bluuebunny/crossref_metadata_2025 huggingface dataset:
Separation ofcis andtrans‐isomers of 1,2‐benzylidene glyceryl esters
Authors: Johnson C. B.
Published: November 2006

Separation of thecis‐ andtrans‐isomers of 1,2‐benzylidene glyceryl esters has not yet been achieved by column or gas liquid chromatography. However these isomers were separated by thin layer chromatography in the present study and the parent cyclic alcohols regenerated by alkaline hydrolysis.
Identification of some polyenoic acids isolated from human testicular tissue
Authors: Grogan W. M. , Coniglio J. G. , Rhamy R. K.
Published: November 2006

Five polyenoic acids present in human testicular tissue have been isolated in pure form by gas chromatography and chemically identified using procedures of hydrogenation and UV absorption spectrometry following alkaline isomerization and ozonolysis. Three of these (20∶3, 22∶4 and 22∶5) belong to the linoleic acid and the other two (22∶6 and 22∶5), to the α‐linolenic acid family. The latter (22∶5ω3) had not been reported previously in human testes; the others had been tentatively identified by retention time using gas chromatography.
Isomers of alpha‐tocopheryl acetate and their biological activity
Authors: Ames Stanley R.
Published: November 2006

α‐Tocopheryl acetate, an ester of the naturally occurring form of vitamin E, has a biopotency of 1.66 IU/mg as determined by bioassays based on biological function. On a similar basis, 2l‐α‐tocopheryl acetate, the 2‐epimer of α‐tocopheryl acetate, has a biopotency of 0.35 IU/mg. Results of hemolysis bioassays indicate relative activities of 1.53 and 0.56 for α‐ and 2l‐α‐tocopheryl acetates, respectively, compared with 2dl‐ or all‐rac‐α‐tocopheryl acetate. Responses to plasma and liver storage tests average 1.35 for α‐tocopheryl acetate compared with all‐rac‐α‐tocopheryl acetate. The configuration at C‐2 is most important but the configurations at C‐4’ and C‐8’ may also be important in determining biopotency. There is no evidence of synergism between α‐tocopheryl acetate and 2l‐α‐tocopheryl acetate. Since the two isomers comprising 2dl‐α‐tocopheryl acetate, the former International Standard, have different rates of absorption, tissue storage, metabolism and excretion, a better standard for vitamin E is needed. α‐Tocopheryl acetate has both the chemical and biological properties required for a new International Standard for vitamin E. Redefinition of an International Unit in terms of 1 IU=0.60 mg of α‐tocopheryl acetate would give a precise reference for future research and a reasonable correlation with data collected in the past.
Distribution and metabolism of two orally administered esters of tocopherol
Authors: Gallo‐Torres Hugo E. , Neal Miller O. , Hamilton James G. , Tratnyek Carol
Published: November 2006

A comparison of the distribution of total radioactivity in rat tissue lipids after the oral administration of d,1‐3,4‐3H2‐α‐tocopheryl nicotinate and d,1‐α‐tocopheryl‐1’,2’‐3H2‐acetate in equimolar concentrations has demonstrated that there is considerable variation in the concentration of vitamin E in organs at different times after dosing. A higher total radioactivity was found in the tissues of animals receiving α‐tocopheryl nicotinate than after α‐tocopheryl acetate 12 hr after feeding with an emulsion, but not at most other time intervals studied. These findings indicate that the tissue uptake of vitamin E after oral dosage with nicotinate ester is, perhaps, poorer than that occurring after feeding with tocopheryl acetate, or that α‐tocopheryl nicotinate has a faster turnover than the acetate ester. Although total radioactivity in the blood and liver of those animals dosed with α‐tocopheryl acetate varied slightly with time, there was a high peak of radioactivity at 12 hr after dosage with nicotinate ester. In both groups of rats, the adrenals, ovaries, adipose tissue and heart appeared to extract vitamin E from the blood for a period of up to 48 hr postabsorptively. Metabolic products of tocopherol detected by glass‐fiber paper chromatography were found in both instances. This analysis revealed that, when orally administered, both α‐tocopheryl nicotinate and α‐tocopheryl acetate are extensively metabolized by the tissues of the rat. The metabolite most abundantly occurring under these conditions was α‐tocopheryl quinone. In the adrenal glands, however, the most highly labeled compound was unesterified tocopherol, which increased with time and comprised up to 90% of the chromatographed radioactivity. From the data obtained, it can be assumed that the adrenal tissue plays a definite role in the metabolism of vitamin E.
Liver triglyceride synthesis failure in post‐spawning salmon
Authors: Phleger C. F.
Published: November 2006

The ability of liver of pink salmon, Onchorhychus gorbuscha, to synthesize triglycerides is lost after migration into fresh water and spawning. Triglyceride fatty acids are probably mobilized as cholesterol esters as energy sources in these starving fish. Total lipid decreases; cholesterol remains constant; and relative values of protein and water increase in the liver of the spawned out fish. Both hepatic lipogenesis and cholesterol synthesis decrease. Control values are given for river whitefish.
Cyanolipids of kusum (schleichera trijuga) seed oil
Authors: Mikolajczak K. L. , Smith C. R.
Published: November 2006

A cyanolipid, consisting of two fatty acid moieties esterified with 1‐cyano‐2‐hydroxymethylprop‐2‐ene‐1‐ol, constitutes 58% ofSchleichera trijuga (Kusum) seed oil.
Improved separation of phospholipids by counter‐current distribution
Authors: Collins F. D. , Trewhella M. A.
Published: November 2006

Separation by counter‐current distribution of individual molecular species of phospholipids are much improved by the use of CCl4:CH3OH:H2O (62∶33∶5 v/v) for lecithins and of heptane: CH3OH:H2O (50∶47.5∶2.5 v/v) for the methyl esters of the dinitrophenyl derivatives of phosphatidylethanolamines.
Mass spectrometry of lipids. I. Cyclopropane fatty acid esters
Authors: Christie W. W. , Holman R. T.
Published: November 2006

A method was developed for the almost quantitative conversion of unsaturated esters (from monoenes to tetraenes) to cyclopropanes using diiodomethane and a highly active zinc‐copper couple. These derivatives are sufficiently volatile for GLC analysis andcis andtrans isomers can be distinguished by this technique. Equivalent chain lengths of the cyclopropane derivatives were measured on polar and nonpolar phases. The mass spectra of the monocyclopropane compounds are very similar to those of the parent unsaturated esters. Those of dicyclopropanes, however, are quite distinctive so that the original structure of the ester can be deduced. Polycyclopropanes give complex spectra which are difficult to interpret in terms of the position of the original double bonds.
The structure of the glycerides of ergot oils
Authors: Morris L. J. , Hall S. W.
Published: November 2006

The oils from sclerotia or from suitable mycelial cultures ofClaviceps purpurea (ergot) contain up to 44% of ricinoleic acid but no free hydroxyl groups. This is due to the presence of, besides normal triglycerides, tetra‐acid, penta‐acid and hexa‐acid triglycerides. These contain respectively one, two and three ricinoleic acids esterified to glycerol, these in turn being acylated at their hydroxy groups with normal long‐chain fatty acids. By suitable complementary use of TLC, GLC and lipase hydrolysis techniques, the proportions, compositions and structures of these novel triglyceride classes were determined. Four types of positional specificities in fatty acid combinations could be shown by our procedures. These are discussed and, on the basis of our results, some tentative proposals as to possible biosynthetic mechanisms are advanced.
Fractionation of triglyceride mixtures by preparative gas chromatography
Authors: Kuksis A. , Ludwig J.
Published: November 2006

A semiautomatic system is described for gas‐chromatographic separation and recovery of triglycerides of uniform molecular weight in milligram quantities. It employs an Aerograph Autoprep 700 (Wilkens Instrument and Research Inc.) equipped with a stream splitter and a hydrogen flame ionization detector. The column is an aluminum or stainless steel tube (1/4 in. O.D.×2 ft) and contains silanized Chromosorb W (60–80 mesh) coated with 5% (w/w) JXR or SE‐30. Five to ten milligrams of mixed triglyceride are injected at a time and the temperature is programmed exponentially from 150 to 350C. With split ratios of 1∶5 to 1∶10 collections of 20 to 50 mg of each peak can be made with some 10 to 20 injections.
A comparative study of the phospholipids and fatty acids of some insects
Authors: Fast Paul G.
Published: November 2006

Phospholipids of 27 species of insects representing 6 orders and 20 families were examined by DEAE cellulose column chromatography to determine the choline/ethanolamine phosphoglyceride ratios, and by gas chromatography to determine the constituent fatty acids.

The phosphorus in the ethanolamine phosphoglycerides accounted for approximately 50% of the total lipid phosphorus in aphids (Homoptera) and in all but one family of Diptera (flies) examined while the phosphorus in the choline phosphoglycerides accounted for only about 25%. Ethanolamine and choline phosphoglycerides were present in approximately equal proportions in one family of Diptera and in the Coleoptera (beetles) examined. In the other insects examined choline phosphoglycerides predominated, ethanolamine phosphoglycerides comprising only about 25–30% of total lipid phosphorus as they do in most mammalian tissues.

Diptera in which ethanolamine phosphoglycerides were the major phosphatides were also characterized by high proportions of fatty acids less than 18 carbons long, particularly palmitoleic acid, in the neutral lipids. Aphids are characterized by a preponderance of 14‐carbon fatty acids. The evidence suggests that predominance of ethanolamine phosphoglycerides is associated with a preponderance of shorter chain fatty acids in the neutral lipids.

Differences also exist between Diptera and other insects in the fatty acid compositions of different phosphatides, particularly with respect to the distribution of 18‐carbon acids. The compositions observed in insects that contained large amounts of the choline phosphoglycerides are similar to those found in vertebrates. Similarities in fatty acid composition of the choline phosphoglycerides in such widely divergent organisms suggest that the fatty acids may play a greater role in phospholipid function than has heretofore been demonstrated.
Glycerides, waxes and sterols in ovaries ofAscaris lumbricoides (Nematoda)
Authors: Tarr George E. , Fairbairn Donald
Published: November 2006

Glycerides (65%), ascaroside esters (33%), waxes (1.5%) and sterols (0.26%) accounted for essentially all the neutral lipids inA. lumbricoides ovaries. Nineteen per cent by weight of the triglycerides contained only long chain fatty acids. Nearly all the remaining triglycerides contained 1 mol volatile acid. Mono‐ and diglycerides, free fatty acids and triglycerides containing 2 mol volatile acids were present in very small amounts. Mole percentages of glyceride volatile acids were α‐methylavaleric (70), α‐methylbutyric (23),n‐valeric (ca. 7), and traces of acetic, propionic, isobutyric andn‐butyric. Mole percentages of the alcoholic component of the waxes were 96% 1‐octadecanol, and 4% of its 16, 17 and 19 carbon homologs. The acid components were α‐methylbutyric (75 mol%), acetic (16 mol%), propionic andn‐valeric (each 4 mol%), and traces ofn‐butyric and α‐methylvaleric. Sterols (42 wt% cholesterol, 30% cholestanol, 9.5% campestanol, 8.2% stigmastanol, 6.6% β‐sitosterol, and 3.8% campesterol) were essentially the same as those found in the whole worm, except that no esterified sterols were present.
Effect of heated fat upon metabolism of 1‐14C‐acetate in the rat
Authors: Govind Rao M. K. , Hemans C. , Perkins E. G.
Published: November 2006

Groups of rats were prefed for 18 weeks with fresh or heated corn oil (≈5% nonurea adduct) at 10, 20 and 30% protein levels and at 10% protein+2% cellulose; 1‐14C‐sodium acetate was injected intraperitonially into each animal and the radioactivity was measured in expelled CO2 and also in the lipid fractions of liver. In the groups of rats fed 10% protein, one‐half of the administered radioactivity was found 50 min after acetate injection into rats fed fresh oil, whereas 90 min were required to reach the same level in rats fed heated oil. The same trend was found in all the groups of rats receiving different protein levels. The conversion of acetate to CO2 was significantly higher at a 10% dietary protein level than at the 20 or 30%, but there appeared to be no significant difference in the conversions at the 20 and 30% protein levels. However addition of 2% cellulose to the 10% dietary protein level significantly increased the conversion of the acetate to CO2 in rats fed heated oil. The livers of animals receiving heated fat diets had a higher lipid content, mainly triglyceride. When the liver lipids from rats fed fresh corn oil were separated by argentation thin layer chromatography, the bulk of the radioactivity was found in the saturated fractions. Monoene, diene and triene fractions from the liver lipid of rats fed heated oil had almost twice the radioactivity of those from fresh oil, suggesting the preferential utilization of acetate in the synthesis of these unsaturated fatty acids.
Novel methods for evaluating deterioration and nutritive value of oxidized oil
Authors: Akiya Toshimi , Araki Chuji , Igarashi Kiyoko
Published: November 2006

The peroxide content of an oxidized oil is of limited value in estimating the toxicity of the oil, because some decomposition products of peroxides are also injurious to health. Methods of evaluating the toxicity of deteriorated fats and oils have been investigated. A method based on the mortality of chicken embryos following injection of oil into the yolk sac has been found to be much more sensitive and reproducible than tests based on growth rate of weanling rats or mice fed deteriorated oils. An enzyme activity method using alkaline phosphatase has been tested and gives promise of being very rapid, but additional work is required to evaluate this method and to look for better enzyme systems.
Characterization of toxic compound in thermally oxidized oil
Authors: Ohfuji Takehiko , Kaneda Takashi
Published: November 2006

In preliminary experiments, soybean oil was heated at 275 C for 12 hr in the presence of N2 or air. Feeding studies with rats showed that the oil heated in the presence of air, oxidatively polymerized oil, retarded weight gain more than that heated with N2, thermally polymerized oil. Oxidatively polymerized oil was fractionated with silicic acid column chromatography, and the fraction eluted with ether (fraction III) proved to be most toxic to mice. For chemical studies combined with bioassays, additional oxidatively polymerized oil was prepared by aeration at 185 C for 90 hr, and the product was fractionated by silicic acid column chromatography. The material originally eluted with ether (fraction III) was eluted in stages, and fraction IIIc proved to be most toxic in a mouse bioassay. IR, UV and NMR analyses did not indicate the presence of C−O−O−C or C−O−C linkages or aldehyde groups or aromatic compounds. Fraction IIIc was converted to its methyl esters and molecularly distilled to yield two fractions: one containing unpolymerized fatty acid esters and one giving evidence of more functional groups per molecule and of dimeric material. This “dimeric” fraction was more toxic to mice. IR analysis of this fraction revealed carbonyl groups, and NMR showed several functional groups on alkyl chains. Treatment with sodium borohydride and with hydroiodic acid revealed no C−O−O−C and no C−O−C linkages. Mass spectrography showed peaks at mass 586 and 293; in the reduced fraction a peak also occurred at mass 143, suggestive of cleavage of some of the chains. It is tentatively concluded that a highly toxic material formed in oil heated in air is a dimer of triglyceride molecules.
Presence of antioxidant materials in bacteria
Authors: Smith James L. , Alford John A.
Published: November 2006

Fourteen species of gram‐positive and gram‐negative bacteria from nine genera were investigated to determine if they produced compounds that have antioxidant activity. Washed bacterial cells were extracted with methanol for 24 hr. This extract was evaporated to dryness and extracted with benzene. The fractions were added to lard and incubated at 58 C. Antioxidant activity was determined by prolongation of the period required for the initiation of rancidity as measured by changes in peroxide value. The methanol soluble‐benzene soluble fractions ofBacillus cereus, Lactobacillus dextranicum, Micrococcus freudenreichii andSarcina lutea showed considerable antioxidant activity. Methanol fractions of threePseudomonas species showed considerable activity that could not be extracted with benzene. The possibilities of using microbial growth on fats as well as extracts of microorganisms added to fats as antioxidants are discussed.
A quantitative determination of phosphonate phosphorus in naturally occurring aminophosphonates
Authors: Snyder William R. , Law John H.
Published: November 2006

A new method is described for the quantitative determination of naturally occurring aminophosphonates. Samples are treated sequentially with hydrochloric acid and alkaline phosphatase to convert esters to inorganic phosphate without destruction of phosphonates. The difference between inorganic phosphate and total phosphorus is then a measure of phosphonate phosphorus.
Structure determinations and synthesis of pharmacologically active phospholipids from kidney and intestine
Authors: Wiley R. A. , Sumner D. D. , Walaszek Edward J.
Published: November 2006

The chemical structures of an acidic phospholipid originally isolated from equine intestine by Vogt and of a phospholipid isolated from rabbit kidney medulla by Walaszek are shown by total synthesis to be similar mixtures of 2‐alkyl (and alkenyl)‐4‐hydroxymethyl‐1,3‐dioxolane‐dihydrogen phosphate esters. In these materials, the alkyl residues derive primarily from oleyl, palmityl and linoleyl aldehydes. The smooth muscle contracting activity observed in the natural substances is shown to reside exclusively in the oleyl aldehyde derivative.
Cyanolipids ofCardiospermum halicacabum L. and other sapindaceous seed oils
Authors: Mikolajczak K. L. , Smith C. R. , Tjarks L. W.
Published: November 2006

A number of sapindaceous seed oils have been investigated with respect to their cyanolipid constituents. All but one of the oils have this new class of lipids in amounts ranging from 13% to 55%. These cyanolipids are of four different types, but all consist of long‐chain fatty acids esterified with an unsaturated isoprenoid hydroxy‐ or dihydroxynitrile. The large amounts of C20 acids usually found in these oils indicate an appreciable cyanolipid content because such acids are preferentially incorporated in nitrile‐containing fractions.Cardiospermum halicacabum L. seed oil was shown to contain 49% of a diester having two fatty acid moieties esterified with 1‐cyano‐2‐hydroxymethylprop‐2‐ene‐1‐ol and 6% of another diester derived from 1‐cyano‐2‐hydroxymethylprop‐1‐ene‐3‐ol. Treatment of the latter diester with methanolic hydrogen chloride produces methyl 4,4‐dimethoxy‐3‐(methoxymethyl) butyrate from the dihydroxynitrile moiety.
Lipids of human atheroma VI. Hydrocarbons of the atheromatous plaque
Authors: Brooks C. J. W. , Steel G. , Harland W. A.
Published: November 2006

The higher hydrocarbons of the atheromatous plaque have been examined and the major compounds present have been found to be a series ofn‐alkanes (C17‐C31), squalene, cholest‐5‐ene and a cholestadiene. Identification of these compounds was based on chromatographic correlations and mass spectrometry.
Application of negative ion mass spectrometry to the identification of long chain aldehydes and alcohols
Authors: Rankin Peter C.
Published: November 2006

The negative ion mass spectra of a number of long chain aldehydes and alcohols are reported. The small number of fragment ions in the mass spectra of these compounds was a characteristic feature. The prominent P‐1 negative ion in the mass spectra enabled identification of the molecular ions of long chain alcohols and aldehydes whose positive ion mass spectra have negligible molecular ion intensities. The potential of the method for analysis of complex mixtures of long chain aldehydes and alcohols has been demonstrated with the identification of the components of a 14 component mixture.
Fatty acid composition of the living layer and stratum corneum lipids of human sole skin epidermis
Authors: Ansari M. N. A. , Nicolaides N. , Fu H. C.
Published: November 2006

Lipids from the living layer and stratum corneum of human sole epidermis were extracted, saponified and the fatty acids analyzed. The proportion of fatty acids to unsaponifiables (mainly cholesterol), was higher in the living layer than in the stratum corneum. Fatty acids of the living layer and stratum corneum of human sole epidermis comprise saturates, monoenes, dienes, traces of polyenes and α‐hydroxy fatty acids. Homologs of monoenoic and dienoic fatty acids for both living layer and stratum corneum lipids have a similar distribution. C16 and C18 were major components for each type of acids. There appeared to be two clusters, especially for saturates of both living layer and stratum corneum acids. One of these clusters ranged from C12 to C20 with C16 or C18 as a maximum and the other ranged from C21 to C30 with C24 as a maximum. The proportion of saturated acids with chain length C20 and above was much higher in the stratum corneum than in the living layer. Position isomers of the monoenoic fatty acids for both the living layer and stratum corneum show a predominance of ω9 acids, due to the overwhelmingly large amount of oleic acid. Linoleic acid was by far the major component of the dienoic acids. Homolog distribution of α‐hydroxy fatty acids for the living layer was similar to that of the stratum corneum and again two clusters of acids below and above C20 with maxima at C16 and C24 were noticeable. Comparison of epidermal acids with those of sebaceous glands showed that each tissue can synthesize the same kind of acids but in widely different amounts. Oxidation of palmitate and stearate could supply the necessary energy for the late stages of keratinization.
Phospholipid oxidation in emulsions
Authors: Corliss G. A. , Dugan L. R.
Published: November 2006

The autoxidation of purified phosphatidyl ethanolamine (PE) and phosphatidyl choline (PC), extracted from egg and soybean lipids, was followed by oxygen uptake measurements in emulsified systems. All emulsified phospholipid fractions had comparable activation energies. Measurement by various physico‐chemical tests was made of specific changes in the phospholipid molecule during autoxidation. PE oxidized more rapidly and absorbed more oxygen than PC. Higher 2‐thiobarbituric acid test and diene and triene conjugation absorbance values were observed for PE than for PC. Of the two major polyunsaturated fatty acids in egg phospholipids, arachidonic acid disappeared at a more rapid rate during oxidation while the concentration of linoleic acid decreased to a level that was relatively constant. Although typical unsaturated fatty acid oxidation appeared to occur in all phospholipid fractions, oxidation in aqueous emulsions was only partly a function of fatty acid composition. The nitrogen moieties, ethanolamine and choline influenced the induction period for the oxidation of PE and PC respectively.
In vitro studies on cholesterol metabolism in the blood flukeSchistosoma mansoni
Authors: Smith Thomas M. , Brooks Thomas J. , Lockard Virginia G.
Published: November 2006

AdultSchistosoma mansoni were axenically maintained in NCTC 109 culture media containing14C labeled acetate or mevalonate. Dibromide derivatives prepared from purified blood fluke cholesterol exhibited a lack of significant radioactivity on examination by liquid scintillation spectrometry. Autoradiographic electron microscopy of tissues from flukes maintained in the presence and absence of labeled acetate and especially fixed to retain cholesterol revealed a similar random distribution of nonspecific grains. However, when particulate labeled cholesterol was supplied, a count of 6,832 dpm was found in the dibromide derivative. Under the above maintenance conditionsS. mansoni adults do not synthesize cholesterol from acetate or mevalonate but most probably obtain this sterol from the host animal.
Uptake and release of fatty acids by rat adipose tissue: Last in—First out?
Authors: Ekstedt Bertil , Olivecrona Thomas
Published: November 2006

Fatty acid labeled chyle was administered iv to ad lib fed rats. At intervals from 1 hr to 50 days later rats were killed and pieces of their parametrial adipose tissue were incubated in vitro with norepinephrine. The specific radioactivity of the mobilized free fatty acids was compared to that of tissue glycerides and that of tissue free fatty acids. The results indicate that fatty acids taken up by the adipose tissue do not mix immediately with the bulk of tissue lipids and that the mobilized free fatty acids do not pass through the tissue free fatty acid pool.
Agents affecting lipid metabolism. XXVI. Specificity of some inhibitors of the late stages of cholesterol biosynthesis
Authors: Kraml M. , Dubuc J. , Dvornik D.
Published: November 2006

The capacity of 22,25‐DAC, AY‐9944 and triparanol to inhibit cholesterol biosynthesis from three precursors, mevalonate, 7‐dehydrocholesterol and desmosterol, has been studied in rat liver homogenates.

Evidence is presented that, in vitro, 22,25‐DAC, a potent inhibitor of the sterol Δ24‐reductase, also inhibits the 7‐dehydrocholesterol‐Δ7‐reductase system.
The nature of the stimulatory role of the supernatant fraction on triglyceride synthesis by the α‐Glycerophosphate pathway
Authors: Johnston John M. , Rao G. Ananda , Lowe Patricia A. , Schwarz Barry E.
Published: November 2006

Evidence is presented as to the nature and mechanism of the stimulatory effect of the supernatant fraction on the biosynthesis of triglycerides via the α‐glycerophosphate pathway in the intestinal mucosa. When microsomes are employed as the enzyme source, the major lipid formed from either labeled palmitic acid orl‐α‐glycerophosphate is phosphatidic acid and only a limited amount of triglyceride is synthesized. The addition of the supernatant fraction to microsomes results in a stimulation of triglyceride biosynthesis at the expense of phosphatidic acid. Employing the same microsomal fraction, the reaction sequence was followed step by step and the intermediates were isolated. The results suggest that the stimulatory role of the supernatant fraction can be attributed to the presence ofl‐α‐phosphatidate phosphohydrolase (EC 3.1.3.4). The hydrolysis of the biosynthesized microsomal phosphatidic acid by the supernatant enzyme occurs at a faster rate than the hydrolysis of added phosphatidic acid prepared from egg lecithin. The initial acylation steps in the biosynthesis of triglycerides or phosphatidic acid via the glycerophosphate pathway occur only in the presence of fatty acid and the cofactors necessary for its activation. Under these conditions, fatty acyl‐CoA will not substitute for the fatty acid activation system.
Interaction of calcium ions with lecithin and sphingomyelin monolayers
Authors: Shah Dinesh O. , Schulman Jack H.
Published: November 2006

Dipalmitoyl lecithin and sphingomyelin monolayers have similar limiting areas, whereas their surface potentials are strikingly different. The double bond at the 4–5 position in sphingomyelin acts as an induced dipole in relation to the surface potentials. This was confirmed by the surface potential of hydrogenated sphingomyelin. The binding of calcium to lecithin and sphingomyelin monllayers resulted in an increase in surface potential. This increase was greater for the dipalmitoyl lecithin monolayer as compared to that for sphingomyelin. It is concluded that the binding of calcium ions to springomyelin monolayers is significantly reduced by the presence of the hydroxyl group at the 3‐carbon position of the molecule.
Mechanism of lipoxidase reaction. I. Specificity of hydroperoxidation of linoleic acid
Authors: Dolev Ami , Rohwedder W. K. , Dutton H. J.
Published: November 2006

Linoleate hydroperoxides from autoxidation of methyl linoleate and from lipoxidase oxidation of linoleic acid are compared. Data indicate an equal amount of methyl 9‐ and 13‐hydroperoxyoctadecadienoate produced by autoxidation of methyl linoleate, and the exclusive formation of 13‐hydroperoxyoctadeca‐9,11‐dienoic acid from the incubation of lipoxidase with linoleic acid. As a result of these findings, a specific mechanism for the reaction of lipoxidase with linoleic acid is postulated.
Mechanism of lipoxidase reaction. II. Origin of the oxygen incorporated into linoleate hydroperoxide
Authors: Dolev Ami , Rohwedder W. K. , Mounts T. L. , Dutton H. J.
Published: November 2006

Two different series of experiments were performed to establish the origin of the oxygen molecule incorporated into hydroperoxide during the incubation of lipoxidase with linoleic acid. These showed, as previously assumed but never demonstrated, that the oxygen introduced into the hydroperoxide molecules comes from the gaseous phase and not from the aqueous phase. Furthermore, soybean lipoxidase does not catalyze the exchange between gaseous oxygen and water oxygen. Possibly, lipoxidase may be involved in the biosynthesis of hydroxytrans,cis conjugated octadecadienoates present in various seeds.
Quantitative analysis of brain and spinach leaf lipids employing silicic acid column chromatography and acetone for elution of glycolipids
Authors: Rouser George , Kritchevsky Gene , Simon Gerald , Nelson Gary J.
Published: November 2006

Abstracts

Quantitative elution of acidic and neutral glycolipids of brain and spinach leaves from silicic acid columns with acetone was demonstrated. Cerebrosides and sulfatides of brain and sulfolipid and glycosyl diglycerides of spinach leaves were eluted quantitatively with acetone while prospholipids remained on the column. The observations provide the basis for an analytical procedure employing column and quantitative thin‐layer chromatography (TLC). Sephadex column chromatography is utilized for separation of lipids from nonlipids; silicic acid column chromatography for separation into neutral lipid, glycolipid and phospholipid fractions; and quantitative TLC for analysis of lipid classes of each column fraction.
Chemical composition of subcellular particles from cultured cells of human tissue
Authors: Tsao Shuang‐Shine , Cornatzer W. E.
Published: November 2006

Chemical composition of subcellular components of HeLa, KB, human heart and liver tissue‐culture cell lines have been studied.

The concentration of RNA, protein and phospholipid (μg/μg of DNA) of total subcellular particles was similar for all four cell lines studied. The greatest RNA concentration and lowest protein concentration is found in the microsomes as compared to the other subcellular fractions of HeLa and KB cells.

The lipid P/Protein N ratio of mitochondria was greater than the other subcellular fractions from tissue‐culture cell lines studied. Phosphatidyl choline and phosphatidyl ethanolamine are the major phospholipids with the former more predominant in all of the subcellular fractions of tissue‐culture cells studied. Phosphatidyl inositol, phosphatidyl serine, sphingomyelin and polyglycerol phosphatide were shown to be present. Phosphatidyl choline composition (per cent of total lipid‐P) is greatest in the microsomes when compared with the other subcellular fractions obtained from all of the cell lines studied except the nuclear fraction of human liver cells. Correspondingly, the mitochondrial fraction for all of the tissue culture cell lines contains the greatest composition of phosphatidyl ethanolamine except for the human liver and heart cells. The mitochondrial fraction contains the lowest amount of phosphatidyl inositol. Polyglycerol phosphatide is mainly present in the mitochondrial fraction of the tissue‐culture cells.
Isolation of a trimer of α‐tocopherol from mammalian liver
Authors: Draper H. H. , Csallany A. S. , Chiu Mei
Published: November 2006

Evidence is presented for the formation in mammalian liver of a trimeric metabolite of α‐tocopherol. This compound has been shown to be identical to a trimer produced by oxidation of α‐tocopherol with alkaline K3Fe(CN)6. In addition, confirmation was obtained for the occurrence in vivo of a dimeric metabolite reported previously. These compounds, together with tocopheryl‐p‐quinone, are postulated to arise from reactions with lipid‐free radicals or peroxides in the course of the antioxidant action of vitamin E.
Phospholipids of the sea anemone: Quantitative distribution; absence of carbon‐phosphorus linkages in glycerol phospholipids; structural elucidation of ceramide aminoethylphosphonate
Authors: Simon Gerald , Rouser George
Published: November 2006

The phospholipid composition of the sea anemone (Anthopleura elegantissima) was determined by quantitative thin‐layer chromatography (TLC). Phosphonic acids were not detected in phosphatidyl choline, phosphatidyl ethanolamine, or phosphatidyl serine following isolation and hydrolysis. The structure of ceramide aminoethylphosphonate, a phosphonolipid, was elucidated by hydrolysis and oxidative degradation followed by characterization of the products by TLC and gas‐liquid chromatography. The long‐chain base was shown to be sphingosine with the 2‐aminoethylphosphonic acid group attached through the primary hydroxyl group at carbon one. Ceramide aminoethylphosphonate is therefore 1‐(O‐phosphonoethylamine)‐N‐acyl sphingosine.
Separation of cholesterol‐desmosterol acetates by thin‐layer and column chromatography on silica gel G‐silver nitrate
Authors: Galli Giovanni , Paoletti Enrica Grossi
Published: November 2006

A chromatographic method, using columns packed with Celite‐Silica Gel G impregnated with silver nitrate, has been developed for the separation of cholesterol from desmosterol (24‐dehydrocholesterol).

The system employed allows a complete separation of the two sterols as acetates, as determined by gas‐liquid chromatography and thin‐layer chromatography.

The recovery of pure cholesterol and desmosterol is quantitative.
DDT absorption and chylomicron transport in rat
Authors: Pocock Dorothy M. E. , Vost Alan
Published: November 2006

Male rats were fed 100 nM dichlorodiphenyltrichloroethane‐14C in oil by gastric tube. Recovery of dichlorodiphenyltrichloroethane‐14C in thoracic duct lymph was 60% in 12 hr. Lymph dichlorodiphenyltrichloroethane‐14C (97%) occurred in lipoproteins of d<1.006, designated chylomicrons. Mechanical separation of chylomicron triglyceride core (labeled with triglyceride‐3H) from chylomicron membrane (labeled with phospholipid‐32P) showed that 97% dichlorodiphenyltrichloroethane‐14C was present in triglyceride core. To investigate possible association of plasma clearance of the two core lipids, rats were pulse injected with chylomicrons, doubly labeled with triglyceride‐3H and dichlorodiphenyltrichloroethane‐14C. The decay of dichlorodiphenyltrichloroethane‐14C in sequential serum samples was rapid (T1/2=2 min) and was independent of triglyceride‐3H decay. In tissues removed 14 min after injection of chylomicrons, 30% administered dichlorodiphenyltrichloroethane‐14C was found in liver but only 1% in adipose tissue. In hepatectomized (eviscerated) rats, the decay of serum dichlorodiphenyltrichloroethane‐14C (T1/2=10 min) was also independent of and more rapid than triglyceride‐3H decay. With sucrose density gradients, it was shown that chylomicron dichlorodiphenyltrichloroethane‐14C transferred to higher density serum proteins in vitro and in vivo and to bovine albumin in vitro. Thus, dichlorodiphenyltrichloroethane was transported from intestine largely in the triglyderide phase of chylomicrons; disappearance of chylomicron‐dichlorodiphenyltrichloroethane from the systemic circulation was rapid and partly independent of the presence of the liver and of triglyceride hydrolysis; some dichlorodiphenyltrichloroethane was transported from serum chylomicrons to albumin or other plasma proteins before tissue uptake.
Prostaglandins of rat testis
Authors: Carpenter Mary P.
Published: November 2006

The purpose of the study was to determine whether prostaglandins were present in mammalian testis, a tissue that has a large concentration of polyenoic fatty acids that are potential precursors of prostaglandins. Acid‐soluble lipids of rat testis were extracted, purified, and fractionated by thin layer and column chromatographies.3H‐Prostaglandins were added as internal reference standards to monitor recoveries and facilitate identification. Initial identification of prostaglandin species was done by chromatography. Further identification was done by elution of the prostaglandin zones followed by rechromatographies (both thin layer and column), measurements of UV absorption spectra, and by gas liquid chromatography. The results of these analyses indicate that prostaglandin E1, 11α,15(S)‐dihydroxy‐9‐oxo‐β‐trans‐prostenoic acid; prostaglandin E2, 11α‐15(S)‐dihydroxy‐9‐oxo‐5‐cis‐13‐trans‐prostadienoic acid; and prostaglandin F1, 9α,11α,15(S)‐trihydroxy‐13‐trans‐prostenoic acid occur in rat testicular tissue and that prostaglandin F2α, 9α, 11α, 15(S)‐trihydroxy‐5‐cis‐13‐trans‐prostadienoic acid and prostaglandin E2, 11α,15(S)‐dihydroxy‐9‐oxo‐5‐cis‐13‐trans‐prostadienoic acid may be the primary species of this tissue. Prostaglandin B1, 15(S)‐hydroxy‐9‐oxo‐8(12),13‐trans‐prostadienoic acid and prostaglandin B2, 15(S)‐hydroxy‐9‐oxo‐5‐cis,8(12),13‐trans‐prostatrienoic acid also were detected, and some evidence was obtained for the presence of prostaglandin metabolites.
Bile acid metabolism in mammals: VI. Effect of ethionine upon bile acids of rat bile
Authors: Yousef I. M. , Kakis G. , Fisher M. M.
Published: November 2006

Sex differences in the effect of ethionine upon rat liver metabolism prompted our investigation into possible sex differences in the effect of ethionine upon bile acid metabolism. The bile ducts of 24 rats, 12 male and 12 female, were cannulated. After 1 hr of bile collection, 6 rats of each sex were given ethionine, 1 mg/g body wt, by feeding tube. The bile acid composition of the bile collected during the subsequent 4 hr was analyzed by combined thin layer and gas chromatography. Ethionine induced a reduction in bile flow (3rd and 4th hr) and in bile acid concentration (4th hr) in female rats. The amino acid had no effect upon bile flow but did increase biliary secretion of bile acids (1st and 2nd hr) in male rats. Cholic acid accounted for the bulk of the reduction in total bile acid secretion in the female studies. The increase in total bile acid secretion in the male studies involved all bile acids. The effects of ethionine upon bile acid secretion were delayed in the female studies, immediate in the male. The changes in bile acid secretion involved only the taurine conjugates in the female studies, both taurine and glycine conjugates in the male. There are substantial sex differences in the effect of ethionine upon bile acid metabolism in the rat.
Mass determination of lipids with automated thermogravimetric analytical procedure
Authors: Leerkamp J. , Siakotos A. N.
Published: November 2006

An automated thermogravimetric system for the microdetermination of lipids is described. A study of the analytical variability experienced with this method revealed that samples can be assayed with considerable accuracy (±3%) down to 100–200 μg, while samples less than this range exhibit variations of ±7–10%. In the absence of other more sensitive methods, even this experimental error is acceptable. In addition, multiple applications of very dilute samples to achieve a lipid mass with an acceptable coefficient of variation is possible. No significant variations were observed with samples assayed on the same day and on different days, indicating a high degree of control of nonoperator errors. A careful application of the method to different lipid classes revealed no significant weighing losses under the experimental conditions of this study, except for cholesterol; however, application of the method to mixtures of lipids containing significant amounts of cholesterol did not reveal abnormal errors.
In vivo and in vitro biosynthesis of free fatty alcohols inEscherichia Coli K‐12
Authors: Naccarato William F. , Gilbertson John R. , Gelman Rose A.
Published: November 2006

In vivo studies have indicated that exogenous free fatty acids may serve as precursors of the free fatty alcohols ofEscherichia coli K‐12. Following disruption of the cells, the enzymatic activity capable of catalyzing the reduction of long chain fatty aldehydes to fatty alcohols was localized in the 100,000 x g supernatant fraction. Nicotinamide adenine dinucleotide phosphate, reduced form, was the required cofactor. The product of the reaction was characterized rigorously as 1‐hexadecanol when hexadecanal was the substrate. Three independent, but complementary, assay methods were developed to assay the aldehyde reductase activity. By employing these methods, an equivalence between nicotinamide adenine dinucleotide phosphate, reduced form, oxidation and 1‐hexadecanol synthesis was established. Two protein fractions catalyzing the reduction of fatty aldehydes to fatty alcohols were detected in the 100,000 x g supernatant fraction following ammonium sulfate fractionation and diethylaminoethyl‐cellulose chromatography. Enzymatic activity (70%) applied to the diethylamino‐ethyl‐cellulose column was eluted at a phosphate concentration of 0.115 M. The remaining 30% was eluted at a concentration of 0.23 M. Following sephadex chromatography, it was observed that the enzyme eluting at 0.115 M phosphate had an apparent mol wt of 250,000 Daltons while that eluting at 0.23 M had an apparent mol wt of 62,000 Daltons. The enzymes were similar with respect to substrate specificity, pH optima, ionic strength optima, and stability with respect to thiol inhibitors, suggesting different sized aggregates of similar subunits.
Embryonic vs tumor lipids: II. Changes in phospholipids of developing chick brain, heart, and liver
Authors: Wood Randall
Published: November 2006

Brain, heart, and liver tissues were excised from embryos and chicks 10, 13, 16, 19, 22, 27, and 53 days after incubation was initiated and the lipids extracted. The quantitative distribution of the phospholipids and the fatty acid composition of the individual phosphatides were determined for each time period. Each tissue exhibited a distinct phospholipid composition that differed from the composition of egg. Elevated concentrations of particular phosphoglycerides that characterize certain mature tissues were observed at the earliest time period. As development progressed, some phospholipid classes in all tissues showed dramatic change, while others remained relatively constant. Brain showed the most stable composition, while the phosphatides of liver were the most dynamic. Each phospholipid class exhibited a characteristic fatty acid profile that was unique for each tissue. All of the phospholipid classes showed a change in fatty acid composition as development progressed, and, in some tissue, the change was dramatic. The fatty acid composition of brain phosphoglycerides showed the least change, while liver showed the greatest fluctuation. Docosahexaenoic acid and, in most cases, arachidonic acid decreased in the phosphoglycerides with increased development. The decrease in docosahexaenoic acid correlated well with the decreasing mitotic indices of heart and liver cells as development progressed. Comparison of observed abnormal lipid patterns between mature and neoplastic tissue with embryonic tissue lipid profiles suggest that some of the observed abnormalities of neoplasms probably are due to changes in lipid metabolism associated with rapidly proliferating cells, whereas other abnormalities appear to be associated with neoplasia.
Effect of phospholipase a upon brain cholesterol ester formation
Authors: Ramsey Robert B. , Davison A. N.
Published: November 2006

On addition of snake venom phospholipase A to homogenates of rat brain we have been able to show increased ester formation. Within certain limits, the amount of ester formed was dependent upon the amount of phospholipase added. The fatty acid patterns of free fatty acid released and of cholesteryl ester fatty acid formed during 18 hr incubation were compared. Although fatty acid patterns were different, the data were still consistent with the hypothesis that, in demyelination, a neural phospholipase A may play a role in cholesteryl ester deposition.
Studies on the in vivo metabolism of retinoic acid in the rat
Authors: Geison R. L. , Johnson B. C.
Published: November 2006

A time study of the metabolism of 6,7‐14C‐retinoic acid after intraperitoneal injection of physiological levels (17 μg, 0.39 μc) into vitamin A deficient rats, which had been repleted with retinoic acid for two weeks up to two days before injection, resulted in a rapid metabolism to more polar compounds in the small intestine and its contents and a slower metabolism to primarily different materials in the liver and kidney. The major route of metabolism resulted in the urinary excretion of 60% of the injected dose in 24 to 27 hr. Urinary metabolites of 15‐14C‐retinoic acid were eluted from silicic acid at a similar concentration of solvents as the ring labeled metabolites although only 32% of the injected dose was recovered in 24 hr. Compounds chromatographically similar to the urinary metabolites were observed at various times in the liver, kidney and small intestine plus contents in addition to retinoic acid and other metabolites. The relative amounts of the metabolites in the different tissues studied varied as a function of the tissue and the time of analysis after injection. Most of the radioactivity from all tissues was extractable into methanol. A liver subcellular distribution of the radioactivity derived from the intraperitoneal injection of 650 μg of 6,7‐14C‐retinoic acid (25.9 μc) after 3 hr indicated a minimal level of association of radioactivity (150–250 dpm/mg protein) with all fractions and a greater association of radioactivity with the lysosomal‐microsomal fraction (300–350 dpm/mg protein) and the 60–100% ammonium sulfate precipitable (750–800 dpm/mg protein) and 100% ammonium sulfate soluble fractions (422 dpm/mg protein) of the soluble supernatant.
Correlation between post‐heparin lipase and phospholipase activities in human plasma
Authors: Vogel William C. , Bierman Edwin L.
Published: November 2006

The hypothesis that a single lipolytic enzyme in post‐heparin plasma effects the hydrolysis of both triglyceride and phospholipid was tested. After intravenous heparin, activity in plasma with the two substrate classes appeared and disappeared in parallel. The activities were not separable by the fractionation methods of zone electrophoresis, gel filtration, anion‐exchange, ultracentrifugation, or by combinations of these techniques. The degree of purification of the two activities with the use ofn‐butanol was similar. Lipolytic activity appeared to be associated with a large high density molecular aggregate. However, the concept of a single post‐heparin enzyme does not explain all the observations since the ratio of activity with triglyceride substrate to activity with phospholipid substrate decreased markedly in some subjects after increased amounts of intravenous heparin.
Specificity of flaxseed lipoxidase
Authors: Zimmerman D. C. , Vick B. A.
Published: November 2006

Mass spectrometric data indicate that products of linoleate oxidation by flaxseed lipoxidase consist of 80% 13‐hydroperoxyoctadecadienoate and 20% 9‐hydroperoxyoctadecodienoate; the products of linolenate oxidation by flaxseed lipoxidase consist of 88% 13‐hydroperoxyoctadecatrienoate and 12% 9‐hydroperoxyoctadecatrienoate. Flaxseed lipoxidase possesses a high degree of specificity for attachment of oxygen to linoleic and linolenic acid molecules.