholesterol and phospholipids (μmol/g) in each organ were within the normal range. Diminished proportions of unsaturated fatty acids were observed in ethanolamine phosphoglycerides (EPG) of the liver. The proportion of linoleic acid decreased to less than half of the normal level in EPG of liver, kidney and spleen.
Diet‐ and hormone‐induced lipid deposition in rat kidney: Correlation with systolic blood pressure
Authors: Fischer G. M. , Swain M. L. , Chacko S.
Published: December 2006

The influence of estradiol on deposition of cholesterol in tissues of ovariectomized rats on normal and high lipid diets was studied. Concomitantly the influence of a contraceptive steroid combination was studied in a similar manner in intact rats. It was found that the high lipid diet resulted in increased deposition of cholesterol in aorta, heart, liver and kidney. The presence of either endogenous or exogenous hormones accentuated the deposition of cholesterol in the kidney and resulted in significantly higher systolic blood pressures in these rats. In the rats on a high lipid diet, the concentration of cholesterol in the kidney correlated positively with systolic blood pressure. It is concluded that estrogen and high lipid diet exert a synergistic effect on deposition of cholesterol in kidney. The positive correlation between kidney cholesterol concentration and systolic blood pressure suggests a possible role for kidney lipid deposition in the hypertensive effect of estrogens.