bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of ATP on the microsomal desaturation of unsaturated fatty acids
Authors: Brenner Rodolfo R. , Catala Angel 
Published: November 2006

AbstractThe effect of ATP on the microsomal desaturation of linoleic acid to γ‐linolenic acid was studied in a system in vitro with the following results: (1) preincubation of rat liver microsomes with ATP alone in N2 or in the presence of CoA and Mg++ followed by subsequent incubation with 1‐14C‐linoleic acid plus NADH in O2 resulted in enhancement of 1‐14C‐linoleic acid desaturation when compared with control samples in which no preincubation was performed; (2) the preincubation of the microsomes with ATP, Mg++ and CoA in the presence of 1‐14C‐linoleic acid decreased the desaturation of the labeled acid to γ‐linolenic acid upon subsequent incubation with NADH, as a consequence of incorporation of the acid into the microsomal lipids; (3) the increase of linoleic acid desaturation depended on the ATP concentration during preincubation and followed a sigmoidal curve. It was specific for ATP, and neither GTP, CTP, ADP nor AMP produced a similar effec. However, GTP or CTP could replace ATP as a cofactor in the microsomal desaturation of free linoleic acid to γ‐linolenic, suggesting that directly or indirectly they may activate conversion of the free acid to linoleyl‐CoA; (4) preincubation of microsomes with ATP activated the acylation of CoA. However, this activation showed no quantitative correlation with enhancement of the desaturation reaction; (5) addition of ATP also stimulated conversion of linoleyl‐CoA to γ‐linolenic acid. This enhancement was not related to inhibition of the linoleyl‐CoA hydrolase; (6) however, in spite of these results, preincubation with ATP did not increase the initial velocity of linoleic acid or linoleyl‐CoA desaturation; (7) preincubation of microsomes with ATP also increased the 6‐desaturation of oleic acid and α‐linolenic acid but did not increase the 9‐desaturation of plamitic and stearic acid.
Lipid composition and endogenous respiration of pig heart mitochondria
Authors: Comte J. , Gautheron D. , Peypoux F. , Michel G. 
Published: November 2006

AbstractLipid composition and endogenous respiration of pig heart mitochondria were studied in parallel, since the level of endogenous respiration affects the oxidation of added substrates and therefore the regulation of oxidative phosphorylation; mitochondrial lipids can interfere either as substrates or as partner in the energy conservation mechanism. O2 uptake kinetics were measured in presence of different additives: ATP, ADP, NAD+ and hexokinase + glucose. The lipid composition of pig heart mitochondria was determined by chromatographic and spectrophotometric methods. Total lipids were 90% phospholipids; the main phosphatides were cardiolipin, phosphatidyl choline and phosphatidyl ethanolamine; the two latter were rich in plasmalogens. The main nonpolar lipids were triglycerides and free fatty acids. The fatty acid composition of total lipids, phospholipids, free fatty acids and triglycerides was determined by gas liquid chromatography. Mitochondrial lipids were characterized by a high content of unsaturation.
The synthesis of 1‐14C‐arachidonate and 3‐14C‐docosa‐7,10,13,16‐tetraenoate
Authors: Sprecher Howard 
Published: November 2006

AbstractMethyl 1‐14C‐arachidonate was prepared by coupling 1‐bromotetradeca‐2,5,8‐triyne with 4‐pentyn‐1‐ol to yield nonadeca‐4,7,10,13‐tetrayn‐1‐ol. This compound was reduced with Lindlars catalyst. The resulting alcohol was converted to the mesylate and then to the nitrile which in turn was converted to methyl 1‐14C‐arachidonate by hydrolysis with anhydrous HCl in methanol. The methyl 1‐14C‐arachidonate was reduced to the alcohol with LiA1H4 and converted to the mesylate which in turn was treated with diethyl malonate. Following saponification and decarboxylation 3‐14C‐docosa‐7,10,13,16‐tetraenoic acid was obtained.
Lipid metabolism of acetate‐1‐14C by leukocytes from dogs fed an arteriosclerosis‐inducing diet
Authors: Ehrhart L. A. , Balachandran R. , Butkus A. , Lewis L. A. , Lazzarini Robertson A. 
Published: November 2006

AbstractDogs were maintainedoon a control ration or on a semisynthetic diet, containing 5% cholesterol and 16% hydrogenated coconut oil, known to induce hyperlipemia and arteriosclerosis. Circulating leukocytes isolated from dogs fed the coconut oil containing diet were shown to incorporate 50% more radioactivity into lipids than control leukocytes when incubated with acetate‐1‐14C. This increase, expressed as dpm/mg of leukocyte DNA, was not specific for any particular lipid since the distribution of radioactivity between neutral lipids and phospholipids, as well as among their subfractions, was the same regardless of the diet fed. The labeling patterns observed suggest that leukocyte fatty acid synthesis from acetate occurs predominantly, and perhaps exclusively, by the chain elongation pathway.
The structures of the branched fatty acids in the wax esters of vernix caseosa
Authors: Nicolaides N. 
Published: November 2006

AbstractBy combined gas liquid chromatography‐mass spectrometry a series of monomethyl branched fatty acids was found in the fatty acid moiety of the wax esters of vernix caseosa. The methyl branch occurred on the even C‐atoms of chains ranging from C11 to C17 (some 43 compounds in all). Except for the iso acids and possibly some of the anteiso acids, these could be formed by replacement of malonyl CoA with a molecule of methyl malonyl CoA at the point of the branch. Smaller amounts of fatty acids also were found with two methyl branches occurring on the even C‐atoms of chains ranging from C9 to C15.
Field ionization mass spectrometry of long chain fatty methyl esters
Authors: Rohwedder William K. 
Published: November 2006

AbstractMass spectrometry is particularly useful for identifying lipid materials. One primary factor in the interpretation of mass spectra is the recording of the molecular ion peak giving the molecular weight of the compound. Regrettably many compounds, including hydroxy compounds, do not give significant molecular ion peaks; consequently their identification is difficult. A mass spectrometer equipped with a field ionization source produces a greatly different mass spectrum consisting almost entirely of the molecular ion peak. This new source was used to measure the mass spectra of methyl esters of saturated, unsaturated and hydroxy fatty acids. Saturated esters gave the molecular ion peak almost exclusively; unsaturated esters yielded molecular plus metastable ion peaks; whereas the hydroxy esters had molecular, M‐18, meaastable and fragment ion peaks.
Isomerization of L‐glyceraldehyde to dihydroxyacetone during glyceride synthesis by rat liver microsomes
Authors: Rao G. Ananda , Puleo L. E. , Sorrels M. F. , Reiser Raymond 
Published: November 2006

AbstractL‐glyceraldehyde is converted to phosphatidic acid by the action of rat liver microsomal enzymes and glycerol kinase in the presence of fatty acid, ATP, CoASH and NADH. L‐glycerol 3‐phosphate is not an intermediate in this synthesis since microsomes in the presence of NADH neither reduce L‐glyceraldehyde nor, in the additional presence of glycerol kinase and ATP, convert it to L‐glycerol 3‐phosphate. However dihydroxyacetone is produced when L‐glyceraldehyde is incubated with microsomes. This was shown enzymatically by the subsequent conversion to dihydroxyacetone phosphate which was confirmed by the oxidation of NADH in the presence of glycerol 3‐phosphate dehydrogenase. Isomerization of L‐glyceraldehyde and the synthesis of dihydroxyacetone phosphate may be one of several possible mechanisms in the conversion of the triose to either glucose or glycerideglycerol which has been reported to occur in tissue.
Structural comparison between triglycerides and phospholipids from pig kidney
Authors: Hagen Per‐Otto 
Published: November 2006

AbstractThe compositional specificity of the major diacyl phosphatides, plasmalogens and triglycerides of pig kidney has been determined. The triglycerides have been shown to be esterified predominantly with saturated fatty acids in the 2 position while the phosphatides have predominantly unsaturated fatty acids in this position. Such complete “inversion” of the structure of triglycerides and phospholipids is not normally seen in mammalian tissue and suggests that the synthesis of structural polar lipids involves other steps than the reaction of a diglyceride with CDP‐ethanolamine or CDP‐choline. This marked difference in the fatty acid distribution of the polar lipids and triglycerides of the pig kidney may render this tissue especially suitable for studies on the turnover and synthesis of structural lipids.
Enzymatic conversion of 5α‐cholest‐8(14)‐en‐3β‐ol to 5α‐cholesta‐8, 14‐dien‐3β‐ol
Authors: Lutsky B. N. , Schroepfer G. J. 
Published: November 2006

Abstract[3α‐3H]‐Cholest‐8(14)‐en‐3β‐ol was incubated with a 10,000 x g supernatant fraction of a rat liver homogenate. The enzymatic formation of labeled cholesta‐8, 14‐dien‐3β‐ol was indicated by the results of studies employing column chromatographic and cocrystallization techniques.
2‐Monoglyceride as an aid to the absorption of cholesterol into the thoracic lymph
Authors: Klauda Harry C. , Quackenbush Forrest W. 
Published: November 2006

AbstractAbsorption of radioactive cholesterol given in triolein was nearly three‐fold that of a similar dose given in ethyl oleate or oleic acid. The difference appears to reflect a need for monoglyceride, since addition of 2‐monoolein to ethyl oleate improved cholesterol absorption.
Relative incorporation of acetate and glucose into glycerides ofGlomerella cingulata
Authors: Jack R. Cecil , Harkness S. H. 
Published: November 2006

AbstractCultures of the fungusGlomerella cingulata were pulse‐labeled for 30 min with 1‐14C‐acetate at ages from 2 to 12 days old. The greatest incorporation into triglycerides and phosphoglycerides occurred in the youngest cultures, but more of the radioactive acetate was diverted to the phosphoglycerides than to the triglycerides in these cultures.In another series of experiments the incorporation of 1‐14C‐acetate or 2‐14C‐glucose into the triglycerides and phosphoglycerides of the fungus was investigated at 15‐minute intervals for 1 hr. Hydrolysis of the two classes of glycerides revealed some labeling of glycerol from acetate; but, not surprisingly, acetate was incorporated into the fatty acid moieties to a greater extent than into the glycerol moieties, and there was relatively greater incorporation of 2‐14C‐glucose into glycerol than into fatty acids. Some relationships of these results to the growth and development ofG. cingulata are suggested, and implications relative to control mechanisms are pointed out.
Glyceride structure ofCardamine impatiens L. Seed oil
Authors: Mikolajczak K. L. , Smith C. R. , Wolff I. A. 
Published: November 2006

AbstractA group of unusual triglycerides, in which one of the acyl groups is a vicinal dihydroxy acid with one of the hydroxyl groups acetylated, has been isolated fromCardamine impatiens L. (Cruciferae) seed oil. Hydrolysis of these triglycerides with castor bean lipase facilitated isolation and identification of a mixture of C18, C20, C22, and C24 hydroxy acetoxy fatty acids. Pancreatic lipase hydrolysis data revealed that these monoacetylated dihydroxy acid residues are esterified exclusively with one of the α‐positions of the glycerol moiety. The remaining acyl groups are comprised of ordinary C18 unsaturated acids (which occupy 98% of the β‐position), palmitic acid, and C20, C22, and C24 monoenoic fatty acids.
Tritium and14C counting in tissue samples by using liquid scintillation method
Authors: Parekh C. K. , Eigen E. 
Published: November 2006

AbstractThe combustion method has been modified to increase the recovery of tritiated water after combustion of a tritium‐labeled tissue sample. This was accomplished by cooling the bottom of the combustion flask in a dry ice‐acetone bath while irradiating the top with an infrared lamp. The procedure resulted in at least 92% to 102% recovery of the tritiated water. The NCS solubilizer was found to be superior to hyamine for solubilizing14C labeled tissue samples. The samples yielded light yellow‐colored solutions when incubated for 15 hr at 50–55C. The counting efficiency of this solution was 75% or higher.
Sterol metabolism. III. Sterols of marine waters
Authors: Stephen Matthews W. , Smith Leland L. 
Published: November 2006

AbstractThe detection and tentative identification of three sterols, cholesterol, stigmasterol, and β‐sitosterol, in hexane extracts of Gulf of Mexico waters has been achieved by using thin‐layer and gas chromatographic procedures. The identifications are assigned on the basis of chromatographic properties of the free sterols, of their acetates, and of their trimethylsilyl ethers.
The lipids of the common house cricket,Acheta domesticus L. I. Lipid classes and fatty acid distribution
Authors: Hutchins Roderick F. N. , Martin Michael M. 
Published: November 2006

AbstractThe lipids of the common house cricket,Acheta domesticus L., have been examined with the following results. The fatty acids associated with the lipid extracts do not change significantly from the third through the eleventh week of the crickets' postembryonic life. The major fatty acids are linoleic (30–40%), oleic (23–27%), palmitic (24–30%), and stearic acids (7–11%). There are smaller amounts of palmitoleic (3–4%), myristic (∼1%), and linolenic acids (<1%). The fatty acid composition of the cricket lipids reflects but is not identical to the fatty acids of the dietary lipids: linoleic (53%), oleic (24%), palmitic (15%), stearic (3%), myristic (2%), and linolenic acid (2%).The amount of triglycerides present in the crickets increases steadily from the second through the seventh or eighth week of postembryonic life, then drops sharply. Other lipid classes, such as hydrocarbons, simple esters, diglycerides, monoglycerides, sterols, and free fatty acids remain about constant. The composition of the fatty acids associated with the tri‐, di‐, and monoglycerides and the free fatty acid fraction are all about the same. The fatty acids associated with the simple esters are high in stearic acid.
Fatty acid composition ofClaviceps species. Occurrence of (+)‐threo‐9, 10‐dihydroxystearic acid
Authors: Morris L. J. 
Published: November 2006

AbstractThe fatty acids from sclerotia ofC. purpurea and of four otherClaviceps species have been examined chromatographically, and all contain greater or lesser amounts of various oxygenated fatty acids.C. sulcata was the most unusual in that it contained some 60% of (+)‐threo‐9, 10‐dihydroxystearic acid.
Hydrophobic enzymes in hydrocarbon degradation
Authors: Van Der Linden A. C. , Van Ravenswaay Claasen J. C. 
Published: November 2006

AbstractPseudomonas aeruginosa (strain 473) constitutively contains an NADP‐linked alcohol dehydrogenase. This enzyme is believed to function only in assimilative processes, because growth on primary alcohols, α,ω‐diols orn‐alkanes induces another alcohol dehydrogenase which is not linked to a pyridine nucleotide. The inducible enzyme reduces bovine cytochromec and various dyes, but not oxygen. At least two variants of the dissimilative NAD(P)‐independent enzyme can be induced by choosing the substrate used for growth. The main difference between the two variants is their different capacity to oxidize ethanol. A noteworthy property of the inducible enzyme is its hydrophobic character. Some of its consequences in paraffin dissimilation are discussed. The paraffin hydroxylase system of the heptane‐grownPseudomonas was found to hydroxylate various types of hydrocarbons and thus shows a low substrate specificity. On the other hand, remarkable specificities were also encountered; in some cases only thetrans configuration of a substrate was hydroxylated. With respect to the site of hydroxylation, the enzyme system was quite specific, even to the extent that, in appropriate cases, the hydroxyl group was introduced in thetrans‐position only. The results obtained with the enzymatic hydroxylations, including some of the specificities encountered, can be explained by assuming that substrate molecules capable of attaining a planar conformation are bound by hydrophobic forces to the enzyme surface.
Metabolism of alkane by yeast
Authors: Lebeault J. M. , Azoulay E. 
Published: November 2006

AbstractWe demonstrated two NAD+‐linked alcohol dehydrogenases in cell free extracts ofCandida tropicalis grown onn‐tetradecane. Comparative studies of localization, properties and regulation indicate that these enzymes are involved in two different pathways ofn‐alkane metabolism, one cytoplasmic and the other mitochondrial. Kinetic properties, such as the variation of the Km and Vmax as a function of substrate chain length of the soluble NAD+‐linked alcohol dehydrogenase, might involve hydrophobic interactions between the substrate and the enzyme.
Microbial subterminal oxidation of alkanes and alk‐1‐enes
Authors: Allen J. E. , Forney F. W. , Markovetz A. J. 
Published: November 2006

AbstractOxidation ofn‐alkanes and alk‐1‐enes by aPenicillium species andPseudomonas aeruginosa resulted in the formation of intermediates arising from the oxidation of methylene groups. A catabolic pathway involving oxidation of the hydrocarbon to a secondary alcohol and the corresponding ketone, followed by the formation and subsequent cleavage of an ester intermediate is presented.
The effect of undernutrition on the development of myelin in the rat central nervous system
Authors: Fishman Marvin A. , Madyastha Prema , Prensky Arthur L. 
Published: November 2006

AbstractNewborn rats were segregated into litters of 6 and 22 pups. Undernourished groups were maintained for 21 and 53 days at which time a portion of each group was sacrificed and the remainder refed until 121 days. The amount of myelin isolated from the central nervous system was decreased in nutritionally deprived animals but there was little change in its chemical composition or intereference in the normal chemical maturation of the membrane. The only consistent change was a reduction in phosphatidyl ethanolamine plasmalogen. This deficit tended to be corrected by nutritional rehabilitation and was most complete in those animals refed ad lib. diets for the longest time periods prior to sacrifice. The relatively normal chemical composition of myelin obtained from undernourished animals differs from changes described in myelin membranes isolated from patients with destructive or degenerative diseases of the nervous system. This seems to be further evidence that the reduction in myelination in undernutrition is a result of decreased synthesis of the membrane.
Ether‐containing lipids of the slime mold,Physarum polycephalum: I. Characterization and quantification
Authors: Poulos Alfred , Le Stourgeon Wallace M. , Thompson Guy A. 
Published: November 2006

AbstractRapidly growing plasmodia of the acellular slime mold,Physarum polycephalum, contain large amounts of ether‐linked lipids. The ether bonds occur principally in the phospholipids, where plasmalogens account for 21–24 mole per cent of the total and alkyl ether phospholipids comprise 12 mole per cent of the total. Plasmalogens account for over half of the ethanolamine phosphatides, while the alkyl ether derivatives are more uniformly distributed among the various phospholipid fractions. The 16 carbon side chain is by far the major component of both the saturated and the α,β‐unsaturated ether derivatives. The nature and amounts of ether lipids present inPhysarum add to the growing evidence that Myxomycetes are more closely related to protozoa than to fungi.
Effects of su‐13437, a new hypolipidemic drug, upon synthesis in vivo of hepatic and carcass total fatty acids and total cholesterol
Authors: Cenedella Richard J. 
Published: November 2006

AbstractThe present study is directed toward obtaining information on the metabolic effects and on the mode of action of CIBA‐Su‐13437, a new hypolipidemic phenolic ether structurally related to clofibrate. The ability of Su‐13437 to affect the net formation of lipids in vivo was studied by measuring the total incorporation of intraperitoneally injected 1,2‐14C‐sodium acetate and uniformly labeled14C‐glucose into total fatty acids and total cholesterol by the liver and carcass of control and Su‐13437‐treated mice. Treated mice received Su‐13437 orally at 25, 100 or 250 mg/kg/day for 14 or 15 consecutive days. Treatment with Su‐13437 resulted in pronounced enlargement of the liver and significant reductions in the plasma levels of triglycerides and total cholesterol. Essentially all of the observed metabolic effects of Su‐13437 were confined to the liver. At all doses studied, in addition to liver enlargement, there were large increases in incorporation of both14C‐acetate and14C‐glucose carbon into hepatic total fatty acids; marked increases in hepatic total fatty acid content; and decreases in the liver's relative cholesterol content of up to 30% with little or no effect upon the net synthesis of cholesterol per gram of liver. These observations are interpreted as indicating that Su‐13437 lowers plasma triglyceride and cholesterol levels by means other than net inhibition of fatty acid and cholesterol formation by either hepatic or extrahepatic tissues.
Mass spectrometric analysis of long chain alk‐1‐enyl ether esters and alkyl ether esters of diols
Authors: Kramer John K. G. , Baumann Wolfgang J. , Holman Ralph T. 
Published: November 2006

AbstractThe mass spectra of homologous series of long chain alk‐1‐enyl ether esters and alkyl ether esters of short chain diols were determined, and general patterns of fragmentation were established. Both types of diol lipids yielded ions characteristic of the alkoxy or alk‐1‐enyloxy moiety and the acyl moiety, as well as ions indicative of the constituent short chain diol. Prominent ions were formed from both types of ether esters due to the loss of the alkoxy or alk‐1‐enyloxy moieties giving rise to ions for which cyclic structures are proposed. High resolution mass spectrometry and deuterium labeling techniques were used to verify the composition of ions and to substantiate fragmentation mechanisms.
Separation of lipids containing phytanic acid by thin‐layer chromatography
Authors: Karlsson K. ‐A. , Nilsson K. , Pascher I. 
Published: November 2006

AbstractCholesteryl phytanate and triglycerides containing phytanic acid were separated from their normal fatty acid analogs by thin‐layer chromatography. The presence of the branched‐chain fatty acid makes the lipid less polar, and this effect becomes more pronounced as the number of phytanic acid residues in the triglycerides is increased. Phytanic acid was prepared from commercial phytol by catalytic hydrogenation, followed by catalytic oxidation. It contained 5% pristanic acid.
Fatty acids of unusual double‐bond positions and chain lengths found in rat skin surface lipids
Authors: Nicolaides N. , Ansari M. N. A. 
Published: November 2006

AbstractThe fatty acids of rat skin surface lipids comprise four main skeletal types of chains which occur both as saturates and monoenes and range from C12 to C38: straight even, straight odd, iso and anteiso (the latter two identified by GC retention data only). Two unidentified series of branched monoenes also occur in trace amounts.Reductive ozonolysis of monoenes reveals two characteristic double‐bond position patterns, one for the straight even chain series and the other for the straight odd chain series. The straight even chain pattern comprises four series, of which ω7 ≫ω9>ω5>ω11; the straight odd chain series in contrast shows a large number of ω series with irregular distribution. The biosynthesis of the even chain fatty acid monoenes can be thought of as occurring in two stages: synthesis of 14∶Δ9, 16∶Δ9, 18∶Δ9 and 20∶Δ9, with 16∶Δ9 predominating; elongation of these chains mostly by 1, 2, or 3 C2 units but up to the unusually long lengths by 11 C2 units. For the formation of the former, two schemes by known pathways are proposed.Iso and anteiso chains which are nearly all saturated comprised 1/3 the total fatty acids.