bluuebunny/crossref_metadata_2025 huggingface dataset:
Dietary regulation of phosphatidic acid synthesis from dihydroxyacetone phosphate and fatty acid by rat liver microsomes
Authors: Rao G. Ananda , Sorrels M. F. , Reiser R.
Published: November 2006

Phosphatidic acid synthesis from dihydroxyacetone phosphate and 1‐14C‐palmitate was studied in liver microsomes of rats maintained on a stock diet (5% fat), fasted for three days after being fed the stock diet, or given a high fat diet (15% fat) or a fat free diet for a week after being fed the stock diet. The amounts of phosphatidic acid synthesized per minute per milligram of microsomal protein in rats ingesting a stock diet or a fat free diet were at least twice the levels observed in rats either fasting or maintained on a high fat diet. Following fasting, realimentation with either a fat free or high fat diet returned the microsomal capacity for phosphatidic acid synthesis to approximately the same level, which was higher than that observed in rats maintained on a stock diet. Analogous results were observed when glyceraldehyde 3‐phosphate was used as the glyceride‐glycerol precursor, probably because microsomes convert glyceraldehyde 3‐phosphate to dihydroxy‐acetone phosphate. These studies demonstrate that phosphatidic acid synthesis from dihydroxyacetone phosphate by particulate enzymes is influenced by diet.
The isolation and specificity of alfalfa lipoxygenase
Authors: Chang C. C. , Esselman W. J. , Clagett C. O.
Published: November 2006

Partial purification of the lipoxygenase from alfalfa seed was accomplished by fractionation of the protein with (NH4)2SO4, phosphate, heavy metal salts and ultracentrifugation. About 24% of the original activity was recovered. The partially‐purified alfalfa lipoxygenase enzyme was free of hydroperoxide‐decomposing activity and was used to determine the positional specificity of linoleic acid oxidation by alfalfa lipoxygenase. Combined gas liquid chromatography‐mass spectrometry was used to analyze known mixtures of 10‐ and 12‐hydroxystearic acid derivatives and was satisfactory for the quantitative determination of the ratio of each component. This combination was used to analyze mixtures containing position isomers of hydroxy fatty acids without separation of each individual compound by other methods. Hydroperoxides produced from linoleic acid oxidation catalyzed by alfalfa lipoxygenase were converted by sodium borohydride reduction, catalytic hydrogenation and bis(trimethylsilyl)acetamide silylation to their corresponding trimethylsilyl either esters and the positional distribution was studied. The 9‐ and 13‐linoleate hydroperoxides produced by alfalfa lipoxygenase were in equal concentrations (50∶50) whereas the distribution for soybean lipoxygenase was 70% 13‐ and 30% 9‐hydroperoxides.
Studies on the hydrolysis and utilization of long chain acyl CoA thioesters by liver microsomes
Authors: Jezyk Peter F. , Hughes Haywood N.
Published: November 2006

Acyl CoA thioester “hydrolase” activity exhibited by liver microsomal preparations using a spectrophotometric assay for released CoA has been shown to be a composite of several enzymatic reactions. Pig liver microsomes form a considerable amount of triacylglycerol from endogenous precursors, with essentially all acyl groups being incorporated into the 1,3 positions. Rat and rabbit liver microsomes form very little triacylglycerol under the same conditions. The true acyl CoA hydrolase activity of pig liver microsomes is relatively insensitive to diisopropylfluorophosphate (DFP), whereas this compound strongly inhibits the rat and rabbit enzymes. The hydrolase remaining in the liver microsomes after DFP treatment is rapidly inactivated when incubated in the presence of substrate.
The inhibitive effects of azasterols on sterol metabolism and growth and development in insects with special reference to the tobacco hornworm
Authors: Svoboda J. A. , Robbins W. E.
Published: November 2006

Several monoazasterols were found to be potent inhibitors of Δ24‐ and Δ22,24‐ reductase enzyme(s) in the tobacco hornworm,Manduca sexta (Johannson). Certain of these inhibitors also prevented normal larval development and pupation in the hornworm at dietary concentrations in the parts per million range. Comparative studies with several different insects indicated differences between the species with respect to the effects of the azasterols. The relationship of azasterol structure to the inhibitory effect(s) on sterol metabolism and larval development is discussed.
The distribution of sterols in algae
Authors: Patterson Glenn W.
Published: November 2006

Available analytical techniques are now sufficient for the separation and identification of sterols from complex mixtures in plants. Gas and thin layer chromatography and mass spectroscopy in particular, have been used to resolve some of the confusion concerning the sterol composition of algae. Red algae (Rhodophyta) contain primarily cholesterol, although several species contain large amounts of desmosterol, and one species contains primarily 22‐dehydrocholesterol. Only a few Rhodophyta contain traces of C‐28 and C‐29 sterols. Fucosterol is the dominant sterol of brown algae (Phaeophyta), apparently the major sterol of every species examined. Most Phaeophyta also contain traces of cholesterol and biosynthetic precursors of fucosterol. The sterols of green algae (Chlorophyta) are much more varied and complex than those of other groups of algae. Whereas the Phaeophyta and Rhodophyta contain one primary sterol, many of the Chlorophyta contain a complex mixture of sterols such as occurs in higher plants. The Chlorophyta contain such sterols as chondrillasterol, poriferasterol, 28‐isofucosterol, ergosterol, cholesterol and others. Sterol composition may be of value in the systematics of plants such as the Chlorophyta. Recently (for the first time) complex mixtures of sterols have been isolated in very small amounts in the blue‐green algae (Cyanophyta). Available data on the sterols of other groups of algae are insufficient for making useful comparisons.
Some pathways and mechanisms in lanosterol‐cholesterol conversion in mammalian tissues
Authors: Paoletti R. , Galli G. , Paoletti E. Grossi , Fiecchi A. , Scala A.
Published: November 2006

Sterol precursors of cholesterol with a double bond in the lateral chain are present in normal human brain and glioblastoma. Biosynthetic experiments with labeled mevalonate show that the unsaturated intermediates are preferentially labeled when compared with the corresponding saturated sterols. The biological role of sterols containing an 8(14) double bond is discussed.
Hepatotoxicity and lipid metabolism‐IV structure and molecular species of hepatic triglyceride in rats treated with carbon tetrachloride
Authors: Sugano Michihiro , Imaizumi Katsumi , Cho Shuji , Wada Masafuto
Published: November 2006

Effects of carbon tetrachloride (CCl4) on the positional distribution of fatty acids and on the molecular species of hepatic triglyceride in female rats were studied. Six hours after a dose of CCl4, the percentages of palmitic and oleic acids were increased at the 1 and 2 positions respectively in comparison to the control, while linoleic acid was decreased at the 3‐position. These changes were not remarkable 20 hr after CCl4. CCl4 treatment generally caused increases in less unsaturated species of triglycerides (S2M, SM2 and S2D) and decreases in more unsaturated species (SD2 and more polyunsaturated). These data suggest that CCl4 induces specific alteration in the metabolism of triglycerides in the liver.
Quantitative determination of glycerol, mono‐ and diglycerides by gas liquid chromatography
Authors: Blum Jaime , Koehler Walter R.
Published: November 2006

Standard chemical procedures for the determination of glycerol, mono‐ and diglycerides in food products are lengthy, particularly when more than one component has to be determined in the same sample. Gaschromatographic techniques are applicable to these compounds when they are converted into their trimethylsilyl derivatives. A simple, rapid and quantitative gas chromatographic procedure has now been developed which is based on the addition of an internal standard (cholesteryl acetate) to samples which are subsequently silylated. This procedure has been applied to the direct determination of glycerol, mono‐ and diglycerides in emulsifiers, shortenings and other samples.
Cerebrosides of rabbit and pigeon aorta: Isolation and fatty acid distribution
Authors: Tao Robert V. P. , Foote J. Lindsley
Published: November 2006

Quantitative determinations have been made on the cerebrosides isolated from aortas of cholesterol‐fed and normal rabbits, and mature and young pigeons. The fatty acid distributions of these cerebrosides were determined. Cerebroside concentration was higher in pigeons than in rabbits and higher in the animals expected to have atherosclerosis. Comparing supposedly atherosclerotic animals to normal animals, the atherosclerotic animals generally had more unsaturated fatty acids and more 18:0 and 18:1 as compared to 16:0 and 16:1. These trends are consistent with fatty acid data from human aorta. Pigeon data were more similar to human data than were the rabbit data.
Fatty acid metabolism inDrosophila melanogaster: II. Metabolic origin of monoenes
Authors: Kiyomoto R. K. , Keith A. D.
Published: November 2006

Evidence is presented thatDrosophilalarvae produce monounsaturated fatty acids by two independent pathways. One of these pathways, involving the direct desaturation of long chain precursors, is sensitive to inhibition by linoleate. The other pathway is resistant to linoleate inhibition and probably has tetradecnoate‐Δ5cisand tetradecnoate‐Δ7cisas intermediates in the synthesis of palmitoleate and oleate, respectively. The use of radioactive precursors of varying chain length and labeled at different positions in the carbon chains provided evidence for the isolation and structure of intermediates involved in the linoleate resistant pathway.
Effect of fructose on rat lipids
Authors: Hill P.
Published: November 2006

Young and mature albino rats were fed Purina chow with and without fructose in the drinking water, and the lipid contents in the serum and livers were determined. Fructose elevated the serum triglyceride and caused an accumulation after 24 hr of liver triglyceride in fed but not fasted mature rats. In young male rats, the liver triglyceride was increased initially but was not found after 10 days. Serum phospholipids were increased in young and mature rats; the content and specific activity of the high density (HD)‐lipoproteins being increased in young rats. In vivo incorporation of labeled acetate into liver cholesterol was reduced. Results suggest that fructose or triglyceride metabolism, or both, in rats differ with age.
Inhibition of renal cortical Rb+ transport by phospholipase C and its relationship to (Na++K+)‐adenosine triphosphatase
Authors: Malila Amra , Masoro Edward J.
Published: November 2006

Treatment of isolated renal cortical tubules with a low concentration of phospholipase C (one which does not lead to a chemically detectable loss of tubular phospholipid) results in a markedly inhibited Rb+ transport function which is referable to the loss of a phospholipid component of the tubules. This treatment also results in an inhibition of the (Na++K+)‐adenosine triphosphatase enzyme of the tubules. The data are consistent with the concept that it is the loss in (Na++K+)‐adenosine triphosphatase activity which is responsible for phospholipase C‐induced inhibition of Rb+ transport.
Liberation of aldehydes from alk‐1‐enyl glyceryl ethers by acid hydrolysis
Authors: Wood Randall , Healy Kathleen
Published: November 2006

Labeled alk‐1‐enyl glyceryl ethers were used in conjunction with thin layer chromatography to study the liberation of aldehydes from alk‐1‐enyl glyceryl ethers by two acid hydrolysis procedures. Both methods gave similar results, but neither liberated the aldehydes quantitatively. Only 75–85% of the alk‐1‐enyl glyceryl ether radioactivity was liberated as free aldehydes. Several nonaldehyde products were detected and one appeared to be a cyclic acetal.
The functioning of the lipids and lipoproteins of sarcotubular membranes in calcium transport
Authors: Masoro E. J. , Yu Byung Pal
Published: November 2006

In the intact muscle cell, an internal tubular membrane system called the sarcoplasmic reticulum (SR) plays an important role in the contraction‐relaxation cycle by controlling the Ca++ of the myoplasm; release of Ca++ from the SR to myoplasm initiates contractile activity and sequestring Ca++ in the SR by means of a transport system causes muscle to relax. Fragments of the SR with a vesicular structure can be isolated from muscle homogenate and these vesicles are able to vigorously transport Ca++ from incubation media into the intravesicular space thus enabling study of Ca++ transport under precisely defined in vitro conditions. A highly purified fraction of SR vesicles called SF1 were prepared from rat muscle by means of density gradient centrifugation procedures. The role of SR lipid in Ca++ transport was studied. SF1 was treated in vitro with either phospholipase A or C or D or polyene antibiotics. The effect of essential fatty acid deficiency, induced in vivo, was also investigated. It was concluded that the only structural feature of SF1‐lipid involved in Ca++ transport and the associated adenosine triphosphatase is the phosphoryl moiety of the phospholipids. Evidence was obtained which inplicated histidine residues of the SF1 protein in this transport function. To study the role of SF1 protein in this process in depth, the membranes were solubilized by a sodium dodecylsulfate system and made free of their lipid components. More than 95% of this protein is soluble in dilute salt solution; of this, more than 90% is composed of a protein fraction which can be isolated by gel filtration (called protein fraction‐2). Protein fraction‐2 contains large molecular aggregates of small polypeptide subunits of identical or nearly identical molecular weight. They contain solely N‐terminal glycine and probably only C‐terminal alanine. The significance of such a high percentage of similar polypeptide subunits in SR is discussed.
Serum lipid transport systems: Recent advances
Authors: Lopez‐S Alfredo
Published: November 2006

Lipids circulating in the plasma are transported in water soluble form as lipid‐protein complexes. Lipoproteins can be classified according to size, density, electrophoretic mobility and protein composition. The ability of low density lipoproteins and very low density lipoproteins (VLDL) to form complexes with different polyanions has been also used as a method for separation and study of serum lipoproteins. Even within classes of lipoproteins closely related otherwise, the amount of different lipids and their ratios to each other and to protein are variable. Two enzymatic systems seem to be at least partly responsible for the different lipid compositions of serum lipoproteins: lipoprotein lipase and lecithin‐cholesterol acyltransferase (LCAT). LCAT, which seems to be associated with α‐lipoproteins, is responsible for the formation of the bulk of cholesteryl‐esters in human serum. Changes in activity of this enzyme may explain the observed changes with age and disease of serum cholesteryl‐ester fatty acids (CEFA). Differences in CEFA pattern are found between newborn and adult animals, including man. The activity of serum LCAT was observed to increase with age in animals and to decrease markedly in patients with liver cirrhosis. These patients show abnormal serum CEFA patterns and abnormally low proportions of pre‐β‐ (VLDL) and α‐ (high density) lipoproteins.
Studies on the role of phospholipids in the triglyceride cycle: III. Liver and plasma phospholipid exchange in depancreatized dogs
Authors: Olmsted C. A.
Published: November 2006

Lipid mobilization from the liver to extrahepatic sites of utilization and to adipose tissue for storage and recycling via the triglyceride cycle requires de novo synthesis of liver lecithins. The role of liver phospholipid (PL) synthesis and plasma phospholipid turnover has been studied under a number of conditions which appear to relate liver lipoprotein formation and release to liver PL synthesis and transport. Conditions which enhance nonesterified fatty acid (NEFA) release from adipose tissue or which inhibit liver PL synthesis prompt liver lipid accumulation. Lipid accumulates in the liver principally as triglyceride when any one of a number of factors required for liver lipoprotein comple formation is blocked, such as by ethionine, or when NEFA release to plasma is increased, such as in cold acclimatization. The relationship of liver PL to liver lipid transport is shown also following recovery from these conditions. Recovery from liver triglyceride (TG) accumulation is accompanied by increased PL synthesis, remobilization of liver PL, and increased turnover of plasma phospholipids. The relative specific activity (RSA) of phospholipid phosphorus (SA of plasma to liver PLP) is increased in depancreatized dogs during liver lipid accumulation. Following the initial depression in liver PL synthesis and transport caused by ethionine administration the RSA increased in all animals studied, indicating a remobilization of the accumulated TG. This remobilization of liver lipid occurs to a greater extent in depancreatized dogs than in normal dogs under the same conditions.
The phospholipids of corynebacteria
Authors: Brennan Patrick J. , Lehane Derek P.
Published: November 2006

The phospholipids ofCorynebacterium diphtheriae, Corynebacterium xerosis, Corynebacterium equi andCorynebacterium ovis were examined, largely by chromatographic procedures. In all of these, lipids of the phosphoinositide and mannophosphoinositide type were prominent. In contrast to the mycobacteria, the mannophosphoinositides of the corynebacteria were all dimannophosphoinositides; however, as in mycobacteria, these dimannophosphoinositides apparently occurred in the diacylated and triacylated forms—the tetraacylated component prominent in mycobacteria was absent. Phosphatidylethanolamine and phosphatidylserine were also absent. InCorynebacterium diphtheriae the major single phospholipid corresponded to phosphatidylglycerol: cardiolipin also appeared to be a major lipid. The fatty acids of the corynebacterial phospholipids were distinguished by the presence of branched chain isomers of medium chain length. The importance of phospholipids in the taxonomy of the actinomycetes and related eubacteria is discussed.
Quantitative analysis of the phospholipids of some marine bioluminescent bacteria
Authors: Eberhard Anatol , Rouser George
Published: November 2006

Quantitative analyses of the phospholipids of three strains of marine bioluminescent bacteria were carried out after separation by two‐dimensional thin layer chromatography. The phospholipids of all three species consisted of about 75% phosphatidyl ethanolamine, 13% phosphatidyl glycerol and 7% cardiolipin. The composition was only slightly affected by drastic changes in the growth conditions. One of the species contained poly‐β‐hydroxybutyrate. The fatty acids of another species contained principally straight and branched‐chain 16 and 18 carbon fatty acids. No clue as to the nature of the elusive “aldehyde factor” of bacterial bioluminescence was found by analysis of aldehyde deficient mutants, indicating that possibly the factor is not a major phospholipid of these bacteria.
Effects of level and type of dietary fat on incidence of mammary tumors induced in female sprague‐dawley rats by 7,12‐dimethylbenz(α) anthracene
Authors: Carroll K. K. , Khor H. T.
Published: November 2006

Female Sprague‐Dawley rats on semisynthetic diets containing 10% and 20% by weight of corn oil developed more mammary adenocarcinomas after treatment with a single oral dose of 7,12‐dimethylbenz(α)anthracene than similar rats on diets containing only 0.5% or 5% corn oil. Experiments with 10 different fats and oils fed at the 20% level indicated that unsaturated fats enhance the yield of adenocarcinomas more than saturated fats. Fibroadenomas and adenomas were also found in small numbers in all dietary groups but the yield did not seem to be influenced by level or type of dietary fat. The possible relevance of these findings to the incidence of breast cancer in humans is discussed.
The infrared spectra and polymorphism of long chain esters: IV. Some esters from tetradecanol, hexadecanol, octadecanol, eicosanol, docosanol and dodecanoic, tetradecanoic, hexadecanoic, octadecanoic and eicosanoic acid
Authors: Aleby S. , Fischmeister I. , Iyengar B. T. R.
Published: November 2006

Infrared spectra and x‐ray diffraction photographs have been recorded for some normal‐chain esters of long chain acids and long chain alcohols. The substances show no polymorphism but two different structure types exist, one with the chains tilting towards the end group planes and one with vertical chains. The IR spectra permit determination of the chain length of the acid methylene chain. The length of the alcohol chain cannot be deduced.
A possible block in the intermediary metabolism of glucose into proteins and lipids in the brains of undernourished rats
Authors: Agrawal H. C. , Fishman M. A. , Prensky A. L.
Published: November 2006

[U‐14C] Glucose or [1‐14C] L‐leucine was injected intraperitoneally into 28‐day‐old undernourished rats and control sibs who were killed 6 hr later. Brain proteins and lipids were extracted and the lipids fractionated by silicic acid column chromatography into cholesterol, glycolipids and phospholipids. The specific activity of labeled carbon derived from [U‐14C] glucose in brain proteins was reduced by 25% in undernourished animals when compared to controls. A similar reduction was seen in the specific activity of brain lipids of undernourished animals: 14% for cholesterol, 21% for phospholipids and 35% for glycolipids. When [1‐14C] l‐leucine was used as a direct precursor of brain protein synthesis, the specific activity in the undernourished group was only 5% less than that found for the controls. This was not statistically significant. The results suggest that there may be a block in the intermediary metabolism of glucose in the brains of undernourished rats that reduces the availability of glucose carbon to the precursor pool used for protein and lipid synthesis.
The labeling of brain ethanolamine phosphoglycerides from cytidine diphosphate ethanolamine in vitro
Authors: Porcellati G. , Biasion M. G. , Pirotta M.
Published: November 2006

Chicken brain microsomes convert14C‐ethanolamine‐labeled cytidine diphosphate ethanolamine (CDPE) to ethanolamine lipids (EPG) at a measurable rate. Mitochondria and particle‐free supernatant fractions are almost inactive. On adding saturating amounts of diacyl glycerol to the microsomes, formation of EPG increases 10‐fold, and is almost totally confined to the diacylsn‐glycero‐3‐phosphorylethanolamine (GPE), whose synthesis increases 20‐fold (from 13.1 to 249 mμmoles/mg protein/hr). The addition of the 1‐alkenyl 2‐acyl glycerol also produces a noticeable increase in the rate of EPG labeling, which is almost exclusively confined to the alkenyl acyl GPE, whose synthesis is stimulated 30‐fold (from 3.1 to 90 mμmoles/mg protein/hr). Synthesis of alkyl acyl GPE from CDPE was not detected in the brain microsomes. Synthesis of EPG from CDPE by chicken brain homogenates has also been examined and results similar to those reported for the brain microsomes were obtained. In addition, small amounts of labeled alkyl acyl GPE are produced from CDPE in the homogenates, but in no case does this synthesis increase on adding various lipid acceptors to the incubation system. Various properties of the phosphorylethanolaminediacyl glycerol phosphotransferase (E.C. 2.7.8.1) of brain microsomes were examined. It is concluded that the enzymic activities which convert CDPE to diacyl GPE and alkenyl acyl GPE, respectively, are similar.
Tumor lipids: Carbon number distribution of triglycerides and glyceryl ether diesters
Authors: Wood Randall , Harlow R. D.
Published: November 2006

Triglycerides and glyceryl ether diesters were isolated from a number of transplantable rat and mouse tumors and analyzed intact by gas liquid chromatography (GLC). The carbon number distributions of the triglycerides were distinctly different from those of the glyceryl ether diesters. Both glyceride classes contained abnormally high molecular weight species. The data support earlier evidence that indicated diglycerides used for the biosynthesis of phosphatides are also precursors of triglycerides in neoplasms. Glycerides isolated from three centrifuged fractions of Ehrlich ascites cells exhibited similar carbon number distributions. The results indicate a random distribution of triglyceride and glyceryl ether diester molecular species among cellular organeiles. Triglycerides, glyceryl ether diesters and neutral plasmalogens of the same carbon number were partially resolved by GLC.
Identification and characterization of fully deuterated fatty acids isolated fromScenedesmus obliquus cultured in deuterium oxide
Authors: Graff Gustav , Szczepanik Patricia , Klein Peter D. , Chipault J. R. , Holman Ralph T.
Published: November 2006

The algaScenedesmus obliquus cultured in deuterated water, synthesized fully deuterated saturated and unsaturated long chain fatty acids. Their methyl esters were purified and their equivalent chain lengths were determined by gas liquid chromatography (GLC). They were characterized by mass spectroscopy, IR and near‐IR spectroscopy, and NMR spectroscopy. Hexadeca‐3,6‐dienoic acid was identified. The fatty acid compositions of the total lipid and of individual lipid classes were measured. The melting point of methyl perdeuteriohexadecanoate was lower than that of its hydrogen counterpart. Methyl esters of perdeuterio fatty acids had shorter retention times in GLC chromatography on polar and nonpolar phases.
Inhibitors of cholesterol synthesis and myelin formation
Authors: Smith Marion Edmonds , Hasinoff Catherine M. , Fumagalli Remo
Published: November 2006

Inhibitors of cholesterol biosynthesis AY 9944 and 20,25 diazacholesterol were administered by stomach tube to suckling rats in varying doses during the time of rapid myelination (15–22 days of age). Purified myelin was prepared from the brains and spinal cords, and the sterol content analyzed. Up to 50% of the myelin sterol consisted of desmosterol in rats treated with 20,25 diazacholesterol, while 7‐dehydrocholesterol comprised at least one third of the myelin sterol in rats administered AY 9944. Myelin from rats treated with both compounds contained desmosterol, 7‐dehydrocholesterol, Δ5,7,24 cholestatriene‐3‐β‐ol and an unknown sterol, the four comprising about 45% of the total sterol. The proportion of phospholipid: galactolipid‐total sterol in myelin from the drug‐treated rats was not significantly different from the normal, although much less myelin was recovered. Brain and spinal cord slices from 22 to 25‐day rats pretreated with inhibitors showed decreased uptake of U‐14C‐glucose into all myelin components. The decreased uptake was approximately proportional in all lipids and the protein was also affected. It is proposed that myelin composition is fixed, and that a deficiency of one of the lipid components will limit the assembly of the whole lipid portion of the membrane.
The positional distribution of fatty acids in the phospholipids and triglycerides ofMycobacterium smegmatis andM. bovis BCG
Authors: Walker R. W. , Barakat H. , Hung J. G. C.
Published: November 2006

Position 1 of the phospholipid and triglyceride fractions isolated fromMycobacterium smegmatis andM. bovis BCG was esterified principally with C18 related fatty acids (18∶0, 18∶1 and 19Br). Position 2 was occupied principally by C16 fatty acids. The third position of the triglycerides was esterified with a preponderance of C20+fatty acids. Seventysix per cent of position 3 fatty acids in BCG and 43% inM. smegmatis triglycerides contained fatty acids of greater than 20 carbon atoms.
Dietary induced alterations in the fatty acids of rat bone marrow
Authors: Elson C. E. , Voichick Sarah J.
Published: November 2006

Weanling rats were fed fat free diets supplemented with 10% added fatty acids so that dietary effects on bone marrow fatty acids could be determined. The addition or deletion of linoleic acid from the fatty acid supplement resulted in alterations of the fatty acid patterns of bone marrow lipids but to a lesser degree than in erythrocyte lipids. With myristic acid supplementation, increased amounts of stearic acid were found in the lipid fractions, the difference between the bone marrow and erythrocyte lipids being less marked than when linoleic acid was fed. The activities of the bone marrow lipases varied with the dietary treatment. When linoleic acid was fed, higher rates of hydrolysis were observed with saturated fatty acid substrates. The reverse occurred when saturated fatty acids were fed.
Incubation of human fecal homogenates with 4‐14C‐cholesterol
Authors: Wood Peter D. S. , Hatoff David
Published: November 2006

Fresh fecal homogenates from nine subjects consuming solid diets have been incubated for seven days at 37 C with 4‐14C‐cholesterol. One series of incubations was conducted under nitrogen, another under air. The extent of bacterial modification of cholesterol to known fecal metabolites varied considerably among the subjects, as expected, but when present such bacteria were shown to be highly active in the conditions used. Production of14CO2 was essentially zero in all incubations. Recovery of added14C from the incubated homogenates following extraction with chloroformmethanol (2∶1 v/v) and evaporation to dryness was quantitative in all cases. About 4% of the labeled cholesterol added appeared to be present in acidic components following incubation. It is concluded that in the incubation system used vigorous bacterial conversion of 4‐14C‐cholesterol to metabolites known to be produced in the human intestine could occur readily, in either aerobic or anaerobic conditions. However, CO2 or other small, relatively volatile fragments labeled with14C could not be detected.
Sphingolipid metabolism II. The biosynthesis of 3‐keto‐dihydrosphingosine by a partially‐purified enzyme from rat brain
Authors: Kanfer Julian N. , Bates Susan
Published: November 2006

A condensation reaction between serine and palmitoyl CoA by a partially‐purified enzyme from rat brain is described. The product of the reaction, 3‐keto‐dihydrosphingosine is characterized by the conversion to several derivatives. The addition of EDTA to the incubation mixture results in inhibition of the conversion of serine to phospholipid, with the result that 3‐keto‐dihydro‐sphingosine is the sole product.
The synthesis of14C‐ and3H‐labeled glycerol ethers
Authors: Oswald Edward O. , Piantadosi Claude , Anderson Carl E. , Snyder Fred
Published: November 2006

The racemic14C‐and3H‐labeled alpha and beta derivatives of octadecyl glycerol ether (batyl alcohol) and of hexadecyl glycerol ether (chimyl alcohol) of high specific activity were synthesized by treating the appropriate alkyl halides with a large excess of the potassium salts of isopropylidene or benzylidene glycerol. By use of the trifluoroacetic anhydride esterification procedure, the labeled diesters of alpha and beta octadecyl and hexadecyl glycerol ethers were prepared. The labeled monoesters of beta octadecyl and of beta hexadecyl glycerol ethers were isolated from the reaction mixtures by silicic acid column chromatography.
Pyrolysis chromatography of lipids. I. Mass spectrometric identification of pyrolysis products of hydrocarbons
Authors: Holman Ralph T. , Deubig Manfred , Hayes Herbert
Published: November 2006

The products of pyrolysis at 600C of normal paraffins C10−C18, 2‐methyl octadecane, 4‐methyl octadecane, 6‐methyl octadecane, cyclohexyl decane, cyclopentyl decane, 2,2,4,4,6,8,8‐heptamethyl nonane, pristane and phytane were studied by means of a pyrolysis gas chromatograph directly coupled to a mass spectrometer. n‐Paraffins yield a homologous series of n‐olefins. Branched paraffins yield two homologous series, one of n‐olefins and one of branched olefins. The n‐olefin corresponding to the position of the branch is not formed. Interpretation of pyrolograms is similar in principle to the interpretation of mass spectra.
Stereochemistry of α‐parinaric acid fromImpatiens edgeworthii seed oil
Authors: Bagby M. O. , Smith C. R. , Wolff I. A.
Published: November 2006

α‐Parinaric acid is a major constituent fatty acid (48%) fromImpatiens edgeworthii Hook F. seed oil. Partial hydrazine reduction of the tetraene gave products which permit defining the stereochemistry of α‐parinaric acid. Its structure iscis‐9,trans‐11,trans‐13,cis‐15‐octadecatetraenoic acid. The tetraene readily reacts with maleic anhydride to give the Diels‐Alder product with notrans‐unsaturation. The formation of this adduct is contrary to previous reports.
Isolation and characterization of glycerides in human hair lipids by thin‐layer and gas chromatography
Authors: Singh Eric J. , Gershbein Leon L. , O'Neill Hugh J.
Published: November 2006

Techniques for the quantitative analysis of hair lipids using thin‐layer chromatography (TLC) together with a proximate analysis of components in one sample deduced by these criteria are presented. Mono‐, di‐ and triglycerides were separated by TLC using Silica Gel G as adsorbent. The chromatoplates were developed with 98% acetone+2% petroleum ether. Glycerides moved with the solvent front. The requisite portions were scraped off the plates and extracted with acetone and ether. Further TLC, limiting the migration of triglycerides and diglycerides was afforded by use of 95% ethanol as solvent in one direction while monoglycerides moved with the solvent front. For the separation of monoglycerides, chloroform was used as solvent in a second direction. Reference standards and several mixtures were run simultaneously and the spots identified by charring with concentrated sulfuric acid containing dichromate. Additional checking was effected by IR spectra. For determination of glyceride composition, methyl esters of the component fatty acids were prepared by transesterification and submitted to gas chromatography. Comparison of the levels of each of the constituent fatty acids showed no remarkable differences between the three classes of glycerides in one hair lipid pool. Although certain discrepancies in the amounts of a few fatty acid components might be construed for one pool of lipids from hair of white full‐headed men (WF‐9A) in contrast to findings with two Negro pools, no unequivocal conclusions can be drawn presently.
Quinones and quinols as inhibitors of lipid peroxidation
Authors: Mellors A. , Tappel A. L.
Published: November 2006

The influence of biological quinonoid compounds upon oxidative polymerization of lipids has been compared with that of simple quinones and antioxidants. A new procedure for the accelerated production and measurement of oxidative polymerization was used for this comparison. The biological quinones were found to be relatively ineffective as retarders of oxidative polymerization. Heme‐catalyzed lipid peroxidation, as measured by oxygen uptake, was inhibited by ubiquinone and ubiquinol, both having about one fourth of the antioxidant capacity ofa‐tocopherol. The peroxidation of mitochondrial lipid in vitro was inhibited by the presence of exogenous ubiquinone indicating that this compound may contribute towards the protection of the organelle in vivo.
Fatty acid composition of phospholipids in different regions of developing human fetal brain
Authors: Srinivasa Rao P. , Subba Rao K.
Published: November 2006

The fatty acid composition of total phospholipids in different regions, viz., cerebrum, cerebellum and medulla oblongata, of developing human fetal brain was studied. All the brains analyzed in the present investigations were obtained from fetuses whose mothers belonged to the poor socioeconomic section of the population. Palmitic, oleic and stearic acids were found to be the dominant fatty acids, and the pattern was similar in all regions of the brain studied between the ages of 22 and 35 weeks. However at birth there appeared to be an increase in polyenoic acids at the expense of lower chain fatty acids, and these changes were of relatively higher magnitude in the cerebellum than in other regions studied. These changes, in terms of increase in polyunsaturated fatty acids near full term, coincided well with the already observed timing of an overall growth spurt of the brain a few weeks preceding birth.
Preferential labeling of phosphatidylcholine during phospholipid synthesis by bovine mammary tissue
Authors: Kinsella J. E.
Published: November 2006

Bovine mammary cells and tissue synthesize de novo the classes of phospholipids, found in mammary tissue and milk, from various precursor molecules. Several short term experiments were carried out in vitro, using labeled precursors, i.e., 1‐14C‐fatty acids; 2‐14C‐acetate; U‐14C‐glycerol; 1,2‐14C‐choline; 1,2‐14C‐ethanolamine; 2‐14C‐serine; and Me‐14C‐methionine. All the phospholipid classes were labeled. The specific activity of tissue phosphatidylcholine was consistently three to six‐fold greater than that of phosphatidylethanolamine. The results indicated that stepwise methylation of phosphatidylethanolamine with labeled methyl group of methionine was occurring to a minor extent, as was a negligible amount of choline exchange. Serine was incorporated into phosphatidylserine and sphingomyelin. Significant quantities of labeled phosphatidylserine were decarboxylated to phosphatidylethanolamine. Apparently phosphatidylcholine was synthesized de novo from choline via phosphorylcholine and CDP‐choline. Based on the present observations and other data, it is suggested that there may be two pools of phosphatidylcholine in lactating mammary cells.
Fatty acid composition of free ceramides of kidney and cerebellum from a patient with Farber's disease
Authors: Sugita M. , Connolly P. , Dulaney J. T. , Moser H. W.
Published: November 2006

The fatty acid composition of ceramides has been determined in kidney and cerebellum of a patient with Farber's disease, which is characterized by ceramidase deficiency. Farber cerebellum and kidney contained a five‐ and ten‐fold excess, respectively, of free ceramides. The nonhydroxy fatty acid patterns of the ceramides from Farber kidney and cerebellum showed considerable similarities to those from control tissues, whereas large amounts of ceramides containing hydroxy fatty acids are found in Farber's disease tissues.
Cyclopropenoic acids ofPavonia sepium seed oil
Authors: Madrigal R. V. , Smith C. R.
Published: November 2006

The seed oil ofPavonia sepium (Malvaceae) contains sterculic (7%) and malvalic (4%) acids. Countercurrent distribution in a hexane‐acetonitrile system concentrated and resolved the homologus cyclopropenoid methyl esters. Reductive ozonolysis of selected countercurrent distribution fractions gave β‐diketoesters, which were identified by gas chromatography‐mass spectrometry as derivatives of sterculic and malvalic acids.Pavonia sepium is the first known species in the plant family Malvaceae whose seed oil contains more sterculic than malvalic acid.
Incorporation of [1‐14C]‐oleic acid into neutral glycerides and phosphoglycerides of mouse brain
Authors: Yau T. M. , Sun G. Y.
Published: November 2006

The incorporation of [1‐14C]‐oleic acid into the neutral glycerides and phosphoglycerides of adult mouse brain was examined between 1 and 80 min after intracerebral injection. Radioactivity of the free oleic acid in brain decreased rapidly with a half‐life of ca. 5 min. The specific radioactivity of the phosphatidic acids was highest at 1 min after injection. This was followed by the diacylglycerols and triacylglycerols which attained a maximum specific radioactivity at 3 and 20 min after injection, respectively. Specific radioactivities of the neutral glycerides were higher than the phosphoglycerides. A larger proportion of the radioactivity in the diacylglycerols was transferred to the phosphoglycerides than to the triacylglycerols. Among the phosphoglycerides, radioactivity was actively incorporated into the inositol phosphoglycerides. The specific radioactivity of the inositol phosphoglycerides was higher than the diacylsn‐glycero‐3‐phosphorylcholines, and the kinetics of incorporation of radioactivity into these lipids was also different. A water soluble material was found which showed maximum specific radioactivity at 6–10 min after injection. The properties of this water soluble material suggested that it may be an intermediate involved in the acyl group metabolism of phosphoglycerides in brain.
Preparation and characterization of mouse intestinal phospholipase
Authors: Ottolenghi Athos
Published: November 2006

Phospholipase has been prepared in a stable, partially purified form from the small intestine of mice infected with the tapewormHymenolepis nana. The enzyme(s) attacks diacylphosphatides with liberation of free fatty acids and a corresponding decrease in phospholipid phosphorus, without accumulation of lysophosphatides. The reactivity with various substrates is strongly influenced by their physical state, the presence of other lipids, proteins or detergents. The phospholipids of some biomembranes (mitochondria, microsomes, red cell ghosts) are readily hydrolyzed under customary reaction conditions. The ensuing biochemical, morphological and functional alterations have been documented. In contrast, the diacylphospholipids of the cell membrane (intact erythrocytes,Pseudomonas aerunginosa) are not accessible to phospholipase action unless some alteration of the integrity of the cell is induced by physical or chemical means (hemolysis, polymyxin). The enzyme is proposed as a tool for the investigation of biomembranes and as a model for the study of phospholipase activity.
High phospholipase content of intestines of mice infected withHymenolepis nana
Authors: Ottolenghi Athos
Published: November 2006

Infection with the tapewormHymenolepis nana results in the presence of very high amounts of phospholipase in the small intestine of the mouse. The time course and location of this response and its changes following treatment with anti‐inflammatory and antiparasitic agents indicate that the enzyme accumulation is part of the reaction of the host to parasitic invasion.
AY‐9944 inhibition of sterol biosynthesis inChlorella emersonii
Authors: Dickson Leal G. , Patterson Glenn W.
Published: November 2006

WhenChlorella emersonii, a green alga, was cultured in the presence of 20 ppm AY‐9944, a number of sterols accumulated which appear to be intermediates of sterol biosynthesis in this organism. The sterols isolated include 14α‐methyl‐ergost‐8‐en‐3β‐ol, 14α‐methyl 24S‐stigmast‐8‐en‐3β‐ol, 14α‐methyl ergosta‐8,24(28)‐dien‐3β‐ol and 4α, 14α‐dimethyl 24S‐stigmast‐8‐en‐3β‐ol. Smaller quantities of several other sterols were found in addition to the normally occurring Δ7, chondrillasterol and Δ7. Control cultures were found to contain, in addition to the normally occurring sterols, smaller quantities of most of the sterols isolated from AY‐9944 inhibited cultures. AY‐9944 is a specific inhibitor of Δ7 in cholesterol biosynthesis in animals. However, sinceC. emersonii terminates sterol biosynthesis one step prior to the Δ7 step, AY‐9944 apparently inhibits sterol biosynthesis prior to this step in this organism. The accumulation of 14α‐methyl sterols in treated cultures suggests that AY‐9944 is an effective inhibitor of the 14α‐methyl removal inC. emersonii.
Acetyl carnitine formation in rat heart
Authors: Vahouny G. V. , D'Amato P. H. , Rodis S. L.
Published: November 2006

The comparative incorporation of acetate into long chain fatty acids and acetyl carnitine by cell‐free preparations of rat heart has been investigated. Whereas the addition of 1 mM carnitine stimulated (45%) fatty acid synthesis by liver preparations in citrate‐containing media, fatty acid synthesis from acetate in rat heart homogenates under the same incubation conditions was markedly depressed. This depression by carnitine of acetate incorporation into long chain fatty acids in 105,000 × g soluble fractions of heart was associated with increased acetyl carnitine formation. Thus in heart tissue acetyl CoA is effectively shuttled into acetyl carnitine and is unavailable for synthesis of fatty acids. These data are in agreement with results obtained earlier in studies with perfused rat heart. A similar conversion of added acetyl CoA to the carntine derivative occurred when labeled malonyl CoA was used as fatty acid precursor, again resulting in reduced fatty acid synthesis. It was shown by direct measurement that acetyl carnitine formation in the absence of carnitine was greatest in heart mitochondria and least in microsomes. In the presence of carnitine, acetyl carnitine formation was increased in all subcellular fractions, with the greatest change again occurring with mitochondria.
Isolation of brassicasterol from steam deodorizer distillate of rapeseed oil: Some properties of its acetate tetrabromide and its reduction to 22,23‐dihydrobrassicasterol
Authors: Hircher H. W. , Rosenstein F. U.
Published: November 2006

Brassicasterol (5,22‐ergostadien‐3β‐ol) was isolated from the steam deodorizer distillate of rapeseed oil and purified by acetylation, bromination, chromatography on 20% AgNO3/SiO2 columns and hydrolysis. Brassicasteryl and stigmasteryl (5,22‐stigmastadien‐3β‐ol) acetates were brominated, and the yields of products and solubilities of the tetrabromides from the two steryl acetates were compared. Stigmasteryl acetate tetrabromide is less soluble than the corresponding brassicasteryl derivative; yet the latter precipitates selectively during bromination of a mixture of the two steryl acetates. This is explained on the basis of the stereochemistry of the bromine atoms in the side chains of the two steryl acetate tetrabromides. Hydrogenation of brassicasteryl acetate over Raney nickel gave the 22,23‐dihydro derivative in excellent yield. The latter was separated from small amounts of ergostanyl acetate on a 20% AgNO3/SiO2 column.
Use of a bile duct T‐cannula as a new technique for studying bile acid turnover in the rat
Authors: Klauda H. C. , McGovern R. F. , Quackenbush F. W.
Published: November 2006

A new technique using T‐cannulated bile ducts has been developed for studying bile acid turnover in the rat by isotope dilution. Applicability of this technique to study the effect of diet on cholate and chenodeoxycholate metabolism is suggested. In tests with the method, the rate of cholate synthesis for rats fed colony diet was twice that for rats fed semisynthetic diet. When sodium glycocholate was fed in the latter diet the half‐life of cholate decreased; the secretion rate of deoxycholate and cholate increased without affecting chenodeoxycholate. Although curves for cholate log specific activity vs. time were linear, those obtained simultaneously for chenodeoxycholate were nonlinear. A double exponential curve was obtained for chenodeoxycholate of colony‐fed rats. Separation of free deoxycholate and chenodeoxycholate was improved through continuous development thin layer chromatography.
Effect of dietary fat saturation of absorption and intestinal secretion of cholesterol by the hypercholesterolemic rat
Authors: McGovern R. F. , Quackenbush F. W.
Published: November 2006

The fate of an oral dose of [4‐14C] cholesterol given to rats grown on diets with 20% safflower oil or 20% hydrogenated coconut oil was determined by analysis of digestive tract, feces and tissues. The pattern of isotope distribution did not support the view that rats fed a saturated fat absorb less cholesterol than those fed an unsaturated fat. Fasted animals growth on the diet with 5% of these two fats and beef fallow showed no clear difference in the amount of digitonin‐peecipitable sterol in their intestines. A shorter transit time for intestinal contents was observed with the saturated fat groups. It is concluded that neither absorption of cholesterol from the gut nor secretion of β‐hydroxy sterol into the gut accounts for the hypocholesterolemic effect of polyunsaturated fat.