bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis of autoxidized fats by gas chromatography‐mass spectrometry: I. Methyl oleate
Authors: Frankel E. N. , Neff W. E. , Rohwedder W. K. , Khambay B. P. S. , Garwood R. F. , Weedon B. C. L. 
Published: November 2006

AbstractA structural investigation of autoxidation products of methyl oleate was carried out by gas chromatography‐mass spectrometry (GC‐MS) of trimethylsilyl (TMS) ether derivatives. GC‐MS using computer plots of selected masses afforded structural assignments of GC peaks due to incompletely resolved mixtures. This method provided evidence of epoxy and keto esters which are not completely separated from the main components consisting of the TMS derivatives of the allylic hydroxy esters. Use of an MS‐computer system also showed that the hydroxyoctadecanoate TMS ethers were partially separated by GC. The use of synthetic hydroxyoctadecanoates for the first time enabled us to demonstrate the quantitative reliability of a GC‐MS computer summation approach to analyze the isomeric composition of oleate hydroperoxides (as the saturated TMS ether derivatives). Consistently higher concentrations were found of the 8‐ and 11‐hydroperoxides than of the 9‐ and 10‐hydroperoxides. Minor products of autoxidation identified by GC‐MS include allylic enones, isomeric epoxyoctadecanoates, dihydroxyctadecenoates, and dihydroxyoctadecanoates.
Analysis of autoxidized fats by gas chromatography‐mass spectrometry: II. Methyl linoleate
Authors: Frankel E. N. , Neff W. E. , Rohwedder W. K. , Khambay B. P. S. , Garwood R. F. , Weedon B. C. L. 
Published: November 2006

AbstractThe gas chromatography‐mass spectrometry (GC‐MS) approach developed in the preceding paper was applied for qualitative and quantitative investigations of autoxidation products of methyl linoleate. A GC‐MS computer summation method was standardized with synthetic 9‐ and 13‐hydroxyoctadecanoate. Equal amounts of 9‐ and 13‐hydroperoxides were found in all samples of linoleate autoxidized at different temperatures and peroxide levels. The results are consistent with the classical free radical mechanism of autoxidation involving a pentadiene intermediate having equivalent sites for oxygen attack at carbon‐9 and carbon‐13. Minor oxygenated products of autoxidation indicated by GC‐MS include keto dienes, epoxyhydroxy monoenes di‐ and tri‐hydroxy monoenes. These hydroxy compounds are presumed to be present in the form of hydroperoxides. The quantitative GC‐MS method was found suitable for the analysis of autoxidized mixtures of oleate and linoleate. By this method, it is possible to determine the origin of the hydroperoxides formed in mixtures of these fatty esters.
Spectrofluorescent detection of malonaldehyde as a measure of lipid free radical damage in response to ethanol potentiation of spinal cord trauma
Authors: Seligman Myron L. , Flamm Eugene S. , Goldstein Bernard D. , Poser Richard G. , Demopoulos Harry B. , Ransohoff Joseph 
Published: November 2006

AbstractStudies of the role of free radical damage to the spinal cord following a 400 g‐cm impact have suggested an increase in at least one free radical product, malonaldehyde, 24–36 hr post injury. To investigate further the role of free radical lipid peroxidation in degeneration of the spinal cord following injury, a study of specific lipid fluorescence (SLF) indicative of the double Schiff‐base adduct formed by a reaction between malonaldehyde and cellular components was carried out in the presence of ethanol, a known potentiator of free radical lipid peroxidation. The study was carried out in cats who received a 200 g‐cm impact 3 hr to 23 days prior to sacrifice. Half of the impacted animals received ethanol, 5 ml/kg, prior to injury. These animals were rendered paraplegic, whereas the nonethanol treated animals were neurologically intact. Controls consisting of laminectomies alone or laminectomies with ethanol but without injury were also studied. Spinal cord segments at the impact or laminectomy site were minced and extracted with chloroform‐methanol, cleared by centrifugation, and examined in a scanning fluorometer with excitation maximum at 360 nm and emission maxima at 420, 440, 450, and 460 nm. SLF was minimal in cats 3 hr and 1 day post injury, but markedly increased at 3 days. By 5 days, background levels were again found in all groups. SLF in the alcohol‐pretreated impact animals rose to a peak at 7 days, followed by a decline to background by 10 days. The presence of SLF supports a role for free radical lipid peroxidation in the degenerative changes in the spinal cord following injury. The findings of two peaks of SLF activity suggest two different sites of damage. One site, found acutely after injury, appears in all groups and was associated with reversible changes, while the other site is associated with later changes and chronic paraplegia only. The two sites could be the gray and white matter.
Phytyl esters in a marine dinoflagellate
Authors: Withers Nancy W. , Nevenzel Judd C. 
Published: November 2006

AbstractThe first naturally occurring phytyl esters from a marine alga were isolated from a dinoflagellate,Peridinium foliaceum (Stein) Biecheler, cultured photosynthetically and harvested at stationary phase of growth. At this stage, phytyl esters were the major wax esters present, constituting 5% of the total lipid, and may be present largely in the “eyespot” structure. The fatty acids esterified to the phytol were predominantly polyunsaturated: 16∶3 n−3 (15%), 18∶5 n−3 (6%), 20∶5 n−3 (36%), and 22∶6 n−3 (17%).
Glyceride structure variation in soybean varieties: II. Silver ion chromatographic analysis
Authors: Fatemi S. H. , Hammond E. G. 
Published: November 2006

AbstractThe glyceride structures of 20 soybean varieties were determined by silver ion chromatography. Plots of the percentage of each triglyceride vs. the percentage of its constitutent fatty acids revealed no genetic variants that had not been found previously by stereospecific analysis. The results deviated significantly from the amounts predicted by the 1‐random‐2‐random‐3‐random hypothesis of glyceride distribution. This deviation can be explained by a noncoincidence of the peak biosynthesis of oleic and linoleic acids during maturation of the beans.
Lipid composition and erucic acid in rat liver cells in culture
Authors: Rogers C. G. 
Published: November 2006

AbstractErucic acid (Δ13‐docosenoic acid) was added to fetal calf serum, then fed to rat liver epithelial cells in culture, and uptake measured at intervals over 24 hr. During the first 6 hr. of incubation, uptake of the docosenoic acid was 21 nmoles/hr/mg protein in 7‐day cells, and 15 mmoles/hr/mg protein in 14‐day cells. Of14C‐labeled erucic acid taken up by the cells in 24 hr, radioactivity measurements showed 60% of the total lipid14C activity derived from [1‐14C] 22∶1 in neutral lipid (NL) and 40% in phospholipid (PL); whereas 55% of lipid14C activity was in NL and 45% in PL when the substrate was [14‐14C] 22∶1. Within the NL fraction, 75% of14C activity derived from [1‐14C] 22∶1 was in triglyceride (TG) and 11% in cholesterol (CHL), while 79% was in TG and 6.5% in CHL when the substrate was [14‐14C] 22∶1. Triglycerides and cholesteryl esters accumulated in the cells during incubation with erucic acid. Among phospholipids separated by thin layer chromatography, 75% of14C activity was in lecithin (PC), 10% in phosphatidylethanolamine (PE), 5% in sphingomyelin (SPH), and 1% or less in cardiolipin (DPG). The highest specific activity (SA) was in PC, followed by SPH and PE. Incubation with erucic acid altered fatty acid composition of PC, PE, and SPH, although amounts of phospholipids were unaffected. Gas liquid chromatography analyses detected 18% erucic acid in PC, 2% in PE, and 4–5% in SPH.
Alveolar lavage and lavaged lung tissue phosphatidylcholine composition during fetal rabbit development
Authors: Rooney Seamus A. , Gobran Laurice I. 
Published: November 2006

AbstractPulmonary surfactant, the major surface‐active component of which in the adult is dipalmitoylglycerophosphocholine, can be obtained by lavaging lungs with physiological saline. We have previously shown that there is an increase in the amount of phosphatidylcholine in fetal rabbit lung lavage during the latter part of gestation. We have now measured the amount of disaturated phosphatidylcholine as well as the fatty acid composition of phosphatidylcholine in lung lavage from fetal rabbits during the period 27 days' gestation to full term (31 days). There was no developmental change in the amount of disaturated phosphatidylcholine during the period examined. About 50% of the total phosphatidylcholine was disaturated which is approximately the same as in adult rabbit lung lavage. The fatty acid composition, however, did change. There was an increase in the amount of 16∶0 from about 20% of the total fatty acids in phosphatidylcholine at 27–28 days to about 60% at full term, after birth, and in the adults. There was a corresponding decrease in the amounts of 14∶0, 18∶0, and longer chain fatty acids, most of which were saturated. In the lavaged lung tissue, there was a 2.6‐fold increase in the percentage of phosphatidylcholine which was disaturated during the period 27–31 days' gestation. It had not decrease to the adult value 24 hr after birth.
Fatty acid and sterol synthesis by rat small intestine in vitro
Authors: Miguel S. G. 
Published: November 2006

AbstractSlices of rat jejunum were incubated with [2‐14C]pyruvate, [1‐14C]acetate, or [3H]H2O to determine lipogenic activity. Under all conditions studied, pyruvate acted as a better precursor than acetate for fatty acid synthesis but not for the synthesis of sterol. Exogenous glucose significantly (P≤0.05) increased the conversion of both pyruvate and acetate to fatty acids. By contrast, fasting resulted in a decrease (p≤0.05) in lipogenic activity. The highest levels of lipogenesis were observed when [3H]H2O + glucose at a concentration of 20 mM was used. From such experiments, the absolute rate of fatty acid synthesis in the tissue preparation was calculated: 734±54 nmoles acetyl units incorporated into fatty acids/g tissue/hr.
Action of three bile acids on hepatic and intestinal cholesterogenesis in the rat
Authors: Reynier M. O. , Marteau CH. , Vigne J. L. , Mule A. , Crotte C. , Gerolami A. 
Published: November 2006

AbstractIncorporation of [114−C] acetate into cholesterol by subcellular particles from the liver and the small intestine of rats with a biliary diversion and a duodenal perfusion of sodium taurocholate, taurochenodeoxycholate or taurodehydrocholate, was studied in vitro. In the liver, taurochenodeoxycholate prevented the increase of cholesterol synthesis induced by biliary drainage. Taurocholate had no action on cholesterol synthesis at any time, day or night. Intestinal synthesis of cholesterol was reduced by taurocholate and taurochenodeoxycholate but was not modified by taurodehydrocholate infusion.
Serum and liver lipid responses to 3‐hydroxy‐3‐methylglutaric acid in rats on different carbohydrate diets
Authors: Yousufzai S. Y. K. , Siddiqi Majid 
Published: November 2006

AbstractGroups of male adult albino rats were administered 3‐hydroxy‐3‐methylglutaric acid (HMG) intraperitoneally along with six diets differing only in the type of carbohydrate used. Groups not treated with HMG served as controls. HMG showed a significant cholesterol‐ and triglyceride‐lowering effect in the whole serum, serum β‐lipoproteins, and liver of animals on all types of dietary carbohydrates. The effect was more marked in glucose, fructose, sucrose, and lactose. The phospholipid levels in whole serum, serum β‐lipoproteins, as well as in liver were also significantly lowered on all types of carbohydrates except dextrin and starch fed animals, where it had no effect on liver levels. The lipid‐lowering effect of HMG seems to be independent of the type of carbohydrate in diet.
Titration of sterol double bonds with dibromopyridine sulfate
Authors: Rosenstein Fumiko U. , Caruso Ramon , Kircher Henry W. 
Published: November 2006

AbstractCis andtrans‐22‐dehydrocholesteryl acetates andcis andtrans‐22‐cholesten‐3β‐yl acetates were prepared and compared to Δ22‐phytosteryl acetates by titration with dibromopyridine sulfate. The cholesterol derivatives absorbed close to the theoretical quantity of bromine (1 Br2 per double bond), whereas the Δ22‐C24‐alkylated sterols consumed 0.14 to 0.23 Br2 in excess of the calculated values. This excess is attributed to the formation of additional unsaturation during bromination. Δ7 and Δ8(14)‐sterols consume more than 2 and 3 moles Br2, respectively, which indicates that at least one or two new double bonds are formed in these molecules during the bromination step.
Identification of the free and conjugated sterol in a non‐photosynthetic diatom,Nitzschia alba, as 24‐methylene cholesterol
Authors: Kates M. , Tremblay P. , Anderson R. , Volcani B. E. 
Published: November 2006

AbstractPrevious studies on the sterol fraction of the nonphotosynthetic marine diatom,Nitszchia alba, indicated the major sterol to be either brassicasterol (24R‐methylcholesta‐5,22‐dien‐3β‐ol) or 22‐dehydrocampesterol (24S‐methylcholesta‐5,22‐dien‐3β‐ol) on the basis only of gas chromatographymass spectral analysis. The present studies using nuclear magnetic resonance, infrared, and gas chromatography‐mass spectrometry on the free and bound sterol fractions isolated by preparative thin layer chromatography showed the presence in both fractions of a single sterol, with spectral and chromatographic properties identical with those reported for 24‐methylenecholesterol (ergosta‐5,24(28)‐dien‐3β‐ol). This sterol may be the precursor of 24‐methyl sterols found in diatoms. The bound sterol fraction was found to consist of a single compound identified as 24‐methylenecholesterol sulfate. No sterol esters or sterol glycosides were detected.
Studies on lipid biosynthesis and cholesterol content of liver and serum lipoproteins in rats fed various phthalate esters
Authors: Bell F. P. , Patt C. S. , Brundage B. , Gillies P. J. , Phillips W. A. 
Published: November 2006

AbstractThe effect of various phthalate ester plasticizers on lipid metabolism in rats was studied in vivo and in vitro. Di‐2‐ethylhexyl phthalate (DEHP) and di‐n‐butyl phthalate (DBP) inhibited (30–70%) hepatic sterologenesis from14C‐acetate and14C‐mevalonate in liver minces from rats fed the phthalates at a level of 2.5 mmoles/100 g of chow diet for 21 days; inhibition of14C‐acetate incorporation into phospholipids, triglycerides, and steryl esters was reduced (35–70%) by DEHP and DBP feeding. In addition, serum cholesterol was lowered ca. 14 mg/dl with dietary DEHP or DBP but not with dimethyl phthalate (DMP). Hepatic total cholesterol levels were reduced significantly (31%, P<0.001) by DMP but not by DBP or DEHP. In other studies with DEHP fed at the 0.5% level in chow diets (1.3 mmoles/100 g), the incorporation (esterification) of3H‐oleate into di‐ and triglycerides was reduced ca. 40%. Furthermore, the addition of DEHP (2%, 5 mmoles/100 g) to a semisynthetic diet containing 10% fat (hydrogenated coconut oil) resulted in changes in serum lipoprotein composition. The percentage of serum cholesterol in LDL rose from 22% to 34% while that in HDL fell from 78% to 66%; these changes occurred without net changes in serum cholesterol levels. Possible mechanisms for the inhibitory effect of phthalates on hepatic lipid biosynthesis are discussed.
Distribution of dietary octadecenoate isomers at the 1‐ and 2‐positions of hepatoma and liver phospholipids
Authors: Wood Randall , Chumbler Fred 
Published: November 2006

AbstractPhosphatidylcholines and phosphatidylethanolamines were isolated from hepatoma 7288CTC, normal liver, and host liver of rats fed one of the following diets: fat‐free diet; fat‐free diet supplemented with safflower oil, safflower oil fatty acids, or partially hydrogenated safflower oil fatty acids; and commercial chow. Thecis andtrans octadecenoate fatty acids were isolated from the 1‐ and 2‐positions of both phosphoglycerides and analyzed quantitatively for chain positional isomers. Octadecenoates from hepatoma and liver phosphoglycerides of animals fed fat‐free or natural fatsupplemented diets contained almost exclusively twocis isomers: oleic and vaccenic acids. Oleic acid predominated in the 2‐position octadecenoates of both phosphoglycerides from hepatoma and liver. In contrast, vaccenic acid predominated in the 1‐position of normal liver phosphatidylcholine and, to a lesser extent, phosphatidylethanolamine. Host liver and hepatoma exhibited a shift to a higher percentage of oleic acid at the 1‐position. Dietarytrans fatty acids were incorporated predominately in the 1‐position of both phosphoglycerides of hepatoma and liver. Except for thecis Δ10 octadecenoate isomer, all of the unnatural dietarycis isomers between Δ8 and Δ14 were incorporated into the 1‐position of the phospholipids, while the unnaturalcis octadecenoates at the 2‐position consisted primarily of the Δ12 isomer. Hepatoma phosphoglycerides contained higher percentages of thetrans Δ10 isomer that was nearly excluded from the 1‐position of the two liver phosphoglycerides. All the othertrans octadecenoate isomers were incorporated into the 1‐position of both phosphoglycerides, but the small amount oftrans fatty acids incorporated into the 2‐position of liver and hepatoma phosphatidylcholine consisted of four isomers, Δ9 to Δ12, including the Δ10 isomer. Phosphatidylethanolamine exhibited a similar distribution, except for the presence of the Δ13 and Δ14 isomers at the 2‐position. A combination of evidence suggests that the 1‐position fatty acids in phosphatidylcholine and phosphatidylethanolamine are of similar origin. The octadecenoates at the 2‐position of these two phosphoglycerides appear to be of the same origin in hepatoma but not in liver. It was also revealed that the 2‐position of hepatoma phosphatidylcholine contained much higher percentages of palmitate than liver.
Incorporation and metabolic conversion of erucic acid in various tissues of the rat in short term experiments
Authors: Ong Nelly , Bezard Jean , Lecerf Jean 
Published: November 2006

AbstractRats were intravenously injected with a mixture of free (14‐14C) erucic acid (22∶1) and (9–103H) oleic acid (18∶1). After 2, 4, 8, 16, and 30 min, radioactivity was examined in blood, liver, heart, kidneys, and spleen. Free (14C) 22∶1 disappeared from the blood more rapidly than free (14C) 18∶1 between 0 and 8 min. Incorporation of label into triglycerides only appeared after 16 min and at 30 min they represented 4% of the injected radioactivity. In this fraction, 63% of14C radioactivity was present as 18∶1 and not as the original 22∶1, while almost all3H radioactivity was recovered as unchanged 18∶1. At all times studied, the majority of radioactivity was found in the liver, primarily as triglycerides (60% of radioactivity in total lipids) and as phospholipids (20–30%).14C was present in nearly the same proportion as3H (13% of injected radioactivity after only 2 min, 11% at 30 min).14C radioactivity was contained in 18∶1 in higher proportion than 22∶1 (45% in triglycerides, 65% in phospholipids). Since labeled triglycerides of blood, rich in (14C) 18∶1, mainly originate from the liver triglycerides, it appears that 18∶1 is the major form of utilization of 22∶1 in the tissues after its conversion in liver. In the other organs tested, radioactivity was found 10–15 times lower than in liver. In the heart,14C was 3 to 4 times higher than3H. More than 80% was recovered as 22∶1 in triglycerides. In spleen and kidneys, the14C:3H ratio was particularly high in free fatty acids and monoglycerides. In kidneys, 60% of14C was present as nervonic acid (24∶1) in monoglycerides and 40% in phospholipids, suggesting that the mononervonin formed was used for phospholipid biosynthesis.
Type and amount of dietary fat affect relative concentration of cholesterol in blood and other tissues of calves
Authors: Wiggers Kenneth D. , Richard Marlene J. , Stewart Jeanne W. , Jacobson Norman L. , Berger P. Jeffrey 
Published: November 2006

AbstractSixteen male Holstein calves consumed by nipple a reconstituted milk containing nonfat dry milk and either soybean oil or tallow for 24 weeks. Calves fed milk in this manner (with no dry feed) are functionally nonruminants because the milk bypasses the ruminoreticulum. The fat in these diets contributed about 30% of total dietary calories. The calves consuming soybean oil milk had significantly greater amounts of cholesterol in blood plasma and adipose tissue than did the calves consuming tallow milk.
Biosynthesis of prostaglandins
Authors: Hemler Martin E. , Lands William E. M. 
Published: November 2006

AbstractHighly purified cyclooxygenase from sheep vesicular glands is stimulated by the presence of protoporphyrin IX compounds. This stimulation may be due to the conversion of an apoenzyme to the holoenzyme, and full activity is achieved when half of the enzyme subunits (70,000 daltons) bind heme. Also, one‐half of the subunits appear to contain non‐heme iron. The apparent molecular weight of the holoenzyme is approximately 300,000 daltons and is compatible with a complex of four 70,000 dalton subunits. Thus, we suggest that heme and non‐heme iron may be attached to different 70,000 daltons subunits that make up an A2B2‐type of peptide chain arrangement.
The effect of long‐chain monoenes on prostaglandin E2 synthesis by rat skin
Authors: Hulan H. W. , Kramer J. K. G. 
Published: November 2006

AbstractIn order to ascertain whether the dermal lesions observed in male rats fed rapeseed oils are due to impaired prostaglandin biosynthesis, endogenous levels of prostaglandin E2 (PGE2) in skin and the capacity of this tissue to synthesize PGE2 from arachidonic acid was investigated. Male Sprague‐Dawley rats were fed from weaning for 8 weeks either a standard rat diet (chow) or semisynthetic diets containing 20% by weight of the following fat sources: corn oil; commercial lard; commercial lard to which was added 5.4% free erucic acid; rendered pig fat; or the following rapeseed oils:Brassica napus var. Zephyr;B. campestris var. Span;B. campestris var. Arlo (15%) and var. Echo (85%) designated HEAR (high erucic acid rapeseed). The long‐chain monoene content (18∶1, 20∶1, and 22∶1) of the diets fed ranged from 30 to 71 mole % and that of skin from 27 to 74 mole %. A significant (P<0.01) correlation was found between the level of 18∶2n−6 in the diet and the endogenous PGE2 levels in skin and the capacity of this tissue to synthesize PGE2. No relationship was found between these two PGE2 parameters and the level of erucic acid in the diet. The rate of turnover of PGE2 appeared to be lower in rats fed rapeseed oil as evidenced by the relatively high endogenous PGE2 levels when these oils were fed (96 to 105 μg/g). On the other hand, the lowest capacity for PGE2 synthesis was found with skin from rats fed Zephyr rapeseed oil, rats which also had the most severe incidence of hair loss and dermal lesions. Significant (P<0.01) negative correlations were observed between the level of monoenes and specifically the level of oleic (18∶1n−9) acid in the diets and PGE2 synthesis capacity of skin, possibly confirming the known inhibitory effect of 18∶1n−9 on the prostaglandin synthesizing enzyme system.
Alchornea cordifolia seed oil: A rich source of a new C20 epoxide, (+)cis‐14,15‐epoxy‐cis‐11‐eicosenoic acid
Authors: Kleiman R. , Plattner R. D. , Spencer G. F. 
Published: November 2006

AbstractA C20 homolog of vernolic acid has been found at the 50% level inAlchornea cordifolia, Euphorbiaceae, seed oil. This new acid, (+)cis‐14,15‐epoxy‐cis‐11‐eicosenoic (alchornoic) acid, was isolated by high‐pressure liquid chromotography and characterized by mass spectrometry, nuclear magnetic resonance and infrared spectroscopy, optical rotary dispersion, and ozonolysis‐gas‐chromotography.