bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fatty acid and positional selectivities of gastric lipase from premature human infants:in vitro studies
Authors: Jensen Robert G. , deJong Felice A. , Lambert‐Davis Lisa G. , Hamosh Margit 
Published: November 2006

AbstractGastric lipase activity in aspirates from premature human infants was tested for fatty acid and positional selectivity using racemic diacid triacylglycerols (TG) as substrates. The resulting free fatty acids and monoacylglycerols (MG) were recovered and analyzed. Octanoic acid (8∶0) and decanoic acid (10∶0) were hydrolyzed with a preference of 61.5∶1 and 2.4∶1 compared to palmitic acid (16∶0) fromrac‐16∶0–8∶8∶0 andrac‐16∶0–10∶0–10∶0, respectively. The ratio of lauric acid (12∶0) to oleic acid (18∶1) hydrolyzed fromrac‐18∶1–12∶0 was 13∶1. Myristic acid (14∶0), 18∶1 and linoleic acid (18∶2) were released at similar rates. These data and the composition of the MG suggest that,in vitro, the lipase is selective for shorter chain fatty acids and for fatty acids on the primary positions of the TG backbone.
Lymphatic fatty acids from rats fed human milk and formula containing coconut oil
Authors: Roche Matthew E. , Clark Richard M. 
Published: November 2006

AbstractHuman milk and infant formula containing coconut/soy oil were infused into the duodenum of rats to determine the incorporation of capric, lauric, myristic and palmitic acids into lymphatic triacylglycerol (TAG). The proportion of capric and lauric acids in the lymphatic TAG reflected the fatty acid composition of the diet. Based on positional analysis, it appears that more than 50% of the capric and lauric acids could have been absorbed from the intestine assn‐2 monoacylglycerols. In the rats fed human milk, 50% of palmitic acid in lymphatic TAG was in thesn‐2 position. Because of the nonrandom distribution of palmitic acid in the lymphatic TAG, the nonspecific lipase in human milk, i.e., bile salt‐stimulated lipase, did not appear to be a factor in milk lipid digestion.
Confirmation by gas chromatography/mass spectrometry of two unusualrans‐3‐monoethylenic fatty acids from the nova scotian seaweedsPalmaria palmata andChondrus crispus
Authors: Lamberto M. , Ackman R. G. 
Published: November 2006

AbstractThe structures of two unusual fatty acids, the knownrans‐3‐hexadecenoic acid and a noveltrans‐3‐tetradecenoic acid, both isolated from the Nova Scotian sea‐weedsPalmaria palmata andChondrus crispus, were positively identified. After the extraction of the total fatty acids by saponification, followed by methylation, the monoenoictrans fractions were isolated by thin‐layer chromatography on silica gel impregnated with silver nitrate. The monoenoictrans fractions were derivatized with 2‐amino‐2‐methyl‐propanol prior to analysis by gas chromatography/mass spectrometry. The mass spectra showed prominent [M+1]+ ions but lacked the 12 amu interval useful for identifying the double bond position. Hence, alternative diagnostic peaks were used to confirm the position of the double bond in these two fatty acids. As thetrans‐3‐hexadecenoic acid is found in the photosynthetic tissue of all plants, it may also be present in ruminant fats and, presumably, in human adipose tissue.
Fluorescent substances derived from the reaction of 13‐monohydroperoxylinoleic acid and methylamine
Authors: Kikugawa Kiyomi , Watanabe Shigenobu 
Published: November 2006

AbstractReaction of 13‐monohydroperoxy linoleic acid and methylamine in the presence of ferric ions produced at least four fluorescent substances. They were separated by high performance liquid chromatography with a reverse phase column, and major fluorescent substances 1 and 3 were isolated. Fluorescent substances 1 and 3 showed the same fluorescence spectra with excitation maxima at 360 nm and emission maxima at 430 nm, and the same ultraviolet spectra with absorption maxima at 275 and 360 nm. Fluorescence of 1 and 3 was lost in alkaline media owing to the instability of the fluorophores. The fluorophores of 1 and 3 were destroyed on treatment with borohydride. The fluorescence characteristics of 1 and 3 were similar to those of the age‐related fluorescent substances produced in tissues. They were different from those of the fluorescent substances derived from malonaldehyde and resembled those of the fluorescent substances derived from monofunctional aldehydes.
Adenylate cyclase and β‐receptors in salivary glands of rats fed diets containingtrans fatty acids
Authors: Ren Y‐F. , Alam S. Q. , Alam B. S. , Keefer L. M. 
Published: November 2006

AbstractThe effects oftrans fatty acids on adenylate cyclase were determined in the submandibular salivary glands (SMSG) of rats fed diets containing 20% corn oil, 20% partially hydrogenated soybean oil (PHSBO) or 18% PHSBO + 2% corn oil. The fluoride‐and isoproterenol‐stimulated adenylate cyclase activities were higher in the SMSG from rats fed 20% PHSBO than in the control group fed 20% corn oil. The feeding of 2% corn oil with the diet containing 18% PHSBO resulted in a complete restoration of isoproterenol‐stimulated and a partial restoration of fluoride‐stimulated adenylate cyclase activity. There was no significant difference in the concentration of the β‐adrenergic receptor or in the receptor‐binding affinity constants among the three dietary groups as measured by [3H]dihydroalprenolol (DHA)‐binding. Higher fluorescence polarization of diphenyl hexatriene (DPH) was observed in SMSG membranes of rats fed diet containing 20% PHSBO than in the other two oils, suggesting that membrane fluidity may play a role in adenylate cyclase activity.
Triacylglycerol structure of plant and fungal oils containing ψ‐linolenic acid
Authors: Lawson Larry D. , Hughes Bronwyn G. 
Published: November 2006

AbstractThe triacylglycerol stereospecific structure was determined for the major plant oils containing ψ‐linolenic acid (GLA): evening primrose oil (EPO), black currant oil (BCO), borage oil (BO), andMucor javanicus fungal oil (MJO). It was found that GLA, although not α‐linolenic acid, resisted pancreatic lipase hydrolysis. Therefore, the 2‐position analysis was determined using phospholipase C‐generated 1,2‐diacylglycerol and phospholipase A2‐generated lysophosphatidylcholine. GLA was found to be concentrated in the 3‐position of EPO and BCO, the 2‐position of BO, and the 2‐ and 3‐positions of MJO. In BCO, octadecatetraenoic acid (n−3), also a †‐6 fatty acid, was distributed similarly to GLA, but α‐linolenic acid was found predominantly in the 1‐position. Linoleic acid was nearly evenly distributed in all positions of EPO and BCO but was concentrated in the 1‐position of BO and the 2‐position of MJO. Both palmitic and stearic acids were found predominantly in the 1‐position of all of the oils. The results demonstrate similarities and differences in the positional distribution of fatty acids in GLA‐containing oils.
Dietary fiber supplements: Effects on serum and liver lipids and on liver phospholipid composition in rats
Authors: Kritchevskya David , Tepper Shirley A. , Satchithanandam Subramanian , Cassidy Marie M. , Vahouny George V. 
Published: November 2006

AbstractRats (6 per group) were fed semipurified diets containing either particulate fibers (alfalfa, 10%; cellulose, 10%; bran, 10%), a soluble ionic fiber (pectin 5%), soluble, nonionic fibers (guar gum, 5%; Metamucil, 10%), a mixed fiber preparation (Fibyrax, 10%, or an insoluble, ionic bile acid‐binding resin (cholestyramine, 2%). The control group was fed the unsupplemented diet. The feeding period, during which diet and water were provided ad libitum, was 28 days.Compared with the control group, serum total cholesterol levels were increased by more than 10% in rats fed alfalfa and decreased by more than 10% in rats fed cellulose, guar gum, Fibyrax and cholestyramine. There were no significant differences in percentage of plasma HDL cholesterol. Serum triglycerides were elevated in the groups fed alfalfa, pectin, guar gum or Fibyrax and reduced in the group fed Metamucil. Plasma phospholipids were elevated in rats fed alfalfa or bran, unaffected in rats fed pectin or Metamucil and reduced in the other groups. Liver total cholesterol was elevated in all groups but those fed wheat bran and cholestyramine. The percentage of liver cholesterol present as ester was elevated in every group except that fed cholestyramine. Liver triglycerides were reduced in rats fed guar gum or Metamucil and elevated in those fed alfalfa. Liver phospho‐lipids were lowered in the group fed cellulose.Liver phospholipids were fractionated by thin layer chromatography to give phosphatidylcholine (PC), phosphatidylethanolamine (PE), sphingomyelin (Sph), lysophosphatidylcholine (LPC) and phosphatidylinositol plus phosphatidylserine (PI+PS). PC was elevated in all test groups (7–25%); PE levels ranged from 14% below to 0.3% above controls; Sph levels were sharply lower (20–53%) in all groups. LPC and PI+PS levels were close to the control value in all test groups.The results demonstrate that different dietary fibers can affect liver phospholipid composition. In view of the critical roles of phospholipids in many biological reactions, it will be interesting to survey the influence of dietary fiber on phospholipid spectra of other tissues.
Changes in plasma lipids, lipoproteins, triglyceride secretion and removal in chicks with estrogen implants
Authors: Park Jeong R. , Cho B. H. Simon 
Published: November 2006

AbstractEstradiol implants in chicks resulted in marked elevation of all major plasma lipids with greatest increase in triglyceride (TG) followed by phospholipid (PL) and cholesterol (C). During the two‐wk period, plasma TG level in estrogen (E)‐treated chicks increased to about 45 times that of controls (139.6 vs 6,368.3 mg/dl). The level of cholesterol also increased steadily during the same period, attaining nearly a six‐fold increase in comparison with the control (150.7 vs 871.8 mg/dl), and the level of PL was markedly elevated from 209 to 2,861 mg/dl. Besides the induction of hyperlipidemia, E treatment also resulted in a notable alteration in the fatty acid composition of plasma lipids; there was an increase in oleic acid concomitant with a decrease in polyunsaturated fatty acids, particularly, linoleic acid. One day after implantation, the percentage of oleic acid in TG fraction increased from 39.2 to 43.7%, reaching 55.4% of the total fatty acids at day 14. In contrast, the levels of linoleic and arachidonic acid decreased significantly from 16.1 to 8.3% and 4.3 to 0.6%, respectively, during the same period. In cholesteryl ester (CE) and PL, the oleic acid level also increased from 25.2 to 47.3% in the former and from 11.9 to 29.6% in the latter, reflecting enhanced hepatic lipogenesis. Analysis of plasma lipoproteins in E‐treated chicks revealed dramatic alterations in the concentrations of lipids and protein in individual lipoprotein fractions, especially very low density lipoprotein (VLDL) fraction. The respective levels of TG, C and PL in the VLDL fractions were 10.0, 0.6 and 1.0 mg/dl in the control, and 3,904.4, 530.3 and 1,365.2 mg/dl in chicks implanted with estrogen for seven days. The concentrations of TG, C and PL also were markedly increased in the low density lipoprotein (LDL) fraction in these birds. However, the cholesterol content of the high density lipoprotein (HDL) fraction was decreased dramatically in E‐treated chicks (47.1) relative to the control (121.5 mg/dl). The protein level in the VLDL fraction from E‐treated chicks was profoundly elevated to a level 300‐fold greater than controls. TG secretion rates were measured in vivo following the administration of Triton WR‐1339. In control chicks, plasma TG secretion rate was 2.29 mg/min; whereas, chicks treated with E for one and three days showed significantly higher TG secretion rates of 3.18 and 5.27 mg/min, respectively. TG removal rates were measured in vivo after administration of a 10% fat emulsion. Although plasma TG concentrations were different between control and E‐treated birds, no significant differences were found in TG removal rates in those birds, indicating no impairment of TG clearance in E‐treated chicks.
Phospholipid profile and production of prostanoids by murine colonic epithelium: Effect of dietary fat
Authors: Robblee N. M. , Farnworth E. R. , Bird R. P. 
Published: November 2006

AbstractDietary fat and abnormal production of various prostanoids have been linked to various disease states of the large bowel, including cancer of the colon. Studies were conducted to determine the effect of dietary fat (beef tallow or corn oil) on the lipid composition and prostanoid production of the murine colon.Female C57BL/6J mice were fed high‐fat (HF) diets (47% of calories as fat) or low‐fat (LF) diets (10% of calories as fat). After four wk of dietary treatment, the mucosa was scraped, and lipids were extracted from the mucosal and muscle layers. The fat content of the diets did not significantly alter the amount of phospholipid (PL) or neutral lipid in the colonic tissue. However, the HF affected the PL profile of the colonic mucosa. For example, the ratio of phosphatidylcholine (PC) to phosphatidylethanolamine (PE) was significantly higher for both the HF groups compared with that of the two LF groups (0.76±0.15 and 0.80±0.13 vs 0.31±0.20 and 0.34±0.18). Production of 13,14‐dihydro‐15‐keto‐PGE2 (measured as bicyclic PGE2) and TXB2 (a stable metabolite of TXA2) and PGF1α (a stable metabolite of PGI2) was unaffected by the dietary treatments. The muscle had a different PL profile (PC:PE is 2.6±0.1) than the mucosa and contributed a larger proportion of the prostanoids formed. This study demonstrates that the phospholipid polar head group composition of normal colonic mucosa is altered by dietary fat, but the ability of the mucosa to synthesize metabolites of PGE2, TXA2 and PGI2 is not affected.
Characterization of HETEs and related conjugated dienes by UV spectroscopy
Authors: Ingram Christiana D. , Brash Alan R. 
Published: November 2006

AbstractThree distinct pairs of HETEs can be distinguished on the basis of their UV spectra. We used hydroxy‐linoleates (hydroxy‐octadeca‐cis‐trans‐dienoates) as a base for comparisons; both the 9‐ and 13‐hydroxy isomers have identical chromophores with λmax near 234 nm. The presence of a double bond three carbons removed from the conjugated diene (the chromophore of 9‐ and 11‐HETE) causes a shift in the observed λmax to near 235 nm. A double bond β to the chromophore (5‐ and 15‐HETE) gives a further shift of 1.5 nm, giving a λmax between 236–236.5 nm. With double bonds in both these positions (8‐ and 12‐HETE), the λmax is observed near 237 nm. It is apparent that the exact λmax of thecis‐trans diene chromophore is influenced in a consistent way by the adjacent methylene interruptedcis double bonds.
A new quantitative method for the analysis of monoacylglycerol isomers using13C nuclear magnetic resonance spectroscopy
Authors: Dawe R. D. , Wright J. J. C. 
Published: November 2006

AbstractCurrent methods for determining the regiochemistry of monoacylglycerols are lengthy, tedious and aggravated by the ready isomerization of 2‐acyl‐sn‐glycerols. A new method employs a very rapid adsorption chromatography step in which isomerization is kept to a minimum, followed by formation of the isopropylidene derivatives using mild procedures. These cyclic derivatives of 1‐ and 3‐acyl‐sn‐glycerols and 2‐acyl‐sn‐glycerols are stable thermally and display certain characteristic13C NMR resonances. Integration of these resonances yields directly the proportion of monoacylglycerol isomers in the mixture. The method was applied to the analysis of monoacylglycerols produced by enzymatic hydrolysis of synthetic and naturally occurring triacylglycerols.
Differential utilization of long chain fatty acids during triacylglycerol depletion. II. Rat liver after starvation
Authors: Cunnane S. C. 
Published: November 2006

AbstractRats starved for 96 hr were shown to have a 94% reduction in liver triacylglycerol. Among the long chain fatty acids in liver triacylglycerol, only stearic acid and arachidonic acid were proportionally increased (2.5 and 6 times, respectively); palmitic and linoleic acids were unchanged, and palmitoleic and oleic acids were proportionally decreased. Stearic and arachidonic acids (mg%) were correlated positively within the triacylglycerol fraction, and both fatty acids varied inversely with total triacylglycerol (mg/g) in fed and starved rats. The utilization of long chain fatty acids from liver triacylglycerol during starvation resulted in selective retention of arachidonic acid and stearic acid and suggests that differential hydrolysis of liver triacylglycerol by hepatic lipase may occur or selective reacylation of these specific fatty acids may occur during starvation.
Thermodynamic characterization of the pretrasition of unilamellar dipalmitoyl‐phosphatidylcholine vesicles
Authors: Lichtenberg Dov , Menashe Moshe , Donaldson Steve , Biltonen Rodney L. 
Published: November 2006

AbstractHigh‐sensitivity differential scanning calorimetry of small unilamellar vesicles (SUV) made by sonication of dipalmitoylphosphatidylcholine (DPPC) reveals that the gel‐liquid crystalline transition at 37 C is preceded by a pretransition at 28 C that is relatively slow (t 1/2≃2–4 min) and has an enthalpy change of ca. 0.2 kcal/mol. On incubation at 4 C, these SUV fuse spontaneously into large unilamellar vesicles (LUV). LUV also exhibit both a pretransition and a main‐phase transition. The temperature of the main transition (Tm) and the enthalpy change of both the pretransition and main transition of these fused vesicles are similar to those of large multilamellar vesicles (MLV). The enthalpy change associated with the transition at 28 C decreases in SUV in a manner directly correlated to the decrease in the apparent enthalpy change of the 37 C main transition, indicating that the smaller (low temperature) transition is indeed a pretransition that is an inherent property of SUV. Therefore, unilamellar vesicles of DPPC appear to exhibit a pretransition at a temperature that varies from 28 C for the small vesicles to 35 C for the much larger vesicles.
Hepatic origin of triglycerides in fatty livers produced by the continuous intragastric infusion of an ethanol diet
Authors: Tsukamoto Hidekazu , Lew Gail , Larkin Edward C. , Largman Corey , Ananda Rao G. 
Published: November 2006

AbstractMale Wistar rats were maintained for 30 days on an independent and continuous intragastric infusion of ethanol and nutritionally defined liquid diet containing only a small amount of corn oil (CO‐4.9% calories). Ethanol intake was progressively increased from 32% to 40.4% of the total calories to maintain a high degree of intoxication during this period. Rats in the control group were infused with an isocaloric diet in which alcohol was replaced by dextrose. The liver triglyceride (TG) content of rats given alcohol (61.5±16.4 mg/g) was ca. 10‐fold greater than that of controls (5.9±2.1 mg/g) and similar to that observed previously in rats fed an ethanol diet containing high levels of fat (35% and 43% calories). In TG of fatty liver, the level of 18∶2 was small (3%), even though CO in the diet contained a high level of this acid. Furthermore, 16∶1 and 16∶0 contents were markedly elevated (16% and 40%, respectively) despite the fact that CO did not contain 16∶1 and had only a small amount of 16∶0. Liver TG having a fatty acid (FA) composition markedly different from that of CO and the presence of high levels of 16∶1 and 16∶0 indicate that the TG accumulated in the fatty liver originated from hepatic lipogenesis rather than from dietary fat.
Composition and metabolism of fatty acids in phospholipids of density‐separated red cells of rats
Authors: Kunimoto Manabu , Kaya Kunimitsu , Miura Takashi 
Published: November 2006

AbstractFatty acid compositions of phosphatidylcholine (PC) and phosphatidylethanolamine (PE) and the rates of fatty acid esterification to these phospholipids (PL) were measured in intact rat red cell populations of different ages separated by density gradient centrifugation in order to clarify changes in membrane lipids of red blood cells during in vivo aging. Fatty acid compositions of PC and PE altered progressively as red cells became denser. Changes in unsaturated fatty acids occurred predominantly at the 2‐position of PC and PE and those in saturated fatty acids at both positions. The esterification rates of 5 major fatty acids decreased as red cells became denser and those of oleic acid, linoleic acid and arachidonic acid to both PC and PE of fraction I cells (oldest cells) were 37–51% those of fraction IV cells (youngest cells). Reduction in the rates of fatty acid esterification appeared to occur in the course of red cell maturation because reticulocyte‐enriched cell fractions showed 4.5–14.5 times higher rates of linoleic acid and arachidonic acid esterifications to PC and PE.
Effects of triarimol, tridermorph and triparanol on sterol biosynthesis in carrot, tobacco and soybean suspension cultures
Authors: Hosokawa Glenn , Patterson Glenn W. , Lusby William R. 
Published: November 2006

AbstractThe effects of triarimol, tridemorph and triparanol on sterol biosynthesis in carrot, tobacco and soybean suspension cultures were studied. The 3 plant species normally contain campesterol, stigmasterol and sitosterol as major sterols. Triarimol inhibited demethylation at C 14 and the second alkylation of the side chain in all 3 species. The primary effects of tridemorph were the inhibition of the opening of the 9β,19‐cyclopropane ring and the second alkylation of the side chain. Triparanol treatments resulted in the accumulation of 14α‐methyl sterols, and the inhibition of second alkylation in the side chain in carrot and tobacco cultures. Cyclopropyl sterols also accumulated in carrot and tobacco cultures treated with triparanol. Triparanol did not alter the sterol composition of soybean cultures except for decreasing concentrations of campesterol and stigmasterol and increasing amounts of sitosterol.
A lack of correlation between linoleate and arachidonate in human breast milk
Authors: Gibson R. A. , Kneebone G. M. 
Published: November 2006

AbstractThe levels of arachidonic acid and linoleic acid found in the lipid fraction of human milk samples were compared. No correlation was found between the level of precursor linoleate and product arachidonate in 80 samples of colostrum (day 3–5) or 60 samples of mature breast milk. We attempted to test the hypothesis that the absence of a precursor‐product relationship was caused by a constant level of arachidonate being secreted in the phospholipids (PL) of breast milk cells. Examination of the fatty acid (FA) composition of the PL and triglyceride fractions revealed arachidonate in high concentration in PL but that most of the total arachidonate existed in triglycerides.
The very long chain fatty acids of the green alga,Chlorella kessleri
Authors: Řezanka Tomáš , Podojil Miloslav 
Published: November 2006

AbstractFatty acids of the fresh‐water green alga,Chlorella kessleri (heterotrophically cultivated), were fractionated (as methyl esters) using high performance liquid chromatography (HPLC). A fraction of fatty acids with chain lengths longer than 28 carbon atoms was analyzed by gas chromatography‐mass spectrometry (GC‐MS). The very long chain fatty acids, ranging from 31 to 36 carbon atoms, were found for the first time in a green alga.