bluuebunny/crossref_metadata_2025 huggingface dataset:
Aliphatic hydroxylamines as lipid antioxidants
Authors: van der Veen J. , Weil J. T. , Kennedy Theresa E. , Olcott H. S.
Published: December 2006

It was previously noted that N,N‐dioctylhydroxylamine is formed from the oxidation of trioctylamine in oxidizing fats and that N,N‐dioctyl‐ and N,N‐diethylhydroxylamine preparations have antioxidant activity. In this paper we summarize some additional observations with these and some other N‐substituted hydroxylamines. ESR spectra indicate that nitroxides are present in oxidized preparations of hydroxylamines. Since some stable nitroxides have been shown to be exceptionally effective antioxidants, we hypothesize that the antioxidant effectiveness of the hydroxylamines is accounted for by their conversion to nitroxides during the inital stages of oxidation.
Phylogeny of lipase specificity
Authors: Berner David L. , Hammond Earl G.
Published: December 2006

Lipase preparations from 19 animal species, representing nine of the animal phyla, were studied. Acetone powders were prepared from the pancreas, hepatopancreas, gastrointestinal tract or whole animal, and the preparations were screened for lipolytic activity by tributyrin agar clearing. The pH optimum of each preparation was determined by using both tributyrin and corn oil emulsions. The positional specificity at the pH optimum of each lipase preparation was determined from the fatty acids released by a 2–5 min reaction with cocoa butter and lard. The vertebrate lipases behaved analogously to hog pancreatic lipase by showing a high specificity for the 1 and 3 positions of long chain triglycerides. Invertebrate preparations that did hydrolyze long chain triglycerides did so randomly, with no strong positional or fatty acid specificity.
Specificity of lipase from several seeds andLeptospira pomona
Authors: Berner D. L. , Hammond E. G.
Published: December 2006

The specificities of lipase preparation from oats,Leptospira pomona DM2H, corn, soybeans, safflower seed and pinion nuts were examined by using cocoa butter, lard and corn oil as substrates. Oat lipase exhibited an acyl group specificity, favoring the hydrolysis of linoleyl groups and discriminating against stearoyl groups. TheL. pomona lipase exhibited a tendency to hydrolyze acyl groups on the 1 and 3 positions of glycerol preferentially. The hydrolysis by the other seed lipases was nonspecific.
Phospholipid complexes with molybdate
Authors: Galanos Dimitris S.
Published: December 2006

Phosphorus‐containing organic‐compounds combine directly with molybdate to form complexes analogous to phosphomolybdate. These complexes are extractable by organic solvents such as ethyl acetate or butanol. The ability of chloroform‐ethanol mixtures in extracting only the phospholipid‐molybdate complexes but not those of water‐soluble phosphates may find some useful applications.
On the biosynthesis of glycerol ethers in mitochondria
Authors: Anderson Robert E. , Sansone Gail L.
Published: December 2006

Mitochondria from mouse preputial glands incubated with 1‐14C‐myristic acid and appropriate co‐factors produced, after LiAlH4 reduction, a compound that resembled a glycerol ether. However, close examination of this material showed that it was not an ether, and we tentatively identified the original compound as a phosphorylated β‐keto (or β‐hydroxy) fatty acid.
Pancreatic lipolysis of enantiomeric triglycerides
Authors: Jensen R. G. , Pitas R. E. , Quinn J. G. , Sampugna J.
Published: December 2006

Pancreatic lipase hydrolyzed fatty acids in equimolar quantities from thesn‐1‐ and 3‐positions of three synthetic enantiomeric triglycerides, two of which could make a racemic pair. The monoglycerides from digestions of five enantiomeric triglycerides were at least 99% representative of the 2‐position. The data confirm that pancreatic lipase did not distinguish between thesn‐1‐ and 3‐positions and that with these triglycerides pancreatic lipolysis can be used to help establish structure.
Effect of alimentation on human serum squalene levels
Authors: Lewis R. W.
Published: December 2006

Five subjects consumed a meal containing ca. 1.5 mg squalene. Postprandial serum samples showed that in three of the subjects squalene and lipid levels reached maxima at 3 hr. Squalene levels in the low density lipoproteins of these subjects also increased. The results indicate that alimentation is a major factor in the variation in serum squalene levels.
Lipids ofKlebsiella pneumoniae: The presence of phosphatidyl choline in succinate‐grown cells
Authors: Wassef Momtaz K.
Published: December 2006

The carbon and energy source for aerobically grown cultures ofKlebsiella penumoniae profoundly influenced the total lipid content and phosphatide composition. Glucose‐grown cells contained 13% lipid, 56% of which was phospholipids. Succinate‐grow cells contained 8% lipid, 66% of which was phospholipids. The predominant phosphatides of glucose‐grown cells were phosphatidyl ethanolamine, 82%; phosphatidyl glycerol, 4.5%; phosphatidic acid, 5%; cardiolipin, 6.5%; phosphatidyl serine; and trace amounts of unidentified phosphatides. Phosphatides of succinate‐grown cells were phosphatidyl ethanolamine, 38%; diphosphatidyl glycerol, 14%; phosphatidyl glycerol, 13%; phosphatidyl choline, 14.5%; phosphatidyl serine, 6%; phosphatidic acid, 4%; and 10% unknown lipids. No trace of phosphatidyl choline was found in glucose‐grown cells.
Autoxidation of polyunsaturated fatty acids: II. A suggested mechanism for the formation of TBA‐reactive materials from prostaglandin‐like endoperoxides
Authors: Pryor William A. , Stanley J. P. , Blair E.
Published: December 2006

The nature and mechanism of formation of the thiobarbituric acid (TBA)‐reactive material produced in the autoxidation of polyunsaturated fatty acids (PUFA) or their esters has been studied. On the basis of chemical studies and
Plasma transport forms of ingested fatty alcohols in the rat
Authors: Friedberg Samuel J.
Published: December 2006

Previous studies have shown that ingested fatty alcohols are absorbed as fatty acids and fatty acid esters, particularly triglycerides. The present study was carried out to determine whether fatty alcohols are also transported as 0‐alkyl glyceryl ethers, alk‐1‐enyl glyceryl ethers, and as wax esters. Oxidation of fatty alcohols to other lipids was assessed by using a mixture of [1‐3H] hexadecanol and [1‐14C] hexadecanol of predetermined ratio. The results indicate that the absorption of fatty alcohol, and of its transport forms, parallels the absorption of labeled fatty acids. Six to 25% of plasma radioactivity was present as 1‐0‐alkyl diacylglyceryl ethers with a smaller proportion of ether lipids in the phospholipid fraction. In addition, 4–13% of the ingested hexadecanol appeared in the plasma as a material having the chromatographic properties of wax ester. Fatty alcohols were not detected in the plasma as alk‐1‐enyl lipids.
Interactions of phospholipase D with 1,2 diacyl‐sn‐glycerol‐3‐phosphorylcholine, dodecylsulfate, and Ca2+
Authors: Heller Michael , Mozes Nava , Peri (Abramovitz) Irena
Published: December 2006

Some properties of the pure, soluble phospholipase D (phosphatidycholine phosphatido hydrolase, EC 3.1.4.4) interactions with phosphatidyl choline (1,2 diacyl‐sn‐glycerol‐3‐phosphoryl choline) in a system also containing dodecylsulfate and Ca2+ ions were studied. Concentrations of Ca2+ greater than 50 mM were necessary both for activity and adsorption of the enzyme to the “supersubstrate.” Ethylenediamine tetraacetic acid caused inhibition of activity, greater than one would expect from its chelating capacity. A nonlinear increase in activity with the increase of enzyme protein was observed, suggesting a subunit aggregation into a higher mol wt protein, catalytically more active. Upon centrifugation of the supersubstrate‐enzyme complex at 4.5×105g·min at 30 C, most of the substrate molecules sedimented regardless of the pH. The reverse was true when centrifugation was done at 1 C. Phospholipase D hydrolyzed phosphatidylcholine molecules present in the supersubstrate at temperatures around 0 C at a rate 1/5 that of a maximal value measured at 30C. The Arrhenius plot was linear in the range from 0 to 30 C, and at that temperature the curve broke with a smaller slope. Activation energy of 9.1 Kcal/mol, below 30 C, was calculated. Adsorption of the enzyme to the sedimentable supersubstrate occurred at pH 8.0, regardless of temperature. At pH 5.6, a considerable portion of phosphatidylcholine was degraded at 30 C, thus minimizing the capacity of the supersubstrate to adsorb the enzyme. Although Mg2+ could replace Ca2+ in the formation of sedimentable supersubstrate, it neither assists in adsorption of the enzyme nor in activation of the phosphatidylcholine hydrolysis.
Metabolism of 2,4‐3H‐14α‐methyl‐5α‐ergost‐8‐enol and 2,4‐3H‐5α‐ergosta‐8,14‐dienol inOchromonas malhamensis
Authors: Adler John H. , Patterson G. W.
Published: December 2006

Tritium‐labeled 14α‐methyl‐5α‐ergost‐8‐enol and 5α‐ergosta‐8,14‐dienol were converted to brassicasterol and poriferasterol inOchromonas malhamensis. This indicates that the organism can rearrange these sterol structures so that they contain the naturally occurring 5(6) double bond, and suggests thatO. malhamensis is able to introduce a 24(28) double bond into a nine‐carbon saturated side chain which is alkylated to produce a C‐29 sterol.
Lipid absorption in the young of protein‐deficient rats
Authors: Zeman Frances J. , Fratzke Marilyn L.
Published: December 2006

The effect of reduced protein in the diet during pregnancy on the subsequent absorption of triolein and of oleic acid which were infused into the intestine of the young was studied. Pregnant rats were fed diets containing either 24% or 4% casein as the sole source of protein. Control and prenatally protein‐deprived (PPD) young were studied at birth, before and after suckling, and at 4, 8, and 12 days. Both body weight and the weight and length of intestine were reduced in PPD young. Uptake of triolein from the lumen and retention in enterocytes increased on suckling in newborn control pups, but the amount transferred from or metabolized by the cells did not change. In suckled PPD young, transfer of triolein increased through the enterocyte as well. Unsuckled PPD pups had reduced absorption and retention per enterocyte, per g body weight, per cm gut, and in total. In intestines of control and PPD suckled newborn and postnatal pups, absorption per cell did not differ. Blood lipid levels were increased markedly between 0 and 4 days and tended to decrease to newborn levels by 12 days in both diet groups. Oleic acid absorption in newborn and 12‐day PPD pups were reduced in total, per g body weight and per cm of gut. The individual enterocytes were shown to be equally capable of absorption and transfer of triolein and oleic acid. Differences in absorption are related primarily to the numbers of absorptive cells.
Effect of dietary fats on ovine adipose tissue metabolism
Authors: Vernon R. G.
Published: December 2006

The effects of different dietary fats on ovine adipose tissue metabolism have been investigated. Six‐month old sheep were fed for 6 weeks a control diet or diets supplemented with either tallow or a mixture of sunflower seed oil and soybean oil, treated to protect the fats from hydrolysis and hydrogenation in the rumen, or with maize oil. The rates of fatty acid, glyceride glycerol, and CO2 formation were measured in perirenal and subcutaneous adipose tissue slices by following the incorporation of either14C from labeled acetate or glucose, or3H from tritiated water into the appropriate product. Feeding protected tallow or maize oil but not protected sunflower seed oil plus soybean oil resulted in reduced rates of fatty acid biosynthesis in both perirenal and subcutaneous adipose tissue slices and CO2 formation in perirenal adipose tissue. Feeding the fat‐supplemented diets had no effect on the rate of glyceride glycerol formation. The fat‐supplemented diets also resulted in reduced activities of various enzymes, thought to be involved in lipogenesis, measured in 105,000× g supernatant fractions from adipose tissue homogenates. The results suggested that ovine adipose tissue lipogenesis is sensitive to both the amount and the nature of dietary fat.
In vitro biosynthesis of prostaglandin E2 by kidney medulla of essential fatty acid deficient rats
Authors: Kaa Elisabet
Published: December 2006

Weanling rats were fed either a semi‐synthetic diet with no fat, with 28% by wt partially hydrogenated fish oil, or with 28% by wt arachis oil (control diet) for 6 or 71/2 months. The in vitro conversion of arachidonic acid to prostaglandin E2 by homogenates of the rat kidney medulla was measured by gaschromatography with electron capture detection. The kidney medulla of essential fatty acid deficient animals showed increased activity for the in vitro conversion of exogenous arachidonic acid to prostaglandin E2 when compared to the controls. The change of the enzymatic activity in the essential fatty acid deficient animals was reversible, as shown by refeeding. Inhibition of the prostaglandin synthetase was found at exogenous substrate concentrations higher than 50–100 μM.
Lipid composition of rat sciatic nerve
Authors: Klein F. , Mandel P.
Published: December 2006

In the course of our study on the lipids of the rat sciatic nerve, the analysis of the neutral lipids allowed us to detect and characterize cholesteryl esters present at a relatively high level (5%). Among the phospholipids, ethanolamine phosphoglyceride is the most abundant fraction and contains nearly all the plasmalogens (20% of total lipid phosphorus). The glycolipids consist of five different fractions; the cerebrosides with hydroxy fatty acids account for 38% of total glycolipids. Monogalactosyl diglyceride represents 7% of total glycolipids.
Sensitive fluorometric method for tissue tocopherol analysis
Authors: Taylor Steve L. , Lamden Merton P. , Tappel AL. L.
Published: December 2006

A sensitive, highly reproducible method for tissue tocopherol analysis that combines saponification in the presence of large amounts of ascorbic acid to remove interfering substances, extraction of the nonsaponifiable lipids with hexane, and fluorometric measurement of the tocopherol is presented. The nonsaponifiable lipid phase contained only one fluorochrome in the 290 nm excitation and 330 nm emission range, and it was identified as tocopherol by thin layer and column chromatography. Column chromatography of the hexane extract of a saponified,14C‐tocopherolspiked microsomal fraction showed that no measurable oxidation to tocopherylquinone has occurred. The fluorometric method for tocopherol analysis was applied to homogenates and subcellular fractions from rat liver, kidney, lung, and heart and red blood cells. The heavy mitochondrial and microsomal fractions had the highest subcellular concentrations of tocopherol.
Low and moderate concentrations of lysobisphosphatidic acid in brain and liver of patients affected by some storage diseases
Authors: Kahma Kauko , Brotherus Jaakko , Haltia Matti , Renkonen Ossi
Published: December 2006

The relative amount of lysobisphosphatidic acid (LBPA), known also as bis(monoacylglyceryl)phosphate, among the total phospholipids was analyzed in post mortem samples of brain and liver of patients affected by four storage diseases. In spite of the extensive accumulation of storage lysosomes, none of the samples revealed a highly elevated LBPA content comparable to that found in the liver in Niemann‐Pick disease and in the liver in lipidosis induced by 4,4′‐diethylaminoethoxyhexestrol. We conclude that, although LBPA is often present in high concentration in lysosomes of many types of cells, it is not always a major component of these organelles.
Study of bound phospholipase activities of fungal mycelia using an organic solvent system
Authors: Blain J. A. , Patterson J. D. E. , Shaw C. E. , Akhtar M. Waheed
Published: December 2006

It has been possible to demonstrate and characterize high phospholipase activities in mycelia ofRhizopus arrhizus andMucor javanicus by use of a system in which substrates were dissolved in diisopropyl ether. Such activities were associated with bound enzymes and would have been difficult to detect using aqueous assay systems. In both cases, phosphatidylcholine hydrolysis was by phospholipase A1 (EC 3.1.1.32) activity followed by the action of lysophospholipase (EC 3.1.1.5). Phospholipase D (EC 3.1.4.4) activity was also detected. The methods used appear to be of general applicability for the detection and study of insoluble phospholipases.
Lipid metabolism of the yellow clam,Mesodesma mactroides: 2‐Polyunsaturated fatty acid metabolism
Authors: De Moreno Julia E. A. , Moreno Victor J. , Brenner Rodolfo R.
Published: December 2006

The fate of labeled linoleic, α‐linolenic, and higher homologs of α‐linolenic acid administered to the yellow clam,Mesodesma mactroides, was investigated. It was found that the clam incorporated the acids dissolved in sea water and converted 18∶2 (n−6) into 20∶2 (n−6) and 18∶3 (n−3) into 18∶4 (n−3) and 20∶3 (n−3). The addition of casein hydrolysate to the sea water increased the desaturation capacity of the clam and allowed the conversion of 18∶2 (n−6) into 18∶3 (n−6) to be demonstrated. An enhanced desaturation of 18∶3 (n−3) into 18∶4 (n−3) was also demonstrated. After 12 hr administration of the acid, no radioactivity was found in arachidonic, 20∶5 (n−3), or 22∶6 (n−3). Feeding the clams a culture ofPhaeodactylum tricornutum previously incubated with 1‐14C‐α‐linolenic acid demonstrated that all the homologs of the α‐linolenic series were found in the clam without any important changes. Six hour administration of labeled linolenic acid resulted in the incorporation of the acid into diglycerides and phospholipids.
Unusually high levels of C24−C30 fatty acids in sponges of the class demospongiae
Authors: Litchfield Carter , Greenberg Anne J. , Noto Gregory , Morales Reginald W.
Published: December 2006

Twenty genera of sponges from the class Demospongiae have been examined for fatty acid composition. All contain unusually high levels (34–79%) of C24−C30 fatty acids not generally found in other organisms. These characteristic “demospongic acids” are mostly polyunsaturated.
A model for studying LCAT reaction: In vitro cholesterol esterification in pig ovarian follicular fluid
Authors: Yao Jeffrey K. , Chang Steve C. S. , Ryan Robert J. , Dyck Peter James
Published: December 2006

Phosphatidylcholine acyltransferase (lecithin:cholesterol acyltransferase or LCAT; EC 2.3.1.43) activity was found to be present in pig ovarian follicular fluid (POFF), in addition to pig serum (PS). The cholesterol esterification rate in both POFF and PS is linear with incubation time up to 2 hr. The mean absolute rate of POFF‐cholesterol esterification was 8.1±0.4 nmoles per ml per hr approximately one‐fourth of that in PS. However, the fractional rate (percent of labeled cholesterol esterified per hr) of POFF‐cholesterol esterification was similar to that observed in PS. There was little variation of absolute rate of cholesterol esterification in the fluid obtained from different sizes of follicles. Fatty acid or triacylglycerol did not participate in the reaction of cholesterol esterification in POFF. No appreciable change in enzymatic activity was found from storing POFF at 4 C for periods of time up to 24 hr or at −70 C up to 2 months, but activity was lost thereafter. On the other hand, PS showed a much longer period of stability (5 days at 4 C and 9 months at −70 C). A discrepancy between the fatty acid composition of cholesteryl esters formed by the LCAT reaction and the fatty acid composition at the C‐2 position of phosphatidylcholine led us to propose a two‐step mechanism for the LCAT reaction. It is concluded that the LCAT of POFF, as well as that of plasma, is specific for individual fatty acids rather than for the fatty acid composition of phosphatidylcholine. The fatty acid concentration of lysophosphatidylcholine decreased during prolonged incubation times (6 to 21 hr) suggesting that the increased lysophosphatidylcholine formed as a product of the LCAT reaction may be reused as substrate for the LCAT reaction or for hydrolysis by lysophosphatidylcholine hydrolase.
The effect of phospholipase D on the function of fragmented sarcoplasmic reticulum
Authors: Fiehn W.
Published: December 2006

Incubations of fresh preparations of fragmented sarcoplasmic reticulum (FSR) were carried out at pH 5.7. This pH was necessary for hydrolysis of phospholipids by phospholipase D. The pH did not influence calcium uptake or the activity of calcium‐stimulated ATPase of FSR. Treatment of FSR with phospholipase D caused hydrolysis of the membrane phospholipids. The phosphatidic acid produced remained bound to the membrane. Increasing phospholipid cleavage was paralleled by loss of calcium uptake, which was complete when about two‐thirds of the membrane phospholipids were hydrolyzed.
Cyclopropene fatty acids of selected seed oils from bombacaceae, malvaceae, and sterculiaceae
Authors: Bohannon M. B. , Kleiman R.
Published: December 2006

Fatty acid compositions of seed oils from three species of Bombacaceae, eleven from Malvaceae, and six from Sterculiaceae were determined. Each of the seed oils contains varying amounts of both malvalic and sterculic acids accompanied by one or both of the corresponding cyclopropane fatty acids. In addition, the seed oil ofPachira aquatic Aubl. (Bombacaeae) contains 12.8% α‐hydroxysterculic acid.
Mass fragmentographic determination of docosenoic acid in rapeseed oils
Authors: Blomstrand Rolf , Svensson Lennart , Herslöf Bengt
Published: December 2006

A highly sensitive and accurate reference method for determination of docosenoic acid (mainly erucic acid, 22∶1n−9) in different rapeseed oils is described. A fixed amount of [1‐14C]erucic acid methyl ester (about 1 μg) is added to a fixed amount of oil. After treatment with sodium methoxide/methanol reagent and extraction with hexane, the amount of unlabeled erucic acid is determined from the ratio between the recordings at m/e 320 and m/e 322 obtained after analysis with a combined gas chromatograph‐mass spectrometer equipped with an MID (multiple ion detector). The two ions used correspond to the M‐32 peak in the mass spectrum of unlabeled and [1‐14C]labeled erucic acid methyl ester. The relative standard deviation of the method is about 1.8%. The method was compared with a gas chromatographic method for determination of erucic acid.
Δ9 desaturase activity in normal mouse liver and hepatoma SS1K
Authors: Mercuri Osvaldo , De Tomas Maria Elena
Published: December 2006

The activity of Δ9 desaturase was determined in the microsomal fraction of normal mouse liver and hepatoma SS1K in the presence of the 105,000 × g supernatant. Neither hepatic nor hepatoma soluble fractions were able to modify the low desaturating capacity. Two enzymes from the microsomal electron transport chain associated with Δ9 desaturase, namely NADH‐cytochrom b5 reductase and NADH‐cytochrome C reductase were also measured. The results indicate that the low Δ9 desaturase activity in hepatoma SS1K could be related to the reduced amount of desaturase.
Effects of storage conditions on rat brain ethanolamine glycerophospholipids, cerebrosides, and cholesterol
Authors: Moscatelli Ezio A. , Duff John A.
Published: December 2006

The effects of storage on rat brain lipid composition were studied in terms of ethanolamine glycerophospholipid, cerebrosides, and cholesterol. Rat brains were stored at several combinations of temperature and time. Storage conditions were: 2 hr at room temperature, 12 hr of refrigeration, and a sequence of both of these conditions. Two‐dimensional thin layer chromatography followed by colorimetric analyses of eluted lipids were used to determine molar ratios of phosphatidylethanolamine, ethanolamine plasmalogen, lysophosphatidylethanolamine, and cerebrosides. Cholesterol was also determined. These studies revealed small but significant increases in lysophosphatidylethanolamine in all three cases. A slight increase was also noted in the apparent molar proportion of cholesterol.
Surface viscosities of phospholipids alone and with cholesterol in monolayers at the air‐water interface
Authors: Evans R. W. , Williams M. A. , Tinoco J.
Published: December 2006

Surface viscosities in lipid monolayers at the air‐water interface were measured by the oscillating pendulum method. The logarithms of successive oscillations decreased linearly with time. Surface viscosity is reported here in terms of the rate constant, k, for decay of oscillation. Viscosities were measured as a function of surface pressure at 22±2 C. Lipids investigated included cholesterol, 1‐palmitoyl‐2‐arachidonoyl phosphatidylcholine (PC), 4 other unsaturated PC, 1‐palmitoyl‐2‐stearoyl PC, 1,2‐distearoyl PC, 1‐palmitoyl‐lysophosphatidylcholine, 1‐palmitoyl‐lysophosphatidylserine, tetrapalmitoyl bisphosphatidic acid, and the dipalmitoyl species of PC, phosphatidylethanolamine (PE), phosphatidyldimethylethanolamine, phosphatidylmonomethylethanolamine, phosphatidylglycerol and phosphatidic acid. Pressure‐area curves are presented for the saturated phospholipids. Surface viscosities of most of the phospholipids were high and increased with increasing surface pressure. However, surface viscosiries in monolayers of cholesterol, 1‐palmitoyl‐2‐arachidonoyl PC, lysophosphatidylcholine or lysophosphatidylserine were very low and barely detectable under our experimental conditions. One mol % of cholesterol in monolayers of dipalmitoyl PC greatly reduced the surface viscosity of the film and, in mixed films containing 10% or more of cholesterol, surface viscosity was too low to measure. Cholesterol also reduced surface viscosities in monolayers of the other dipalmitoyl phospholipids. It is suggested that cholesterol functions in lung surfactant by reducing the surface viscosity of its highly saturated phospholipid components.
Singlet oxygen oxidation of methyl linoleate: Isolation and characterization of the NaBH4‐reduced products
Authors: Thomas Michael J. , Pryor William A.
Published: December 2006

The mixture of diene hydroperoxides from methylene blue‐sensitized oxidation of methyl linoleate was reduced with NaBH4 and the resulting alcohols were separated by high pressure liquid chromatography (HPLC). Four diene alcohols were isolated in approximately equal yields from adsorption and reversed phase HPLC; the isomers were identified as methyl esters of 9‐hydroxy‐10,12‐, 10‐hydroxy‐8,12‐, 12‐hydroxy‐9,13‐ and 13‐hydroxy‐9,11‐octadecadienoate. Formation of equal yields of both conjugated and nonconjugated diene alcohols from methyl linoleate is characteristic of singlet oxygen oxidations. The detection of the easily separated nonconjugated isomer methyl 10‐hydroxy‐trans‐8,cis‐12‐octadecadienoate from methyl linoleate is proposed as a test to probe the involvement of singlet oxygen in biological oxidations.
Study of free and bound lipids ofBrassica campestris, var yellow sarson
Authors: McKillican Mary E. , Larose J. A. G.
Published: December 2006

Mature seeds ofBrassica campestris var. yellow sarson were extracted with hexane to yield free lipid. The residue then was extracted with chloroform‐methanol to release bound lipid. Free and bound lipids were separated into polar and nonpolar fractions chromatographically. The nonpolar fraction of both free and bound lipid consisted mainly of triglycerides with small amounts of steryl esters, free sterols, mono‐ and di‐glycerides, and free fatty acids. The principal components of polar bound lipid were phosphatidyl choline, phosphatidyl ethanolamine, phosphatidyl inositol, and steryl glycoside. In the free polar lipid, there was more phosphatidyl inositol and less phosphatidyl choline and phosphatidyl ethanolamine. Erucic acid content was much greater in the nonpolar fractions and in the polar free lipid than in the polar bound lipid.
Unusual lipids II: Head oil of the north Atlantic pilot whale,Globicephala melaena melaena
Authors: Blomberg Jonas
Published: December 2006

Pilot whale head oil (blackfish head oil, raw) was analyzed by means of IR spectroscopy, NMR, thin layer chromatography, and gas liquid chromatography‐mass spectrometry. The oil consisted of hydrocarbons (mainly pristane) (3%); waxes and cholesterol esters (9%); triglycerides (87%) (i.e. non‐11%, mono‐19% and di‐57% isovalero triglycerides) and cholesterol and diglycerides (1%). By mass spectrometry, the diisovalero triglycerides were shown to be mainly symmetrical. Fatty acids were isobranched or normal (only traces of anteiso acids were found), saturated, or monounsaturated. Isovaleric acid predominated (54 mole % fatty acids), the rest having 10–18 carbon atoms. A 5‐carbon fatty acid was the only acid found in the waxes. The alcohol composition qualitatively resembled that of the fatty acids, but major quantitative differences were present. This rules out direct interconversion of all fatty acids and alcohols. The possible role of these lipids in ultrasound transmission is discussed.
Hydrolysis of synthetic triacylglycerols by pancreatic and lipoprotein lipase
Authors: Morley N. H. , Kuksis A. , Buchnea D.
Published: December 2006

The stereochemical course of the hydrolysis of synthetic sn‐glycerol‐1‐palmitate‐2‐oleate‐3‐linoleate, sn‐glycerol‐1,2‐dipalmitate‐3‐oleate and their antipodes by pancreatic and milk lipoprotein lipase was investigated by thin layer and gas liquid chromatographies of the diacylglycerol intermediates. The enzymic hydrolyses were made with bile salts or lysolecithin in a 1∶1 molar ratio to the substrate as emulsifiers and were limited to short time intervals which minimized isomerization and the reversal of lipolysis. In all instances, the products of hydrolysis by lipoprotein lipase contained a marked preponderance of the 2,3‐diacylglycerols, while the composition of the diacylglycerol intermediates in the products of pancreatic lipase varied with the nature of the fatty acid in the 1 and 3 positions of the triacylglycerol molecule. Pancreatic lipase, but not lipoprotein lipase, gave a preferential release of unsaturated fatty acids. The above results are similar to those obtained with radioactive trioleoylglycerol and conventional stereospecific analyses and suggest that lipoprotein lipase may favor attack on the sn‐1 position. It is hypothesized that the small amounts of the 1,2‐diacylglycerols present may have arisen from a reversal of lipolysis also catalyzed by this enzyme.
In vitro activity of Δ6 and Δ9 desaturases in hepatomas of different growth rates
Authors: Chiappe L. E. , De Tomas M. E. , Mercuri O.
Published: December 2006

The in vitro activity of Δ9‐ and Δ6‐desaturases was determined in the microsomal fraction of C3H/S normal mouse liver, SS1K fast growing hepatoma, and SS1H slow growing hepatoma. These tumors are two different sublines of a spontaneous hepatoma transplanted in 1949 by J.W. Wilson, Brown University, Providence, R.I., into C3H/ST W: strain. The activity of the two enzymes showed a parallel decrease in the two studied hepatomas. These alterations could be attributed to a fundamental change in structure or function in the tumors. The fatty acid desaturase activity seems to be independent of cell division in malignant tissues.
A simple, sensitive method for lipid phosphorus
Authors: Lowry Robert R. , Tinsley Ian J.
Published: December 2006

A method is described for quantitatively determining lipid phosphorus with a linear range from 0.7–10.0 μg. The method is simple and rapid, requiring one stable reagent and a single extraction with 1‐butyl acetate after the phosphorus is converted to inorganic phosphate by means of a perchlorate digestion. The stable complex is read at 310 nm.
Effects of chronic alcohol ingestion on the fatty acid composition of the heart
Authors: Reitz Ronald C. , Helsabeck Eric , Mason David P.
Published: December 2006

The effects of alcohol on the total fatty acid composition of the heart have been measured, and two highly significant differences were noted between the alcohol‐treated animals and the two control groups. Linoleic acid was elevated, and arachidonic acid was decreased. The increase in linoleate appeared to be a generalized increase within the various lipids analyzed, whereas the decrease in arachidonate was accounted for largely in the phosphatidyl cholines. The ratios of 20∶4ω6/18∶2 were calculated and compared to data from other researchers. The decrease in this ratio in the hearts from the alcohol‐treated animals was similar to the data from the liver of animals treated with various agents which produce a fatty liver. Various mechanisms that could cause such changes in these two essential fatty acids are discussed, and it was concluded that a combination of effects could cause these changes in linoleate and arachidonate. These effects include: (a) increased mobilization of linoleate from adipose tissue; (b) decreased β‐oxidation of linoleate; and (c) inhibition of the elongation‐desaturation system which converts linoleate to arachidonate.
Lecithin‐cholesterol acyltransferase: Inhibition by local anesthetics in plasma from man and experimental animals in vitro
Authors: Bell Frank P. , Hubert Edna V.
Published: December 2006

Lecithin‐cholesterol acyltransferase (LCAT, EC 2.3.1.43) was assayed in vitro in plasma from normal man, rat, rabbit and dog by following the formation of14C‐cholesteryl esters subsequent to labeling the plasma with14C‐cholesterol in vitro. In all species examined, various local anesthetics were found to inhibit LCAT when studied over the concentration range of 1 to 5 mM. The order of inhibition was dibucaine>benzocaine>tetracaine>lidocaine>procaine. Since LCAT activity represents the combined effect of a deacylation step and an esterification step, inhibition of LCAT by local anesthetics could theoretically involve either or both steps.
Effect of chronic ingestion of DDT on physiological and biochemical aspects of essential fatty acid deficiency
Authors: Sampson David A. , Pitas Robert E. , Jensen Robert G.
Published: December 2006

Male weanling rats were fed semipurified diets with and without essential fatty acid (EFA) and DDT (150 ppm) for 14 weeks to determine the effects of the pesticide on physiological and biochemical aspects of EFA deficiency (EFAD). DDT did not affect EFAD‐induced reduction in growth rate or final body weight, nor did the pesticide affect EFAD‐induced changes in feed efficiency or skin dermatitis. The pesticide did increase liver/body mass ratios, but did not interact with EFAD, which also increased this ratio. The pesticide produced complex changes in total fatty acid composition of liver and tail skin: liver levels of 18∶0, 18∶2 and 20∶3ω9 were increased, whereas levels of 12∶0, 14∶0 and 16∶0 were decreased. In both tissues, DDT interacted with EFA to increase 18∶2 levels. DDT did not change the total fatty acid 20∶3ω9/20∶4ω6 ratio in either tissue. In this study, although DDT did not exacerbate the physiological aspects of EFAD, DDT‐induced changes in fatty acid composition of liver and tail skin indicated that 150 ppm DDT in the diets did alter lipid metabolism of the rats in an unexplained manner.
Studies on phospholipase activities inneurospora crassa mycelia
Authors: Chakravarti Deb N. , Chakravarti Bulbul , Chakrabarti Parul
Published: December 2006

Phospholipase A activity has been detected in mycelial homogenate ofNeurospora crassa. A submycelial fraction, obtained by differential centrifugation containing the highest specific activity of phospholipase A has been shown to contain ca. 66% phospholipase A1 and 34% phospholipase A2 activity along with lysophospholipase and degergent‐stimulated phospholipase D activity. Phospholipase A activity bound toN. crassa mycelia also has been observed.
Quantitative determination of isomeric glycerides, free fatty acids and triglycerides by thin layer chromatography‐flame ionization detector system
Authors: Tanaka Masamichi , Itoh Toshihiro , Kaneko Hiroshi
Published: December 2006

Partial glyceride mixtures, which include 1‐monoglyceride, 2‐monoglyceride, free fatty acid, 1,2‐diglyceride, 1,3‐diglyceride and triglyceride, could be separated from each other on a 3% boric‐acid‐impregnated Chromarod S‐II (silica gel sintered quartz rod) with either chloroform/acetone (96∶4, v/v) or chloroform/acetone/acetic acid (100∶1∶1, v/v) as the developing solvent mixtures. The components separated on the boric‐acid‐impregnated rod were automatically quantitated in a hydrogen flame ionization detector (Iatroscan). The relative responses of 1,2‐diglyceride, 1,3‐diglyceride, free fatty acid and triglyceride were slightly lower than theoretical responses based on weight percentage, whereas 1‐monoglyceride and 2‐monoglyceride showed slightly higher responses. These responses were converged within a maximal error of 5–10% (SD). Boric‐acid‐impregnated rods could be used repeatedly, ca. 5 times without any reconditioning procedure.
Influence of culture filtrate ofTrichoderma viride and barley on lipid metabolism of laying hens,
Authors: Oureshi Asaf A. , Prentice Neville , Din Zafeer Z. , Burger Warren C. , Elson Charles E. , Sunde Milton L.
Published: December 2006

The suppression of hepatic 3‐hydroxy‐3‐methylglutaryl coenzyme A (HMG CoA) reductase and cholesterol 7 α‐hydroxylase, previously noted in studies of the influences of barley and the filtrate ofTrichoderma viride culture (CF) on cholesterol metabolism in sexually immature birds, is shown in sexually mature birds. Barley, CF or both were fed in one study from the day of hatching, in another during the period of sexual maturation and, in a third study, CF was fed to mature layers. CF suppressed HMG CoA reductase by 30–50% and cholesterol 7 α‐hydroxylase by 32–45% when added to the control diet. In birds fed barley rather than corn, the respective activities were 25–36% and 24–31% lower. These effects were expressed in the lowering of plasma cholesterol by 11–36%. Lipogenic activity based on the assays of 4 enzymes was increased 2–3 times by the treatments and plasma triglyceride elevated by 12–86%. The start of egg production by birds fed CF preceded the controls by 17 days. Birds fed barley trailed controls by 11–14 days. CF countered the barley‐conditioned delay. Egg yolk cholesterol concentrations were lowered by both treatments. Eggs produced by hens fed barley were lower in weight; CF increased egg and yolk weights. Tissues from birds fed CF or barley for up to 30 weeks appeared to be normal.
Thermal decomposition of individual positional isomers of methyl linolenate hydroperoxides, hydroperoxy cyclic peroxides and dihydroperoxides
Authors: Peers Kenneth E. , Coxon David T. , Chan Henry W. ‐S.
Published: December 2006

The methyl esters of 4 individual positional isomers of hydroperoxides, 2 positional isomers of hydroperoxy cyclic peroxides and a 9,16‐dihydroperoxide were prepared by autoxidation of methyl linolenate and separated by preparative high pressure liquid chromatography. Isolated hydroperoxide isomers were thermally decomposed and the resulting volatile components analyzed. Each hydroperoxide or hydroperoxy cyclic peroxide isomer yielded characteristic volatile products. The major volatiles from each acyclic hydroperoxide corresponded with those predicted to arise by carboncarbon scission on either side of the corresponding alkoxy radical intermediate and little evidence was found of isomerization between the various positional isomers occurring during the process. A similar mechanism would account for the volatile products obtained from the cyclic peroxides. 2,3‐Pentanedione was a significant odor contributor arising from the 13,15‐epidioxy‐16‐hydroperoxide isomer although it was only a minor decomposition product.
Alterations of phospholipids in ischemic canine myocardium during acute arrhythmia
Authors: Man Ricky Y. K. , Slater Tracy L. , Pelletier Marc P. , Choy Patrick C.
Published: December 2006

Myocardial ischemia was produced in the left ventricle of the canine heart by a Harris two‐stage occlusion of the left anterior descending coronary artery. The lipid content in the ischemic myocardium was analyzed and compared with the control tissue. No significant change in total phospholipid and cholesterol was detected. A 2‐fold elevation in the levels of the major lysophospholipids was observed during acute ventricular arrhythmias at 24hr after the onset of ischemia. Such increases were not caused by preferential hydrolysis of phospholipid plasmalogens from the parent phospholipids.
Extremely decreased release of prostaglandin E2‐like activity from chopped lung of ethyl linolenate‐supplemented rats
Authors: Hansen Harald S. , Fjalland Bjarne , Jensen Benny
Published: December 2006

Three groups of weanling male rats were reared on a fat‐free diet for 13 weeks. One group received only the fat‐free diet (FF rats), the other 2 groups received the fat‐free diet and a daily supplement of 2 energy% ethyl linoleate ([n−6] rats), or 2 energy% ethyl linolenate ([n−3] rats). The chopped lung preparation was used to illustrate an in vitro prostaglandin formation. PGE2‐like activity was quantified on rat stomach strip. The release of PGE2‐like activity expressed as ng PGE2‐equivalent per g lung tissue (mean±SD) was 23±7, <6, and 65±20 for the FF rats, the (n−3) rats, and the (n−6) rats, respectively. PGE2 quantification by radioimmunoassay of the chopped lung effluent collected after passing over the rat stomach strip revealed the same release pattern as the bioassay. Fractionation of chopped lung effluent on HPLC with radioimmunoassay detection indicated that the lung tissue from (n−3) rats released very little PGE3, if any, in spite of a 20∶5(n−3)/20∶4(n−6) ratio of 5.2 in the lipids of the lung. It is suggested that the pool of arachidonic acid for prostaglandin production in vitro is different from the one which functions in vivo, and that these pools are differently affected by dietary EFA.
The binding of micellar lipids to chitosan
Authors: Nauss J. L. , Thompson J. L. , Nagyvary J.
Published: December 2006

The lipid binding capacity of chitosan (partially deacetylated chitin) was determinined with respect to micellar solutions of bile salts, dodecyl sulfate, natural ox bile and an artificial mixed microemulsion. The stoichiometry was determined following the separation of the solid phase by filtration or centrifugation. The major variables in the extent of binding were the pH and ionic strength, suggesting that the interactions are mainly of ionic nature. It is noteworthy that under optimal conditions chitosan could bind, i.e., coprecipitate, with 4–5 times of its weight with all the lipid aggregates tested. These results have a bearing on the nutritional and pharmacological applications of chitosan. The analyses of the components from the precipitates with microemulsion and ox bile show a significant selectivily of binding caused by hydrophobic interactions.
Phospholipid synthesizing enzymes of dermatophytes: II. Characterization of choline kinase
Authors: Kasinathan C. , Govindarajan U. , Chopra A. , Khuller G. K.
Published: December 2006

Choline kinase was located in the cytosolic fractions of the filamentous, pathogenic fungi,Microsporum gypseum andEpidermophyton floccosum. A broad pH optima (6.0–9.0) was observed for theM. gypseum enzyme, but theE. floccosum enzyme was active at pH 8.4 as well as 10.5, the activity being higher at pH 8.4. Enzyme from both dermatophytes had Km value of 3.3×10−4 M for choline; however, for ATP, it was 6.6×10−4 M and 12.6×10−4 M forM gypseum andE. floccosum, respectively. Choline kinase of both dermatophytes showed SH‐group requirement. TheM. gypseum choline kinase was inhibited to a greater extent by Mn2+, Ca2+ and Ba2+ than was theE. floccosum enzyme. In comparison to other nucleotides, ATP was the most effective phosphate donor for phosphorylating choline in both dermatophytes. Higher concentrations of ATP inhibited the enzyme inM. gypseum as well asE. floccosum. Phosphorylcholine inhibited the choline kinase activity from both fungi, whereas phosphoethanolamine and glycerol 3‐phosphate were stimulatory.
Sterols of the spongeTethya amamensis: Occurrence of (24E)‐24‐ethylidenecholesta‐5,7‐dienol, (24E)‐24‐propylidenecholesta‐5,7‐dienol, and (24Z)‐24‐propylidenecholesta‐5,7‐dienol
Authors: Teshima Shin‐Ichi , Kanazawa Akio , Yamada Ichimaro , Tanaka Yoshito
Published: December 2006

The spongeTethya amamensis, collected from Kagoshima Bay, Japan, contained at least 24 sterols, including Δ5‐sterols (82.2% of total sterols) and Δ5, 7‐sterols (17.8%). The predominant sterols were cholesterol (29.0%), cholesta‐5,22‐dienol (13.8%), 24‐methylcholesta‐5,22‐dienol (10.9%), 24‐methylenecholesterol (8.3%), 24‐methylcholesta‐5,7,22‐trienol (6.8%), 24‐ethylcholest‐5‐enol (6.1%), and isofucosterol *4.1%). Combined gas liquid chromatography‐mass spectrometry suggested the presence of 3 uncommon sterols, (24E)‐24‐ethylidenecholesta‐5,7‐dienol, (24E)‐24‐propylidenecholesta‐5,7‐dienol, and (24Z)‐24‐propylidenecholesta‐5,7‐dienol as minor components. The sterols ofT. amamensis also contained small amounts of 24‐norcholesta‐5,7,22‐trienol and (24Z)‐24‐ethylidenecholesta‐5,7‐dienol.
Initiation of lipid peroxidation by a peroxidase/hydrogen peroxide/halide system
Authors: Kanner Joseph , Kinsella John E.
Published: December 2006

A lactoperoxidase/H2O2/halide system caused the initiation of linoleate peroxidation as indicated by diene conjugation. Coupled lipid peroxidation was accelerated by iodide, chloride and bromide ions at pH 4.0 and 6.2. No peroxidation occurred in the presence of H2O2 or lactoperoxidase alone. The rate of linoleate peroxidation by lactoperoxidase in the presence of chloride depended on the concentration of H2O2. Linoleate peroxidation by the enzymatic system was inhibited by high concentration of H2O2 by methionine, tryptophan and BHT. Oxygen was absorbed during peroxidation and the major products were the 13‐hydroperoxides. The mechanisms of the initiation of lipid peroxidation by a peroxidase/H2O2/halide system are discussed.
Effect of the plasticizer di(2‐ethylhexyl) adipate (dioctyladipate, DOA) on lipid metabolism in the rat: I. Inhibition of cholesterolgenesis and modification of phospholipid synthesis
Authors: Bell Frank P.
Published: December 2006

DOA (di[2‐ethylhexyl] adipate, dioctyladipate), a plasticizer used in the manufacture of polyvinylchloride plastic products, has been considered as a suitable substitute for di(2‐ethylhexyl)phthalate (DEHP) in some applications. In the present studies, hepatic lipid metabolism was examined in liver mince preparations from rats fed 0.5% or 1.0% DOA in the diet for 2 weeks. By studying patterns of lipid synthesis from [14C] acetate, [14C] oleate, [14C] mevalonate, and [14C] octanoate, it was concluded that DOA feeding inhibits hepatic cholesterolgenesis and alters the pattern of phospholipids synthesized by the liver. DOA also exerted a cholesterol‐lowering effect at the 1% level but did not affect plasma triglyceride levels. The results suggest that the biological effects of DOA in the rat are similar to those produced by DEHP.
Absorption and metabolic fate of dietary3H‐squalene in the rat
Authors: Tilvis Reijo S. , Miettinen Tatu A.
Published: December 2006

The absorption and metabolic fate of dietary squalene were investigated on the rat by administering a single oral dose of3H‐squalene and14C‐cholesterol. Experiments on rats with cannulated thoracic duct revealed that3H‐squalene was, like14C‐cholesterol, absorbed through the lymphatic vessels and that ca. 20% of absorbed3H‐squalene was cyclized to sterols during the transit through the intestinal wall. Feces contained3H‐sterols, indicating that newly synthesized mucosal sterols had been secreted into the gut lumen. In intact animals,3H‐squalene appeared in the circulation more rapidly than14C‐cholesterol and did not persist to any significant extent in the squalene‐rich adipose and muscle tissues. The increase in dietary squalene load (8–48 mg) decreased the absorption percentage of3H‐squalene (45–26%) but did not affect the absorption of14C‐cholesterol (47%). Determination of fecal steroids revealed that during the first days absorbed3H‐squalene was eliminated to a significantly higher extent than14C‐cholesterol as fecal bile acids (34% vs 11%). The experiments indicate that the rat intestine has a marked capacity for absorbing dietary squalene and that the absorbed squalene is preferentially converted to bile acids in the liver.