bluuebunny/crossref_metadata_2025 huggingface dataset:
Methanolysis of cerebrosides with boron trifluoride‐methanol
Authors: Moscatelli Ezio A.
Published: November 2006

A 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

Procedures 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

14C‐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

Improved 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

Lithocholic 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

Cholinephosphotransferase [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

Detailed 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

Heart 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

A 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

The 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

A 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

About 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

The 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

The 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

Human 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

Three 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

Unsaturated 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.
Influence of trichloracetic acid‐phosphotungstic acid on the thin layer chromatographic mobility of gangliosides
Authors: Seyfried T. N. , Weber E. J. , Yu R. K.
Published: November 2006

Trichloroacetic acid (TCA)‐phosphotungstic acid (PTA) precipitation has been used as a faster procedure than dialysis for the isolation of gangliosides, but the TCA‐PTA treatment causes striking abnormalities in the thin layer chromatographic mobilities of the gangliosides. However, a normal chromatographic pattern can be restored by treating the precipitated gangliosides with the tetrasodium salt of ethylenediamine tetraacetic acid followed by dialysis. Hence, TCA‐PTA treatment does not appear to cause artifacts or hydrolysis of the gangliosides.
Identification of positional isomers of lysophosphatides in butter serum
Authors: Cho B. H. S. , Irvine D. M. , Rattray J. B. M.
Published: November 2006

The separation of individual classes of phospholipids by two‐dimensional thin layer chromatography revealed the presence of lysophosphatides (monoacyl glycerophosphoryl compounds) in minor quantities in butter serum. The naturally occurring lysophosphatidyl ethanolamine (LPE) and lysophosphatidyl choline (LPC) were prepared by the combined use of a diethylaminoethyl (DEAE) cellulose column and thin layer chromatography. Gas chromatographic analysis of methyl esters of LPE and LPC showed that both lysophosphatides contained, in addition to saturated fattya cids, considerable quantities of unsaturated fatty acids. A comparison of the fatty acid pattern of naturally occurring LPE and LPC with that of LPE and LPC prepared by phospholipase A hydrolysis of phosphatidyl ethanolamine (PE) and phosphatidyl choline (PC) suggested that both the 1‐and 2‐forms of positional isomers were present. Hydrolysis of naturally occurring LPE and LPC with phospholipase C, and separation of the monoglycerides formed, confirmed the occurrence of two positional isomers of lysophosphatides.
Effect of polyunsaturated fatty acids of the α‐linolenic series on the development of rat testicles
Authors: Ayala Sixta , Brenner Rodolfo R. , Dumm César Gómez
Published: November 2006

The effect of 22∶6ω3 acid provided by dietary fish oil on the development of germinal tissue of rat testes, fatty acid composition of lipids, and linoleic or α‐linolenic acid Δ6 desaturation capacity was investigated. Results were compared to those obtained in animals fed methyl palmitate and sunflower seed oil (linoleate). At 7 and 9 weeks of age, development of germinal tissue of animals fed fish oil was normal. The fatty acid composition showed a decrease in 22∶5ω6 acid content and an increase in 22∶6ω3 acid in triacylglycerol, phosphatidylcholine, and phosphatidylethanolamine. The fatty acid Δ6 desaturation capacity of testicules microsomes was increased. It is suggested that 22∶6ω3 acid may functionally replace 22∶5ω6 acid in germinal tissue.
p‐Chlorophenoxyisobutyrate enhanced retention of homologous lipoproteins by human aortic smooth muscle cells
Authors: Filipovic Ivan , Buddecke Eckhart
Published: November 2006

Human aortic smooth muscle cells (SMC) specifically bind and take up indiscriminately both the lipid and protein moietics of homologous25I‐very low density lipoproteins (VLDL) and125I‐low density lipoproteins LDL). Sixty‐five to 80% of absorbed lipids are incorporated into the cell lipids, preferentially into the phospholipid fraction. Twenty to 35% of the lipid bound and the protein moiety are eliminated from the cells. Half of the eliminated protein label is recovered as TCA soluble products. Five mM of p‐chlorophenoxyisobutyrate (CPIB) raise the level of intracellular radioactivity derived from the lipid moieties of VLDL and LDL by about 40% via a reduced elimination. The processing of the protein moiety and lipoprotein binding to the cell surface are not affected by 5.0 mM of CPIB. CPIB lowers the incorporation of14C‐acetate,14C‐pyruvate, and32phosphate radioactivity into fatty acids and phospholipids of aortic SMC. Five mM of CPIB reduce the overall palmitic acid synthesis by shifting from de novo synthesis to the mechanism of chain elongation, although the further elongation to saturated C18–C24 fatty acids is also depressed. The CPIB‐enhanced retention of the lipid‐derived lipoprotein radio‐activity is interpreted as a compensatory mechanism providing cellular fatty acids which are deficient as a result of the CPIB inhibited synthetic processes.
Tissue lipid responses to 3‐hydroxy‐3‐methylglutaric acid with different dietary fats
Authors: Yousufzai S. Y. K. , Siddiqi Majid
Published: November 2006

Simultaneous administration of 3‐hydroxy‐3‐methylglutaric acid (HMG) for 4 weeks to rats fed 20% saturated fats prevented rise of serum cholesterol, triglycerides, and phospholipids. Except phospholipids, other liver lipids were significantly decreased. HMG administration for 4 weeks along with atherogenic diet significantly decreased cholesterol and phospholipids of serum, liver, aorta, and heart. The phospholipids of epididymal fat and brain were also significantly lowered. The triglyceride levels in serum, liver, and epididymal fat were significantly decreased. The maximal hypolipidemic effect of HMG was observed in serum.
Glycerokinase in human adipose tissue
Authors: Ryall Rosemary L. , Goldrick R. B.
Published: November 2006

The presence of glycerokinase has been demonstrated in human omental and subcutaneous adipose tissue. The enzyme reaction showed a linear time course for 5 min at 30 C and pH optima at pH 7.6 and 9.0. Saturation of the enzyme was observed at 1.8 mM adenosine triphosphate (ATP) and the double reciprocal plot of activity vs. ATP concentration was nonlinear giving two apparent Km values of 0.094 and 0.518 mM. The apparent Km for glycerol, 0.112 mM, was obtained from a linear double reciprocal plot, and the enzyme was saturated at about 0.4 mM glycerol. The activity of glycerokinase in human adipose tissue excised under general anaesthesia was low and was unrelated to adipose cell size or the degree of obesity of the subject from whom the fat was obtained.
A comparison of simplified methods for lipoprotein quantification using the analytic ultracentrifuge as a standard
Authors: Lindgren F. T. , Silvers A. , Jutagir R. , Layshot L. , Bradley D. D.
Published: November 2006

Two simplified methods for quantitative lipoprotein analysis have been calibrated and compared with each other using analytic ultracentrifugation as a standard reference procedure. The first method was the Friedewald procedure and the second was an automated agarose gel electrophoresis system. Both procedures offer comparable quantitative lipoprotein analysis with potential for large scale screening purposes at low cost ($4.00–$5.00 per analysis). There were advantages and limitations to both procedures. The Friedwald procedure can be used on frozen sera but requires 3 ml sera. In contrast, the electrophoresis system must be used with fresh serum but requires only 50 μl serum and the electrophoretic slides may be quantitatively analyzed several years retrospectively.
Sterol composition and phytosterol utilization and metabolism in the milkweed bug
Authors: Svoboda J. A. , Dutky S. R. , Robbins W. E. , Kaplanis J. N.
Published: November 2006

Analysis of the sterols of the milkweed bug,Oncopeltus fasciatus (Dallas) and dietary sunflowerseeds revealed that there is little, if any, conversion of dietary C28 or C29 phytosterols to cholesterol in this phytophagous insect. The dietary sterols are apparently utilized with little alteration both during development to the adult stage and egg production, and cholesterol comprises <1% of the sterols in either adult males and females or in the eggs. The significance of these findings are discussed in light of the recent discovery that the C28‐ecdysone, makisterone A, is the predominant molting hormone in the enbryonated egg of the milkweed bug.
Measurement in vitro of the esterification of yeast sterols
Authors: Parks L. W. , Stromberg V. K.
Published: November 2006

A highly reproducible and rapid procedure is described for isolating free sterols and sterol esters from cell‐free extracts of yeast. Using this technique, the sterol esterifying enzyme has been studied. Sterol ester hydrolase has also been demonstrated. In agreement with whole cell experiments, the enzyme activity for sterol ester synthesis has been found to increase on entrance of the culture into the stationary phase of growth.
Nutritional and metabolic studies of distillable fractions from fresh and thermally oxidized corn oil and olive oil
Authors: Gabriel H. G. , Alexander J. C. , Valli V. E.
Published: November 2006

A semisynthetic diet containing 15% by weight of dietary fat was fed to six groups of male Wistar rats for 28 days. Two groups received the distilable fraction of fresh corn oil (DCO) or fresh olive oil (DOO), two groups the distillable fraction of the thermally oxidized fats (OCO,OOO), and two groups received the respective fresh fats as controls (FCO, FOO). Substantial changes in the fatty acid composition occurred in the fats upon thermal oxidation. Only the rats that received OOO showed overt symptoms of heated fat toxicity. This was reflected in the histological scores of these animals, with the liver sustaining the most numerous and severe lesions. Tissue fatty acid changes of any significance were confined largely to the polar liver lipids of the rats that were fed OCO or OOO. The results of this study would suggest that the relatively greater toxicity of OOO, compared to OCO, may in part be due to the high oleic:linoleic acid ratio of the fresh olive oil and in part to a higher tocopherol content of the corn oil.
Composition and synthesis of three higher ganglioside homologs in bovine mammary tissue
Authors: Bushway Alfred A. , Keenan T. W.
Published: November 2006

Three higher gangliosides were identified as constituents of bovine mammary gland. The structures of these three gangliosides were shown to be ceramide‐glucose‐galactose‐(sialic acid)‐N‐acetylgalactosamine‐galactose, ceramide‐glucose‐galactose‐(sialic acid)2‐N‐acetylgalactosamine, and ceramide‐glucose‐galactose‐(sialic acid)2‐N‐acetylgalactosamine‐galactose These gangliosides accounted for only a small fraction (<20%) of the lipid‐bound sialic acid in mammary gland. While fatty acids with even carbon numbers from C14 to C26 were predominant in these gangliosides, they also contained C23 and C25 fatty acids. Mammary gland Golgi apparatus‐rich fractions had all glycosyltransferases required for synthesis of these gangliosides starting with ceramide.
Visualization of primate high density lipoproteins isolated by density gradient ultracentrifugation
Authors: Hojnacki Jerome L. , Nicolosi Robert J. , Llansa Norma , Hayes K. C.
Published: November 2006

High density lipoproteins (HDL) isolated by density gradient ultracentrifugation from the plasma of monkeys ingesting semipurified diets are barely visible. This creates difficulty in separating HDL from other lower density lipoproteins following centrifugation and necessitates collecting large quantities of background density solution to insure complete recovery of the HDL fraction. A simple procedure is described involving the addition of β‐carotene to nonhuman primate plasma prior to centrifugation which results in the delineation of HDL as a discrete yellow‐orange band without affecting certain physical properties of HDL or interfering with standard lipid and protein assays.
Isotopic labeling of phosphatidylcholine in the choline moiety
Authors: Smith G. A. , Montecucco C. , Bennett J. P.
Published: November 2006

Two simple methods for the synthesis of phosphatidylcholine (lecithin) isotopically labeled in the methyl group of the choline moiety are described. Phosphatidylcholine is converted to phosphatidyl‐ethanolamine by enzymic transphosphatidylation, and this is methylated using either methyl iodide or diazomethane to give a product isotopically enriched in all three choline methyl groups.
Non‐methylene‐interrupted and ω4 dienoic fatty acids of the white shrimpPenaeus setiferus
Authors: Pearce Robert E. , Stillway Lewis W.
Published: November 2006

The total lipid fatty acids from the white shrimpPenaeus setiferus were found to contain several unusual dienoic fatty acid species. These included two methylene‐interrupted species: Δ11, 14‐C18∶2 (18∶2ω4) and δ13, 16‐C20∶2 (20∶2ω4). Also found were several non‐methylene‐interrupted dienoic fatty acids including δ7, 11 and Δ7, 13‐C20∶2, Δ7, 13‐C21∶2, Δ7, 13, Δ7, 15, Δ9, 13, Δ9, 15, and Δ7, 17‐C22∶2. Many minor C20∶2 non‐methylene‐interrupted dienes were found but could not be unequivocally characterized.
Glyceride metabolism in the myopathic hamster
Authors: Barakat Hisham A. , Tapscott Edward B. , Smith Carlton
Published: November 2006

Analysis of plasma lipids of 30‐ and 185‐day‐old BIO 82.62 myopathic hamsters and age‐matched normal controls revealed a decrease in only the concentration of cholesteryl esters of 185‐day‐old diseased animals. Measurement of lipoprotein lipase (LPL) activity in heart, muscle, and adipose tissue showed no difference between the activity of the enzyme in the heart and muscle of the cardiomyopathic hamsters and that of the age‐matched controls. In adipose tissue, however, LPL activity was depressed in the diseased animals in both age groups. No difference was found in the activity of hormone sensitive lipase. Incorporation of sn[U‐14C] glycerol‐3‐phosphate into total lipids was found to be depressed in homogenates of heart, muscle, and adipose tissue but unchanged in liver homogenates of diseased animals. It was concluded that the decrease in the capacity to synthesize glycerides, rather than limiting substrate concentrations, could be the cause of the decrease in the lipid content in some tissues of the cardiomyopathic hamster.
Changes in the fatty acid composition of rat lung lipids during development and following age‐dependent lipid peroxidation
Authors: Kehrer James P. , Autor Anne P.
Published: November 2006

Analyses of the fatty acid content and composition of various lung lipids were conducted in rats 1 day, 5 days, and 12 days after birth and in adult animals in order to define more clearly the specific lipid peroxidizing system found in neonatal rat lungs. Lipid peroxidation occurs in the 900×g supernatant fraction of rat lung homogenates in an age‐dependent manner independent of the addition of any factor and is maximal at 5 days of age. No lipid peroxidation is evident in similar preparations of either newborn or adult lung tissue. As the animals develop, arachidonic and docosahexaenoic acids, fatty acids which are both highly susceptible to lipid peroxidation in the presence of a suitable catalyst, decrease gradually when measured as the percentage of the total fatty acids in the triglyceride fraction of the lung. The total quantity of triglycerides, however, is significantly lower in lungs from 1‐day‐old rats than at any other age. The fatty acid composition and total quantity of both lung phospholipids and lung free fatty acids do not show similar changes. Following in vitro incubation of the 900×g supernatant fraction of peroxidizing lung homogenates, an appreciable decrease in the amount of arachidonic and docosa‐hexaenoic acid could be detected in lung triglycerides. Less extensive decreases were observed in the phospholipid fraction. No changes in these components were observed in newborn or adult animals. The addition of triarachidonin to the 900×g supernatant fraction of lung homogenates resulted in increased malondialdehyde release at all ages tested while added arachidonic acid increased the formation of malondialdehyde only in 5‐ and 12‐day‐old rat lung preparations. The addition of triolein, cholesterol arachidonate, and diarachidonyl phosphatidylcholine had no effect on malondialdehyde formation at any age. The age‐dependent lipid peroxidation observed after in vitro incubation of rat lung homogenate preparations, therefore, may result from the relatively high concentration of triglycerides containing polyunsaturated fatty acids present in the neonatal tissue. As the susceptible polyunsaturated fatty acids of lung triglycerides are replaced by less unsaturated species, this activity may diminish concomitantly.
Composition ofO‐alkyl andO‐alk‐1‐enyl moieties in the glycerolipids of the human adrenal
Authors: Lin Hsiang Ju , Lie Ken Jie M. S. F. , Hing Lee Clara Lai , Seng Lee Daniel Hong
Published: November 2006

A comparison of human adult and fetal adrenals with respect to their levels of glyceryl ether lipids and other lipid components is reported. Fetal glands contained significantly lower levels of alk‐1‐enyl phosphoglycerides and of cholesterol. Neutral glyceryl ether diesters, and ethanolamine and choline phosphoglycerides were isolated from adult adrenal tissue. The composition of theO‐alkyl glycerol groups in these lipid fractions was obtained by means of gas chromatography of the trimethylsilyl ethers and diacetyl derivatives;O‐alk‐1‐enyl glycerols were analyzed as their diacetates. About one‐half of the alkyl and alk‐1‐enyl glycerol moieties present in glyceryl ether diesters contained hydrocarbon side chains with 20, 22, or 24 carbon atoms. Long hydrocarbon chains (C19–24) were also found in theO‐alkyl glycerol moieties present in the total lipids of fetal adrenals.
Mass spectrometric identification of C20 fatty acids bovine lens using the pyrrolidide derivative
Authors: Valicenti Anthony J. , Chapman Clifford J. , Holman Ralph T. , Chipault Jacques R.
Published: November 2006

Unsaturated C20 fatty acids from bovine lens have been examined via gas chromatography‐mass spectrometry of their pyrrolidine derivatives. The presence of arachidonic acid and 5,8,11‐20∶3 in bovine lens has been confirmed by this study. In addition, the 10‐, 11‐, 12‐, and 13‐isomers of 20∶1 and the 7,13‐, 8,14‐, and 12,15‐isomers of 20∶2 were identified.
Studies on biosynthesis of waxes by developing jojoba seed tissue
Authors: Ohlrogge J. B. , Pollard M. R. , Stumpf P. K.
Published: November 2006

Slices of developing jojoba cotyledons incorporated a variety of precursors in to wax, free alcohols, and polar lipids.14C‐Decanoic and14C‐lauric acids were elongated and desaturated, whereas14C‐myristic and14C‐longer chain fatty acids, although incorporated into wax, were insignificantly modified. Exogenously added14C‐acetate contributed mainly to chain elongation of endogenous oleic acid, whereas14C from added glucose was uniformly distributed throughout the acyl chain of the fatty acids. These data suggest the existence of metabolically separate pools of acetate and/or sites for de novo synthesis and elongation of acyl chains.
Changes in the cholesterol and phospholipid content of mouse spleen after Rauscher Leukemia Virus infection
Authors: Montfoort A. , Boere W. A. M. , Van Griensven L. J. L. D.
Published: November 2006

The effect of Rauscher Leukemia Virus (MuLV‐R) infection on the lipid composition of mouse spleen from BALB/c mice was investigated. Drastic changes in the lipid composition of the spleen as a result of tumor growth induced by the virus could be demonstrated at 21 days after infection. The molar ratio of cholesterol to phospholipids was found to be low, while a shift within the choline containing phospholipid classes resulted into a lower sphingomyelin and a higher phosphatidyl choline content of the MuLV‐R infected spleen. The cholesterol ester content increased more than two‐fold during tumor growth, and shifts in the fatty acid patterns of the lipids were demonstrated.
Retarding effects of DNA on the autoxidation of liposomal suspensions
Authors: Pietronigro Dennis D. , Seligman Myron L. , Jones W. Barrie G. , Demopoulos Harry B.
Published: November 2006

Deoxyribonucleic acid (DNA) is associated with the cell membrane of prokaryotes and the inner nuclear membrane of eukaryotes. The unsaturated fatty acids of phospholipids, which constitute the bilaminar structure of membranes, undergo autoxidation in the presence of O2. Calf thymus DNA was incubated with methyl archidonate‐enriched phosphatidyl choline liposomes in order to study the effect of DNA upon the oxidation of phospholipids while present in their natural in vivo bilayer configuration. DNA retarded the rate of lipid oxidation and the TBA test, but it did not alter the induction period. These results suggest that DNA is scavenging free radicals produced within the phospholipid bilayer.
Blood sampling techniques for studying rapidly turning over metabolic fuels in mice
Authors: Baker Nome , Morris Daniel , Sandborg Christy
Published: November 2006

Experiments were carried out in control and Ehrlich ascites carcinomatous mice to determine whether orbital venous sinus blood could be used to reflect blood in the systemic circulation (decapitation blood) in the case of a rapidly turning over metabolic fuel such as free fatty acids. The early time course of intravenously injected, labeled free fatty acids was measured using [9,10‐3H]palmitic acid and [1‐14C]linoleate complexed to mouse serum. No significant differences between decapitation and orbital sinus blood were found at early times in either group of mice. The orbital sinus clearly contains blood that is not stagnant and is replaced so rapidly that it is suitable for studying very rapidly turning over, circulating metabolites.
Influence of elevated levels of linoleic acid on the thermal properties of bovine milk fat
Authors: Morrison I. M. , Hawke J. C.
Published: November 2006

The thermal properties of bovine milk fat containing 15.5% linoleic acid have been compared with those of milk fat containing a normal level (1.8%) of linoleic acid in order to examine the influence of altered triglyceride (TG) composition on their physical characteristics. The total TGs of 18∶2‐rich milk fat melted over the range −38 to 30 C compared with the range −33 to 34 C for control milk fat. Polymorphism exhibited by the high mol wt TGs of control milk fat was absent in the same fraction of 18∶2‐rich milk fat. Similarly, the complex melting thermogram of the low mol wt TGs of control milk fat and its obvious polymorphic behavior contrasted with the single broad melting peak of the low mol wt TGs of 18∶2‐rich milk fat. This solid miscibility in the 18∶2‐rich milk fat could be a consequence of the lower proportion of saturated TGs or the presence of high proportions of diene and triene TGs containing 18∶2 instead of monoene and diene TGs containing 18∶1.
Effect of lecithin on jejunal absorption of micellar lipids in man and on their monomer activity in vitro
Authors: Ammon H. V. , Thomas P. J. , Phillipis S. F.
Published: November 2006

The effect of lecithin on jejunal absorption of fatty acids and octadecenoylglycerol was studied in healthy volunteers with a jejunal perfusion system which excluded pancreatic and biliary secretions from the test segment. Lecithin significantly reduced the absorption of oleic acid (P<0.05) and octadecenoylglycerol (P<0.01), while it had no effect on the absorption of ricinoleic acid. In vitro, lecithin reduced monomer activities of all three lipids; the changes were greater for oleic acid and octadecenoylglycerol than for ricinoleic acid (P<0.02). From these data it is concluded that lecithin reduces monomer activity of fatty acids in mixed micellar solutions and that it can thereby reduce the absorption rates of micellar lipids. Intact lecithin is not absorbed under these conditions. Maldigestion of lecithin in pancreatic insufficiency may, therefore, aggravate the steatorrhea observed in this condition.
Stearoyl‐coenzyme A desaturase activity in novikoff hepatoma
Authors: Renuka Prasad M. , Joshi Vasudev C.
Published: November 2006

The activities of microsomal stearoyl‐CoA desaturation, NADH‐cytochrome b5 reductase, NADH‐cytochrome c reductase, and the content of cytochrome b5 were similar in livers of normal and host rats. On the other hand, stearoyl‐CoA desaturation activity was absent in Novikoff hepatoma. The activities of NADH‐cytochrome b5 and NADH‐cytochrome c reductases in the hepatoma microsomes were 4.8% and 2.2%, respectively, of those in normal liver. Furthermore, in hepatoma microsomes, cytochrome b5 was absent. An active stearoyl‐CoA desaturation was reconstituted only on addition of both cytochrome b5 and the terminal desaturase enzyme to the hepatoma microsomes. These results indicated that a complete absence of cytochrome b5 and terminal desaturase is responsible for the lack of stearoyl‐CoA desaturation in Novikoff hepatoma microsomes.
Characterization and composition of sterols in the free and esterified sterol fractions ofAspergillus oryzae
Authors: Fujino Yasuhiko , Ohnishi Masao
Published: November 2006

Free and esterified sterol fractions were isolated fromAspergillus oryzae, and their components analyzed mainly by gas chromatography‐mass spectrometry. Cholesterol, brassicasterol, episterol (5α‐ergosta‐7,24[28]‐dien‐3β‐ol), 4α‐methyl‐5α‐ergosta‐8[9],24[28]‐dien‐3β‐ol, lanosterol and 24‐methylene‐24‐dihydrolanosterol were well characterized, whereas 5‐dihydroergosterol, sitosterol and 24[28]‐dehydroergosterol were tentatively characterized. The principal sterol of the free sterol fraction was brassicasterol, and that of the esterified sterol fraction was episterol. Ergosterol, which is reported to be widely distributed in the fungi kingdom, was not detected.
Mitochondrial and microsomal phospholipid phosphorus metabolism during postnatal growth in rat heart and liver
Authors: Hallman Mikko , Kankare Paavo
Published: November 2006

The relative specific activities of phospholipids of hearts and livers of newborn and older rats were measured 2 hr after intraperitoneal32P‐orthophosphate. There was a close linear correlation between the specific activity of cardiolipin and the net increase in the amount of this phospholipid. In one‐day‐old animals, the relative specific activities in the heart and liver were highest and exceeded by 7.3‐ and 3‐fold, respectively, the corresponding activities in the adult. The apparent half‐lives of cardiolipins were calculated on the basis of the linear correlation that was found between the net increase in cardiolipin and the rate of incorporation. These half‐lives were 4.7 days in liver and 6.4 days in heart. Though the changes in the phospholipid composition of the organelles during neonatal development were small, the relative specific activities of the individual phospholipids varied considerably. In addition to cardiolipin, there was a good correlation between the specific activity and the net increase in mitochondrial phosphatidylinositol. At birth, the specific activity of mitochondrial phosphatidylcholine in liver was 2.9 times that in microsomes. During the 12 neonatal hours, the specific activity of microsomal phosphatidylcholine increased 6.3‐fold and exceeded the corresponding mitochondrial activity. The relation between the activation of microsomal phosphatidylcholine synthesis and the induction of serum lecithin synthesis in newborn liver is discussed. The finding that at birth the specific activity of mitochondrial phosphatidylcholine unexpectedly was higher than that of microsomal phosphatidylcholine points out the difficulties in interpreting the in vivo evidence for precursor‐product relationship.
In vitro and in vivo effects of exogenous lipids on the enzymatic hydrolysis of rat bile phospholipids
Authors: Reisser D. , Boucrot P.
Published: November 2006

The addition of total phospholipids, phosphatidylcholines, triglycerides, cholesterol or glycerol to incubation media containing rat pancreatic juice and bile labeled with [9,103H2] oleic acid (90% of the radioactivity present as phospholipids) had no effect on the hydrolysis of bile endogenous phospholipids. The introduction of 2 or 10 mg of phosphatidylcholines and 0.5 ml of bile (≈ 1.5 mg of phospholipids)into the rat upper duodenum decreased the rate of absorption of rative bile phospholipids. It was not followed by an increase of free fatty acids released from biliary phospholipids in the intestinal lumen. The introduction of bile (0.5 ml) and small amounts of triolein (1.4–3.5 mg) into the duodenum had little effect on the rate of hydrolysis and absorption of native bile phospholipids, but caused a reduced absorption of the free fatty acids released or those coming from initial nonphosphorus biliary lipids. The introduction of bile (0.5 ml) and large amounts of triolein (30 mg) into the duodenum increased the rates of hydrolysis and absorption of endogenous bile phospholipids. These observations suggest that luminal lipid components can modify the organization of luminal micelles and, consequently, the action of the pancreatic phospholipase A2 and the absorption of bile lipids.
The optical rotation of a major component of plant cutin
Authors: Espelie Karl E. , Kolattukudy P. E.
Published: November 2006

The major component of cutin from the fruit of both tomato and papaya, dihydroxypalmitate, is shown to have plain positive rotation and is, therefore, assigned L configuration in analogy to other known hydroxy fatty acids.
Effect of serum lipoproteins of bile obstructed rats on 3‐hydroxy‐3‐methylglutaryl coenzyme A reductase activity in perfused rat liver
Authors: Barak A. J. , Sorrell M. F. , Tuma D. J.
Published: November 2006

Total lipoproteins as well as fractionated VLDL+LDL and HDL from fasted control rats and bileligated rats were tested in liver perfusion for their effect on 3‐hydroxy‐3‐methylglutaryl CoA reductase to increase 3‐hydroxy‐3‐methylglutaryl CoA reductase activity than that of the control total lipoproteins. When the fractionated lipoproteins were tested from fasted control rats, it was found that the major stimulating activity was in the HDL fraction with minor activity in the VLDL+LDL fraction. When these plasma components isolated from fasted bile‐ligated rats were tested, it was found that the major activity had shifted to the VLDL+LDL fraction with the HDL having only a minor stimulatory role. The possible mechanism of action of the abnormal lipoproteins associated with bile obstruction in regulating 3‐hydroxy‐3‐methylglutaryl CoA reductase activity is discussed.