bluuebunny/crossref_metadata_2025_split huggingface dataset:
Localization of a marine source of odd chain‐length fatty acids. I. The amphipodPontoporeia femorata (Kröyer)
Authors: Paradis M. , Ackman R. G. 
Published: November 2006

AbstractThe amphipodPontoporeia femorata (Kröyer) contains approximately equal amounts of odd chain length and even chain length fatty acids. Mature males of this species are released into the waters of Jeddore Harbour during winter months as the result of a regular reproductive cycle and become food for smeltOsmerus mordax moving into the harbor in preparation for spring spawning runs, thus accounting for the previously reported unusual fatty acid composition of these smelt. The exceptionally high levels of odd chain length fatty acids inP. femorata occur at all stages of maturity in both sexes of the animal and are found inP. femorata in other locations.
Determination of the specific positions ofcis andtrans double bonds in polyenes
Authors: Privett O. S. , Nickell E. C. 
Published: November 2006

AbstractA method is described for the determination of the positions and geometric configurations of double bonds in polyunsaturated fatty acids. The procedure consists of three steps:
Partial reduction of the double bonds with hydrazine under conditions which give high yields of monoenes.
Isolation of thecis‐ and thetrans‐monoene fractions by thin‐layer chromatography (TLC) directly or in the form of their ozonide derivatives. In the former technique, selective argentation is employed, in the latter, silicic acid adsorption.
Determination of the structure of the monoenes via reductive ozonolysis.
The position of the double bonds is determined from the structures of the monoenes. Since thecis‐monoenes are separated from thetrans‐monoenes the geometric configuration of each double bond is determined.The method also provides a direct determination of the spacings of the internal double bonds and it may be employed for the determination of the structures of mixtures of fatty acids in conjunction with direct ozonolysis procedures. The various ramifications of the method are demonstrated on pure fatty acids and model mixtures thereof.
An electrostatic precipitator for preparative gas‐liquid chromatography
Authors: Borka L. , Privett O. S. 
Published: November 2006

AbstractThe effect of the operating variables of electrostatic precipitators on the recovery and structure of methyl esters and related aerosol forming compounds collected in preparative gas‐liquid chromatography was studied.Aerosol formation was prevented by AC or DC voltages of 5000 to 12000 volts. AC was more effective than DC but caused changes in structure which were detectable by both thin‐layer and gas‐liquid chromatographic methods of analysis.An apparatus of simple construction and operation was designed for the collection of methyl esters and its use demonstrated with several model compounds.
Lipid peroxidation in rat tissue homogenates: Interaction of iron and ascorbic acid as the normal catalytic mechanism
Authors: Barber Albert A. 
Published: November 2006

AbstractIron and ascorbic acid appear to be the normal catalytic components responsible for the lipid peroxidation reaction in aerobically incubated rat tissue homogenates. The amounts of each present in the catalytically‐active fractions of rat liver, brain, testis, and kidney are appropriate to explain the lipid peroxidation reaction measured. Utilization of ascorbic acid as part of the normal catalytic mechanism is indicated by the following: The catalytic activity of the tissue soluble phase occurs only in the small molecule fraction eluted from Sephadex, and ascorbic acid occurs only in this fraction; the extent of catalysis by the small molecule fractions of the soluble phases from several tissues is proportional to their ascorbic acid content; and pH effect on lipid peroxidation is the same for both soluble‐phase and ascorbic acid catalysis. Utilization of iron as part of the normal catalytic mechanism is indicated by EDTA inhibition studies and by measurements of pH effects. Previous studies have demonstrated the lack of catalytic activity by cations other than iron for the lipid peroxidation reaction in homogenates. Lipid peroxidation is inhibited at high tissue concentration and the inhibition is due to components occurring in the large molecule fraction of the soluble phase.
Glyceryl ethers in insects: Biosynthesis of ethanolamine phosphoglycerides containing alkyl and alk‐1‐enyl glyceryl ether linkages
Authors: Lambremont Edward N. 
Published: November 2006

AbstractWhen14C‐labeled acetate, fatty acids or fatty alcohols were injected into or fed to the tobacco budworm, acyl, alkyl and alk‐1‐enyl moieties of the phospholipids incorporated radioactivity. Fatty acids were the principal precursor in acyl bond formation and fatty alcohols in the synthesis of alkyl and alk‐1‐enyl glyceryl ethers. Detailed analysis of the etherlinked phosphoglycerides revealed that most of the radioactivity was in the ethanolamine phosphoglycerides, and very little14C was found in the choline phosphoglycerides. In experiments of a short duration, the alkyl glyceryl ethers incorporated more radioactivity than the alk‐1‐enyl glyceryl ethers. The reverse was found with long term experiments, when the alk‐1‐enyl ethers had higher radioactivity. In addition to demonstrating the synthesis of ether‐linked ethanolamine phosphoglycerides, the data suggested that fatty alcohols and acids were interconverted by insects and that the alk‐1‐enyl ethers were derived from the alkyl ethers.
Ratio of in vivo incorporation of3H arachidonic acid and14C linoleic acid into liver lipids from normal and diabetic rats
Authors: Mercuri Osvaldo , De Tomas Maria Elena 
Published: November 2006

AbstractNormal and streptozotocin diabetic rats were injected via the portal vein with a labeled solution containing3H arachidonic acid and14C linoleic acid (3H/14C ratio, 0.5) during a 1 min period. Livers were quickly frozen, pulverized, and the lipids extracted and fractioned by thin layer chromatography. The incorporation of3H and14C into liver lipids was measured and the percentage distribution of radioactivity into the different lipid fractions was determined. The incorporation of14C linoleic acid and3H arachidonic acid into liver lipids is apparently reduced in rats with severe diabetes. The higher3H/14C ratio found in the 1,2 diglycerides from diabetic rats may be explained by the apparently smaller incorporation of14C linoleic acid or by an isotopic dilution attributable to the great availability of this acid in diabetic rats. On the other hand, the higher3H/14C ratio observed in triglycerides and phospholipids from diabetic rats, due to a relatively large incorporation of3H arachidonic acid into this fraction, may be explained by the affinity of the enzymes involved in their synthesis for some 1,2‐diglyceride units. Insulin was unable to correct the changes observed in the diabetic rats.
Inhibition of hepatic sterol and squalene biosynthesis in rats fed di‐2‐ethylhexyl phthalate
Authors: Bell Frank P. 
Published: November 2006

AbstractDi‐2‐ethylhexyl phthalate (DEHP), a commonly used plasticizer, was found to be an inhibitor of the biosynthesis of hepatic nonsaponifiable lipids in the rat. The addition of DEHP at levels of 0.5% or 1.0% to a stock diet of rats resulted in a decreased conversion of acetate‐1‐14C and mevalonate‐5‐3H into squalene, C30 sterols, and C27 sterols by liver minces or slices, in vitro. In studies conducted with 0.5% DEHP feeding from 2 to 11 days, the degree of inhibition was found to increase with the duration of DEHP feeding; the inhibition of3H‐mevalonate conversion to squalene and sterols developed more slowly, being reduced to ca. 70% of control values in 11 days, whereas14C‐acetate conversion was reduced to ca. 35% of control values during the same period.3H‐mevalonate conversion to sterols and squalene was, however, found to be suppressable to the same extent as14C‐acetate conversion when diets containing 1.0% DEHP were fed for 18 days. The inhibitory effect of dietary DEHP on sterol and squalene biosynthesis from14C‐acetate and3H‐mevalonate by rat liver preparations is unlikely to be accounted for by the negative feedback of cholesterol secondary to hepatic sterol accumulation since, in these studies, hepatic total lipid and hepatic total sterol levels were simialr in control and DEHP‐fed rats.
Long chain fatty acid methyl ester hydrolase activity in mammalian cells
Authors: Spector Arthur A. , Soboroff Janice M. 
Published: November 2006

AbstractLong chain fatty acid methyl esters were hydrolyzed by cell free homogenates and subcellular fractions prepared from Ehrlich ascites tumor cells. The highest enzyme specific activity was observed in the microsomal fraction. Maximum hydrolase activity occurred in the pH range of 6.5–7.0. The relative activities for the methyl ester substrates that we tested were: methyl palmitate > methyl laurate > methyl oleate > methyl stea‐rate. Butyl palmitate also was hydrolyzed by this enzyme. Enzymatic activity increased when the methyl ester‐albumin complex concentration or the methyl ester‐albumin molar ratio was raised. In addition to Ehrlich cells, methyl ester hydrolase activity was observed in homogenates of rat heart and liver. The highest enzyme specific activities also occurred in the microsomal fractions prepared from these tissues.
Hydroperoxides from oxidation of linoleic and linolenic acids by soybean lipoxygenase: Proof of thetrans‐11 double bond
Authors: Gardner H. W. , Weisleder D. 
Published: November 2006

AbstractHydroperoxides produced by oxidation of linoleic and linolenic acids with soybean lipoxygenase were analyzed by nuclear magnetic resonance. The isomerized double bond α,β to the hydro‐peroxide group at carbon‐13 was determined to betrans. The complete structures of the major products proved to be 13‐hydroperoxy‐cis‐9,trans‐11‐octa‐decadienoic acid from linoleic acid and 13‐hydroperoxy‐cis‐9,trans‐11,cis‐15‐octadecatrienoic acid from linolenic acid. The configuration of the double bonds indicates that oxidation took place through a free radical mechanism as proposed previously by others.
Subfractionation of Sf 4–105, Sf 4–20 and high density lipoproteins
Authors: Lindgren F. T. , Jensen L. C. , Wills R. D. , Stevens G. R. 
Published: November 2006

AbstractSubfractionation of the total low density Sf 4–105, the low density Sf 4–20 and high density plasma (or serum) lipoproteins has been accomplished using a cumulative flotation rate procedure. Fractionation employs nonlinear salt gradients and high performance swinging bucket rotors. Subfractionation of the total low density lipoproteins with minimal contamination allows and extremely accurate lipoprotein mass measurement of Sf > 400, total very low density lipoproteins and low density lipoproteins (LDL) by elemented CHN analysis. Physical and chemical data on LDL and high density lipoprotein (HDL) subfractions are in general agreement with earlier data. Lower molecular weight data are obtained for HDL subfractions than reported earlier; however this may be the result of the different fractionation procedures used.
Long term human studies on the lipid effects of oral calcium
Authors: Bierenbaum Marvin L. , Fleischman Alan I. , Raichelson Robert I. 
Published: November 2006

AbstractIngestion of 2 g of supplemental dietary calcium carbonate daily over a period of one year by eight hyperlipemic men and two hyperlipemic women caused a significant 25% decrease in serum cholesterol, after these subjects had shown stable levels for the previous year, and when compared to a group without therapy. Body weights for both groups remained stable throughout the period of observation. The experimental group also showed a reversal in the cholesterol‐phospholipid ratio from a preexperimental ratio of 1.04 to a ratio of 0.92. In addition there was a 113 mg per 100 ml decrease in serum triglycerides and a 48 mg per 100 ml decrease in serum phospholipids, but these were not statistically significant due to the large between individual variations and the limited sample size. Calcium carbonate should be considered as a potential agent for usage in long term studies designed to produce hypolipemia, since it appears to be effective and without significant side effects.
Lipid composition of further purified bovine liver nuclear membranes
Authors: Keenan T. W. , Berezney Ronald , Crane F. L. 
Published: November 2006

AbstractThe lipid content, distribution and fatty acid composition of highly purified bovine liver nuclear membranes was determined and compared to those of microsomes prepared in parallel. Contrasted with microsomes, nuclear membranes while containing nearly the same levels of lipid had more cholesterol and total neutral lipid and less phospholipid. Phospholipid and neutral lipid patterns generally were similar for the two types of membranes. The same fatty acids, in similar proportions, were observed in respective total lipid, total polar lipid, phosphatidyl choline and phosphatidyl ethanolamine fractions of the two membrane types. The microsomal lipid fractions contained slightly greater percentages of unsaturated fatty acids. With respect to previous results from preparations contaminated with nonmenbranous nuclear material, purified fractions contained more total lipid on a protein basis and more total unsaturated fatty acids. Only minor differences in levels and distribution of phospholipids and neutral lipids were observed between the crude and highly purified fractions.
Stereospecific analysis of triglycerides fromMonnina emarginata seed oil
Authors: Phillips B. E. , Smith C. R. 
Published: November 2006

AbstractInMonnina emarginata seed oil triglycerides, more than two‐thirds of theS‐coriolic (13l‐hydroxy‐cis‐9,trans‐11‐octadecadienoic) acid occurs in position 3 (relative tosn‐glycerol). All but a trace of the remainder is in position 1.
Some monomethyl‐branched fatty acids from ruminant fats: Open‐tubular GLC separations and indications of substitution on even‐numbered carbon
Authors: Ackman R. G. , Hooper S. N. , Hansen R. P. 
Published: November 2006

AbstractIsomeric methyl esters of fatty acids in three groups (C15, C17, C19) have been isolated from ruminant fats. Basic structural analysis by physiochemical techniques indicated that these odd‐numbered fatty acids were even chain with a single methyl branch on the chain. High resolution open‐tubular gas liquid chromatographic studies indicate that, with the exception of iso acid impurities in these fractions, only even‐numbered carbons of the fatty acid chains bear the methyl branch.
Lipid composition of rat superior cervical ganglion
Authors: Organisciak D. T. , Klingman J. D. 
Published: November 2006

AbstractExcised rat superior cervical ganglion were incubated in Krebs‐Ringer solution, freeze‐dried, and lipids extracted with chloroform: methanol (2∶1) v/v. Chromatography of lipid extracts in three separate thin layer chromatography solvents was accomplished on a single thin layer chromatography plate coated with acid‐washed Silica Gel H. Individual lipids were eluted from the silica gel using a modified Swinny filter holder technique and transesterified with methanolic‐BF3. Fatty acid methyl esters were separated and quantitated by gas liquid chromatography, while phospholipids were determined with a Malachite green dye organic phosphorus assay. Quantitation of neutral lipids was accomplished with a micro Liebermann‐Burchard technique and sphingolipids estimated colorimetrically as free sphingosine. The composition of lipids from freezedried rat ganglia resembles the lipid composition of rat brain. Phosphatidylcholine and phosphatidylethanolamine represent 76% of the glycerolphosphatides. The sphingolipids were comprised primarily of sphingomyelin with moderate levels of cerebroside and sulfatide. Cholesterol was the predominant neutral lipid. The major phospholipid fatty acids included palmitic, stearic, and oleic acids.
Effects of different culture media and oxygen upon lipids ofEscherichia coli K‐12
Authors: Naccarato William F. , Gilbertson John R. , Gelman Rose A. 
Published: November 2006

AbstractThe effects of altering the chemical composition of the culture media and the oxygen content of the environment upon the lipid metabolism ofEscherichia coli K‐12 were investigated. WhenE. coli cells were grown on the same culture medium but under aerobic and anaerobic conditions, an increase in the free fatty acids of anaerobically grown cells was observed with a disproportionate increase in the unsaturated fatty acids. When glucose was the sole carbon source, both fatty alcohols and hydrocarbons were detected as component lipids of these cells, whether growth occurred under aerobic or anaerobic conditions. Based upon this observation, acetate is considered the initial precursor for fatty alcohol and hydrocarbon biosynthesis. A possible metabolic pathway involving fatty alcohols in hydrocarbon synthesis has been postulated.
Preparation of fatty acid methyl esters from triglycerides on thin layer plates
Authors: Saha S. , Dutta J. 
Published: November 2006

AbstractA simple and convenient procedure for the preparation of methyl esters from triglycerides with potassium methoxide (KOMe) as catalyst on thin layer chromatoplates has been described. The triglyceride was separated and the reaction was carried out on a thin layer chromatoplate without extraction of triglyceride. A final extraction with CS2 was sufficient for injection of the product into a gaschromatograph. The method has been tested with coconut, peanut, and watermelon seed oils. The method is applicable to 10–20 mg of oil sample and is rapid.
Synthesis of conjugated trienoic fatty acids by a cell‐free preparation of tung endosperm
Authors: Jacks T. J. , Yatsu L. Y. 
Published: November 2006

AbstractAn acetone‐insoluble fraction that catalyzes the synthesis of conjugated trienoic fatty acid was prepared from maturing tung nuts. Greatest synthesis with the enzymic fraction occurred in the presence of CoASH, NADH and either ATP or ADP.
Effect of dietary linolenic acid and docosahexaenoic acid on growth and fatty acid composition of rainbow trout (Salmo gairdneri)
Authors: Yu T. C. , Sinnhuber R. O. 
Published: November 2006

AbstractMethyl linolenate 18∶3ω3 and docosahexaenoate 22∶6ω3 were incorporated in semipurified diets at several levels and fed to trout previously maintained on a fat‐free diet. After 14 weeks, the weight gain and feed conversion of the fish on each diet were determined. The fatty acid composition of the lipid from each group of fish was analyzed by gas liquid chromatography. Both 18∶3ω3 and 22∶6ω3 fed at the 1% level supported maximum growth of the fish. The control group, which were fed no ω3 fatty acids, exhibited a shock syndrome, poor appetite and a very slow growth rate. Tissue fatty acid analysis revealed eicosatrienoic acid 20∶3ω9 accumulated in the phospholipid fraction of this group. The 20∶3ω9 level was lowered when either 18∶3ω3 or 22∶6ω3 was included in the diet. Analysis showed that the dietary 18∶3ω3 was rapidly converted by the fish into 22∶6ω3 with a high concentration in the phospholipid. However 22∶6ω3 fed to the fish remained unchanged and little or no retroconversion of this fatty acid was observed.
The intravenous use of fat for the total parenteral nutrition of the infant
Authors: Coran Arnold G. 
Published: November 2006

AbstractA new program for the total iv feeding of the postoperative neonate has been described and evaluated. The program is based on a crystalline 1‐amino acid solution as the nitrogen source and a soybean fat emulsion as the major source of calories. This program has three main advantages over ones based on hypertonic glucose as the main calorie source: (a) no central venous catheter is needed, (b) the complication of osmotic diuresis is eliminated, and (c) the high caloric value of fat allows small volumes of fluid to be infused into the infant. The present regimen has been shown to sustain nitrogen and potassium retention in amounts similar to those found in normal newborns and in other parenteral feeding programs. In the initial phase of this study, 32 newborns were treated with this program and 26 survived, following surgery for life‐threatening congenital anomalies. Since this first evaluation, over 75 infants have been placed on this iv feeding protocol.
cis andtrans Analysis of fatty esters by gas chromatography: Octadecenoate and octadecadienoate isomers
Authors: Emken E. A. 
Published: November 2006

AbstractA gas chromatographic method has been developed for quantitative determination of thecis andtrans percentages in octadecenoate and octadecodienoate esters. To separatecis‐ andtrans‐monoene and diene isomers on a packed GC column, the fatty esters were stereospecifically epoxipized with peracetic acid. A simple and quantitative epoxidation procedure allows thecis‐ andtrans‐epoxyoctadecanoates to be analyzed without prior isolation from the reaction mixture. No positional or geometric isomerization of the double bond occurred during epoxidation. Synthetic mixtures containingcis‐ andtrans‐6,‐9 and‐12 octadecenoate isomers were completely separated intocis andtrans fractionstrans‐15‐Octadecenoate was the only isomer investigated that partially interfered in the analysis. Diene mixtures containingrans,trans‐, cis,trans‐ andcis,‐cis‐9,12‐octadecadienoates were also successfully analyzed by gas liquid chromatography (GLC) after epoxidation with peracetic acid. Each diene isomer formed two pairs of diepoxy diastereomers, some of which could be separated. Onecis,cis‐diepoxyoctadecanoate diastereomer peak overlapped thecis,trans‐diepoxyoctadecanoate peaks. The totalcis,‐cis‐diepoxyoctadecanoate percentages were calculated by using the ratio of the twocis,cis‐diepoxyoctadecanoate diastereomers. Other positional octadecadienoate isomers were also epoxidized and analyzed by GLC. The large number of possible octadecadienoate isomers requires that some preeiminary fractionation be made before GC analysis is practical for diene isomers.
A comparative study of the lipids of globule membrane and fat core and of the milk serum of cows
Authors: Huang T. C. , Kuksis A. 
Published: November 2006

AbstractNine samples of fresh raw cow's milk were separated into fat globules and milk serum by centrifugation. After destabilization by freezing and thawing, the milk fat globules were resolved into membranes and fat cores. The lipid composition of these structures was compared to that of the surrounding milk serum. Of the total milk fat, 95–98% was in the fat cores, 0.5–1% in the globule membranes and the rest (1.5–4%) in the milk serum. The fat cores contained 88–93% triglyceride, 5.2–9.8% diglyceride, 1.5–7.3% free fatty acid and 0.2–0.4% cholesterol, but no phospholipid. The lipids of the membrane contained 21–44% phospholipid, made up of about equal proportions of phosphatidyl ethanolamine, phosphatidyl choline, and sphingomyelin. The other lipids of the membrane (56–79%) consisted of 83–88% triglyceride, 5.1–10.7% diglyceride, 1–5.1% free fatty acid and 0.4–1.9% cholesterol. The milk serum contained 30–45% phospholipid divided about equally among phosphatidyl ethanolamine, phosphatidyl choline and sphingomyelin. The rest (55–70%) of the milk serum lipids was made up of 71–83% triglycerides, 4.3–10.1% diglycerides, 8.7–15.7% free fatty acids, and 1.2–8.4% cholesterol. Corresponding phospholipid classes of milk serum and globule membranes had identical fatty acid compositions. The triglycerides and diglycerides of the globule membranes possessed increased proportions of palmitic and stearic acids in comparison to the glycerides of the fat cores.