bluuebunny/crossref_metadata_2025_split huggingface dataset:
Lipid metabolism of the yellow clam,Mesodesma mactroides: 2‐Polyunsaturated fatty acid metabolism
Authors: De Moreno Julia E. A. , Moreno Victor J. , Brenner Rodolfo R. 
Published: December 2006

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

AbstractMyocardial ischemia was produced in the left ventricle of the canine heart by a Harris two‐stage occlusion of the left anterior descending coronary artery. The lipid content in the ischemic myocardium was analyzed and compared with the control tissue. No significant change in total phospholipid and cholesterol was detected. A 2‐fold elevation in the levels of the major lysophospholipids was observed during acute ventricular arrhythmias at 24hr after the onset of ischemia. Such increases were not caused by preferential hydrolysis of phospholipid plasmalogens from the parent phospholipids.