bluuebunny/crossref_metadata_2025 huggingface dataset:
Plasma lipid and lipoprotein concentrations in an Egyptian male sample
Authors: Shoukry Malak I. , Fareed Samia
Published: December 2006

The distributions of plasma total cholesterol and triglyceride levels as well as plasma lipoprotein abnormalities were studied in 50 Egyptian males aged 20–69 years. Total cholesterol increased gradually with advancing age up to the seventh decade. In contrast, triglycerides peaked in the fifth decade, then declined. Type IV lipoprotein pattern was the most common abnormality (12%). Type II was less common (2.0%). Types I, III and V were not encountered. The mean plasma triglyceride and cholesterol levels were not markedly different from similar studies done on non‐Arab populations. The high incidence of hyperlipidemia among this group is worth noting, especially in the search for the coronary‐prone, since all of the type IV group had normal total cholesterol levels.
The effect of dihydroergotoxine on lipid peroxidation in vitro
Authors: Koréh Kinga , Seligman Myron L. , Demopoulos Harry B.
Published: December 2006

Dihydroergotoxine mesylate (DHET), an ergot alkaloid derivative, is widely used to treat senile cerebral vascular insufficiency. Aspects of this age‐related phenomenon may be due to deterioration by lipid oxidation of cellular membranes. DHET stabilizes EEG alpha frequencies, increases cerebral blood flow and oxygen uptake and accumulates in lipid‐rich structures of the brain. The effect of DHET was studied on iron‐catalyzed peroxidation of liposomes as measured by the thiobarbituric acid assay. It was found that DHET inhibits peroxidation in vitro in a dose‐dependent manner. These results suggest that DHET acts in part as a lipid antioxidant when used to treat senile cerebral vascular insufficiency.
A prostaglandin‐like fatty acid from a species in the cyperaceae
Authors: Van Aller Robert T. , Clark Leonard R. , Pessoney George F. , Van Rogers A.
Published: December 2006

A C20 cyclic trihydroxy unsaturated fatty acid was isolated and characterized as a representative member of a group of oxygenated fatty acids from the aquatic sedge,Eleocharis microcarpa, Torr. Characterization of the compound as 11‐hydroxy‐14‐(3,5‐dihydroxy‐2‐methylcyclopentyl)‐tetradec‐9‐ene‐12‐yneoic acid was accomplished by various chemical and spectral methods.
Detection and determination of lipase (acylglycerol hydrolase) activity from various sources
Authors: Jensen Robert G.
Published: December 2006

Methods for the detection and determination of lipases (acylglycerol hydrolases) and preparation of assays are reviewed including substrates, conditions and screening. Some newer methods for the determination of lipase activity are discussed. Several of these are: (a) titrimetry, (b) colorimetry of Cu soaps of free fatty acids (FFA), (c) colorimetry of chromophores in the acyl chain of FFA or in glycerol, (d) radioassay, (e) gas liquid chromatography, (f) enzymatic treatment of FFA and measurment of the resulting products, and (g) direct immunological determination of the lipase. Examples and sensitivities are given and advantages and disadvantages are described.
Fatty acid composition of liver lipids in rats fed brominated fatty acids
Authors: Wilson Glenn R. , Tinsley Ian J. , Lowry Robert R.
Published: December 2006

Feeding rats diets containing brominated corn oil or di‐ or tetrabromostearate as the monoglyceride produced changes in fatty acid composition of liver lipids. Those changes associated with the feeding of brominated corn oil or tetrabromosterates could be explained by the accumulation of triglyceride, and the changes associated with the feeding of dibromostearate could result from the proliferation of a membrane system. A unique response to the feeding of diets containing brominated corn oil is an increase in the level of γ‐linolenic acid.
Effect of methylmercuric chloride on gangliosides of mouse neuroblastoma cells in culture
Authors: Rebel G. , Guerin P. , Prasad K. N.
Published: December 2006

The effect of methylmercuric chloride (CH3 HgCl) on the levels of gangliosides in mouse neuroblastoma cells (NBP2) in culture was studied. The treatment of NB cells with low concentrations (0.1 μM and 0.2 μM) of CH3 HgCl, which did not affect the growth rate or morphology, caused an increase in the level of the GM3 ganglioside without changing the level of other gangliosides. The treatment of NB cells with higher concentrations (0.5 μM and 1 μM) of CH3 HgCl, which inhibited the growth of NB cells, caused a decrease in the level of GM3 and an increase in the level of GM2. These results show that alterations in the levels of specific gangliosides can be observed in cells which do not exhibit any detectable change in growth rate or morphology. This change may be associated with subtle changes in brain functions, including behavioral and psychological changes, after exposure to low concentrations of organic mercury.
Conversion of cyclolaudenol to 24α‐ and 24β‐ethylsterols in the cucurbitaceae
Authors: Balliano Gianni , Caputo Otto , Viola Franca , Delprino Laura , Cattel Luigi
Published: December 2006

[2‐3H]Cyclolaudenol was converted into α‐spinasterol, 24β‐ethylcholesta‐7,25‐dien‐3β‐ol and 24β‐ethylcholesta‐7,22,25‐trien‐3β‐ol by seedlings ofCucurbita maxima. As 24‐methylenecycloartanol is the obligatory precursor of 24‐ethylsterols, it can be assumed that the transformation of cyclolaudenol to 24‐methylenecycloartanol must have occurred. These results lead us to postulate the existence, in the Cucurbitaceae family, of an enzymatic system capable of isomerizing Δ25 alkylsterols into Δ25(28) sterols.
Regulation of phosphatidylinositol turnover, calcium metabolism and enzyme secretion by phorbol dibutyrate in neutrophils
Authors: Kramer Caroline M. , Franson Richard C. , Rubin Ronald P.
Published: December 2006

The action of the tumor promoter, phorbol 12,13‐dibutyrate (PDBu), on rabbit peritoneal and human neutrophils is associated with stimulation of14C‐arachidonic acid incorporation into phospholipids within 1–2 min. Stimulated14C‐arachidonate incorporation was relatively selective for phosphatidylinositol (PI) in rabbit neutrophils. In contrast, the secretory response of human neutrophils to PDBu coincided with stimulated label incorporation into phosphatidylserine (PS), phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidic acid (PA) and PI. Significant increases in label incorporation were observed with PDBu concentrations as low as 2 nM, and the dose response of stimulated label incorporation paralleled that of evoked lysozyme secretion. A parallel, but partial, inhibition of PDBu‐stimulated PI labeling and enzyme release was observed after exposing rabbit neutrophils to calcium‐deprived medium, whereas calcium deprivation failed to significantly depress either of these stimulant actions of PDBu in human neutrophils. Further, in rabbit neutrophils PDBu elicited an increase in cell associated45Ca. However, PDBu was unable to promote the incorporation of32P orthophosphate into PI or enhance phospholipase A2 activity in broken cells. These findings suggest that one expression of the interaction between phorbol esters and their receptors on neutrophils involves the turnover of arachidonic acid in phospholipids. This stimulated turnover of arachidonate may be a critical step in the cascade of events associated with neutrophil activation.
Partial purification of a triacylglycerol lipase isolated from steelhead trout (Salmo gairdneri) adipose tissue
Authors: Sheridan Mark A. , Allen William V.
Published: December 2006

A triacylglycerol (TG) lipase (EC 3.1.1.2), assayed by monitoring [1‐14C]‐oleic acid release from [carboxyl‐14C]‐triolein after liquid‐liquid partition of the fatty acid from the unhydrolyzed triacylglycerol substrate, was isolated and partially purified from steelhead trout adipose tissue. The TG lipase was resolved from contaminating lipoprotein lipase by heparin‐sepharose affinity chromatography and purified ca. 71‐fold over the original fraction. Optimal enzyme activity occurred at pH 7.5. The purified enzyme migrated on SDS‐polyacrylamide gels with an apparent molecular weight of 48,000.
Acyl‐acyl carrier protein as substrate of the acyltransferase of rat liver microsomes
Authors: Pugh E. L. , Kates M.
Published: December 2006

Acyl‐acyl carrier protein (acyl‐ACP) can serve as well as acyl‐CoA as substrate of the 1‐acyl‐sn‐glycero‐3‐phosphocholine (1‐acyl‐GPC) acyltransferase of rat‐liver microsomes. The product of the acylation with either thioester substrate is predominantly phosphatidylcholine (PC) (92–95%). The acyl‐group transferred from either myristoyl‐CoA or myristoyl‐ACP is located at the C‐2 position of the phospholipid (PL). The apparent Km values for the myristoyl‐CoA and myristoyl‐ACP were 46 μM and 63 μM, and the corresponding apparent Vmax values were 1.0 and 1.6 nmol/min/mg. The rate of acylation with the acyl‐ACP was unaffected by the addition of free CoA‐SH. These data suggest that acyl‐CoA and acyl‐ACP are transferred to 1‐acyl‐GPC by the same or similar enzyme systems.
Tissue phospholipid fatty acid composition in the diabetic rat
Authors: Huang Y. S. , Horrobin D. F. , Manku M. S. , Mitchell J. , Ryan M. A.
Published: December 2006

Tissue phospholipid fatty acid compositions in streptozotocin‐induced diabetic rats were studied. The major changes in liver, plasma, erythrocyte and heart were increased proportions of linoleic and dihomo‐γ‐linolenic acids and a decreased proportion of aracchidonic acid. The latter was not significantly changed in phospholipids of kidney, adrenal gland and testis. Skin fatty acids in diabetic rats showed an increase in the proportion of arachidonic acid and a reduction in the proportion of linoleic acid. The fatty acid desaturating activity in diabetes may be regulated differently in different tissues.
Hepatic contribution to newly made fatty acids in adipose tissue in rats and inhibition of hepatic and extrahepatic lipogenesis from glucose by dietary corn oil
Authors: Baker N. , Mead J. , Kannan R.
Published: December 2006

We have reexamined an earlier rat study in which the authors concluded that 60 min after [U‐14C]‐glucose injection half of labeled fatty acids found in adipose tissue had been made in liver and then transported to the adipose tissue. We have shown that even under conditions in which the lipogenic role of the liver is optimized (fed‐refed rats on a fat‐free, high‐carbohydrate diet), almost none of the labeled fatty acids found in adipose tissue of rats 60 min after they were fed a labeled glucose test meal was derived from the liver. This conclusion was based experimentally on (a) the use of the blocking agent Triton WR 1339 to measure the total labeled triglyceride fatty acids (TGFA) synthesized and secreted by the liver in 60 min and (b) comparison of plasma TGFA‐14C data with radioactivity found in liver and in adipose tissue in 60 min. Without using Triton WR 1339, mathematical analysis of plasma TGFA‐14C following the glucose test‐meal leads one to the same conclusion: 97% of14C‐labeled fatty acids found in adipose tissue at 60 min was made in situ. Additional studies in rats established that the source of error in the earlier studies was an incorrect assumption that dietary corn oil could inhibit hepatic lipogenesis from glucose C without inhibiting fatty acid synthesis in adipose tissue. In our studies, 10% corn oil inhibited equally both hepatic and adipose tissue fatty acid synthesis from glucose C under conditions that precluded any significant transport of labeled TGFA‐14C from liver to adipose tissue.
Chain length dependent thermodynamics of saturated symmetric‐chain phosphatidylcholine bilayers
Authors: Mason Jeffrey T. , Huang Ching‐Hsien
Published: December 2006

A molecular interpretation for the chain length dependent thermotropic behavior of saturated symmetric‐chain phosphatidylcholine bilayers is proposed. It is suggested that the bilayer interface region and conformationally inequivalent terminal ends of the fatty acyl chains perturb the packing associations of the rest of the hydrocarbon chains in the gel phase of the bilayer. These perturbing effects, which are seen to increase with decreasing acyl chain length, have been quantitatively defined by a perturbation parameter, P. The thermodynamic parameters of the thermal phase transition of these phosphatidylcholines are found to be linearly correlated to P and these linear relationships can be used to predict the minimum number of carbon atoms in the acyl chain necessary in order for a bilayer phase transition to occur.
Determination of fatty acid composition via chemical ionization‐mass spectrometry
Authors: Erdahl W. L. , Beck W. , Jones C. , Jarvis D. E. , Privett O. S.
Published: December 2006

The analysis of fatty acid methyl esters by chemical ionization‐mass spectrometry via a new interface system is described. The sample is applied to the interface system in dichloromethane containing trideuteromethyl (CD3) fatty acid esters as internal standards and dodecanol as a carrier. The esters are evaporated into a carrier gas of nitrogen in the interface and then drawn through a transfer system where residual traces of solvent are removed and the esters are concentrated by a porous silver membrane separator. The sample, now enriched in the carrier gas, is passed into the mass spectrometer where it is analyzed by selective multiple ion monitoring using isobutane as the reagent gas. The method, which takes less than a minute, is computerized for the quantitative analysis of the 19 most common fatty acids occurring in major portions in animal and plant tissues. The accuracy and precision of the method was demonstrated and compared to fatty acid analysis by gas liquid chromatography on several fats.
Essential fatty acid‐supplemented diet decreases renal excretion of immunoreactive arginine‐vasopressin in essential fatty acid‐deficient rats
Authors: Hansen Harald S.
Published: December 2006

Essential fatty acid (EFA)‐deficient rats have been reported to have very concentrated urine and low urinary prostaglandin E2 (PGE2) excretion. Both parameters were normalized by feeding an EFA‐supplemented diet (H.S. Hansen [1981] Lipids 16, 849–854). The urinary excretion rate of immunoreactive arginine‐vasopressin (iAVP) has been determined in these rats. The iAVP excretion rate was high: ca. 4.8 mU/24 hr, during the EFA‐deficient period compared to the controls, 0.7–1.3 mU/24 hr. One day after the dietary change, iAVP excretion rate was still high, but it decreased significantly (p<0.05) at the second measurement 7 days later. It is suggested that the water‐conserving effect of vasopressin 1 day after the dietary change was suppressed by the very high PGE2 production, resulting in normal renal water excretion. PGE2 and water excretion data were published in the paper just cited.
Effects of acute administration of chlorinated water on liver lipids
Authors: Chang Jung‐Hwa S. , Vogt Corazon R. , Sun Grace Y. , Sun Albert Y.
Published: December 2006

An acute administration of chlorinated water to rats caused “fatty liver” and indicated a more than 2‐fold increase in liver triacylglycerols at 2 days after administration. The acyl group composition of triacylglycerols and phospholipids in both liver mitochondria and liver whole homogenate were also altered by the chlorine treatment. Among the phospholipid acyl groups, there was an increase in the proportion of 20∶4 but a decrease in most other polyunsaturated acyl groups. The acyl group changes were more obvious with phosphatidylcholines than with phosphatidylethanolamines. Other phospholipids, including cardiolipin in the mitochondrial membranes, were not greatly altered. Both morphological and biochemical changes were maximum at 2 days after the treatment and were fully recovered after 10 days. The disturbance of a number of enzymatic processes in the liver membranes may account for a large part of the changes observed.
Temperature acclimation in the crayfish: Effects on phospholipid fatty acids
Authors: Farkas Tibor , Nevenzel Judd C.
Published: December 2006

Acclimation to different temperatures by a poikilothermous animal must include modification of its membrane lipids to maintain the proper physical properties. The simplest way to achieve this acclimation would seem to be by modification of the phospholipid fatty acids. In a freshwater cray‐fish,Procambarus clarkii, rapid changes in the degree of unsaturation of newly synthesized phospholipid fatty acids were correlated with changes in environmental temperature, both in whole animals and in slices of hepatopancreas tissue. At 5 C, the rate of fatty acid synthesis was about half that occurring at 23 C. Hepatopancreas tissue from animals acclimated to either 5 C or 23 C, when incubated for 2 hr at 5 C, incorporated a higher percentage of exogenous [1‐14C] acetate into polyunsaturated acids (27–38% of the radioactivity in total fatty acids) than when incubated at 23 C (12–14%); conversely, more saturated fatty acids were synthesized at 23 C (73–80% vs 51–73%). The higher average unsaturation of the fatty acids biosynthesized at 5 C constitutes an effective response to the animal's need for modification of lipids to maintain adequate membrane function at the lower environmental temperature.
Syntheses of radioactive furan fatty acids
Authors: Rahn Curtis H. , Sand Donald M. , Krick Thomas P. , Glass Robert L. , Schlenk Hermann
Published: December 2006

A novel route for the synthesis of naturally occurring furan fatty acids with particular emphasis on labeling with14C is described. Methyl [2‐14C] 9‐(5‐pentyl‐3,4‐dimethyl‐2‐furyl)nonanoate was synthesized from 3,4‐dimethyl‐2‐pentylfuran by a new route. [3‐14C]11‐(5‐Pentyl‐3‐methyl‐2‐furyl)undecanoate and [2‐14C] 9‐(5‐pentyl‐2‐furyl)nonanoate were prepared from their lower homologs. The label was introduced in all cases by means of the Arndt‐Eistert method for chain elongation, using14CH2N2. Comparisons of yields show that, with increasing number of substituents on the ring, the furan compounds are increasingly subject to uncontrollable side reactions.
Mitochondrial hydroxylation of the cyclohexane ring as a result of β‐oxidation blockade of a cyclohexyl substituted fatty acid
Authors: Tulliez Jacques E. , Durand Elizabeth F. , Peleran Jean‐Claude
Published: December 2006

Among the urinary metabolites of dodecylcyclohexane or cyclohexylacetic acid, the glycine conjugate of 1‐hydroxy‐cyclohexylacetic acid was identified and its origin studied, using cyclohexylacetic acid as the starting molecule, as it results from β‐oxidation of cyclohexyldodecanoic acid produced by terminal oxidation of the alkyl chain of the cycloparaffin. Three hypotheses were tested: (a) hydroxylation by the liver microsomal mixed‐function oxidases involved in detoxication mechanisms; (b) hydroxylation by a cyt. P450‐containing mitochondrial hydroxylase; and (c) β‐oxidation blockade after the reaction catalyzed by enoyl‐CoA‐hydratase. Liver microsomal or mitochondrial fractions were prepared and incubated in the presence of [14C] cyclohexylacetic acid, glucose‐6‐phosphate dehydrogenase and a NADPH‐producing system. On the other hand, mitochondria were incubated in a suitable respiratory medium with or without cofactors required for ATP production. The reaction products were extracted and analyzed by thin layer radiochromatography and radio gas chromatography. Evidence is given that hydroxylation of cyclohexylacetic acid in position 1 is a mitochondrial step requiring activation in the acyl‐CoA form and results from β‐oxidation blockade, the cyclohexane ring hindering hydroxyacyl‐CoA‐dehydrogenase action.
Studies of biosynthesis of waxes by developing jojoba seed: III. Biosynthesis of wax esters from Acyl‐CoA and long chain alcohols
Authors: Wu Xiang‐Yu , Moreau Robert A. , Stumpf Paul K.
Published: December 2006

Acyl‐CoA: alcohol transacylase activity was demonstrated in cell‐free homogenates of developing jojoba seeds. The optimal pH was 8.0–8.1. Under optimal conditions, wax formation had a nearly linear relationship with extract concentration; the time course of wax formation was also linear up to 30 min.cis‐11‐Eicosenol was the most effective alcohol substrate whereas tetradecanol, octadecanol, dodecanol,cis‐9‐octadecanol, andcis‐13‐eicosenol gave progressively lower activities. Either saturated or unsaturated acyl‐CoA with 18 or 20 C‐atoms had similar activity. The enzyme was fairly stable at 0 C, less stable at RT and labile above 30 C. Differential centrifugation showed that the 12,000 × g fat pad was the most active in wax formation; to maximize the activity, a 12,000 × g supernatant appeared to be necessary. This factor in the supermatant was thermolabile and nondialyzable.
Exchange of phosphatidylcholine between rabbit erythrocytes and plasma in vivo
Authors: Smith Norman B. , Rubinstein David
Published: December 2006

Phosphatidylcholine exchange between rabbit erythrocytes and plasma was studied in vivo. The erythrocyte phosphatidylcholine was labeled by exchange in vivo with [32P] phosphatidylcholine and in vitro by acylation with [3H] 16∶0 and [14C] 18∶2. The erythrocytes were then injected into rabbits and the loss of labeled phosphatidylcholine from the cells by exchange was followed. The rate constants for the exchange of [32P]‐, [3H] 16∶0‐, and [14C] 18∶2‐phosphatidylcholine were .0131±.0010, .0093±.0014 and .0074±.0013 h−1, and the exchange rates of the labels relative to that of [32P] were 1.0, 0.71±.16, and 0.56±.14, respectively. These results confirm our earlier in vitro findings and represent the first in vivo demonstration of the dependency of the exchange rate of erythrocyte phosphatdylcholines on their metabolic prehistory.
Sterol biosynthesis in the oyster,Crassostrea virginica
Authors: Teshima Shin‐Ichi , Patterson Glenn W.
Published: December 2006

Sterol biosynthesis in the oyster,Crassostrea virginica, was examined by injection of [2‐14C]acetate and [2,3‐3H] lanosterol. The oyster incorporated [2‐14C] acetate into squalene 4,4′‐dimethylsterols, 4‐monomethylsterols, cholesterol, desmosterol, isofucosterol, and 24‐methylenecholesterol, and also converted [2‐3H] lanosterol to cholesterol. Therefore, the oyster was concluded to synthesize cholesterol, desmosterol, isofucosterol, and 24‐methylenecholesterol from acetate via squalene, probably using the lanosterol pathway.
Separation of the apoprotein components of human very low density lipoproteins by ion‐paired, reversed‐phase high performance liquid chromatography
Authors: Hancock W. S. , Bishop C. A. , Gotto A. M. , Harding D. R. K. , Lamplugh S. M. , Sparrow J. T.
Published: December 2006

A number of crude apolipoprotein samples isolated from human very low density lipoproteins (VLDL) were analyzed by reversed phase high performance liquid chromatography. The mobile phase consisted of a 1% solution of the polar ion‐pairing reagent triethylammonium phosphate. A slow, nonlinear gradient of acetonitrile (37–42%) was used to elute the apolipoproteins. The order of elution was as follows: apolipoprotein Cx, apolipoprotein C‐I, apolipoprotein C‐III2, apolipoprotein C‐III1, apolipoprotein C‐III0 and apolipoprotein C‐II. This order is consistent with the known polarity of the proteins, i.e., the most nonpolar, apolipoprotein C‐II, was the last to be eluted, whereas apolipoprotein C‐I, with the lowest nonpolar surface area eluted first. The recovery of the individual apolipoproteins was 80–95% and the individual peaks were characterized by amino acid analysis, UV absorption spectra and chromatography of pure protein standards.
Fatty acid composition of seed oils from sixAdansonia species with particular reference to cyclopropane and cyclopropene acids
Authors: Ralaimanarivo Auguste , Gaydou Emile M. , Bianchini Jean‐Pierre
Published: December 2006

The oil content of sixAdansonia species (Bombacaceae family) of Madagascar (Adansonia grandidieri, A. za, A. digitata, A. fony, A. madagascariensis andA. suarenzensis) and Africa (A. digitata) ranges from 8 to 46%. All the oils give a positive response to the Halphen test. Malvalic, sterculic and dihydrosterculic acids were detected using gas liquid chromatography‐mass spectrometry (GLC‐MS). Epoxy or hydroxy fatty acids were not found in these oils. Fatty acid composition was determined by GLC using glass capillary columns coated with BDS and Carbowax 20 M. Results obtained for cyclopropenic fatty acids (CPEFA) were compared to those given by glass capillary GLC after derivatization with silver nitrate in methanol, by hydrogen bromide titration and by proton magnetic resonance (PMR). Good agreement was observed for the results given by the various methods. Malvalic acid content ranges from 3 to 28%, sterculic acid from 1 to 8% and dihydrosterculic acid from 1.5 to 5.1%. Odd‐numbered fatty acids (Pentadecanoic and hepatadecanoic) were also observed in minute amounts (0.1–1.1%). Among the normal fatty acids, we observed mainly palmitic (21–46%), oleic (15–40%) and linoleic (12–32%). The relationship between fatty acid composition andAdansonia species is discussed.
Interrelationship between dietarytrans fatty acids and the 6‐ and 9‐desaturases in the rat
Authors: De Schrijver Remi , Privett Orville S.
Published: December 2006

Studies are reported on the effects of dietarytrans fatty acids on the 6‐ and 9‐acyl desaturase activities in the liver microsomes of rats fed essential fatty acid (EFA)‐deficient and non‐FFA‐deficient diets. In experiment I, weanling male rats were fed a semisynthetic diet with either 10% safflower oil (SAF) or 10% hydrogenated coconut oil (HCO). At the age of one year, half of the dietary fat was replaced by a supplement containing elaidate, linolelaidate andcis,trans‐trans,cis‐18∶2 (TRANS) for 12 weeks. In experiment II, male rats which were kept from weaning on a 10% SAF diet for one year received one of the following fat supplements for a 12‐week period: 10% HCO, 9% HCO+1% TRANS, or 5% HCO+5% TRANS. Feeding TRANS depressed the 6‐desaturase activity in the liver microsomes, especially in the EFA‐deficient rats (HCO+TRANS group of experiment I). Unlike the 6‐deaturase activity, the 9‐desaturase activity was not inhibited by the dietarytrans fatty acids and was significantly stimulated in the non‐EFA‐deficient rats (SAF+TRANS group of experiment I and HCO+TRANS groups of experiment II). This was evidenced by incubation reactions and by comparisons of fatty acid consumptions and microsomal fatty acid levels, showing extra biosynthesis of 16∶1 and 18∶1 when TRANS was fed. The biosynthesis of essential (n−6) fatty acids was depressed by the TRANS supplement in EFA‐deficient as well as in non‐EFA‐deficient animals.
Isolation and purification of perfluorodecanoic and perfluorooctanoic acids from rat tissues
Authors: Vanden Heuvel John P. , Van Rafelghem Marc J. , Menahan Lawrence A. , Peterson Richard E.
Published: December 2006

A procedure for the extraction, separation, and isolation of perfluorodecanoic and perfluorooctanoic acids from biological samples is described. The use of conventional lipid extraction procedures leads to substantial loss of the perfluorinated fatty acids added to tissue. The presence of sulfuric acid in aqueous saline during phase partitioning is essential for the recovery of perfluorodecanoic and perfluorooctanoic acids in the organic phase following their extraction from tissue. The perfluorinated fatty acids are co‐eluted with simple lipids from silica gel columns using diethyl ether/trifluoroacetic acid (100∶1, v/v). Simple lipids are separated by thin layer chromatography. By substituting trifluoroacetic acid for acetic acid in the developing solvents, perfluorodecanoic and perfluorooctanoic acids migrate with other free fatty acids.
In vivo and in vitro antilipolytic effects of some various substituted homocysteine‐thiolactone‐nicotinamides: Structure‐activity study
Authors: Maccari F. , Ghirardi O. , De Witt P. , Ramacci M. T.
Published: December 2006

The antilipolytic activity of homocysteine‐thiolactone‐nicotinamide (ST22) and its 2‐chloro (ST71), 6‐chloro (ST82) and 6‐hydroxy (ST90) derivatives was investigated by evaluation of serum free fatty acids (FFA) and triglycerides (TG) (in vivo) and FFA release from adipose tissue (in vitro). Increased FFA levels in 17‐hr fasted rats at 60 min following treatment with 7·10−4 mol kg−1 p.o. were reduced by 70% (ST22), 60% (ST82) and 18% (ST71), whereas ST90 provoked no change; TG levels showed similar changes. Basal FFA release from epididymal rat adipose tissue at 60 min following treatment with 7·10−4 mol kg−1 p.o. of ST22 and ST82 was reduced by 79 and 45%, respectively. Lipid mobilization induced by noradrenaline (NA) was diversely affected by the compounds according to the tests employed: with in vivo experiments, serum FFA levels were reduced by 60, 70, 10 and 5% at 60 min following treatment with ST22, ST82, ST71 and ST90, respectively (7·10−4 mol kg−1 p.o.; NA bitartrate, 2 mg kg−1 s.c.); in vitro, ST22 produced no change, whereas the other compounds induced a significant mobilization of FFA. The results suggest that: (a) antilipolytic activity can be greatly modified when various substituents capable of influencing either the inductive (‐I) or the resonance (+M) effect are introduced into the different positions of the pyridine ring; and (b) the lipolysis experiments did not evince any direct relationship between the effects obtained by the in vivo tests and those obtained by the in vitro tests.
Effect of ethanol on transport from rat intestine during high and low rates of oleate absorption
Authors: Saunders D. R. , Sillery J. , McDonald G. B.
Published: December 2006

Long‐chain fatty acids (LCFA) are transported predominantly in the intestinal lymph when rates of LCFA absorption are high, and oral ethanol has been shown to enhance this lymphatic transport. A greater proportion of absorbed LCFA is transported via portal blood when rates of LCFA absorption are low. We tested the hypothesis in unanesthetized lymph‐fistula rats that ethanol might also enhance the mucosal absorption and lymphatic transport of oleic acid when oleate absorption rates were low. The results did not support this hypothesis. Ethanol enhanced oleate absorption and transport from the intestine when 360 μmol, but not when 8 μmol of [14C] oleate was infused intraduodenally over 4 hr. There were major differences in intestinal mucosal metabolism of high and low loads of oleic acid. After the high load, the proportion of intestinal [14C] phospholipid to [14C] neutral lipid was 8∶92. This ratio changed to 37∶63, and the percentage of neutral14C as triglyceride decreased from 87 to 68% when the low load of oleate was infused. We suggest that a portion of absorbed LCFA is incorporated into phospholipid and transported as high‐density lipoproteins in portal blood. This portal pathway for LCFA was uninfluenced by ethanol in the present experiments.
Phospholipid synthesis inS. cerevisiae strain GL7 grown without unsaturated fatty acid supplements
Authors: Buttke Thomas M. , Reynolds Rebecca , Pyle Amy L.
Published: December 2006

In the absence of exogenous unsaturated fatty acids (UFA),Saccharomyces cerevisiae strain GL7 synthesizes low levels of UFA and large amounts of decanoic, dodecanoic and tetradecanoic fatty acids. Supplementation with hemin leads to slightly higher levels of UFA, but synthesis of the medium‐chain saturated fatty acids (SFA) continues. Under these conditions of limited UFA availability, strain GL7 incorporates most of its UFA into phosphatidylethanolamine (PE), whereas phosphatidylcholine (PC) and phosphatidylserine+phosphatidylinositol (PS+PI) are enriched with the mediumchain SFA. The association of specific fatty acids with the various phospholipids is not accompanied by changes in the proportions of newly synthesized phospholipids, demonstrating that the fatty acid composition of PE can be modulated independently of the other phospholipids. The effect of sterol structure on the fatty acid composition of cells grown with limiting UFA was also examined. Yeast cells grown with either ergosterol or stigmasterol contained less UFA and more medium‐chain SFA in their phospholipids than did cholesterol‐grown cells, suggesting that the former sterols allow strain GL7 to grow with a lower UFA content.
Studies on the biosynthesis of the oogoniols
Authors: Barrow Susan E. , McMorris Trevor C.
Published: December 2006

In feeding experiments withAchlya heterosexualis, [3‐3H] fucosterol was efficiently incorporated into oogoniols possessing an unsaturated side chain as well as those with a saturated side chain (clionasterol skeleton). [23,25‐3H]‐29‐Hydroxyfucosterol was also efficiently incorporated into the oogoniols and its role as an intermediate in the biosynthesis was confirmed by a trapping experiment. This indicated the presence of a small pool of endogenous 29‐hydroxyfucosterol in the mycelium. [23, 25‐3H]‐29‐Oxofucosterol was also well incorporated into the oogoniols and it is probably an intermediate in the biosynthesis. It was found to be converted to 29‐hydroxyfucosterol in a trapping experiment. Reduction of the C‐24(28) double bond make take place after all the functional groups have been introduced, at C7, C‐11 and C‐15, in the tetracyclic structure.
Cyclic fatty esters: Synthesis and characterization of methyl ω‐(6‐alkyl‐3‐cyclohexenyl) alkenoates
Authors: Awl R. A. , Frankel E. N.
Published: December 2006

Diunsaturated C18 cyclic fatty acid methyl esters of known structure and configuration were synthesized as model derivatives of cyclic fatty acids formed in heat‐abused vegetable oils for characterization and further biological evaluation. The Wittig reaction was used to prepare 5 pure methyl esters: (a) 12‐(3‐cyclohexenyl)‐11‐dodecenoate, (b) 11‐(6‐methyl‐3‐cyclohexenyl)‐10‐undecenoate, (c) 10‐(6‐ethyl‐3‐cyclohexenyl)‐9‐decenoate, (d) 9‐(6‐propyl‐3‐cyclohexenyl)‐8‐nonenoate and (e) 8‐(6‐butyl‐3‐cyclohexenyl)‐7‐octenoate. Diels‐Alder cycloaddition reactions between 1,3‐butadiene and appropriate (E)‐2‐alkenals produced 3‐cyclohexenal intermediates. The appropriate methyl ω‐bromoesters and their triphenylphosphonium bromides were made and converted to their respective ylids with NaOCH3 in DMF. The appropriate 3‐cyclohexenals and phospho‐ylids were reacted, and the desired cyclic ester products were isolated in crude yields of 30–83% as liquids and fractionally distilled. The crude cyclic esters were purified either by preparative TLC or by saponification‐esterification. Double bonds in purified cyclic esters weretrans‐isomerized and hydrogenated. Each derivative was characterized by IR,1H‐NMR,13C‐NMR, capillary GLC and GC‐MS. On the basis of these analyses, no positional isomers were detected, Z‐unsaturated isomers were produced in better than 90% purity, and the alkyl and ester ring substituents were predominantlytrans to each other.
Improved methods for the isolation and study of the C18, C20 and C22 monoethylenic fatty acid isomers of biological samples: Hg adducts, HPLC, AgNO3‐TLC/FID, and ozonolysis
Authors: Sebedio J‐L. , Farquharson T. E. , Ackman R. G.
Published: December 2006

The monoethylenic isomers of C18, C20 and C22 chain lengths of the depot fat of a nonhominid primate (cynomolgus monkeys,Macaca fascicularis), fed a partially hydrogenated herring oil (IV=76.0) for 30 months, were examined by 2 different approaches. The first isolation method involved preparative gas liquid chromatography and argentation thin layer chromatography (TLC). The second sequence involved a chain‐length fractionation system based on the TLC of the methoxy‐bromomercuri quence involved a chain‐length fractionation system based on the TLC of the methoxy‐bromomercuri adducts of the total methyl esters to isolate groups of acids of common degrees of unsaturation, and then high performance liquid chromatography on a reverse‐phase column. In both cases, the monoethylenic isomer distribution was determined by ozonolysis in BF3/MeOH. Comparable results were obtained with the 2 methods. The second approach is recommended for small biological samples, especially for those containing a relatively high proportion of di‐ and other polyethylenic isomers which might interfere.
Antioxidant activities of tocopherols on Fe2+‐ascorbate‐induced lipid peroxidation in lecithin liposomes
Authors: Fukuzawa Kenji , Tokumura Akira , Ouchi Setsuhiro , Tsukatani Hiroaki
Published: December 2006

The antioxidant activities of 4 tocopherols, tocol, and a water‐soluble model analog of α‐tocopherol were compared. Egg lecithin liposomes were used and oxidation was catalyzed by Fe2+‐ascorbate. The activities decreased in the order α‐>β‐>γ‐>δ‐tocopherol>tocol, in agreement with their potencies in vivo. The water‐soluble analog was the least effective. Activity depended on the molar ratio of antioxidant to unsaturated lipid, with one molecule each of the α‐, β‐, γ‐, δ‐tocopherol and tocol capable of protecting, respectively, 220, 120, 100, 30 and 20 molecules of polyunsaturated fatty acid. The mechanism of possible antioxidant effect of the compounds used is discussed.
Synthesis of Δ5,22‐cholestadien‐3β‐ol from Δ5,7,22‐cholestatrien‐3β‐ol by a liver enzyme
Authors: Koroly Mary J. , Dempsey Mary E.
Published: December 2006

The rat liver enzyme system, which catalyzes reduction of Δ5,7,24‐cholestatrien‐3β‐ol to cholesterol (Δ5‐cholesten‐3β‐ol), converted radiolabeled Δ5,7,22‐cholestatrien‐3β‐ol to Δ5,22‐cholestadien‐3β‐ol, but not to cholesterol. This enzyme system thus contains membrane‐bound Δ7 and Δ24‐reductases and no Δ22‐reductase. Kinetic and competition studies showed that the enzymes system contains a single Δ5,7‐sterol Δ7‐reductase, which is not influenced by unsaturtion at the Δ22‐position of the sterol side chain. The identity of Δ5,22‐cholestadienol was established by chromatographic, spectral and chemical analyses. Use of the enzyme system and readily available Δ5,7,22‐cholestatrienol provides a facile procedure for specific production of Δ5,22‐cholestradien‐3β‐ol in quantity.
High pressure liquid chromatographic separation of molecular species of phosphatidic acid dimethyl esters derived from phosphatidylcholine
Authors: Hsieh John Y‐K. , Welch David K. , Turcotte Joseph G.
Published: December 2006

A majority of the individual molecular species of phosphatidic acid dimethyl esters derived from multispecies egg yolk and soybean phosphatidylcholines have been separated by reverse‐phase high pressure liquid chromatography. Two Partisil‐10 ODS columns connected in tandem and the eluents acetonitrile or methanol/water (95∶5) were used for molecular species resolution, based on total fatty acyl carbon number and degree of unsaturation.
Occurrence of 3‐keto triterpenes in the unsaponifiable matter of sal (Shorea robusta) seed fat
Authors: Kolhe J. N. , Bhaskar Anil , Bringi N. V.
Published: December 2006

The unsaponifiable matter from sal (Shorea robusta) seed fat contains, in addition to the usual sterols and triterpenes, 12% of another fraction mainly consisting of 3‐keto triterpenes. The major constituents of the keto triterpene fraction have been identified as β‐amyrenone, cycloartenone and lupenone. The structural assignments were based on physical and spectral characteristics (infrared,1H‐ and13C‐nuclear magnetic resonance, and gas chromatography‐mass spectroscopy) of the alcohol acetates obtained by reduction, acetylation and fractionation of individual components by argentation thin layer chromatography. This appears to be the first recorded instance of the occurrence of 3‐keto triterpenes in vegetable fats.
Composition and biosynthesis of sterols in selected marine phytoplankton
Authors: Lin Don S. , Ilias Ajmal M. , Connor William E. , Caldwell Richard S. , Therese Cory H. , Doyle Daves G.
Published: December 2006

Six species of phytoplankton,Pseudoisochrysis paradoxa, Isochrysis galbana, Monochrysis lutheri, Platymonas suecica, Thalassiosira fluviatilis and aChaetoceros species, were cultured in the laboratory and their sterol contents analyzed utilizing digitonin precipitation, thin layer and gas chromatography and gas chromatography‐mass spectrometry. A total of 7 sterols were found in phytoplankton. The occurrence of these sterols, cholest‐5‐en‐3β‐ol, cholest‐5,22‐dien‐3β‐ol, 24‐methylcholesta‐5,24(28)‐dien‐3β‐ol, 24‐methylcholest‐5‐en‐3β‐ol, 24‐methylcholesta‐5,22‐dien‐3β‐ol, 24‐ethylcholest‐5‐en‐3β‐ol and 24‐ethylcholest‐5,22‐dien‐3β‐ol, differed significantly among the various phytoplankton species. Cultures ofP. paradoxa biosynthesized both of the sterols found in this species when incubated in the presence of14C‐ or3H‐mevalonic acid for 0.5–9 days. These sterols were cholesterol and 24‐methylcholesta‐5,22‐dien‐3β‐ol. Since 5 of the sterols found in the phytoplankton commonly occur in mollusks which feed on phytoplankton, it is likely that at least some of the tissue sterols in mollusks are of dietary origin.
Quantitative measurement of prostaglandins E2 and E3 by selected ion monitoring
Authors: Ferretti Aldo , Flanagan Vincent P. , Roman John M.
Published: December 2006

A method for the simultaneous quantative analysis of prostaglandin E2 (PGE2) and PGE3 is described. The PG were analyzed by selected ion monitoring as the methyl ester‐TMS ether derivatives of PGB2 and PGB3, respectively. The internal standard for the quantification of both species was [3,3,4,4‐2H4]PGE2. A linear response over the range 0.6–50 ng (1.7–143 pmoles) was demonstrated for PGE3. The chromatographic conditions used (2% SP‐2330 column) afforded nearly baseline separation of the prostaglandins. New standard curves for PGE3 must be developed each time the ion source parameters are changed. In a typical calibration run, the instrumental precision, expressed as coefficient of variation, ranged from 1.1 to 7.2% for PGE2 (3 to 100 ng injected) and from 1.6 to 11.1% for PGE3 (1.5–50 ng injected). The method was applied to the PG analysis of rat renomedullary tissues. The recovery of synthetic PGE2 added to medullary homogenates was 100.5±1.7% (mean±SEM, n=9), and the recovery of PGE3 was 91.3±1.4% (n=9).
Influence of partially hydrogenated vegetable and marine oils on lipid metabolism in rat liver and heart
Authors: Hølmer G. , Høy C. ‐E. , Kirstein D.
Published: December 2006

Partially hydrogenated marine oils containing 18∶1‐, 20∶1‐ and 22∶1‐isomers and partially hydrogenated peanut oil containing 18∶1‐isomers were fed as 24–28 wt % of the diet with or without supplement of linoleic acid. Reference groups were fed peanut, soybean, or rapeseed oils with low or high erucic acid content. Dietary monoene isomers reduced the conversion of linoleic acid into arachidonic acid and the deposition of the latter in liver and heart phosphatidylcholine. This effect was more pronounced for the partially hydrogenated marine oils than for the partially hydrogenated peanut oil. The content oftrans fatty acids in liver phospholipids was similar in groups fed partially hydrogenated fats. The distribution of various phospholipids in heart and liver was unaffected by the dietary fat. The decrease in deposition of arachidonic acid in rats fed partially hydrogenated marine oils was shown in vitro to be a consequence of lower Δ6‐desaturase activity rather than an increase in the peroxisomal β‐oxidation of arachidonic acid. The lower amounts of arachidonic acid deposited may be a result of competition in the Δ6‐desaturation not only from the C22‐and C20‐monoenoic fatty acids originally present in the partially hydrogenated marine oil, but also from C18‐ and C16‐monoenes produced by peroxisomal β‐oxidation of the long‐chain fatty acids.
Fatty acid synthesis in isolated spermatocytes and spermatids of mouse testis
Authors: Grogan W. McLean , Lam James W.
Published: December 2006

In vitro incorporation of [1‐14C] acetate into fatty acids and lipid classes of spermatocytes, round spermatids and condensing spermatids enriched by Staput 1×g sedimentation was measured by thin layer and gas radiochromatography. All three cell fractions showed the full range of de novo synthetase, elongation and desaturase activities necessary for biosynthesis of fatty acids characteristic of mouse testis, but synthesis of fatty acids of >16 carbons declined with progressive stages of differentiation. The magnitudes and patterns of distribution of fatty acid synthesis in the germinal cells were similar to those of whole testis incubated in vitro or injected in vivo with [14C] acetate. On the other hand, complex lipid synthesis was much more variable and incorporation into triacylglycerol was generally much lower in dispersed germinal cells than in whole testis in vitro or in vivo. Cells remained viable throughout the 15‐hr incubation. Thus, isolated germinal cells are fully capable of synthesizing their constituent fatty acids, including the long‐chain polyenoic acids which they accumulate, but the intratubular environment or association with Sertoli cells may be necessary for maintenance of adequate complex lipid synthesis.
Estolide triglycerides ofTrewia nudiflora seed oil
Authors: Madrigal Richard V. , Smith Cecil R.
Published: December 2006

The seed oil ofTrewia nudiflora is known to contain glycerides of α‐kamlolenic (18‐hydroxy‐cis‐9,trans‐11,trans‐13‐octadecatrienoic) acid. We have shown that a large part of these glycerides contain estolides in which the hydroxyl group of α‐kamlolenic acid is esterified to a molecule of another acid, either a hydroxy acid or an ordinary fatty acid. By preparative thin layer chromatography, we isolated a series of tri‐, tetra‐, penta‐ and hexaacyl glycerols. By lipolysis and gas chromatography‐mass spectrometry, we isolated and characterized estolide‐linked fatty acids containing two acid moieties.
Direct estimation of dolichyl phosphate in rat liver by high pressure liquid chromatography
Authors: Chaudhary Nilabh , Freeman David J. , Rip Jack W. , Carroll Kenneth K.
Published: December 2006

A method involving reverse‐phase high pressure liquid chromatography has been developed for determining the concentration of dolichyl phosphate (Dol‐P) in tissues. Individual Dol‐P homologs are resolved and amounts as small as 50 ng can be detected. Rat liver was found to contain 2.4 μg Dol‐P/g wet weight, or ca. 4% of total liver dolichol. In contrast, rat liver microsomes contained 64 ng Dol‐P/mg protein, which is about 40% of total microsomal dolichol. This enrichment in Dol‐P is consistent with the role of microsomes as the major site of Dol‐P‐mediated, glycoprotein biosynthesis in liver
Long‐chain phenols: XX. Synthesis of oxidative degradation products from the methylated component phenols ofAnacardium occidentale and other phenolic lipids: Confirmation of the structure of the parent phenols and of a related material
Authors: Durrani Aziz A. , Cheng sun Goh , Tyman John H. P.
Published: December 2006

A general procedure for the determination of the first double bond position in the side‐chain of a phenolic lipid has been investigated and, in the first place, the phenols of natural cashew nut‐shell liquid (Anacardium occidentale) have been examined. An improved oxidative degradation procedure has been applied consisting of methylation by the phase transfer procedure, hydroxylation with performic acid and oxidation of the mixture of vicinal diols with periodic acid (Malaprade reaction) followed by reduction of the aldehyde fragments with sodium borohydride. The aromatic moieties from the 15∶1, 15∶2 and 15∶3 constituents of cardanol methyl ether, cardol dimethyl ether and dimethyl anacardate were shown to be 8‐(3‐methoxyphenyl)octan‐1‐ol, 8‐(3,5‐dimethoxyphenyl)octan‐1‐ol and 6‐(8‐hydroxyocyl)salicylate methyl ether, respectively. The first two octanols were identical to synthetic materials, thus confirming the 8‐position for the first double bond in the side‐chain of cardanol methyl ether and cardol dimethyl ether constituents. Methyl 6‐(8‐hydroxyoctyl)salicylate relationship in a series of synthetic reference materials of log (retention time) to the methylene chain length. The synthetic acids 8‐(3‐methoxyphenyl)octanoic acid, 8‐(3,5‐dimethoxyphenyl)octanoic acid and 6‐(7‐carboxyheptyl)salicylic acid methyl ether have been obtained pure for the first time and correspond to the oxidation products of the aromatic aldehyde fragments from the Malaprade reaction stage. The unsaturation in peladjauol, 17∶1‐bishomocardanol methyl ether, fromPentaspadon officinalis was confirmed to be at the 8‐position by the identity of the anilides of synthetic 8‐(3‐methoxyphenyl) octanoic acid and of the oxidative degradation product.