bluuebunny/crossref_metadata_2025_split huggingface dataset:
Location of double bonds in fatty acids of fish oil and rat testis lipids. Gas chromatography‐mass spectrometry of the oxazoline derivatives
Authors: Yu Q. T. , Liu B. N. , Zhang J. Y. , Huang Z. H. 
Published: November 2006

AbstractA new approach to the derivatization and analysis of long chain polyunsaturated fatty acids is described. The method is based on the formation of 2‐alkenyl‐4,4‐dimethyloxazolines by condensation of the starting material with 2‐amino‐2‐methylpropanol. The derivatization method is rapid, efficient and specific with respect to the chain feature of the parent acids. Volatility, comparable with that of the corresponding simple esters, and improved gas chromatographic separation are achieved without difficulty. The derivatives exhibit clear and regular fragmentation patterns that allow easy discrimination of positional isomers and assignment of double bond location in the chain.
Plasma esterase‐1 (ES‐1) activity is increased in rats fed high‐fat diets
Authors: Van Lith H. A. , Meijer G. W. , Van Zutphen L. F. M. , Beynen A. C. 
Published: November 2006

AbstractThe question addressed is whether the amount and type of dietary fat affects esterases in plasma. Rats were fed semipurified diets containing 2.0 to 19.4% (w/w) of fat in the form of coconut fat or corn oil. Fat was added to the diets at the expense of isocaloric amounts of carbohydrates. Plasma total esterase activities measured with 4‐nitrophenylacetate as substrate were slightly increased with increasing fat intakes. However, an increase in fat concentration of the diet was associated with a pronounced increase in the activity of the so‐called ES‐1 isozyme in plasma. ES‐1, which represents very little plasma total esterase activity, was quantified densitometrically as the high‐mobility, anodal esterase band on polyacrylamide gel electrophoresis. The positive association between amount of dietary fat and ES‐1 activity was identical for coconut fat and corn oil.
Recent advances in the purification, characterization and structure determination of lipases
Authors: Antonian Edna 
Published: November 2006

AbstractRecently, lipases have been purified from mammalian, bacterial, fungal and plant sources by different methodologies. Purified lipases subsequently have been characterized for molecular size, metal binding capabilities, glycoside and phosphorus contents, and substrate specificities. Primary structures of several lipases have been determined either from amino acid or nucleic acid sequences. Lipases sequenced to date share sequence homologies including a significant region, Gly‐X‐Ser‐X‐Gly, that is conserved in all. The Ser residue is suspected to be essential for binding to lipid substrates.
Effect of host sterols on the sterol composition and virulence of a nuclear polyhedrosis virus ofHeliothis zea
Authors: Donald Dorothy L. Mac , Ritter Karla S. 
Published: November 2006

AbstractThe type of sterol in the diet ofHeliothis zea affected not only the sterol composition of the insect larva but also the virulence and/or sterol composition of a single‐nucleocapsid nuclear polyhedrosis virus (HzSNPV). This baculovirus, which was purified by differential and sucrose density gradient centrifugation, had a sterol content of 40 ng per 106 polyhedra. When the sterol composition of HzSNPV was characterized by gas liquid chromatography, reversed phase‐high performance liquid chromatography, mass spectrometry, proton nuclear magnetic resonance spectrometry and/or ultraviolet spectroscopy, the sterols in the virus were similar to those of the host. The HzSNPV isolated from larvae fed Δ5_, Δ0_ or Δ5,7‐sterols contained primarily cholesterol, cholestanol or 7‐dehydrocholesterol, respectively. Changes in the sterol composition of HzSNPV affected its LD50, but not LT50, in larvae containing Δ5‐sterols. The LD50 of virus isolated from larvae containing Δ0_, Δ5_ and Δ7‐sterols decreased from 275,423 to 32,359 to 5,012 polyhedra/larva, respectively. The latter virus was also more virulent than the one that was isolated from larvae containing Δ5,7‐sterol and had an LD50 of 58,884 polyhedra/larva. In contrast, the LD50 of an HzSNPV (Sandoz, Inc.) containing Δ5‐sterol was not affected by the presence of Δ5_, Δ0_ or Δ5,7‐sterols in the tissues of the host (1,413; 1,288 and 355 polyhedra/larva, respectively). The results of this study indicate that the sterol composition ofH. zea can affect the sterol composition of HzSNPV and therefore may affect the ability of this biological control agent to control its economically important insect host.
Lipid composition of normal male rat islets
Authors: Díaz Graciela B. , Cortizo Ana Maria , Garciía María Elisa , Gagliardino Juan José 
Published: November 2006

AbstractLipid composition was studied in fresh isolated isolets from normal male rats. Extractable lipids represent 1856 μg per mg islet protein. In such extracts, phospholipids and neutral lipids reprsent 13.5% and 86.5%, respectively. Phosphatidylcholine (45.8%) and phosphatidyl‐ethanolamine (20.6%) were the major components of the phospholipid fraction, and phosphatidylinositol (8.9%) was the minor component. Esterified cholesterol (38.5%), cholesterol (25.5%) and free fatty acids (24.4%) were the major components of the neutral lipid fraction. Fatty major components of the neutral lipid fraction. Fatty acids esterified to phospholipids account for 619.7 pmol/islet, and, 2710 pmol/islet were esterified to neutral lipids. In the phospholipid fraction, saturated and unsaturated fatty acids were in a similar proportion. Conversely, in the neutral lipids, two‐thirds of the fatty acids were unsaturated. The ω6 family was the main component of the phospholipid unsaturated fatty acids. In the ω6 and ω3 families, the long‐chain fatty acids represent the main components. In the neutral lipid fraction, a different percentage of each family was found: ω3>ω6>ω9. The long‐chain polyunsaturated fatty acids were also predominant species in the ω6 and ω3 families. Further studies on the lipid composition of islets, obtained from rats with normal and altered islet functions, could provide new insights into the knowledge of the mechanism of insulin secretion.
New oxidation products of 2,2,5,7,8‐pentamethyl‐6‐chromanol
Authors: Suarna Cacang , Sumarno  , Nelson Derek , Southwell‐Keely Peter T. 
Published: November 2006

AbstractOxidation of the α‐tocopherol model compound 2,2,5,7,8‐pentamethyl‐6‐chromanol (1) byt‐butyl hydroperoxide in chloroform, to which an alcohol has been added, produces 5‐alkoxymethyl‐2,2,7,8‐tetramethyl‐6‐chromanol as the major product. In the present study,1 was oxidized byt‐butyl hydroperoxide in water‐saturated chloroform to determine whether water would influence product formation in the same way as alcohols.In addition to the usual products of oxidation such as 2‐(3‐hydroxy‐3‐methylbutyl)‐3,5,6‐trimethyl‐1,4‐benzoquinone (9), 5‐formyl‐2,2,7,8‐tetramethyl‐6‐chromanol (11), the spirodimer and spirotrimer of1, three new products have been identified−2,2,7,8‐tetramethyl‐5‐(2,2,5,7,8‐pentamethyl‐6‐chromanoxy)methyl‐6‐chromanol (4), 5‐hydroxymethyl‐2,2,7,8‐tetramethyl‐6‐chromanol (5) and 3‐hydroxymethyl‐2‐(3‐hydroxy‐3‐methylbutyl)‐5,6‐dimethyl‐1,4‐benzoquinone (7).
Molecular species of mycolic acid subclasses in eight strains ofMycobacterium smegmatis
Authors: Baba T. , Kaneda K. , Kusunose E. , Kusunose M. , Yano I. 
Published: November 2006

AbstractThin layer chromatographic and gas chromatographic separation and mass spectrometric identification of mycolic acid subclasses and molecular species from eight strains ofMycobacterium smegmatis were established. Two major adjacent spots and a lower minor one were detected on silica gel thin layer chromatograms of methyl esters. The most abundant subclass showing the highest Rf value on TLC was that of α‐mycolic acids (M1), the second was that of α′‐mycolic acids (M1′) a shorter homologue than α‐mycolates, and the third was the hydroxy mycolic acids (M4) derived from epoxy mycolic acids. They were identified by gas chromatography‐mass spectrometry as their trimethylsilylether derivatives. α′‐Mycolic acids were monoenoic acids ranging from C60 to C66 and possessing an α‐unit of C24∶0. Such profiles of α′‐mycolic acids were common in eight strains. α‐Mycolates were dienoic acids ranging from C75 to C79 and possessing an α‐unit of C24∶0. In most strains, the major molecular species of α‐mycolates were odd‐carbon‐numbered, centering at C77 and C79, possessing a methyl branch in the even‐carbon‐numbered straight chain. The average carbon number of α‐mycolates, from seven strains examined, was about 78, but that of the Takeo strain was 76.3. The profiles of epoxy mycolic acid molecular species composition from eight strains ranging from C75 to C81 were very similar to their M1 subclass profiles.
Fatty acids as biological markers for bacterial symbionts in sponges
Authors: Gillan Francis T. , Stoilov Ivan L. , Thompson Janice E. , Hogg Ronald W. , Wilkinson Clive R. , Djerassi Carl 
Published: November 2006

AbstractAnalyses of fatty acids with carbon numbers between C12 and C22 are reported for five Great Barrier Reef sponges. These analyses indicate that phototrophic cyanobacterial symbionts (blue‐green algae) present in three of the sponges are chemically distinct, whereas the other two sponges do not contain cyanobacterial symbionts. All the sponges contain other, nonphototrophic bacteria. The fatty acid analyses indicate that the nonphototrophic bacterial populations present in the different sponges are distinct in both their chemical compositions and their abundances. Nonphototrophic bacteria are estimated to account for between 60 and 350 μg/g (extractable fatty acids:tissue wet weight), whereas cyanobacteria account for between 10 and 910 μg/g. One sponge (Pseudaxinyssa sp.) contains a relatively large amount of the isoprenoid acid, 4,8,12‐trimethyltridecanoic acid; this acid is presumed to be derived from phytol, a degradation product of chlorophyll. This sponge also contains relatively large amounts of the nonmethylene interrupted fatty acid, octadeca‐5,9‐dienoic acid. Analyses of interior and cyanobacteria‐rich surface tissues of this sponge indicate that these two acids are probably not associated with the symbiotic cyanobacteria.
Rapid separation of neutral lipids, free fatty acids and polar lipids using prepacked silica sep‐Pak columns
Authors: Hamilton James G. , Comai Karen 
Published: November 2006

AbstractA method is described for the separation of neutral lipid, free fatty acid and polar lipid classes using small (600 mg), prepacked silica Sep‐Pak columns. Combinations of hexane and methyltertiarybutylether were used to progressively elute cholesteryl ester first then triglyceride from the column. After column acidification, fatty acids were eluted followed by cholesterol. Recoveries of these lipids were 96% or greater. Polar lipids were eluted from the column using combinations of methyltertiarybutylether, methanol and ammonium acetate. Phospholipid classes could not be separated completely from each other. Phosphatidylethanolamine and phosphatidylinositol eluted together, whereas the more polar phosphatidylcholine, sphingomyelin and lysophosphatidylcholine were eluted as a second fraction. Recoveries of each phospholipid was greater than 98%.
Separation of neutral lipid, free fatty acid and phospholipid classes by normal phase HPLC
Authors: Hamilton James G. , Comai Karen 
Published: November 2006

AbstractNormal phase high performance liquid chromatography methods are described for the separation of neutral lipid, fatty acid and five phospholipid classes using spectrophotometric detection at 206 nm. Separations were accomplished in less than 10 min for each lipid class. A mobile phase consisting of hexane/methyltertiarybutylether/acetic acid (100∶5∶0.02) proved effective in separating cholesteryl ester and triglyceride with recoveries of 100% for radiolabeled cholesteryl oleate and 98% for radiolabeled triolein. Free fatty acid and cholesterol were separated by two different mobile phases. The first, hexane/methyltertiarybutylether/acetic acid (70∶30∶0.02) effectively separated free fatty acids and cholesterol, but did not separate cholesterol from 1,2‐diglyceride. A mobile phase consisting of hexane/isopropanol/acetic acid (100∶2∶0.02) effectively separated free fatty acid, cholesterol, 1,2‐diglyceride and 1,3‐diglyceride. Recoveries of oleic acid and cholesterol were 100% and 97%, respectively. Five phospholipid classes were separated using methylteriarybutylether/methanol/aqueous ammonium acetate (pH 8.6) (5∶8∶2) as the mobile phase. The recoveries of phosphatidylinositol, phosphatidylethanolamine, phosphatidylcholine, sphingomyelin and lysophosphatidylcholine were each greater than 96%.
Phytophthorols‐novel lipids produced byPhytophthora cactorum
Authors: David Nes W. 
Published: November 2006

AbstractLipid‐phytophthorols are a series of saturated and unsaturated odd chain fatty alcohols (C17–C21) esterified to myristic acid (14∶0) with each possessing two hydroxyl functions in a 1,2‐diol relationship centered toward the ester terminus. They have been identified, and their biosynthetic relationship to other fatty acid and alcohols produced byPhytophthora cactorumhave been determined. Because phytophthorols are crystalline materials and elute in TLC and HPLC with sterols, an architectural function is implied. In the absence of cholesterol, dietary phytophthorol failed to induce reproduction.
Lysophosphatidylcholine accumulation in the ischemic canine heart
Authors: Kinnaird Anne A. A. , Choy Patrick C. , Man Ricky Y. K. 
Published: November 2006

AbstractThe production of cardiac arrhythmias and the elevation of lysophosphatidylcholine level in the ischemic myocardium have been well‐documented in a number of studies. However, the relationship between the production arrhythmias and the elevation of tissue lysophosphatidylcholine level was not reported. In this study, the lysophosphatidylcholine level and the occurrence of cardiac arrhythmias in the ischemic canine heart were monitored. A temporal relationship between the accumulation of lysophosphatidylcholine and the occurrence of arrhythmias was established after five hr of ischemia. A significant elevation of lysophosphatidylcholine was detected at three hr of ischemia without the occurrence of arrhythmias. The results indicate that cardiac arrhythmias did not cause the elevation of lysophosphatidylcholine and if lysophospholipids are causally related to the arrhythmias that a critical level of the lysophospholipid must accumulate in order to elicit electrophysiological alterations.
Subcellular distribution of disaturated phosphatidylcholine in developing rabbit lung
Authors: Oulton M. , Dolphin M. 
Published: November 2006

AbstractTo determine the subcellular distribution of disaturated phosphatidylcholine (DSPC) in lung tissue during perinatal development, fetal rabbits at 24, 26, 28 and 31 (term) days gestation and newborns were studied. Following alveolar lavage, fractions enriched in nuclei‐cellular debris, mitochondria, microsomes, surfactant (lamellar bodies) and cytosol were prepared from the residual tissue homogenate, and their DSPC content was determined. The DSPC content of the unfractionated residual lung tissue homogenate progressively and significantly increased during fetal development, rising from 9.09±0.91 to 17.45±2.88 mg/g dry lung between 24 days gestation, and term. Between 24 and 26 days gestation the overall increase in tissue DSPC was due to a two‐fold increase in the mitochondrial, microsomal and cytosolic pools. Lamellar bodies were first isolable at 26 days gestation. The DSPC content of this fraction increased six‐fold (from 0.10±0.02 to 0.67±0.15 mg/g dry lung) between 26 and 28 days gestation and a further seven‐fold (to 4.63±1.06 mg/g dry lung) by term, accounting for the overall increase in the tissue homogenate value during this time period. By the first postnatal day, microsomal and cytosolic DSPC increased another two‐fold, but no significant change occurred in the other subcellular fractions. Alveolar lavage DSPC progressively increased over the time period studied. While there was no change in the lamellar body DSPC/total PC ratio during fetal development, each of the mitochondrial, microsomal and cytosolic ratios decreased between days 26 and 28 of gestation and then increased at term. Our results indicate that in addition to the pulmonary surfactant, for which DSPC is often used as a marker, other subcellular organelles contain significant DSPC pools that undergo dynamic changes in size during perinatal development.
Differential utilization of long chain fatty acids during triacylglycerol depletion. I. Rat heart after ischemic perfusion
Authors: Cunnane S. C. , Karmazyn M. 
Published: November 2006

AbstractRat hearts were perfused with Krebs‐Henseleit buffer for 90 min according to the Langendorff procedure. Normoxic perfusion for 90 min resulted in minor changes in fatty acid composition and a decrease in residual heart triacylglycerol to 60% of preperfusion values. When the protocol included 30 min of slow perfusion‐induced ischemia, the hearts were observed to be depleted of 89% of their initial triacylglycerol content. The triacylglycerol fatty acid composition (mg %) remained similar after compared to before perfusion except for a 121 mg % increase in stearic acid and a 225 mg % increase in arachidonic acid. The percentage composition of both fatty acids was significantly inversely correlated with the amount of triacylglycerol remaining in the heart after perfusion. Postperfusion, arachidonic acid and stearic acids were present at nearly 1∶1 in the residual heart triacylglycerol, suggesting that a common mechanism may be involved in the selective retention of these fatty acids by the heart.
Fluorescence formation from hydroperoxide of phosphatidylcholine with amino compound
Authors: Iio Toshihiro , Yoden Kazuaki 
Published: November 2006

AbstractThe hydroperoxides of methyl linoleate, 1‐palmitoyl‐2‐linoleoyl‐phosphatidylcholine and trilinolein each produced similar fluorescent substances through reaction with amino compounds after decomposition by heme methyl ester. Fluorescent substances formed from methyl linoleate with 1‐aminopentane revealed characeristic fluorescence peaks on HPLC, while those obtained from 1‐palmitoyl‐2‐linoleoyl‐phosphatidylcholine and trillinolein were not eluted under the same conditions. However, when both of these fluorescent substances were transesterified to methyl ester, the same fluorescence peaks were observed. This result suggests that fluorescent substances formed from oxidized membrane lipids with amino compounds remain attached to phospholipids without being released from their glycerol backbone.
Effects of dietary peanut oil on serum lipoprotein patterns of rats
Authors: Miller Josephine , Worthington R. E. 
Published: November 2006

AbstractOils prepared from two varieties of peanuts and from a hybrid corn having linoleic acid concentrations substantially different from the respective commercial oils were compared with commercial oils for their effects on serum lipids of weanling female rats. In the first experiment, serum lipid patterns appeared to reflect linoleic acid content of the dietary oil. However, with a longer feeding period in the second experiment, serum lipid patterns were determined by the plant source of the dietary oil rather than its linoleic acid content; all peanut oils differed from both corn oils in their physiological effects. Diets containing triglyceride, hydrocarbon and sterol fractions obtained by liquid chromatography of peanut and corn oils were fed to female rats. The data provide no evidence that the hydrocarbon or sterol fractions of peanut oil are responsible for its unusual atherogenicity when fed as the sole fat source or that similar fractions from corn oil are protective against the effects of peanut oil.
Biological effects of fish oils in relation to chronic diseases
Authors: Carroll Kenneth K. 
Published: November 2006

AbstractThe low incidence of cardiovascular disease in Greenland Eskimos appears to be due to their high intake of seal, whale and fish. The lipids of these marine animals lower serum triglyceride and cholesterol levels and help to prevent blood clotting. The latter effect has been related to a change in the balance of prostacyclin and thromboxane as a result of replacing n‐6 polyunsaturated fatty acids in the body by n‐3 polyunsaturated fatty acids present in marine lipids. Dietary fish oils have also been shown to inhibit development of mammary, pancreatic, intestinal and prostatic tumors in experimental animals. This effect may likewise be due to changes in the production of prostaglandins or related compounds. The involvement of prostaglandins and leukotrienes in immune responses has led to studies on the effects of fish oil on various chronic diseases associated with abnormalities of the immune system. Some of these diseases, such as multiple sclerosis and psoriasis, are also relatively uncommon in Eskimos. Preliminary results of these studies are encouraging, but more work is required to assess the usefulness of dietary fish oils in treatment of these diseases. In addition to their apparent therapeutic value, n‐3 fatty acids are considered essential dietary components since they cannot be synthesized in the body and appear necessary for normal vision and probably other body functions.
Comparative study of the blood pressure effects of four different vegetable fats on young, spontaneously hypertensive rats
Authors: Hoffmann P. , Block H. ‐U. , Beitz J. , Taube Ch. , Forster W. , Wortha P. , Singer P. , Naumann E. , Heine H. 
Published: November 2006

AbstractFollowing the suckling period, four groups of male four‐week‐old spontaneously hypertensive rats (SHR) were fed semisynthetic diets with 14% (by weight) of either sunflower seed oil [46% 18∶2(n−6); linoleic acid (LA)‐rich], linseed oil [62.5% 18∶3(n−3)+12.9% 18∶2(n−6); α‐linolenic acid (LNA)‐rich], evening primrose oil [9.2% 18∶3(n−6)+71% 18∶2(n−6); γ‐linolenic acid (LNA)‐rich] or hydrogenated palm kernel fat [1.5% 18∶2(n−6); polyunsaturated fatty acid (PUFA)‐deficient], respectively, up to an age of 18 wk. All diets enriched with PUFA provoked an attenuation of hypertension development. The effect was lowest in the LA‐rich group and highest in the γ‐LNA‐rich group. Differences in fatty acid composition of renal phospholipids between groups reflect the fatty acids present in the respective dietary fats. Renomedullary production of PGF2α was significantly reduced in α‐LNA‐rich and slightly diminished in γ‐LNA‐rich fed rats. Aortic formation of 6‐keto‐PGF1α and TXB2 was increased in animals fed the γ‐LNA‐rich diet. Thus, the attenuation of hypertension development cannot be explained only by changes in prostanoid formation. Other mechanisms possibly involved should be pursued.
Intestinal absorption and fecal excretion of 5,6α‐epoxy‐5α‐cholesta‐3β‐ol by the male wistar rat
Authors: Bascoul J. , Domergue N. , Mourot J. , Debry G. , de Paulet A. Crastes 
Published: November 2006

AbstractThe intestinal absorption of 5,6α‐epoxy‐5α‐cholesta‐3β‐ol, an oxysterol formed by cholesterol autoxidation, has been evaluated in the male Wistar rat. Measurement of the14C/3H ratio in the serum (by the method of Zilversmit and Hugues) and in the feces showed that a large proportion of the epoxide was absorbed. Epoxide clearance from the blood was very rapid, but its excretion in the stool continued for several days, corresponding to the fraction of the epoxide stored in the animal.