bluuebunny/crossref_metadata_2025_split huggingface dataset:
Skin lipids of the Florida indigo snake
Authors: Ahern David G. , Downing Donald T. 
Published: November 2006

AbstractCast skins of the Florida indigo snake (Drymarchon corais) yielded up to 8% chloroform: methanol‐extractable lipid, which was found to contain methyl ketones (20%), free secondary alcohols (15%), free primary alcohols (30%), free cholesterol (15%), free fatty acids (5%), and hydrocarbons (5%). The hydrocarbons appeared to be contaminants, because gas chromatography revealed a distribution characteristic of petroleum hydrocarbons. The methyl ketones were predominantly monounsaturated, with double bonds almost exclusively in the ω7 position. The structures of the secondary alcohols corresponded with the methyl ketones in regard to chain length distribution, location of the oxygen function in the 2 position, and the proportion and position of unsaturation. The primary alcohols were also predominantly straight, odd‐carbon, unsaturated compounds, with ω7 double bonds, but with chain lengths principally of 29 and 31 carbon atoms. The free fatty acids were mainly even‐carbon monounsaturated compounds of 16–20 carbon atoms with double bonds mainly in the Δ9‐position. Inspection of the lipid structures obtained from the Indigo snake suggest a biogenetic relationship whereby palmitic and palmitoleic acids are extended in chain length mainly to 32 and 34 carbonatom fatty acids. Retention or introduction of an oxygen function in the 3 position, followed by decarboxylation, could then yield structures corresponding with the methyl ketones and the related secondary alcohols. Insertion of an oxygen atom between carbons 2 and 3 of the methyl ketones, followed by loss of the two carbon atoms thereby isolated from the chain, would produce the series of odd‐carbon primary alcohols that were observed.
Removal of lipid from intact erythrocytes and ghosts by aqueous solutions and its relevance to membrane structure
Authors: Turner John D. , Rouser George 
Published: November 2006

AbstractMolar values for cholesterol, total phospholipid, and individual phospholipid classes of intact erythrocytes and their membranes (ghosts) washed with various aqueous solutions are presented. The data show that lipid can be washed from erythrocyte ghosts prepared rapidly from freshly drawn blood but that lipid is not removed from intact erythrocytes under the same conditions. Thus, it appears that the polar groups of lipids of intact cells are not exposed as they are in ghosts. In the preparation of hemoglobin‐free ghosts, up to 25% cholesterol and phospholipid can be removed, while loss of ca. 50% cholesterol and phospholipid from ghosts can be achieved with aqueous solutions containing ethylenediamine tetraacetate. No significant loss of membrane protein was encountered even when almost half of the lipid had been removed from the ghosts. Phospholipid classes were removed to different extents with different wash solutions. Lipid loss from ghosts can be prevented, in part, by adding 0.5% albumin or calcium to wash solutions containing ethylenediamine tetraacetate. These findings contrast a report where insignificant lipid loss was noted in the preparation of hemoglobin‐free human erythrocyte membranes, but agree with results reported for bovine red cell ghosts.
Detritylation by silicic acid boric acid column chromatography
Authors: Buchnea Dmytro 
Published: November 2006

AbstractChromatography on silicic acid‐boric acid columns permits detritylation of ester lipids, essentially without acyl migration, and simultaneous separation of the reaction products. Described is the preparation of the column and its application for the synthesis of diacyl‐sn‐glycerols and 2‐acyl‐1,2‐propaneiols.
The emulsifying properties of egg yolk phosphatidylcholine
Authors: Horwitz C. , Krut L. , Kaminsky L. S. 
Published: November 2006

AbstractThe effects of lipid concentration and w/w ratios on the formation of emulsions by some combinations of phosphatidylcholine, cholesterol oleate, cholesterol and triglyceride were studied, with the following results. Phosphatidylcholine emulsified cholesterol oleate and triglyceride, the degree of dispersion and emulsion stability increasing with phosphatidylcholine concentration. Cholesterol reduced the degree of dispersion of phosphatidylcholine‐triglyceride emulsions but enhanced the emulsion stability. Triglyceride disrupted the colloidal phase of phosphatidylcholine and cholesterol in high concentrations and did so more effectively when the proportion of cholesterol to phosphatidylcholine was high.
The synthesis of prostaglandins in human platelets
Authors: Clausen J. , Srivastava K. C. 
Published: November 2006

AbstractHuman blood platelets were found to possess the whole biological system for synthesis of prostaglandins from C14‐labeled acetate and inherent derivatives of essential fatty acids. The incorporation of radioactive acetate into prostaglandins, polar lipids and neutral lipids was followed as function of acetate concentration and time. Of the fractions mentioned, ca. 10% of the label was found in PGEs. Among the PGEs, PGE1 and PGE2 account for 48.6 and 43.4% of the radioactive label. The results obtained were related to the theory of the inhibiting function of prostaglandins on the platelet agglutination.
Methanolysis of cerebrosides with boron trifluoride‐methanol
Authors: Moscatelli Ezio A. 
Published: November 2006

AbstractA time study was carried out to determine conditions under which BF3‐methanol could be used reliably for methanolysis of cerebrosides. Results indicate that heating at 100 C in a sealed tube with 14% w/v BF3‐methanol for 60 min yields satisfactory cleavage of cerebrosides to fatty acid methyl esters without significant destruction of normal or hydroxy fatty acids.
Analysis of commercially available ganglioside standards
Authors: Carter T. P. , Sampugna J. , Campagnoni A. T. 
Published: November 2006

AbstractProcedures for the quantitative estimation of sialic acid, sphingosine and fatty acid were employed to assess the purity of commerically available ganglioside standards. Based on the weight printed on the label, experimental values of mono‐, di‐ and trisialoganglioside standards represented approximately 7, 77 and 25%, respectively, of the expected value. Thin layer chromatography (TLC) revealed that the monosialoganglioside was contaminated with phospholipid, possibly phosphatidyl choline. Trisialoganglioside was resolved into three spots on TLC, two of which were ninhydrin positive and resorcinol negative. These results suggest that caution should be observed when dealing with commercially available standards even though a high degree of purity is guaranteed.
Metabolism of an n‐paraffin, heptadecane, in rats
Authors: Tulliez J. E. , Bories G. F. 
Published: November 2006

Abstract14C‐heptadecane incorporated in rat diet was largely absorbed, and a balance study showed extensive14CO2 excretion (65%). There was no elimination of the hydrocarbon in the urine, and only minute quantities of labeled metabolites. Radioactivity in the feces was entirely in heptadecane. About 7% of the heptadecane absorbed was stored in the carcass, whereas the rest was ω‐oxidized to heptadecanoic acid. This fatty acid was incorporated into neutral lipids and phospholipids, underwent the normal fatty acid degradation pathway, and contributed to the synthesis of lipids, including fatty acids, squalene and cholesterol, and nonlipids (7–10%). Heptadecanoic acid was desaturated to heptadecenoic acid. The even distribution of radioactivity in the fatty acids of the various phospholipid classes indicated that heptadecane did not interfere with the biochemical mechanisms of these functional lipids.
Determination of peroxide value by the colorimetric iodine method with protection of iodide as cadmium complex
Authors: Takagi Toru , Mitsuno Yuichiro , Masumura Mayumi 
Published: November 2006

AbstractImproved procedures of the Swoboda and Lea method for the determination of peroxide values (POV) of fats and lipids are presented. After oxidation of iodide to iodine with the sample for 5 min under an inert atmosphere, an excess of the iodide ion is immediately converted to cadmium complex for protection from atmospheric oxygen. The iodine is measured colorimetrically at 358 or 410 nm, and POV is calculated from the absorbance. This method permits the rapid determination of POV with a small amount of sample at a moderate cost using usual glasswares. For the analysis of lipids in biological materials or food products, the chloroform solution obtained by the Bligh and Dyer method is directly subjected to this procedure without evaporation of the solvent. Conversions between POV obtained by the different methods are discussed.
The metabolism of lithocholic acid‐3α‐sulfate by human intestinal microflora
Authors: Kelsey Morris I. , Muschik Gary M. , Sexton Sharyn A. 
Published: November 2006

AbstractLithocholic acid‐3α‐sulfate is metabolized by human intestinal microflora to nonpolar metabolites which have been partially purified by Sephadex LH‐20 chromatography. These metabolites were characterized by thin layer and gas liquid chromatography as well as combined gas liquid chromatography‐mass spectrometry. The chromatographic properties of one of the metabolites are consistent with those described for a Δ2‐or Δ3. The formation of cholenates by the microflora may represent a retoxification of the sulfate ester of lithocholic acid.
Inhibition of diacylglycerol: CDPcholine cholinephosphotransferase activity by dimethylaminoethylp‐clorophenoxyacetate
Authors: Parthasarathy S. , Cady R. K. , Kraushaar D. S. , Sladek N. E. , Baumann W. J. 
Published: November 2006

AbstractCholinephosphotransferase [EC 2.7.8.2] activity of rat liver microsomes, with 1,2‐di‐0‐[3H]acyl glycerol or 1‐0‐hexadecanoyl [U‐14C]ethanediol as substrate, was inhibited byN,N‐dimethylaminoethylp‐chlorophenoxyacetate (centrophenoxine). Inhibition progressed in a linear fashion with increasing drug levels and was complete at 30 mM concentration. It appears that the microsomal enzyme was largely affected by the drug itself because the hydrolysis products of centrophenoxine, viz.,N,N‐dimethylaminoethanol andp‐chlorophenoxyacetic acid, were less inhibitory.
Acylglycerol structure of peanut oils of different atherogenic potential
Authors: Myher J. J. , Marai L. , Kuksis A. , Kritchevsky D. 
Published: November 2006

AbstractDetailed investigation was made of the triacylglycerol structure of native, simulated, and interesterified peanut oils, which had previously been shown to differ markedly in their atherogenic potential. By means of chromatographic and stereospecific analyses, it was shown that the more atherogenic native oil contains a significantly greater proportion of triacylglycerols with linoleic insn‐2‐position and arachidic, behenic, and lignoceric acids insn‐3‐position than the synthetic oils. It is suggested that the atherogenicity may arise from a relative metabolic unavailability of the linoleic acid from the native oil, which may be due in part to the presence of long chain saturated acids in the outer position. This might render the oil metabolically more saturated than the interesterified oils of the same total fatty acid composition, which contain a much greater proportion of the linoleic acid in the primary positions of the triacylglycerol molecule. The identification of specific triacylglycerols may allow the experimental testing of this hypothesis by feeding synthetic triacylglycerols incorporating the potentially atherogenic features.
Heart mitochondrial metabolism after feeding herring oil to rats and monkeys
Authors: Forsyth G. W. , Carter K. E. , Loew F. M. , Ackman R. G. 
Published: November 2006

AbstractHeart mitochondrial oxidation of palmityl CoA and pyruvic acid was studied in rats and in the monkeyMacaca fascicularisto determine the effects of feeding partially hydrogenated herring oil. Herring oil glycerides contain cetoleic acid (cis‐11‐docosenoic) which could have a similar effect to erucic acid (cis‐13‐docosenoic) in causing a rat cardiomyopathy. The initial rat heart mitochondrial response to dietary cetoleic acid (67%cis, 33%trans) was an in vitro decrease in palmityl CoA oxidation. Prolonged feeding of cetoleic acid mixture was associated with a significant metabolic adaptation, increasing pyruvate and palmityl CoA oxidation above control levels. In vitro addition of cetoleyl CoA (purecisisomer) stimulated pyruvate dehydrogenase activity, a possible response to decreased β‐oxidation. There was no significant adaptive change in pyruvate or palmityl CoA use in monkeys after prolonged feeding of partially hydrogenated herring oil. Cetoleyl CoA was a good substrate for monkey heart carnitine acyl transferase even in the presence of palmityl CoA. These observations suggest that C22fatty acids may be matabolized more rapidly in monkey heart than in rat heart. Metabolic differences argue against using the rat as an experimental model for studying possible cardiotoxic effects of docosenoic acids in primates.
A new system for lipid analysis by liquid chromatography‐mass spectrometry
Authors: Erdahl W. L. , Privett O. S. 
Published: November 2006

AbstractA simple system for interfacing liquid chromatography with mass spectrometry for the analysis of lipids is described. The system is based on the moving chain transport principle and employs an endless stainless steel belt of perforated construction that gives it superior surface properties and capacity to entrain solvent. The entire column eluent is collected on the belt which transports it into an evaporator where the solvent is removed. The solute, which remains as a residue on the belt, is transported into a reactor where it is converted to hydrocarbons by reaction with hydrogen at 400–450 C. The hydrocarbons, which are characteristic of the structures of the parent compounds, are swept into an outlet tube where ca. 15% are drawn into the ion source of a mass spectrometer operating in the chemical ionization mode using methane as the reagent gas. The spectrum is recorded on an oscillographic recorder for identification purposes. Detection and quantitative analysis is performed by single ion monitoring of the most intense ion using a conventional analog recorder. The system is demonstrated by application to a standard mixture of tripalmitin, cholesteryl palmitate, and cholesterol separated on a 3.2×250 mm silica column, and exhibited a sensitivity of ca. 1 nanogram per component injected on the column.
Autoxidation of methyl linolenate: Analysis of methyl hydroxylinolenate isomers by high performance liquid chromatography
Authors: Chan Henry W. ‐S. , Levett Gordon 
Published: November 2006

AbstractThe mixture of methyl hydroxylinolenates obtained by reduction of the hydroperoxide isomers formed by autoxidation of methyl linolenate was resolved by high performance liquid chromatography into eight major components. These are positional isomers with the hydroxyl group at positions 9, 12, 13, and 16. Two geometrical isomers of each positional isomer are present; these differ in the configuration of the conjugated double bonds (cis‐trans andtrans‐trans). Autoxidation of methyl linolenate is regioselective and favors the formation of positional isomers 9 and 16.
Potential for employing the distribution of anomalous non‐methylene‐interrupted dienoic fatty acids in several marine invertebrates as part of food web studies
Authors: Paradis M. , Ackman R. G. 
Published: November 2006

AbstractA group of homologous, nonmethylene‐interrupted dienoic fatty acids (NMID) recently reported in oysters has been found in several other shellfish species and also in other marine phyla. The distribution of most other “normal” fatty acids among several species of shellfish is basically similar but mantle lipids from two other molluscan species, both squid, differ radically. The squid mantle fatty acids do not include NMID, suggesting that in molluscs NMID may accumulate primarily in filter‐feeders or herbivores. The distribution of these anomalous fatty acid components in higher species suggests that they reflect invertebrates in the diet and are biochemically inert.
The nonpolar egg wax lipids of the cattle tick,Boophilus microplus (Canestrini)
Authors: McCamish Malcolm , Cannell G. R. , Cherry Lois M. 
Published: November 2006

AbstractAbout 40% of the lipids of the egg wax ofBoophilus microplus are nonpolar and comprise hydrocarbons (10%) and was esters (90%). The hydrocarbon fraction is 87% unbranched alkanes, the major components being n‐nonadecane (10.8%), n‐eicosane (12.1%), and n‐heneicosane (9.8%). This fraction also contains 2,4,6‐cholestatriene (4.6%). The majority of the acids are branched (77%), the major components being 12‐methyl‐tetradecanoic (16.3%) and branched hexadecanoic acids (28%). The major alcohols are n26∶0 (20.4%), n28∶0 (47.3%) and n36∶0 (18.2%). A steroid, possibly 2,4,6‐cholestatrien‐25‐ol (5.6%), is also present.
Characterization of bovine rumen liquor isoprenoid hydrocarbons with reference to dietary phytol
Authors: Body D. R. 
Published: November 2006

AbstractThe isoprenoid hydrocarbons,trans‐phyt‐2‐ene (82.2%), phyt‐1‐ene (6.5%), and phytane (11.3%), were detected in bovine rumen liquor by means of AgNO3‐impregnated thin layer chromatography and gas liquid chromatography with mass spectrometry and infrared spectrophotometry. The unsaturated hydrocarbons were identified by comparing their chromatographic, physical, and chemical properties with those of synthetic isoprenoid hydrocarbons prepared from dihydrophytol. The natural level of the original isoprenoid components within the rumen is comprised of phytol and dihydrophytol (of the ratio of 2∶1). These represented at least 60% of the total free fatty alcohol content of the rumen liquor lipid extract and could, therefore, be the origin of the isoprenoid hydrocarbons observed.
Glycerol ester hydrolase activity in the pulp of unerupted calves' teeth
Authors: McMahon Kathleen E. , Pitas Robert E. , Jensen Robert G. 
Published: November 2006

AbstractThe pulp from unerupted calves' teeth was found to contain low levels of glycerol ester hydrolase activity. Solutions in Tris buffer cleared tributyrylglycerol agar and hydrolyzed emulsified olive oil. The average quantity of free fatty acids released in five assays with olive oil was: 2.8, S.D.±1.4. Specific activities were: 0.25, S.D.±0.13, mkatals/kg protein.
Lithocholic acid in human liver: Identification of ∈‐lithocholyl lysine in tissue protein
Authors: Nair P. P. , Mendeloff A. I. , Vocci M. , Bankoski J. , Gorelik M. , Herman G. , Plapinger R. 
Published: November 2006

AbstractHuman liver had been shown to contain two forms of lithocholic acid. One form is extractable by 95% ethanol‐ammonia, 1000∶1, v/v (soluble lithocholate, SL) and the other form is firmly bound to the tissue residue. The latter, tissue‐bound lithocholic acid (TBL), can be enzymatically released by means of the specific clostridial peptide bond hydrolase, cholylglycine hydrolase (cholanoyl amino acid hydrolase, EC no. 3.5). Solvolytic procedures for the analysis of hepatic lithocholic acid sulfate revealed that almost all of the TBL was non sulfated, while in the SL fraction there was an apparent preponderance of the sulfated form. Cholylglycine hydrolase liberates free labeled lithocholic acid from synthetic [24‐14C] lithocholyl‐bovine serum albumin and from [24‐14C]lithocholyl polylysine. By analogy, the enzyme releases lithocholic acid from tissue protein in which the bile acid is conjugated through amino groups of basic side chains. Hydrolysis of [24‐14C] lithocholyl polylysine with 6n HC1 yielded ∈‐[24‐14C] lithocholyl lysine, which was chromatographically similar to the product obtained by acid hydrolysis of TBL. Chromatographic, infrared, and mass spectroscopic studies with synthetic N‐α‐lithocholyl lysine, N‐∈‐lithocholyl lysine, and N‐α‐∈‐Bis lithocholyl lysine showed the hydrolytic product from TBL to be N‐∈‐lithocholyl lysine. Since monohydroxy bile acids, such as lithocholic acid, are known to show unusual cytotoxic properties, the identification of TBL in human liver poses important questions regarding the role of lithocholate in liver injury.
The effect of dietary fatty acid balance on myocardial lesions in male rats
Authors: Hulan H. W. , Kramer J. K. G. , Corner A. H. 
Published: November 2006

AbstractThree hundred (experiment I) and 350 (experiment II) weanling, 3‐week‐old male Sprague‐Dawley rats weighing between 40–50 g were randomly assigned two per cage and 50 per dietary treatment to study the effect of dietary fatty acid balance on myocardial lesions. The following oils were tested: Experiment I.Brassica napusvar. Tower rapeseed oil [Tower RSO, 1974 cultivar and 1975 cultivar, each containing 0.3% erucic (22∶1) acid];B. napusvar. Zephyr RSO containing 0.9% 22∶1; corn oil; olive oil; and soybean oil. Experiment II.B. napusvar. Tower RSO (1974 cultivar), olive oil, soybean oil, and the following oils to which was added the indicated level of free 22∶1; Tower +0.5% 22∶1; Tower +5.6% 22∶1; olive oil +4.4% 22∶1; soybean oil +5.7% 22∶1. In each case the oils were incorporated in a semisynthetic diet at a level of 20% by weight. Heart and heart lipid weights of rats fed the different oils did not differ statistically from each other. Fatty acid analyses of heart lipids revealed that the fatty acid composition of the cardiac lipids reflected that of the diet fed. In experiment I, there was a definite but significantly lower incidence (P<0.01) and severity (P<0.01) of heart lesions in rats fed control oils (corn, olive, soybean) than in rats fed rapeseed oils. Also, in experiment II, a definite but lower incidence and severity of heart lesions occurred in rats fed control oils (soybean, olive) compared to rats fed Tower RSO or this oil with added free 22∶1. Adding 22∶1 to an oil naturally high in 18∶3 (soybean) did not alter the incidence of heart lesions, whereas adding 22∶1 to an oil naturally high in 18∶1 (olive) increased significantly (P<0.01) both the incidence and severity of heart lesions. Thus, it appears that the background incidence of heart lesions that are found in the rat in any case, and which are increased by rapeseed oil feeding, is caused by the imbalanced fatty acid composition of the oil for the growing rat, i.e. high monoenes (18∶1, 20∶1, and 22∶1) and high 18∶3 and is not only due to the presence of excess 18∶3.
Autoxidation of fatty acid monolayers adsorbed on silica gel: II. Rates and products
Authors: Wu Guey‐Shuang , Stein Robert A. , Mead James F. 
Published: November 2006

AbstractUnsaturated fatty acid monolayers on silica gel have been autoxidized, and the rate of fatty acid disappearance and products obtained from those membrane‐like assemblies have been studied Fatty acid monolayers consisting of pure linoleic acid, linolelaidic acid, and oleic acid were autoxidized at 60 C. The rates of autoxidation of linoleic acid and linolelaidic acid monolayers followed by the disappearance of substrates are considerably faster than that in bulk phase, and the rates conform to apparent first order kinetics. Autoxidation of linoleic and linolelaidic acid monolayers, unlike bulk phase, produced only a small amount of diene conjugation, and the major products formed were identified as 9,10‐epoxy and 12,13‐epoxyoctadecenoic acid in roughly equal quantities. The epoxidation is stereospecific, withcis andtrans olefins givingcis andtrans epoxides, respectively. Oleic acid was autoxidized to only a small extent during 27 hr and produced no detectable amount of epoxide.