bluuebunny/crossref_metadata_2025_split huggingface dataset:
Unique pathways of sterol metabolism in the Mexican bean beetle, a plant‐feeding insect
Authors: Svoboda J. A. , Thompson M. J. , Robbins W. E. , Elden T. C. 
Published: November 2006

AbstractRadiolabeled sterols,14C‐cholesterol,14C‐cholestanol,3H‐stigmasterol,3H‐stigmastanol, and3H‐sitosterol, were fed to larvae of the Mexican bean beetle,Epilachna varivestis Mulsant, by coating soybean leaves. Free sterol and sterol ester fractions from treated insects were isolated and analyzed, and in each case nearly 30% or more of total radiolabeled sterols retained by the insect were found in the sterol ester fraction after 8 days. Δ5 sterols were readily reduced to stanols, and C29‐stanols thus produced were dealkylated to cholestanol. Significant amounts of labeled lathosterol were formed from Δ5‐C29 sterols; little, if any, radiolabeled cholesterol was detected in insects fed either of the labeled Δ5‐phytosterols, stigmasterol or sitosterol. Sterol metabolism of this insect thus differs considerably from that found for most phytophagous insects.
Erucic acid metabolism by rat heart preparations
Authors: Cheng Chak‐ki , Pande Shri V. 
Published: November 2006

AbstractRat heart preparations metabolized erucic acid at much slower rates than palmitic acid. This applied for activation reaction, for the conversion of acyl‐CoA to acylcarnitine, and for the utilization of acyl group for oxidation. As compared to palmityl‐CoA, erucyl‐CoA exhibited a lower affinity for carnitine palmityltransferase (EC 2.3.1 23), the respective apparent Michaelis constants were 43 and 83 μM. Presence of erucyl‐CoA or erucylcarnitine slowed the mitochondrial oxidation of palmityl groups apparently because of the slower oxidation of erucyl groups. However, presence of erucate did not inhibit the activation of palmitate. Heart mitochondria obtained from rats fed rapeseed oil (50 cal %) or corn oil diet for 3 days showed similar abilities for the coupled oxidation of various substrates and similar carnitine palmityltransferase activities. Thus a suggestion of gross mitochondrial malfunction following rapeseed oil consumption was not confirmed.
Optically active trihydroxy acids ofChamaepeuce seed oils
Authors: Mikolajczak K. L. , Smith C. R. 
Published: November 2006

AbstractTwo trihydroxy acids have been isolated fromChamaepeuce afra (Jacq.) DC, seed oil and identified as (+)‐threo‐9,10,18‐trihydroxyoctadecanoic (phloionolic) acid (9%) and (+)‐threo‐9,10‐,18‐trihydroxy‐cis‐12‐octadecenoic acid (14%). The unsaturated acid has not previously been found in nature. Nuclear magnetic resonance, infrared, thin‐layer chromatography, optical rotation, and identification of the oxidative cleavage products show that these two trihydroxy components have the structures indicated.Chamaepeuce hispanica DC. seed oil and the seed oil of an unidentifiedChamaepeuce species apparently contain these same two acids but in different proportions fromC. afra oil.
Phospholipid exchange proteins in rat intestine
Authors: Lutton C. , Zilversmit D. B. 
Published: November 2006

AbstractThe 105,000 g supernatant and pH 5.1 supernatant fractions from rat intestinal homogenates stimulate phosphatidylcholine exchange between [32P] phosphatidylcholine liposomes and beef heart mitochondria. This active fraction shows the characteristics of a protein. Isoelectric focusing of the intestinal pH 5.1 fraction shows two peaks of phosphatidylcholine exchange activity: one at an acidic pH (4.5–5.3), the other in a basic pH range (8–9). The second peak of activity appears to be a new phospholipid exchange protein. The anatomic distribution of phosphatidylcholine exchange activity in intestine has been investigated. Expressed per mg of protein, phosphatidylcholine exchange activity is higher in mucosa than in the intestinal wall. No significant differences have been found between villi and crypts cells or between jejunal and ileal villi. Furthermore, exchange activity per mg of protein in mucosa is unaffected by fasting or by feeding a high fat or high cholesterol diet. This suggests that phospholipid exchange activity in the absorptive cells is not a rate limiting step in the process of fat absorption.
In vitro activity of the fatty acyl desaturases of human cancerous and noncancerous tissues
Authors: Nakazawa Ichiro , Mead James F. , Yonemoto Robert H. 
Published: November 2006

AbstractThe microsomal desaturase activity of human cancerous and noncancerous tissues was measured in vitro using 1‐14C,‐11,14‐eicosadienoic and 1‐14C‐oleic acids as substrates. Tissues used were a case of ovarian cancer, a urinary bladder cancer, a rectal cancer, and a nonspecific colonic ulcer with appropriately normal tissues. When 11,14–20∶2 was used as substrate, radioactive tetraene and triene were produced. The tetraene was identified by radio gas chromatography as arachidonic acid (5,8,11,14–20∶4), and the triene had a retention time of 5,11,14–20∶3. Thus, the possibility arises that a Δ8 desaturase was involved. In the Δ6 desaturase, with the urinary bladder
Regulation of lipid metabolism in in vitro cultured minimal deviation hepatoma 7288C
Authors: Watson John A. 
Published: November 2006

AbstractHepatoma tissue culture (HTC) cells (derived from minimal deviation hepatoma 7288C) were cultivated in a complete medium containing either glucose, fructose or glycerol as the primary carbon source. Growth was rapid on glucose and very low on fructose containing media. Glycerol did not support any growth. Glucose‐14C (U) and fructose‐14C (U) are incorporated into the total lipid fraction of HTC cells. However the level of conversion of glucose into lipid is much greater than fructose. Tritiated water is rapidly incorporated into the saponifiable and nonsaponifiable lipid fractions of growing HTC cells. The level of incorporation is greater than that observed with glucose‐14C (U) and the difference is constant over the experimental period studied. Lipoprotein poor serum (LPPS) isolated from a calf‐fetal calf serum mixture (1∶1) supported growth at a similar rate as the unfractionated serum combination (DS). However the total lipid and total cholesterol content of the fractionated serum was one sixth and one fiftieth the level found in the whole serum mixture, respectively. The level of incorporation of glucose‐14C (U), acetate‐14C (U) and tritiated water into the nonsaponifiable fraction of HTC cells grown on LPPS was 3 to 8‐fold greater than that for DS. However mevalonate‐2‐14C incorporation was stimulated only 1.3 to 1.7‐fold. In general there was a much smaller response in the level of incorporation of radioactive metabolites into the saponifiable lipids. From these studies and additional data, it was tentatively concluded that HTC cells can respond to nutritional pertubations caused by changes in the exogenous lipid content. It was not determined if the apparent responsiveness in the lipids of the nonsaponifiable fraction is due to “feedback control” or some other regulatory mechanism.
Lipids of retina: I. Analysis of gangliosides in beef retina by thin layer chromatography
Authors: Handa Shizuo , Burton Robert Main 
Published: November 2006

AbstractLipids were extracted from beef retina by chloroform‐methanol (2∶1); the gangliosides were removed from the total lipid extract by partitioning into water and chromatographing on thin layer plates coated with silica gel. The analytical methods are described for estimating ganglioside components, i.e., N‐acetyl neuraminic acid, hexoses, hexosamine, sphingosine and fatty acids, in the presence of silica gel. Major gangliosides present in beef retina have been tentatively identified as follows: a ganglioside containing two N‐acetyl neuraminyl groups but no hexosamine; two gangliosides containing two N‐acetyl neuraminyl groups and one hexosamine; and a ganglioside with three N‐acetyl neuraminyl moieties and one hexosamine.
Effect of eicosa‐5,8,11,14‐tetraynoic acid on fatty acid composition of selected organs in the rat
Authors: Coniglio John G. , Buch David , Grogan William M. 
Published: November 2006

AbstractEicosa‐5,8,11,14‐tetraynoic acid or arachidonic acid or no supplement (controls) was given orally to rats maintained on a fat free diet and the fatty acid composition of total lipids of several organs determined. No changes were noted in the total fatty acid concentrations of the organs examined in the various groups. A decrease in the amount of arachidonic acid, 22∶4ω6 and 22∶5ω6 (as percent of total fatty acids), and an increase in the amount of 20∶3ω6 and linoleate were observed in total lipids of several organs. In the group receiving the arachidonate supplement, there was less linoleate and 20∶3ω6 and more arachidonate than in the controls. Both eicosa‐5,8,11,14‐tetraynoic acid and arachidonate supplements resulted in a decrease in 20∶3ω9 in most organs studied. Generally, the most marked changes were seen in liver but, of the other organs examined (heart, kidney, testis, brain, and adrenals), only the adrenals failed to show any significant differences between the controls and each of the two supplemented groups. Although the experimental conditions preclude conclusive interpretation of the changes observed, it is suggested that eicosa‐5,8,11,14‐tetraynoic acid was effective in inhibiting the conversion of linoleate to arachidonate and the conversion of arachidonate to 22∶4 and 22∶5.
Incorporation of choline‐1,2‐14C into molecular species of phosphatidylcholine by alfalfa leaflet tissue
Authors: Willemot C. , Verret G. 
Published: November 2006

AbstractAlfalfa leaflet tissue incorporated choline‐1,2‐14C into at least 6 molecular speies of phosphatidylcholine. After 7 hr incubation the species containing palmitic and linoleic acids (16∶0–18∶2) and the species containing linolenic and linoleic acids (18∶3–18∶2) had the highest specific activities. After 24 hr incubation, the species containing palmitic and linolenic acids (16∶0–18∶3) and the species containing 2 linolenic acids (18∶3–18∶3) had the highest specific activities. The most likely interpretation of these data is that choline is accepted by diglycerides containing one linoleic acid residue and that this residue is then desaturated within the phosphatidylcholine molecule to linolenic acid.
Physiological and analytical variation in cholesterol and triglycerides
Authors: Warnick G. Russell , Albers John J. 
Published: November 2006

AbstractPlasma cholesterol and triglyceride levels were determined, on each of two AutoAnalyzer systems in 11 healthy subjects, weekly over a 10‐week and monthly over a 12‐month period. Analytical variation was 1–2% for cholesterol and 2–5% for triglyceride. Cholesterol and triglyceride values on frozen quality control serum pools were not indicative of absolute values on fresh plasma. Even though the two AutoAnalyzer systems averaged within 1–2 mg/dl for triglyceride and cholesterol on the serum quality control pools during the 12‐month period, the two systems differed by 7–8 mg/dl on fresh or frozen plasma samples. The coefficient of physiological variation on the 10 weekly samples averaged 5% (range 3–10%) for plasma cholesterol and 18% (range 9–27%) for plasma triglyceride. Analysis of the monthly samples suggested significant (P<0.05) seasonal trends: cholesterol was highest in the winter months and lowest in October, whereas triglyceride was highest in January and February and lowest in May and December. We conclude that intra‐individual variation can be an important source of error in attempting to make a genetic diagnosis of hyperlipidemia and/or in evaluating hypolipidemic regimens in a given subject.
Preparation of specifically dideuterated octadecanoates and oxooctadecanoates
Authors: Tulloch A. P. 
Published: November 2006

AbstractSixteen methylgem dideuterooctadecanoates with two deuterium atoms at positions 2‐ to 17‐ and seven oxo esters, 8‐oxooctadecanoate‐5,5‐d2, 8‐oxooctadecanoate‐11,11‐d2, 11‐oxooctadecanoate‐8,8‐d2, 11‐oxooctadecanoate‐14,14‐d2, 12‐oxooctadecanoate‐9,9‐d2, 7‐oxooctadecanoate‐10,10‐d2 and 13‐oxooctadecanoate‐16,16‐d2 with two deuteriums on the carbon γ to the oxo group, have been synthesized. Two principal methods of introducing deuterium were used: preparation of 2,2‐dideutero acids by exchange with deuterium oxide followed by chain extension giving dideuteroxooctadecanoates, which were then reduced, as tosylhydrazones, with sodium cyanoborohydride to dideuterooctadecanoates and stepwise introduction by reduction of oxooctadecanoates with sodium borodeuteride, formation of tosylate or mesylate, reduction with lithium aluminium deuteride to tetradeuterooctadecanol and oxidation to dideuterooctadecanoic acid.
Cardiac lipids in rats and gerbils fed oils containing C22 fatty acids
Authors: Beare‐Rogers J. L. , Nera E. A. , Craig B. M. 
Published: November 2006

AbstractDocosenoic acid from rapeseed oil or herring oil in the diet of the young rat promoted an accumulation of cardiac lipid. The triglyceride fraction accounted for most of the deposited fat and contained a high concentration of the docosenoic acid. Liquid rapeseed oil, partially hydrogenated rapeseed oil or partially hydrogenated herring oil increased the amount of cardiac fatty acids at 1 week and led to the development of degenerative lesions at 16 weeks. Whale or seal oils low in C22 fatty acids produced little effect on the amount of lipids in the heart of rats or gerbils. The latter species receiving 20% rapeseed oil in the diet showed a peak in cardiac lipid deposition at 4 days with similar levels of total fatty acids to that of rats, but with a lower concentration of erucic acid. Oil fromLimnanthes douglasii and hydrogenated herring oil also increased the amount of cardiac fatty acids in gerbils. A high intake of docosenoic acid was common to the animals displaying the cardiac alterations.
Ceramide, triglyceride, and sterol ester in normal human whole brain at different ages
Authors: Rouser George , Yamamoto Akira 
Published: November 2006

AbstractSeparation of ceramides from other lipids by two dimensional thin layer chromatography, characterization of ceramide in human brain lipid extracts, and the levels of ceramide, triglyceride, and sterol ester in human brain at different ages (25 week fetus and postnatal ages of 1 day, 3 weeks, 6, 8 and 22 months, and 6, 8.5, 10, 18, 33, 55 and 98 years) are described.
Characterization of branched monounsaturated hydrocarbons ofSarcina lutea andSarcina flava
Authors: Tornabene T. G. , Markey S. P. 
Published: November 2006

AbstractThe exact position of the double bond and the probable branch assignments of each hydrocarbon isomer ofSarcina lutea andSarcina flava were determined by derivatives and gas chromatography and combined gas chromatography‐mass spectrometry. It was shown by mass spectral data that in all isomers the double bond position was in or near the center of the molecule and, that some of the resolved isomers contained an additional positional isomer. The hydrocarbons were identified as containing methyl branches in the iso or anteiso or both configurations, symmetrically and asymmetrically disposed on the ends of the isomers. The assignment of the methyl branches for each tetrad of four isomers as the isomers emerged from the gas chromatographic column was iso‐iso’; anteiso‐iso; anteiso‐anteiso’; and isonormal for odd carbon‐numbered chains, and iso‐iso’; anteiso‐iso; iso‐normal; and anteiso‐normal for even carbon‐numbered chains. A fifth isomer was identified as a normal‐olefin.
Role of the bases and phosphoryl bases of phospholipids in the autoxidation of methyl linoleate emulsions
Authors: Tsai Lee‐Shin , Smith Lloyd M. 
Published: November 2006

AbstractMethyl linoleate, emulsified in borate buffer with sodium lauryl sulfate, was used to study the pro‐ or antioxidant effect of 0‐phosphocholine, 0‐phosphoethanolamine, 0‐phosphoserine, as well as the corresponding nonphosphoryl compounds. Oxygen uptake was calculated from rate data obtained at 37 C with an oxygen electrode. The results were similar for the corresponding phosphoryl and nonphosphoryl bases. 0‐Phosphocholine and choline had little effect at either pH 7.9 or 10.2. 0‐Phosphoethanolamine and ethanolamine significantly increased oxygen uptake at pH 7.9, but significantly decreased uptake at pH 10.2. 0‐Phosphoserine and serine decreased oxygen uptake at both pH values. The catalytic activities of the bases investigated may be attributed to their functional groups. The phosphoryl and β‐hydroxy groups exhibited no catalytic activity in the autoxidation of methyl linoleate emulsions at either pH 7.9 or 10.2. The α‐carboxyl amino group of 0‐phosphoserine and serine decelerated autoxidation at both pH values. The amino group H3N+ of the primary amine accelerated autoxidation, but the H2N: group and the reverse effect. Since the quaternary amino group (CH3)3N+ did not affect autoxidation at either pH 7.9 or 10.2, we concluded that the presence of the N−H bond may be necessary for the prooxidant activity of an amine, and that the presence of a pair of free electrons on the nitrogen of an amine is necessary for its antioxidant activity. Kinetically, the autoxidation of methyl linoleate emulsion without added base was in agreement with Farmer's proposed mechanism involving a bimolecular dissociation of hydroperoxides. However, methyl linoleate emulsion at pH 7.9 and 37 C in the presence of ethanolamine or 0‐phosphoethanolamine was autoxidized by a mechanism involving a combined mono‐ and bimolecular dissociation of hydroperoxides.
Nutrition and metabolic studies of methyl esters of dimeric fatty acids in the rat
Authors: Hsieh Alexander , Perkins Edward G. 
Published: November 2006

AbstractMethyl esters of dimeric fatty acids were prepared by fractionating a mixture of conjugated linoleic and oleic acids that was heated for 24 hr at 300 C in the absence of air. Rats fed diets containing less than 1% dimers showed no significant difference (P<0.05) in the growth rate, feed efficiency, liver: body weight ratio, and lipid: liver weight ratio from those fed normal diets. A lymph cannulation study using14C labeled dimers showed that ca. 0.4% of the dimers fed were absorbed within 12 hr and were transported as free acids in the lymph. Within a 28 hr period, 2% of the labeled dimers fed by gastric intubation were oxidized to14CO2, and 1% radioactivity was recovered from the urine. The metabolism of methyl oleate appeared normal for rats prefed diets containing dimers.
Possible mechanisms of autoxidative rancidity
Authors: Loury M. 
Published: November 2006

AbstractRancidity appears as a very complex phenomenon if we consider the numerous reaction products that have been identified. Based on gas liquid chromatographic analysis of the aldehydes, alcohols, alkyl formates and hydrocarbons produced by the autoxidation of oleic acid and nonanal, an explanation of some possible reaction pathways is presented. Rancidity is described as a result of a succession of reactions, some of which are free radical in form, initiated by oleic monohydroperoxides. These yield aldehydes that are autoxidizable and also yield, by specific recurrent reactions, the wide variety of products encountered that are offensive in taste and odor.
Effect of subacute toxic levels of dietary cyclopropenoid fatty acids upon membrane function and fatty acid composition in the rat
Authors: Nixon J. E. , Eisele T. A. , Wales J. H. , Sinnhuber R. O. 
Published: November 2006

AbstractThe effect of subacute toxicity levels of dietary cyclopropenoid fatty acids upon several physiological parameters was determined in the rat. Diets containing 2% corn oil, 2%Sterculia foetida oil or 2% hydrogenatedSterculia foetida oil were fed.Sterculia foetida oil (50% cyclopropenoid fatty acids) fed rats exhibited retarded growth, elevated organ to body wt ratios, increased saturation of tissue lipid, and abnormal histopathology when compared to corn oil and hydrogenatedSterculia foetida oil fed rats. Growth was retarded 50%, liver/body wt doubled, and the percentage of saturated fatty acids in adipose tissue increased 2.5‐fold forSterculia foetida oil vs. corn oil comparisons. Three membrane systems were examined in corn oil andSterculia foetida oil fed rats. Erythrocyte hemolysis rate in 0.3 M glycerol was increased by 30%; induction of mitochondrial swelling by reduced glutathione was inhibited completely and microsomal codeine demethylase activity was depressed nearly 50% inSterculia foetida oil fed rats. The ability of cyclopropenoid fatty acids to inhibit fatty acyl desaturase and influence tissue and membrane lipid composition is discussed. Most of the detrimental effects observed in cyclopropenoid fatty acids fed rats may be associated with alteration of normal lipid metabolism and membrane function.
Purification of campesterol and preparation of 7‐dehydrocampesterol, 7‐campestenol and campestanol
Authors: Kircher Henry W. , Rosenstein Fumiko U. 
Published: November 2006

AbstractCampesterol ([24R]‐24‐methyl‐5‐cholesten‐3β‐ol) was isolated from a soybean sterol mixture and purified on a small scale by column chromatography and on a large scale by crystallization from acetone to 97% purity. From this, 7‐dehydrocampesterol ([24R]‐24‐methyl‐5,7‐cholestadien‐3β‐ol) and campestanol ([24R]‐24‐methyl‐cholestan‐3β‐ol) were prepared. The acetates and benzoates of all four compounds also were obtained and compared to the corresponding members of the ergostane series.
Toxicity of fatty ozonides and peroxides
Authors: Cortesi Reto , Privett O. S. 
Published: November 2006

AbstractStudies on the acute toxicity of the ozonides and hydroperoxides of methyl linoleate are reported. High purity preparations of these compounds were injected intravenously or administered orally to adult male rats. The lethal dose by iv injection of these compounds was virtually the same −0.07 mmol/100 g body wt. No deaths were caused in a 24 hr period by single oral dosages of these compounds of ca. 10‐fold that causing death by the iv route. The major effect of these compounds was on the lungs. The lungs became enlarged from edema and accumulation of fluid, and the animals died of lung congestion and injury similar to the effects of ozone toxicity. There was no destruction of vitamin E in the tissues of animals given lethal dosages of ozonides or peroxides intravenously, but significant changes occurred in fatty acid composition of the lipids of the serum and lung. Arachidonic acid increased at the expense of linoleic and oleic acids in these tissues. Only small amounts of peroxidic and TBA positive substances were detected in lung and serum, indicating that the injected ozonides and hydroperoxides were destroyed in the tissues.
Enzymatic oxidation of linolenic acid in aqueous wheat flour suspensions
Authors: Graveland A. 
Published: November 2006

AbstractLinolenic acid oxidation by the enzyme lipoxygenase in an aqueous wheat flour suspension does not lead to accumulation of linolenic acid hydroperoxides but immediately to secondary oxidation products. The 3 most important products among these were identified as 9‐hydroxy‐trans‐10,cis‐12,cis‐15‐octadecatrienoic acid, 9‐hydroxy‐10‐oxo,cis‐12,cis‐15‐octadecadienoic acid, and 9,12,13‐trihydroxy‐trans‐10,cis‐15‐octadecadienoic acid.