bluuebunny/crossref_metadata_2025_split huggingface dataset:
Antioxidant activities of tocopherols on Fe2+‐ascorbate‐induced lipid peroxidation in lecithin liposomes
Authors: Fukuzawa Kenji , Tokumura Akira , Ouchi Setsuhiro , Tsukatani Hiroaki 
Published: December 2006

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

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

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

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

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

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

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

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

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

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

AbstractA general procedure for the determination of the first double bond position in the side‐chain of a phenolic lipid has been investigated and, in the first place, the phenols of natural cashew nut‐shell liquid (Anacardium occidentale) have been examined. An improved oxidative degradation procedure has been applied consisting of methylation by the phase transfer procedure, hydroxylation with performic acid and oxidation of the mixture of vicinal diols with periodic acid (Malaprade reaction) followed by reduction of the aldehyde fragments with sodium borohydride. The aromatic moieties from the 15∶1, 15∶2 and 15∶3 constituents of cardanol methyl ether, cardol dimethyl ether and dimethyl anacardate were shown to be 8‐(3‐methoxyphenyl)octan‐1‐ol, 8‐(3,5‐dimethoxyphenyl)octan‐1‐ol and 6‐(8‐hydroxyocyl)salicylate methyl ether, respectively. The first two octanols were identical to synthetic materials, thus confirming the 8‐position for the first double bond in the side‐chain of cardanol methyl ether and cardol dimethyl ether constituents. Methyl 6‐(8‐hydroxyoctyl)salicylate relationship in a series of synthetic reference materials of log (retention time) to the methylene chain length. The synthetic acids 8‐(3‐methoxyphenyl)octanoic acid, 8‐(3,5‐dimethoxyphenyl)octanoic acid and 6‐(7‐carboxyheptyl)salicylic acid methyl ether have been obtained pure for the first time and correspond to the oxidation products of the aromatic aldehyde fragments from the Malaprade reaction stage. The unsaturation in peladjauol, 17∶1‐bishomocardanol methyl ether, fromPentaspadon officinalis was confirmed to be at the 8‐position by the identity of the anilides of synthetic 8‐(3‐methoxyphenyl) octanoic acid and of the oxidative degradation product.
The effects of fasting and streptozotocin diabetes on the triglyceride lipase activity of rat liver plasma membranes
Authors: Nomura Takahide , Iguchi Akihisa , Matsunaga Hitoshi , Sakamoto Nobuo 
Published: December 2006

AbstractThe activity of hepatic triglyceride lipase (H‐TGL) of plasma membranes isolated from rat liver is shown to be reduced by fasting. Refeeding restores the enzyme activity. The suppressed activity of H‐TGL in streptozotocin diabetic rats is restored by insulin treatment. The behavior of the enzyme activites in both situation coincides with that of plasma insulin levels. The results suggest that the H‐TGL of rat liver plasma membranes is under hormonal regulation by insulin.
Waxes and volatile oils inHypericum ericoides (Guttiferae)
Authors: Cardona M. L. , Marco J. A. , Sendra J. M. , Seoane E. , Ibañez J. Torres 
Published: December 2006

AbstractA wax isolated from an hexane extract ofHypericum ericoides L. was shown to contain only an, aldehydic and an alcoholic fraction. The aldehydic fraction was found to be largelyn‐octacosanal (≈77%), with minor amounts of other linear homologous aldehydes, whereas the alcoholic fraction was almost puren‐octacosanol. From the same hexane extract, a volatile oil was also isolated and studied by combined gas chromatography‐mass spectrometry (GC‐MS). Monoterpene, sesquiterpene and aliphatic straight chain (C8–C11) hydrocarbons, sesquiterpene alcohols and aliphatic long‐chain acids (C8, C9, C10, C11, C12, C14, C16 and C18) were found. Biogenetic relationships are discussed.
Abnormal lipid composition of fat tissue in human mesenteric panniculitis
Authors: Cherayil G. D. , Scaria K. S. , Hensley G. T. , Elliott W. H. 
Published: December 2006

AbstractMesenteric fat tissue obtained at autopsy from 6 patients with mesenteric panniculitis (MP) were found to contain significant amounts of cholesteryl esters (CE). In addition, samples from 3 of these cases were found to contain 0.5–1.3% free cholesterol, 0.9–1.9% free fatty acids (FFA), 0.6–2.5% 1‐alkyl glyceryl ether diesters and small amounts of squalene. Two of these tissues also contained alk‐1‐enyl glyceryl ether diesters. The fatty acid compositions of the CE, FFA, triacylglycerides and glyceryl ether diesters (GEDE) were determined and oleic acid (18∶1) was found to be the major fatty acid. The alkyl group composition of the GEDE consisted essentially of 16∶0 and 18∶0 and 18∶1 carbon atoms in both types of ethers.
Quantitative estimation of C‐24 epimeric sterol mixtures by 220 MHz nuclear magnetic resonance spectroscopy
Authors: Chiu P. ‐L. , Patterson G. W. 
Published: December 2006

AbstractFour pairs of 24‐alkyl epimeric sterols: 24α‐ and 24β‐methylcholesterol; 24α‐ and 24β‐ethylcholesterol; 24α‐ and 24β‐methyl‐5, 22‐E‐cholestadienol; and 24α‐ and 24β‐ethyl‐5, 22‐E‐cholestadienol, were mixed in known proportions (0, 20, 40, 50, 60, 80 and 100% of β‐epimer to α‐epimer). The 220 MHz nuclear magnetic resonance spectra of each of the mixtures were obtained and compared. Areas of these spectra useful in quantitative determinations were identified and discussed.
Seasonal changes in lipid and fatty acid composition of the freshwater mollusk,Diplodom patagonicus
Authors: Pollero R. J. , Brenner R. R. , Gros E. G. 
Published: December 2006

AbstractDiplodom patagonicus is a freshwater bivalve mollusk living in lakes of the patagonian Andes mountains in Argentina. Lipid composition and seasonal changes in the mollusk were studied in the natural habitat. In addition to common nonpolar and polar lipids, small amounts of alk‐1‐enyldiacylglycerol ethers and significant quantities of ceramide aminoethyl phosphonate were present. Total lipid content changed during the year, primarily because of decreased triacylglycerols in winter. The fatty acid composition of the lipids, remarkably different from that of marine bivalves, and even from other fresh water animals, was especially rich in the ω6 fatty acids, linoleic and arachidonic (ca. 25%), and poor in the ω3 acids, 20∶5 and 22∶6. The ω6/ω3 acid ratio was ca. 2, which is very high compared to marine bivalves. The fatty acid composition and the ω6/ω3 acid ratio were constant during the whole year, suggesting a very stable diet, rich in vegetal detritus and poor in diatoms. The influence of environmental temperature fluctuation with season on fatty acid composition also was negible. Modest proportions of 22∶2 nonmethylene‐interrupted (NMI) acids were detected and confirmed by mass spectrometry. It was shown that 20∶2 NMI acids were absent.
Sterol ester hydrolase inFusarium oxysporum
Authors: Madhosingh Clarence , Orr Winson 
Published: December 2006

AbstractTwo electrophoretically different forms of sterol ester hydrolase (EC 3.1.1.13) were obtained from the cytoplasmic extract of the mycelia ofFusarium oxysporum. The entities, estimated at 60,000 (I) and 15,000 (II) molecular weights, were obtained in Sephadex G100 column chromatography of the ammonium sulfate precipitate from the cytoplasmic extract. A third form III, 75,000 MW, was obtained from the culture filtrate. The activity of the enzyme was increased by Triton X‐100 and was not inhibited byp‐chloromercuribenzoate (PCMB), a sulfhydryl reagent. The enzymes I and II were inhibited differentially by NaCl. The optimal activities of forms I, II and III occurred at pH 4.8, pH 8.0 and pH 7.0, respectively. the apparent Km values of 7.7×10−5, 8.3×10−5 and 10.5×10−5, respectively, indicate a similar order of affinity for cholesteryl oleate at pH 7.1. The rate of hydrolysis of cholesteryl esters were in the order: linoleate>oleate>valerate>butyrate > acetate. Cholesteryl benzoate and palmitate were not hydrolyzed. The properties of the microbial enzyme are discussed in relation.
Mitochondrial membrane fatty acid composition in the marmoset monkey following dietary lipid supplementation
Authors: McMurchie Edward J. , Gibson Robert A. , Charnock John S. , McIntosh Graeme H. 
Published: December 2006

AbstractDiets supplemented with high levels of saturated fatty acids derived from sheep kidney (perirenal) fat or unsaturated fatty acids derived from sunflowerseed oil were fed to marmoset monkeys for 22 wk. The effect of such diets on plasma, red blood cell phospholipids, and liver, heart, kidney and brain mitochondrial phospholipid fatty acids was determined. Despite large differences in the level and type of lipid present in the experimental diets, there was little effect on the proportion of saturated to unsaturated fatty acids in the phospholipids of the membranes examined. The diets did, however, alter the proportion of the various classes of polyunsaturated fatty acids in the membrane phospholipids, with the sunflower‐seed oil diet elevating and the sheep kidney fat diet reducing the n−6/n−3 unsaturated fatty acid ratio, relative to a low (mixed fat) reference diet. This change occurred in all membranes except brain, in which only a small response to altered dietary lipid intake was observed. Elevation of dietary linoleic acid led to an increase in membrane linoleic acid and a marked decrease in membrane arachidonic acid, such that the membranes from animals fed the sunflowerseed oil diet exhibited the lowest proportion of arachidonic acid. In this latter respect, the response of the marmoset monkey to dietary lipid supplementation differs markedly from the rat. Our inability to alter significantly membrane lipid saturation/unsaturation supports the notion that a homeostatic mechanism is in some way responsible for buffering membranes from the effects of significant changes in the nature of the dietary lipid intake.
Elongation of (n−9) and (n−7)cis‐monounsaturated and saturated fatty acids in seeds ofsinapis alba
Authors: Mukherjee Kumar D. 
Published: December 2006

AbstractLipids in developing seeds ofSinapis alba contain appreciable proportions of (n−7)octadecenoic (vaccenic) acid besides its (n−9) isomer (oleic acid), whereas the constituent very long chain (>C18) monounsaturated fatty acids of these lipids are overwhelmingly composed of the (n−9) isomers. Cotyledons of developingSinapis alba seed use [1‐14C]acetate, [1‐14C]malonate or [1,3‐14C]malonyl‐CoA for de novo synthesis of palmitic, stearic and oleic acids and for elongation of preformed oleic, vaccenic and stearic acids to their higher (n−9), (n−7) and saturated homologs, respectively. Moreover, elongation of preformed (n−7)palmitoleic acid to vaccenic acid is observed. Stepwise C2‐additions to preformed oleoyl‐CoA by acetyl‐CoA or malonyl‐CoA yielding (n−9)icosenoyl‐CoA, (n−9)docosenoyl‐CoA and (n−9)tetracosenoyl‐CoA are by far the most predominant reactions catalyzed by the elongase system, which seems to have a preference for oleoyl‐CoA over vaccenoyl‐CoA as the primer. The pattern of14C‐labeling of the very long chain fatty acids formed from either acetate or malonate shows a close analogy in the mode of elongation of monounsaturated and saturated fatty acids.
Cholesterol and phospholipid composition of erythroblasts isolated from Mouse Spleen after Rauscher Leukemia virus infection
Authors: Montfoort A. , Boere W. A. M. 
Published: December 2006

AbstractErythroblasts (more than 95% pure) were isolated from MuLV‐R infected mouse spleen. The cholesterol, phospholipid, and fatty acid composition of the diacyl and plasma logen derivatives of the choline and ethanolamine phosphoglycerides of mouse erythroblasts, red blood cells enriched with reticulocytes, and mature erythrocytes have been compared. It was demonstrated that during maturation of the mouse red blood cells, the following relative changes in the lipid composition occur: (a) The cholesterol/phospholipid molar ratio increases from 0.35 to 0.77 (b) The sphingomyelin concentration increases from 3.0 to 12.1 and the phosphatidylserine concentration from 5.3 to 11.2 as percentage of the total phospholipid. (c) Phosphatidylcholine decreases from 52.0 to 46.2% and phosphatidylinositol from 6.7 to 3.1%, respectively. (d) The percentage of linoleic acid in the phosphatidylcholine fraction increases more than two fold and is predominantly found at the 2‐position. However, molecules containing linoleic acid at the 1‐position are found to be more abundant in erythroblasts than in mature erythrocytes. (e) Phosphatidylethanolamine has been found to contain a high percentage of arachidonic acid, which was mainly found at the 2‐position. The percentage of arachidonic acid at the 1‐position increases during maturation, while the percentage at the 2‐position decreses. (f) The plasmalogen derivatives of the choline phosphoglycerides were found to be almost absent in mouse red blood cells (<0.5%), while the ethanolamine plasmalogen phosphoglycerides represented about 8% of the phospholipids.