bluuebunny/crossref_metadata_2025 huggingface dataset:
Localization of fatty acid double bonds by gas chromatography of intermediate aldehydes as 1,3‐dioxane
Authors: Lakshminarayana Gollamudi , Cornwell David G.
Published: November 2006

A semi‐micro quantitative method has been developed for the determination of double bond positions in unsaturated fatty acid methyl esters differing in position, number of double bonds and chain length. This method involves ozonolysis in methylene chloride in the presence of 1,3‐propanediol, reduction of the hydroperoxides with dimethyl sulfide and conversion of aldehyde and aldester fragments to stable dioxanes, followed by gas chromatographic analysis under programmed temperature. Propanediol acts as a proton donor for the generation of hydroperoxides as well as a reactant for the formation of dioxanes. All the steps are carried out in a culture tube without any transfers. The absence of unoxidized ester and unreduced hydroperoxide or ozonide has been shown by thin layer chromatography. The method has been tested with pure esters and their binary mixtures. Experimental values for mole percentage composition in the mixtures agreed with the actual values. This method enabled us to isolate and estimate malondialdehyde for the first time as a stable bis‐dioxane derivative.
Effects of a (n−3) polyunsaturated fatty acid‐deficient diet on profiles of serum vitellogenin and lipoprotein in vitellogenic trout (Salmo gairdneri)
Authors: Frémont L. , Léger C. , Petridou B. , Gozzelino M. T.
Published: November 2006

During the 6 months of vitellogenesis, 3‐year‐old female trout (Salmo gairdneri) were fed either an enriched (E) or an (n−3) polyunsaturated fatty acid (PUFA)‐deficient (D) diet; serum vitellogenin (VG) and lipoproteins (d<1.21 g/ml) were analyzed at the third month of vitellogenesis (September) and at ovulation (December). The serum content of high density lipoproteins (HDL), the major protein class, maintained a mean value of 1500 mg/dl at both stages and with both diets. On the contrary, very low density lipoproteins (VLDL) were 90% higher during vitellogenesis than at spawning time, whereas excess vitellogenin circulated at this period (6580 mg/dl serum with diet E). The diet deficient in (n−3) lowered serum vitellogenin content by 16% in September and by 26% in December. The degree of (n−3) PUFA incorporation moderately decreased in low density lipoproteins (LDL) and in HDL with the (n−3)‐deficient diet. The effect was more pronounced for 20∶5. On the other hand, essential 22∶6 was incorporated into vitellogenin at the same rate in September as in December with diet E (23% and 25%, respectively), whereas after a 3‐month deficiency, the percentage fell to 12%; this percentage rose again to 19% at spawning time. These findings show that, although stored (n−3) PUFA were not exhausted after a 6‐month dietary deficiency, the incorporation of essential fatty acids (EFA) into vitellogenin during the early stages of oogenesis was low, suggesting changes in egg composition that may influence hatching.
The biosynthesis of n‐[2H7] fatty acids byArthrobacter globiformis from [U‐2H15] octanoic acid
Authors: White Robert H.
Published: November 2006

The principal fatty acids present whenArthrobacter globiformis is grown on a glycine medium free of normal fatty acids were found to be the C15 and C16 anteiso fatty acids; only a small amount of the normal fatty acids (C14 and C16) were present. Cells grown on the same medium but supplemented mented with 0.1 mg/ml [U‐2H15]octanoic acid were found to contain an increased amount of the normal fatty acids and these fatty acids were found to be labeled with 7 deuteriums. I concluded that the octanoic acid is degraded by β‐oxidation in these cells to [U‐2H7] butyryl‐CoA, which then competes with 2‐methylbutyryl‐CoA for the initiation of fatty acid biosynthesis.
Daily variations of the biosynthesis and composition of fatty acids in rats fed on complete and fat‐free diets
Authors: de Gómez Dumm I. N. T. , de Alaniz M. J. T. , Brenner R. R.
Published: November 2006

This report describes the daily changes in fatty acid composition and fatty acid desaturation in rats feeding on a complete diet and a fat‐free diet successively. Rats on a complete diet showed a good homeostasis in the percentage of fatty acid in plasma, with a possible palmitic acid rhythm, but the fat‐free diet initiated an essential fatty acid‐deficient pattern in a few hours. The light‐dark period in animals feeding on a complete diet motivates a feeding rhythm that causes changes in linoleic and arachidonic acids in the whole liver and microsomes that are related to Δ6 and Δ5 desaturase activities. The patterns of Δ6 and Δ5 desaturase changes were different. Linoleic acid intake during the dark periods (complete diet feeding) caused a decrease of Δ6 desaturase activity and the activation of Δ5 desaturation that led to an increase of arachidonic acid biosynthesis. The feeding of a fat‐free diet eliminated the rhythm observed in linoleic and arachidonic acid composition in the liver and changed the desaturase rhythms. The Δ9 desaturase activity in the liver also showed a daily rhythm in the complete‐diet period that disappeared with the change to a fat‐free diet, while the activity increased markedly. A negative correlation existed between the percentage of linoleic acid in the liver and the Δ9 desaturase activity. However, no correlation was found between Δ9 desaturase activity and the percentage of 16∶1 and 18∶1 in the complete‐diet period.
Effect of different amino acid diets on δ5, δ6 and δ9 desaturases
Authors: Peluffo Raul O. , Nervi Anibal M. , Gonzalez Maria S. , Brenner Rodolfo R.
Published: November 2006

A high‐protein diet with 45% calories from casein increased δ6 desaturase activity in rat‐liver microsomes. High‐protein diets with 45% calories from a synthetic mixture of amino acids in the same proportion as casein decreased the δ9 desaturase, slightly increased the δ5 desaturase and greatly increased δ6 desaturase activities compared with a high‐carbohydrate diet. The elimination of phenylalanine and tyrosine from the synthetic mixtures of amino acids increased the δ6 desaturase activity. Massive amounts of phenylalanine or tyrosine in the diet inhibited δ6 desaturase activity. Tyrosine and phenylalanine may, by conversion to tyrosine, decrease the activity of the δ6 desaturase.
The effects oftrans fatty acids on fatty acyl Δ5 desaturation by human skin fibroblasts
Authors: Rosenthal Miriam D. , Doloresco Mark A.
Published: November 2006

The effectiveness of different fatty acids as inhibitors of fatty acyl Δ5 desaturation activity in human skin fibroblasts has been investigated. When incubated with 2.25 μM [14C] eicosatrienoate (20∶3ω6) in otherwise lipid‐free medium, these cells rapidly incorporate the radiolabeled fatty acid into cellular glycerolipids and desaturate it to produce both [14C] arachidonate and [14C] docosatetraenoate. The Δ5 desaturation activity can be enhanced by prior growth of the cells without serum lipids. Elaidate (9t–18∶1) is a potent inhibitor of Δ5 desaturation whiletrans‐vaccenate (11t–18∶1) is virtually without effect. Oleate and linoleate are only mildly inhibitory. Linoelaidate (9t, 12t–18∶2) is more inhibitory than linoleate but significantly less effective than elaidate. The effects of elaidate can be readily overcome by increasing the concentration of exogenous eicosatrienoate. Studies with a variety oftrans monounsaturates of differing chain lengths indicate that the ω9trans fatty acids are potent inhibitors of Δ5 desaturation, while ω7trans fatty acids are relatively ineffective. Intact human fibroblasts could thus be important in characterizing novel fatty acids as selective inhibitors of arachidonate synthesis in vivo.
Effect of protein depletion on the VLDL triacylglycerol secretion and apoprotein synthesis by the perfused liver from pregnant rats
Authors: Tournier H. , Yaryour G. , Mercuri O. , De Tomás M. E.
Published: November 2006

The effect of protein depletion in the pregnant rat on the polyunsaturated fatty acid incorporation into very low density lipoproteins (VLDL) has been investigated. The apoprotein pattern of these particles was determined. In in vivo experiments the amounts of serum and liver triacylglycerol were determined. VLDL were isolated and their apo C concentration calculated. In in vitro experiments the radioactivity of [3H] leucine incorporated into VLDL apoproteins was measured. The results show that protein depletion during pregnancy promotes a drastic increase in serum and liver triacylglycerol. The VLDL isolated from these animals show an increase in the triacylglycerol/protein ratio and a decrease in their content of apo C. Meanwhile, a significant reduction in the [3H]leucine incorporation into apo C peptides by the perfused liver of protein depleted rats was detected. On the other hand, protein deprivation did not affect labeled linoleic and arachidonic acid incorporation into triacylglycerol of the newly secreted VLDL. Taking these results together, let us deduce that a defective VLDL is secreted by the liver of the protein depleted pregnant rats. The abnormal composition of these particles may influence its normal metabolism through their effects on lipoprotein lipase and this fact could affect the normal supply of polyunsaturated fatty acids to the fetus.
Occurrence of a 22∶2 nonmethylene interrupted dienoic fatty acid and its seasonal distribution among lipids and tissues of the fresh water bivalveDiplodon delodontus from an isolated environment
Authors: Irazu C. ‐E. , Pollero R. J. , Brenner R. R.
Published: November 2006

Realatively high levels of a non‐methylene‐interrupted dienoic fatty acid were detected in the freshwater molluscDiplodon delodontus. The (7,13) 22∶2 NMID fatty acid was separated from total fatty acids by TLC, and its structure was determined by GLC and reductive ozonolysis. Its seasonal distribution was investigated in different tissues and lipids of the mollusc. High concentrations of this acid were found in polar lipids. The absence of the 22∶2 NMID fatty acid in the lipids of plankton and sediment in the same habitat suggests that it may be biosynthesized by themollusc. Possible synthesis and functions of the NMID fatty acids are discussed.
The effects of dietary cholesterol on blood and liver polyunsaturated fatty acids and on plasma cholesterol in rats fed various types of fatty acid diet
Authors: Huang Y. S. , Manku M. S. , Horrobin D. F.
Published: November 2006

Male rats were fed on a fat‐free diet for 8 weeks and then switched to diets containing 10% hydrogenated coconut oil (HCO), safflower oil (SFO) or evening primrose oil (EPO). Half of each group was also given 1% of cholesterol in the diet. After 5 further weeks, plama, red cell and liver fatty acids were measured in the various lipid fractions. Plasma and liver cholesterol also were estimated. In almost all fractions and on all three diets, feeding cholesterol led to accumulation of the substrates of desaturation reactions and to deficits of the products of these reactions. The results were consistent with inhibition of Δ‐6, Δ‐5 and Δ‐4 desaturation of n−6 essential fatty acids. Since the diets were deficient in n−3 fatty acids, levels were very low but were also consistent with inhibition of desaturation. In contrast, cholesterol had relatively less consistent effects on 20∶3n−9, suggesting that desaturation of n−9 fatty acids was less inhibited. Plasma cholesterol levels rose sharply in the HCO and SFO groups but not at all in the EPO group. EPO contains the product of Δ‐6 desaturation, 18∶3n−6, suggesting that conversion of linoleic acid to 18∶3n−6 and possibly to further metabolites may be important for the cholesterol‐lowering effect of polyunsaturates.
Lipid and fatty acid characterization and metabolism in the sea anemonePhymactis clematis (Dana)
Authors: Pollero Ricardo J.
Published: November 2006

Neutral lipid, phospholipids and fatty acids of the sea anemonePhymactis clematis from the south‐west Atlantic were characterized and quantified in spring and autumn. Neutral lipids predominated over phospholipids in both seasons. Triacylglycerol and diacylglycerol ethers were the major lipids. In spring, an increase of esterified sterols was noted. The major fatty acids found were 22∶5ω3, 20∶5ω3 and 16∶0. The sea anemones were also incubated in vivo with either [1‐14C]linoleate or [1‐14C] α‐linolenate for 2 hr. Isotope incorporation into lipids and their transformations into higher fatty acids were examined. Both precursors were incorporated into the lipids, mainly in triacylglycerols and mono‐acylglycerols, while α‐linolenate was also incorporated into phospholipids. The radioactive linoleate was elongated to 20∶2, 22∶2 and 24∶2 fatty acids, but not desaturated to 18∶3ω6. α‐Linolenate was desaturated by Δ6 desaturase to 18∶4ω3. The specificity of Δ6‐desaturase is discussed.
Effects of purified eicosapentaenoic acid on arachidonic acid metabolism in cultured murine aortic smooth muscle cells, vessel walls and platelets
Authors: Morita I. , Saito Y. , Chang W. C. , Murota S.
Published: November 2006

The effects of highly purified eicosapentaenoic acid (97% pure) on the arachidonic acid cascade in isolated murine vascular cells and platelets were studied. The incorporation of eicosapentaenoic acid was not as active as that of arachidonic acid in platelets. The ratio of incorporation of eicosapentaenoic acid to arachidonic acid into platelet phospholipids was about 0.7. Analysis of the phospholipid fractions of platelets after labeling with14C‐eicosapentaenoic acid and14C‐arachidonic acid revealed that the incorporation of14C‐eicosapentaenoic acid into the phosphatidylinositol fraction is significantly less than that of14C‐arachidonic acid, while the incorporation of both fatty acids into other phospholipid fractions was almost the same. On the other hand, no significant difference between either fatty acid in incorporation rate, kinetics or distribution in cellular phospholipids was found in cultured aortic smooth muscle cells. Following treatment with eicosapentaenoic acid, cells produced less prostacyclin from endogenous arachidonic acid than did control cells. This was not due to the decrease in fatty acid cyclooxygenase activity, but rather, due to the decrease in arachidonic acid content in cellular phospholipids. In addition, eicosapentaenoic acid was neither converted to prostaglandin I3 by the vascular cells nor to thromboxane A3 by platelets. Furthermore, similar results were also obtained by in vivo experiments in which rats were fed with eicosapentaenoic acid enriched diet.
Effects of streptozotocin‐induced diabetes on microsomal long‐chain fatty acyl‐CoA synthetase and hydrolase
Authors: Dang A. Q. , Faas F. H. , Carter W. J.
Published: November 2006

Streptozotocin‐induced diabetes significantly decreased rat liver microsomal long‐chain fatty acyl‐CoA (LCA‐CoA) hydrolase. The decrease was observed using either palmitoyl‐CoA (35 per cent, p<0.01) or oleoyl‐CoA (23 per cent, p<0.01) as the substrate for the enzyme. Under the same conditions, diabetes did not significantly alter activity of LCA‐CoA synthetase. Daily subcutaneous injections of protamine zinc insulin (10–12 units/day) into the diabetic rats returned their blood glucose to normal but only partially corrected the LCA‐CoA hydrolase activity and did not effect LCA‐CoA synthetase activity. The decreased LCA‐CoA hydrolase and the unchanged LCA‐CoA synthetase activities in the diabetic rat liver were interpreted as factors that may contribute to elevation of fatty acyl‐CoA levels in the diabetic liver.
Fatty liver caused by chronic alcohol ingestion is prevented by dietary supplementation with pyruvate or glycerol
Authors: Rao G. Ananda , Riley Diana E. , Larkin Edward C.
Published: November 2006

Earlier studies showed that the fatty liver, caused by feeding rats the Lieber‐DeCarli alcohol diet for four weeks, was prevented if the diet was supplemented with dihydroxyacetone (22 g/l), pyruvate (22 g/l) and riboflavin (2.2 g/l). In the present study, we observed that fatty liver was prevented if the alcohol diet was supplemented with glycerol and lactate (22 g/l each) and riboflavin (2.2 g/l). Hence, the prevention of alcoholic fatty liver by the dietary supplementation with dihydroxyacetone and pyruvate may not be related to their capacity to serve as hydrogen acceptors and to oxidize NADH produced during ethanol metabolism. When rats were fed the alcohol diet supplemented with either glycerol or pyruvate, the hepatic triglyceride (TG) levels were similar to those in rats pair‐fed a Lieber‐DeCarli control diet in which alcohol was replaced with an isocaloric amount of dextrins. Therefore, the prevention of fatty liver does not require the simultaneous presence of several supplements. Dietary dihydroxyacetone or riboflavin did not reduce alcoholic fatty liver. Supplementation of the ethanol diet with isocaloric amounts of lactate or glucose, instead of pyruvate, did not abolish the development of fatty liver but caused a marked reduction in the hepatic TG levels. Animals fed the alcohol diet consumed only small amounts of carbohydrate for long periods of time. Since the inclusion of glucose or its metabolites in the alcohol diet fed to rats caused a marked decrease in the liver TG content, it is likely that the production or prevention of fatty liver is related to carbohydrate metabolism.
Changes in the structure of soybean triacylglycerols due to heat
Authors: Yoshida Hiromi , Alexander J. C.
Published: November 2006

Commercially refined soybean oil was heated at 180 C for 50, 70 or 100 hr with aeration. The triacylglycerol fractions separated from the oils by column chromatography on silica gel were fractionated further by silicic acid thin layer chromatography (TLC), and species compositions were determined by argentation TLC and lipase hydrolysis. There was a decrease in the absolute amounts of the triacylglycerols with longer heating periods, such as 21% for 50 hr and 42% for 100 hr. Relatively large changes occurred in the proportion of the molecular species of the triacylglycerols during heating; there was an increase in the more saturated species, 1–4 double bonds, and a decrease in species containing 5–7 double bonds. Although these changes occurred in the percentage of each triacylglycerol species, the positional distribution of the fatty acids in the 2‐position remained virtually unchanged throughout heating. Oleic and linoleic acids were commonly found in the 2‐position of the acylglycerol moiety, whereas most of the palmitic and stearic acids favored esterification in the 1‐ and 3‐positions. The results indicate that unsaturated fatty acids located in the 2‐position are protected significantly from thermal oxidative decomposition.
The effects of streptozotocin diabetes on tissue specific lipase activities in the rat
Authors: Nomura Takahide , Hagino Yasumichi , Gotoh Minehiro , Iguchi Akihisa , Sakamoto Nobuo
Published: November 2006

Fasting in normal rats produced a fall in hepatic triglyceride lipase (H‐TGL) activity as well as lipoprotein lipase (LPL) activities of adipose tissue and psoas minor muscle. On the other hand, LPL activities of heart and diaphragm were not decreased by fasting; the former, in fact, was increased significantly. Changes in tissue specific lipase activity caused by withdrawal of insulin from insulin‐treated diabetic animals paralleled in direction the changes induced by starvation of normal rats. Furthermore, it was shown in the present paper that the tissue specific lipase activity of diabetic rats became stuck in the starve phase of the starve‐feed cycle regardless of dietary intake. The changes of the tissue specific lipase activities, especially of liver, adipose tissue and heart, appeared to coincide with those of plasma insulin levels. These results strongly suggest that the tissue specific lipase system is under hormonal regulation by insulin. Streptozotocin diabetes produced hypertriglyceridemia. The possible mechanism of the hypertriglyceridemia in diabetic animals was discussed in connection with the role of the tissue specific lipase system in the serum triglyceride metabolism.
The effects of hypophysectomy and testosterone treatment on the composition and metabolism of testicular lipids
Authors: Marzouki Zohair M. H. , Coniglio John G.
Published: November 2006

The effects of hypophysectomy and of testosterone administration on lipid composition and metabolism of rat testicular tissue have been investigated. Increased concentrations of triacylglycerols and cholesterol were observed in testes of hypophysectomized compared to control (non‐hypophysectomized) rats on the eighth day posthypophysectomy. Administration of testosterone maintained the concentrations of these lipids at about normal levels. The concentration of phospholipids was not affected by the hypophysectomy. Incorporation of14C from 1‐[14C] linoleate into testicular lipids was determined 24 hours after intratesticular injection. In hypophysectomized compared to control rats there was more14C in C 16∶0, C 20∶2 and C 20∶3 and less14C in C 20∶4 and C 22∶4 of both phospholipids and triacylglycerols. After intratesticular injection of 1‐[14C] eicosatrienoate there was more14C in C 16∶0 and C 20∶3 and less14C in C 20∶4 and C 22∶4 of both phospholipids and triacylglycerols of hypophysectomized compared to control rats. Intratesticular injection of 1‐[14C]‐arachidonate resulted in less14C incorporation in C 22∶4 in testes of hypophysectomized than in those of control rats. Treatment with testosterone did not affect the metabolism of any of the14C‐substrates. These results indicate that the testicular desaturation of C 20∶3 to arachidonate, requiring a Δ5 desaturase, is inhibited by hypophysectomy and that testosterone by itself may control the concentrations of some testicular lipid classes but not the metabolism of the polyenoic acids.
Mass spectrometric evidence for the presence of platelet‐activating factor (1‐0‐alkyl‐2‐acetyl‐sn‐glycero‐3‐phosphocholine) in human amniotic fluid during labor
Authors: Nishihira Jun , Ishibashi Teruo , Imai Yoh , Muramatsu Toshio
Published: November 2006

Evidence is presented for the existence of platelet‐activating factor (PAF) in human amniotic fluid during labor by gas‐liquid chromatographic (GLC) and mass‐spectrometric (MS) analysis. The unique ether‐linked phospholipid was identified only in an amniotic fluid obtained from women during labor, and its alkyl side chain was composed exclusively of octadecyl residue.
Effect of dietary vitamin E upon fluorescent compounds of the rat uterus
Authors: Csallany A. Saari , Ayaz K. Lund , Menken B. Zaspel
Published: November 2006

Several water soluble and organic solvent soluble fluorescent peaks were observed in extracts of uteri from vitamin E deficient or supplemented rats following Sephadex column chromatography and spectrophotofluorometric analysis. Levels of one of the organic and two of the water soluble fluorescent peaks were found to be significantly higher in the uteri of vitamin E deficient rats than in vitamin E supplemented rats. Some of these fluorescent fractions may contribute to the brown discoloration that is known to occur in the uterus of vitamin E deficient animals.
Molecular species and fatty acid distributions of triacylglycerols from germinating soybean cotyledons
Authors: Yoshida Hiromi
Published: November 2006

Molecular species and fatty acid distributions of triacylglycerols obtained from cotyledons of soybean seedlings were investigated. Changes observed in triacylglycerol content were closely related to levels of total lipids present in the cotyledons. At day 12 of seedling growth, ca. 85% of triacylglycerols had been consumed. Immediately after the beginning of imbibition the oil consisted of triacylglycerols with even carbon numbers (from C‐50 to C‐60) based on the combined length of the fatty acyl chains present in a triacylglycerol. The dominant components throughout germination were C‐52 and C‐54 triacylglycerols. Fourteen molecular species of triacylglycerols were identified in the cotyledons. As soybean seedlings grew, the percentages of triacylglycerols decreased to 0.9–36.2% during the 12 days. Triacylglycerols containing one or more saturated fatty acids were hydrolyzed slightly faster than other species. Unsaturated fatty acids were dominant in the 2‐position throughout germination. These results suggest the mechanism of initial triacylglycerol hydrolysis may be different in various molecular species.
Photosensitized oxidation of methyl linolenate monohydroperoxides: Hydroperoxy cyclic peroxides, dihydroperoxides and hydroperoxy bis‐cyclic peroxides
Authors: Neff W. E. , Frankel E. N.
Published: November 2006

To elucidate the biological and flavor significance of lipid secondary oxidation products, cyclic peroxides were prepared by photosensitized oxidation of the hydroperoxides in autoxidized methyl linolenate. The oxidation product was fractionated by silicic acid chromatography, followed by high pressure liquid chromatography (HPLC) on a microporous silica column. Products characterized by thin layer chromatography (TLC), gas chromatography (GC), ultraviolet (UV), infrared (IR), nuclear magnetic resonance (NMR) and mass spectroscopy (MS) included 6‐membered cyclic peroxides (9‐hydroperoxy‐10,13‐epidioxy‐11, 15‐and 16‐hydroperoxy‐12,15‐epidioxy‐9, 13‐octadecadienoates), 15‐membered cyclic peroxides (9‐hydroperoxy‐10,12‐epidioxy‐13,15‐ and 16‐hydroperoxy‐13, 5‐epidioxy‐9,11‐octadecadienoates), dihydroperoxides (9,12‐; 9,16‐; 10,12‐; 10,15‐; 10,16‐; 13,15‐; 13,16‐dihydroperoxy octadecatrienoates) and hydroperoxy bis‐cyclic peroxides, each with one 5‐and one 6‐membered ring (9‐hydroperoxy‐10,12,13,16‐bis‐epidioxy‐14‐ and 16‐hydroperoxy‐9,12,13, 15‐bis‐epidioxy‐10‐octadecenoates). The 6‐membered cyclic peroxides are formed by 1,4‐addition of singlet oxygen to the conjugated diene system in 9‐ and 16‐linolenate hydroperoxide isomers after their isomerization to thetrans, trans configuration. The bis‐cyclic peroxides are formed by 1,4‐addition of singlet oxygen to the hydroperoxy 5‐membered cyclic peroxides derived from the 12‐ and 13‐linolenate hydroperoxide isomers. Secondary oxidation products similar to those identified in this study previously have been shown to be important precursors of volatile compounds that may contribute to flavor deterioration of fat‐containing foods.
Mass spectrometric location of double bonds in unsaturated fatty acids including conjugated acids as their methoxybromo derivatives
Authors: Shantha N. C. , Kaimal T. N. B.
Published: November 2006

Methoxybromo derivatives of unsaturated fatty acids including conjugated acids yield simple mass spectra and can be used to locate the position of double bonds in these acids. The derivatives are prepared under mild conditions by bromination of the unsaturated fatty acids in methanol. The method is illustrated with the methoxybromo derivatives from methyl esters of oleic, petroselenic, erucic, undecenoic, linoleic, linolenic, the conjugated diene acids from dehydrated castor oil, α‐eleostearic, punicic and parinaric acids. Unlike other methods using methoxy derivatives, the methoxybromo derivatives yield fewer ions, the diagnostic peaks forming the most intense ions of the spectra. While unambiguous double bond location is possible with monoenoic acids and conjugated fatty acids, only the end carbon atoms of the unsaturation system in nonconjugated polyenoic acids is located. But the characteristic appearance of fragments corresponding to [CH3(CH2)nCH(OMe)CH(Br)CH2−2H]+ and fragments 24 mass units higher than those which locate the end carbons in such fatty acids indicate a methylene‐interrupted system of double bonds.
Wide variations of plasma triglyceride concentrations in guinea pigs
Authors: Mori N. , Murase T. , Yamada N. , Arakawa N. , Takaku F.
Published: November 2006

Guinea pigs have varying plasma triglyceride concentrations ranging from 28 to 1392 mg/dl, with relatively uniform plasma cholesterol and phospholipid levels. To understand why the animals exhibit such wide variations of plasma triglyceride concentrations, we have explored the triglyceride hydrolyzing system by measuring tissue lipoprotein lipase activities and plasma activator for the enzyme. Lipoprotein lipase activities of epididymal adipose tissue of these animals were 759±117 (mean±SE) n moles FFA·min−1·g wet tissue−1, markedly low compared with those of rats. There were no relationships between plasma triglyceride concentrations and tissue lipase activities. Plasma activator for lipoprotein lipase was lacking in this animal. Guinea pigs with ascorbic acid deficiency for 2 weeks also showed marked variations of plasma triglyceride concentrations, without any changes in tissue lipoprotein lipase activities. Low adipose tissue lipoprotein lipase activities with deficient plasma activator for the enzyme suggest that the lipoprotein lipase‐mediated triglyceride degradation could be impaired in this animal, and this may account for the marked variation of plasma triglyceride concentrations.
The positional distributions of fatty acids in the triacylglycerols and phosphatidylcholines of the intestinal and popliteal lymph and plasma of sheep
Authors: Christie W. W. , Clegg R. A. , Calvert D. T. , Noble R. C.
Published: November 2006

As part of a study of the contribution of the intestinal lymph lipoproteins and their lipid constituents to the plasma lipids in sheep, the positional distributions of the fatty acids in the triacyl‐sn‐glycerols and phosphatidylcholines in very low density/low density lipoprotein and high‐density lipoprotein fractions were determined by stereospecific analysis procedures. The triacyl‐sn‐glycerols of these lipoprotein fractions in intestinal lymph did not differ appreciably in structure and resembled the plasma triacyl‐sn‐glycerols in the composition of positionsn‐2 especially. However, there were appreciable amounts of the essential fatty acid, linoleic acid, in positionssn‐1 andsn‐3 of the triacylglycerols in lymph but not in plasma. This result is discussed in terms of the metabolism of the triacylglycerols of lymph after they enter the plasma as part of a mechanism for the conservation of essential fatty acids in ruminants. No differences of metabolic note were observed in the structures of the phosphatidylcholines between lipoprotein fractions and among tissues.
Activation of polyunsaturated fatty acids by rat tissues in vitro
Authors: Reddy T. Sanjeeva , Bazan Nicolas G.
Published: November 2006

The conversion of labeled palmitic, linoleic, arachidonic and docosahexaenoic acids to their respective acyl CoA’s was studied in homogenates and microsomes of rat tissues. The highest activity, both in homogenates and microsomes, was seen in liver and heart. There was moderate activity in retina, brain, lung, kidney and testes and the lowest activity was found in spleen. Docosahexaenoic acid was activated much less actively in heart tissue than the other fatty acids. In all tissues examined, the highest activation was observed with arachidonic acid and the lowest with docosahexaenoic acid. Except for liver, those tissues that contained high levels of docosahexaenoic acid also had the highest activation capacity for this fatty acid.
Short term essential fatty acid deficiency in rats. Influence of dietary carbohydrates
Authors: Trugnan G. , Thomas‐Benhamou G. , Cardot P. , Rayssiguier Y. , Bereziat G.
Published: November 2006

The effects of long term (8–14 wk) essential fatty acid (EFA)‐deprived diets in rats are well documented. In the present study, we compared, in weanling rats, the effect of a short term (two wk) hydrogenated coconut oil, EFA‐deprived, diet (D) with that of a corn oil, EFA‐adequate, diet (A), using either sucrose (SU) or starch (ST) as carbohydrate. After two wk, rats fed the sucrose/hydrogenated coconut oil diet developed some characteristic features of EFA deprivation: slower growth rate, decreases in linoleic and arachidonic acid of plasma phospholipids and an increase in n−9 eicosatrienoic acid of plasma phospholipids. When rats ate the starch/hydrogenated coconut oil diet, there was a similar decrease in linoleic acid of plasma phospholipids, but only a small effect on growth rate and no change in the arachidonic acid content of plasma phospholipids. EFA deprivation and sucrose had opposite effects on plasma triglyceride (TG) levels: deprivation induced a decrease, whereas the sucrose induced an increase in very low density lipoprotein (VLDL) triglycerides. The observed decrease in plasma triglyceride during EFA deporivation might result from an activation of lipoprotein lipase during the early stages of deprivation.
Changes in Δ5‐ and Δ7‐sterols during germination and seedling development ofCucurbita maximaduring germination and seedling development ofCucurbita maxima
Authors: Garg Vipin K. , Nes William R.
Published: November 2006

While seeds ofCucurbita maxima contain both Δ5‐ and Δ7‐sterols, the former, which have been described earlier, now have been found to disappear during germination. This suggests that a function exists for the Δ5‐compounds only in the early part of the life cycle ofC. maxima, unlike most of the other higher plants studied. In contrast to the Δ5‐sterols, the level of Δ7‐sterols increased during germination as well as during seedling development and maturation. The period of transition between germination and seedling development appeared to be of special importance in terms of sterol changes. This period represented a surge of sterol biosynthesis with an ontogenetic shift in sterol composition from approximately equal amounts of 24α‐ and 24β‐ethyl stereochemistry to a predominance of the former. The sterol composition of the mature plants included only about 5% of the 24β‐ethylsterols. The configurational relationships were demonstrated by high resolution1H‐NMR. The sterols of the mature plants were: 25(27)‐dehydrochondrillasterol, 24β‐ethyl‐25(27)‐dehydrolathosterol, avenasterol, spinasterol, 22‐dihydrospinasterol and 24ξ‐methyllathosterol. Based on the changes which occurred in the relative amounts of the Δ7‐sterols, it did not appear that the Δ5‐components were being converted to their Δ7‐analogs.
Potential antineoplastic dihydroxy‐fatty acids
Authors: Piatak David M. , Tang Pui‐Fun Louisa
Published: November 2006

The fatty acid aglycones of two naturally occurring glycosides, one of which is reported to possess antitumor activity, were synthesized for biological evaluation. The preparation of 3,11‐dihydroxyhexadecanoic acid and 3,12‐dihydroxyhexadecanoic acid started with the monoethyl esters of nonanedioic acid and decanedioic acid, respectively, and proceeded through the corresponding C14 ketoesters, ketalesters, and ketalaldehydes and C16 ketalhydroxyesters and dihydroxyesters. Various products and intermediates were found to have no inhibitory action in the P388 lymphocytic leukemia screen. A rearrangement of the ethylene glycol ketal‐protecting group from the initially protected ketone group to a newly formed aldehyde moiety was observed.
Positional distribution of fatty acids in cardiolipin of mitochondria from 21‐day‐old rats
Authors: Wolff Robert L. , Combe Nicole A. , Entressangles Bernard
Published: November 2006

Pure cardiolipins (1,3‐diphosphatidylglycerol) were prepared from mitochondria of heart, liver and kidney from 21‐day‐old male Wistar rats and submitted toNaja naja venom phospholipase A2 (EC 3.1.1.4) action. Incubation conditions were controlled carefully, and a complete hydrolysis of cardiolipin to lysocardiolipin {di [1 (1″) acylsn‐glycero‐3‐phosphoryl] 1′, 3′‐sn‐glycerol} and fatty acids from positions 2 (2″) was obtained in less than two hr practically without side reactions. Cardiolipins from the three organs contained low levels of saturated fatty acids; stearic acid accounted for 0.4–0.7% and palmitic acid for 1.4–3.5% of total fatty acids. These percentages apparently depended on the organ. In all three cases, linoleic acid was the major component, but its percentage varied from 62–78% of total fatty acids. Acyl chains linked to positions 1 (1″) of all three cardiolipin preparations exhibited a similar pattern; they were composed of linoleic acid for 85–89%. This fatty acid also was the main component esterified at position 2 (2″), but its percentage was much more variable: from 39.8% in heart to 51.2% in kidney and 67.8% in liver mitochondria. The remaining acids comprised octadecenoic and polyunsaturated fatty acids with more than 18 carbon atoms in different proportions. As opposed to other phospholipids,cis‐vaccenic acid, and not oleic acid, was the main octadecenoic acid present in cardiolipins.

Octadecenoic acids were nine‐ to 10‐fold more concentrated at positions 2 (2″) than at positions 1 (1″). The percentage ofcis‐vaccenic acid was four‐ to five‐fold higher than that of oleic acid at positions 2 (2″), whereas oleic acid dominated at positions 1 (1″). From results presented in this study and selected literature data, it may be concluded that fatty acids are asymmetrically distributed in cardiolipins of different origins, with linoleic acid showing a definite preference for position 1 (1″).
Physical state of inhibitor fatty acids and linoleate solutions under lipoxygenase assay conditions
Authors: Gibian Morton J. , Colanduoni John
Published: November 2006

A variety of fatty acids, which are potential competitive inhibitors of soybean lipoxygenase (EC 1.13.11.12), give kinetically unstable mixtures in standard assay solutions containing linoleate (substrate). In the assay solution (pH 10, 0.1 M borate, 1.63% ethanol), each fatty acid by itself shows normal surface tension vs concentration behavior; but, despite a range of solubilization techniques in the presence of 10 μM or higher linoleate and low concentrations of these materials, irreproducible surface‐tension readings and inhibition kinetics results. This inhomogeneity (or kinetic instability) disappears as the concentration increases. Critical micelle concentration (CMC) values of mixtures are not additive, and binary mixture behavior depends on fatty acid structure. Several lines of observation, including CMC values and actual surface tension (γ) values for several systems, suggest premicellar heterodimer or higher mixed aggregate formation. Lipids with Ki significantly above the irreproducible surface‐tension range give good kinetic behavior, and Ki is reported. The results are in accord with earlier work on aspects of these systems. Complementary solution physical studies must be done for any kinetic (or specificity) determinations of enzymes using lipids.
Long‐chain acyl‐CoA levels in liver from rats fed high‐fat diets: Is it of significance for an increased peroxisomal β‐oxidation?
Authors: Nilsson A. , Thomassen M. S. , Christiansen E.
Published: November 2006

The levels of long‐chain acyl‐CoA in the livers of rats given diets containing various amounts of dietary oils were investigated. Increasing the amount of soybean oil in the diet from 5% to 25% (w/w) led to a 40% increase in long‐chain acyl‐CoA. With partially hydrogenated marine oil, a sigmoidal doseresponse curve was obtained, giving a 60% increase when 20% or more of this oil was in the diet.

All high‐fat diets tested resulted in higher levels of long‐chain acyl‐CoA than the low‐fat control containing soybean oil. The increase was most prominent with partially hydrogenated marine and rapeseed oils.

With diets containing partially hydrogenated marine oil, the ratio of long‐chain acyl‐CoA to acid‐soluble CoA was increased after 3 days, but decreased after 3 weeks, to a value similar to that observed in animals fed soybean oil because of an extensive increase in acid‐soluble CoA.

Increased levels of long‐chain acyl‐CoA were also observed after clofibrate was administered, but the increase was less prominent than observed with high‐fat diets.

When comparing the levels of long‐chain acyl‐CoA observed after 3 days on different diets with the peroxisomal β‐oxidation activity previously determined after 3 weeks on the corresponding diets, a straight line was obtained. These results are discussed in relation to the possibility that long‐chain acyl‐CoA induces peroxisomal β‐oxidation activity.
Comparative study of the molecular species of chloropropanediol diesters and triacylglycerols in milk fat
Authors: Kuksis A. , Marai L. , Myher J. J. , Cerbulis J. , Farrell H. M.
Published: November 2006

In an effort to establish the origin of the fatty acid esters of 3‐chloropropanediol, which recently have been isolated in small amounts from goat milk, we compared the molecular species composition of the chlorohydrin diesters and of goat milk triacylglycerols. The chloropropanediol diesters were found to be composed of molecular species containing C10−C18 fatty acids and corresponded closely in carbon number to those calculated for the long chain sn‐1,2‐diacyl‐glycerol moieties of goat milk triacylglycerols. The molecular species of goat milk total triacylglycerols contained C4−C18 fatty acids. It is suggested that triacylglycerols and chloropropanediol diesters are derived from the same pool of long chain fatty acids. A molecular distillate of bovine milk fat did not contain chloropropanediol diesters, while the available samples of human milk fat were shown to contain alkyldiacylglycerols as the major components of a neutral lipid fraction corresponding in polarity to the chloropropanediol diesters.
Partial specific volume and preferential hydration of low density lipoprotein subfractions
Authors: Kahlon Talwinder S. , Adamson Gerald L. , Glines Laura A. , Orr Joseph R. , Lindgren Frank T.
Published: November 2006

We have determined the partial specific volume () for five low density lipoprotein (LDL) subfractions (n=5–7) and evaluated preferential hydration (n=2) for LDL subfraction 3 in normolipoproteinemic subjects in order to characterize these highly atherogenic components of the human plasma lipoprotein spectra. Values for at 1 g were determined by sixth place density measurements of the solvent and lipoprotein solutions and carbon, hydrogen and nitrogen (CHN) absolute mass of the lipoprotein concentrations. Mean values for were 0.9757±0.0019, 0.9701±0.0007, 0.9674±0.0016, 0.9616±0.0016 and 0.9550±0.0025 ml/g for subfractions 1, 2, 3, 4 and 5, respectively. However, molecular densities (σ) obtained from ϱ(rho)=1/ for respective LDL subfractions were 1.0249, 1.0308, 1.0337, 1.0399 and 1.0471 g/ml, respectively. The preferential hydration of lipoprotein subfraction 3 (n=2) in NaCl/H2O solutions was 2.9–4.8 wt percent, whereas values were much lower (0.3–0.6 wt percent) in NaCl/NaBr/H2O solvent system. Unhydrated densities for LDL subfraction 3 (n=2) at 1 g (sixth‐place density meter) were 1.0287 and 1.0269 g/ml, whereas at 200,000 × g (used in D2O flotation ηFo vs ϱ determinations) both values were 1.0308 g/ml, indicating that these similar LDL fractions have 23 and 53% higher compressibility than the solvent at 200,000 × g force. It was observed that the linearity of ηFo vs ϱ may not be valid for solvents NaCl/NaBr/H2O of density as high as 1.4744 g/ml. Thus, flotation velocity data using extreme salt concentrations (1.4744 g/ml and higher) may be viewed with caution.
Complete separation of phospholipids from human heart combining two HPLC methods
Authors: Juanéda Pierre , Rocquelin Gérard
Published: November 2006

The separation of phospholipid classes from human heart was achieved in two steps by high performance liquid chromatography (HPLC) using a silica column with an ultraviolet spectromonitor at 206 nm. A complete partitioning of phosphatidylcholines (PC), phosphatidylethanolamines (PE), phosphatidylinositols (PI), phosphatidylserines (PS), cardiolipins (CL), lysophosphatidylcholines (LPC) and sphingomyelins (Sph) was obtained for further analysis.
Tissue distribution of phytanic acid and its analogues in a kinship with Refsum's disease
Authors: Yao Jeffrey K. , Dyck Peter James
Published: November 2006

Three of six kin were identified, by high performance thin layer chromatography, capillary gas chromatography and mass spectrometry, as having phytanic acid storage disease. Phytanic acid was found in triacylglycerol and, to a lesser degree, in phosphatidylcholine and free fatty acids. An unsaturated analogue of phytanic acid was additionally identified in plasma and erythrocyte triacylglycerols. In plasma, branched chain fatty acids were primarily localized in the low density lipoprotein fraction. The concentration of plasma major fatty acids was not affected by the presence of these branched chain fatty acids. In contrast to plasma, only small amounts of phytanic acid were found in cerebrospinal fluid and biopsied sural nerve. The nerve phytanate was mainly associated with triacylglycerol in epineurial and perineurial tissues. Lack of phytanate accumulation in sural endoneurium, even in cases with severe fiber degeneration, suggests that demyelination in Refsum's disease may not be due to myelin instability resulting from the incorporation of branched chain fatty acids into peripheral nerve membrane.
Ether glycerophospholipids of gills of two pacific crabs,Cancer antennarius andPortunus xantusi
Authors: Chapelle S. , Hakanson J. L. , Nevenzel J. C. , Benson A. A.
Published: November 2006

Phospholipids and sterols constituted 70 and 20%, respectively, of the total lipids of the gills of two crabs,Cancer antennarius andPortunus xantusi. Phosphatidylcholine (46–55% of the total phospholipid phosphorous) and phosphatidylethanolamine (24–25%) were the principal phospholipids present. In both species 1′‐alkenyl glycerols were present in about 20% of the phospholipid molecules but were not detected in the neutral gill lipids. The total ether phospholipids ofC. antennarius gills contained 62% 1‐(1′‐alkenyl) groups, with the remainder probably being 1‐alkyl moieties. Total gill plasmalogen contents were in the range of 163–184 μmol/g lipid, 82–87% of which was in the phosphatidylethanolamine fraction in both crab species.
Free and esterified sterols of cotton buds and anthers
Authors: Lusby William R. , Oliver James E. , McKibben Gerald H. , Thompson Malcolm J.
Published: November 2006

Capillary gas liquid chromatography analyses were conducted on free and esterified sterol fractions of cotton (Gossypium hirsutum cv. Stoneville 213) floral buds and anthers. The free sterols of both cotton buds and anthers consist mainly of the common plant sterols sitosterol, stigmasterol and 24ζ‐methylcholest‐5‐en‐3β‐ol. The composition of esterified sterols of cotton buds and anthers were similar, and consisted of pollinastanol, 31‐norcycloartanol, cycloartenol, 31‐norcycloartenol, 24‐dehydropolinastanol and sitosterol. Desmosterol was also present in both the free and esterified sterols of anthers. The identities of the sterols were confirmed by gas chromatography‐mass spectrometry analyses. Esterified sterols accounted for 46.7 and 88.7% of total sterols of cotton bud and anthers, respectively. The ratio of esterified sterol to free sterol per gram of tissue is about 8∶1 in anthers. The Δ5‐sterols of the esterified sterols of cotton buds and anthers account for only 17 and 9.2% of the total sterols, respectively.