bluuebunny/crossref_metadata_2025_split huggingface dataset:
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

AbstractThe 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

AbstractEssential 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

AbstractAn 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

AbstractAcclimation 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

AbstractA 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

AbstractAmong 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

AbstractAcyl‐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

AbstractPhosphatidylcholine 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

AbstractSterol 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

AbstractA 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

AbstractThe 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

AbstractStudies 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

AbstractA 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

AbstractThe 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

AbstractLong‐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

AbstractIn 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

AbstractIn 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

AbstractDiunsaturated 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

AbstractThe 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.