Fatty acid composition of sterol esters from Citrus sinensis,C. paradisi,C. limon aurantifolia and C. limettioides sacs

The fatty acid compositions of sterol esters from 4 citrus species, viz, orange. grapefruit, lemon and lime, were determined by GLC. Each species possessed its own intrinsic fatty acid pattern which could be used to differentiate it from the other species. In most cases varieties within a species had fatty acid patterns which could be used for varietal differentiation. In all citrus tested except Columbia lime, the major acid was linoleic acid; this acid varied from 10 to 56% of the total acid content. The ratios of 16/16:1 were distinct for each citrus species. The C₂₂-C₂₉ fatty acids were prevalent in citrus sterol esters ranging from 6·5% for some orange and grapefruit varieties to over 41% for two lime varieties. In all varieties C₂₄ was the most prominent of these longer chain fatty acids. Argentation TLC indicated that these longer chain fatty acids primarily were esterified to dimethyl sterols. ft*|One of the laboratories of the Southern Region, Agricultural Research Service, U.S. Department of Agriculture.     

Identification of natural and semisynthetic ω-cycloalkyl fatty acids

The experimental criteria, principally GLC behaviour and spectroscopic data, by which ω-cycloalkyl fatty acids (cyclobutyl to cycloheptyl, C₁₄ to C₂₁) can be identified, are described.     

Comparative studies on simple lipids ofSclerotium cepivorum,the causal agent of white rot of onion,and other fungi of the class Deuteromycetes

Summary The simple lipids ofSclerotium cepivorum, the causal agent of white rot of onion and nine other fungal species of the same class were investigated. The fatty acid composition of the simple lipids of these fungi were determined by GLC. The main fatty acids common to these fungal species were C₁₆ (saturated) and C₁₈ (unsaturated) acids. The sterol fraction was isolated by column chromatography and its components were detected by GLC and mass spectrometry. Ergosterol and γ-Ergostenol were found mostly in all fungal species under investigation. However, two fungal species namelyAlternaria alternata andScolecobasidium constrictum showed no Ergosterol.     

Lipid synthesis in vitro by rabbit Meibomian gland tissue and its inhibition by tetracycline

Rabbit Meibomian gland tissue was incubated with radioactive acetate, propionate, valine, leucine or isoleucine. The time-course of incorporation of radioactivity into total lipids from acetate and isoleucine was studied in Hanks' or Krebs medium. Incorporation of acetate or isoleucine into lipid classes was followed by TLC, and of acetate label into individual fatty acids and alcohols by GLC with radioactivity detection. Radioactivity was highest in the minor acid components C_16:1 and C_18:1. Levels in branched fatty acids fell with chain length, reflecting the time-course of successive chain elongations. Use of amino acids or propionate as precursors suggested that molecules containing a specific branched structure were preferentially incorporated; this indicates a binding preference at the level of the fatty acid synthase which might explain the very high proportion of anteiso-branched structures in the rabbit secretion. Incorporation of label into total lipids was significantly reduced by tetracycline in the medium, with 50% reduction at about 1.5 mg/ml for acetate and 0.7 mg/ml for isoleucine.     

In vitro culture of coconut endosperm: callus induction and its fatty acids

Summary Successful induction of callus from coconut endosperm was achieved by using the tissue situated near the micropylar end of a young fruit. For initiation of callus, a high concentration of auxin (20 to 100 ppm) was added to the basal medium containing activated charcoal. Subcultured callus showed a 40-fold increase during culture of three months. Based on the analysis of fatty acid composition, the maturation of endosperm was characterized by an increase in short chain fatty acids (C₈, C₁₀, C₁₂, C₁₄)and a decrease in long chain fatty acids (C₁₆, C_{18: 1}, C_{18: 2}). In developing endosperms, proportion of short chain fatty acids was higher in lipids of the antipodal than those of other regions. In the final stage of maturation, around 82% of total fatty acids was short chain fatty acids, while the proportion of long chain fatty acids decreased up to 16%. The fatty acid composition of callus subcultured for six months was comparable to that of the immature endosperm. Lipids were accumulated in callus as globular bodies.     

GLYCOSPHINGOLIPIDS IN FETAL TAY-SACHS DISEASE BRAIN AND LUNG CULTURES

Abstract— A study was undertaken of the glycosphingolipids in cell cultures derived from cerebellum of Tay-Sachs disease fetal brain in order to determine the suitability of such cell strains as a model for Tay-Sachs disease. The glycosphingolipids in the Tay-Sachs disease cultured cerebellar cells were compared with those found in normal cultured cerebellar cells, normal and Tay-Sachs cultured lung cells, and normal and Tay-Sachs fetal brain. The glycolipids were separated by TLC, then analyzed by GLC of the trimethylsilyi derivatives of the methylglycosides of the sugar moieties. In the cultured cerebellar lines, the predominant gangliosides were G_M2, G_M3, and G_D3. There was a 4-fold increase of G_M2 in the Tay-Sachs as compared with the normal line. Only G_M3 and G_D3 gangliosides were found in the Tay-Sachs and the normal fetal lung cell cultures. The major neutral glycosphingolipids in all of the cultured cells which were analyzed were glucosylceramide, lactosylceramide, digalactosyl-glucosylceramide, and globoside. When the Tay-Sachs cerebellar cells were labelled with [1-¹⁴C]gluco-samine, some radioactivity was observed in the trihexosylceramide band, indicating the presence of a small amount of a galactosamine-containing trihexosylceramide which may be asialo-G_M2 (G_A2). The trihexosylceramide in Tay-Sachs fetal brain was identified as G_A2 by GLC. Both Tay-Sachs and normal fetal brain gangliosides were more complex than those found in the cultured cells. Long chain fatty acids (C_24:0 and C_24;1) predominated in all of the glycosphingolipids of the Tay-Sachs and the normal cultured cerebellar cells. In contrast, the glycosphingolipids of Tay-Sachs and normal fetal brain contained mainly the shorter chain fatty acids (C₁₆:₀, C₁₈:₀, and C_18:1). The cerebrosides in both the Tay-Sachs and normal fetal brains were mainly glucosylceramide with only small amounts of the galactosylceramide which predominates in infant brain. Cultured cells from the fetal Tay-Sachs disease     

ISOLATION AND CHARACTERIZATION OF GLUCOCEREBROSIDES FROM ADULT RAT BRAIN1

Abstract— By chromatography on borate-coated silicic acid, glucocerebrosides, galactocerebrosides, sulfatides and sphingomyelins from brain tissue could be efficiently separated. Adult rat brain was found to contain 54.1 ± 1.5 nmol of glucocerebrosides per gram fresh weight. Ninety percent of the glucocere-broside fatty acids were palmitate, stearate and oleate; fatty acids with chain lengths above C₂₀ were virtually absent. No hydroxy fatty acids were found. The long chain bases of adult rat brain glucocerebrosides consisted of 74.6% C₁₈-sphingosine, 24.4% C₁₈-sphinganine and 1.1% C₂₀-sphingosine. These results are compared to those obtained from glucocerebrosides from immature rat brains (Abe & Norton , 1974) and discussed in respect to changes occurring during brain development.     

Degradation of long-chain n-alkanes by the yeast Candida maltosa

Summary The yeast Candida maltosa precultivated on liquid n-alkanes utilized different solid n-alkanes (especially C₂₀–C₂₅) in the presence of pristane as an organic phase with rates comparable to, or somewhat larger than, those of liquid n-alkanes. Analysis of cellular fatty acids indicated an assimilation of solid n-alkanes via monoterminal oxidation. The resulting fatty acids with substrate chain length were chain-shortened by C₂ units down to an optimal range of chain length from C₁₆ to C₁₈ and incorporated into cellular, lipids directly or after desaturation. The intermediates of chain-shortening with numbers of carbon atoms higher than C₁₈, as well as the unusually long-chain fatty acids of substrate chain length, were detected in trace amounts only. Even-carbon-numbered and odd-numbered fatty acids predominated in experiments with evenchain and odd-chain n-alkanes, respectively. Studies with cerulenin indicated that de novo synthesis of fatty acids was negligible. Oxidation of solid n-alkanes by the yeast C. maltosa yielded fatty acid patterns similar to those of cells grown on liquid n-alkanes.     

An approach to improve methanogenesis through the use of mixed cultures isolated from biogas digester

Biogas production has been shown to be inhibited by branched chain fatty acids (isobutyric, isovaleric) produced in the digester by cellulolytic organisms. Performance of these mixed cellulolytic cultures isolated at 25°C (C₂₅) and at 35° (C₃₅) in a batch digester using cattle manure confirmed that C₃₅, which forms mainly straight chain fatty acids from cellulose was more suitable for use as an inoculum than C₂₅ which formed predominantly branched chain fatty acids. Reconstitution of cellulolytic culture C₃₅ and mixed methanogens M₃₅ almost doubled both the amount and rate of methane production. Cellulolytic culture was useful in pretreatment of water hyacinth prior to its use as a substrate for methane generation A method for preservation and transportation of mixed cellulolytic culture for use as an inoculum in the digester is described.     

Cellular fatty acid composition ofCorallococcus coralloides

The fatty acid composition of five strains ofCorallococcus coralloides and three reference species ofMyxococcus were determined by gas-liquid chromatography. Methyl esters of fatty acid containing from 12 to 22 carbon atoms were identified. The major fatty acids present were C₁₅ and C₁₇ saturated branched chain, and both C₁₆ saturated and unsaturated straight chain acids. The C₁₇ saturated branched and straight chain acids, which were in valuable concentration in species ofMyxococcus, were not, however, detected in all strains ofC. coralloides. The application of these results in the distinction ofC. coralloides from the genusMyxococcus is discussed.     

Isolation and Characterization of a Neutral Glycosphingolipid from the Epimastigote Form of Trypanosoma mega1

ABSTRACT. A glycosphingolipid fraction from Trypanosoma mega was isolated after acetylation and was further purified on a silicic acid column. Final purification was by preparative thin-layer chromatography. The carbohydrate components of the glycolipid were fucose and galactose in approximately equimolar amounts. The neutral glycolipid of T. mega has a sphingosine base composition that consists of sphingosine and traces of dihydrosphingosine. Fatty acids forming amide groups with the sphingosine bases were analyzed by gas-liquid chromatography-mass spectrometry and are a mixture of normal and α-hydroxy fatty acids. Normal C_16:0, C_18:0, and 2-hydroxy C_18:0 are the predominant fatty acids.     

Fatty acids of Pinus elliottii tissues

The total fatty constituents of slash pine (Pinus elliottii) tissue cultures, seeds and seedlings were examined by GLC and MS. Qualitatively, the fatty acid composition of these tissues was very similar to that reported for other pine species. The fatty acid contents of the tissue cultures resembled that of the seedling tissues. In addition to the fatty acids common to botanical materials, Δ⁵-C₁₈ and -C₂₀ nonmethy lene-interrupted polyunsaturated acids were present in low relative abundances. The branched-chain C₁₇ acid reported for several other Pinus species was confirmed as the anteiso isomer.     

Elongation of mitochondrial fatty acids during brain development

Abstract— Elongation of mitochondrial fatty acids was studied in whole brain samples from rats before, during and after the period of myelination. The mitochondria were isolated by centrifugation in a discontinuous sucrose gradient and incubated under N₂ in a medium containing NADH, NADPH, ATP and acetyl-[1-¹⁴C]coenzyme A. Fatty acids were extracted, methylated and analysed by gas-liquid chromatography. A distinct pattern emerged in which brain mitochondria from rats undergoing myelination synthesized longer chain fatty acids preferentially, particularly C_22:4. Mitochondria from brains of mature rats synthesized shorter chain fatty acids preferentially, mainly C_18:0 and C_20:4. We suggest that eicosamonoenoic acid (C_22:1) is a precursor in vivo of nervonic acid (C_24:1).     

Synthesis of β-hydroxy fatty acids and β-amino fatty acids by the strains of Bacillus subtilis producing iturinic antibiotics

The iturinic antibiotics, which contain long chain β-amino acids, are produced by Bacillus subtilis. Screening these strains for the presence of a possible precursor of the iturinic antibiotics, we isolated a lipopeptide containing β-hydroxy fatty acids. The structure of this compound was studied and it appears to be identical or structurally very similar to surfactin. The carbon chain of its β-hydroxy fatty acids was n C₁₆, iso C₁₆, iso C₁₅ or anteiso C₁₅. The percentages of each β-hydroxy fatty acids varied according to the strain producing iturinic antibiotics and were influenced by addition of branched-chain α-amino acids to the culture medium. These results demonstrate for the first time that iso C₁₄ β-hydroxy fatty acid is a constituent present in such a surfactin like lipopeptide. Besides, the presence of radioactive β-hydroxy fatty acids in the phospholipids when the strains were grown in the presence of sodium [¹⁴C]acetate seems also characterize the different strains producing iturinic antibiotics.     

Fatty acids and long-chain bases of gangliosides of human gastrointestinal mucosa

The fatty acid and long-chain base composition of five major gangliosides from human stomach and small and large intestine mucosa were analyzed with gas chromatography. All the gangliosides greatly resembled each other in the fatty acid pattern. The main fatty acids were C_16:0, C_18:0 and C_24:0. No hydroxy fatty acids could be detected. In all the gangliosides 4-sphingenine was the predominant long-chain base (70–75%). About 15% of the long-chain bases had 20 carbon atoms in their chain. No trihydroxy long-chain bases could be detected.     

Gesaettigte fettsaeuren in boeden von Kaffeepflanzungen

Zusammenfassung Böden aus Kaffeepflanzungen in Arusha (Tanzania), Campinas (Brasilien) und Sukamade (Java) wurden auf n-gesättigte Fettsäuren analysiert. Es konnten sämtliche Fettsäuren von C₁₂ bis C₃₄ nachgewiesen werden. Die Gesamtmengen lagen zwischen 0,07 und 0,26 mg/g getrocknete Erde. Mit zunehmendem Alter der Kaffeepflanzungen konnte eine Anreicherung der Fettsäuren und der Gesamtlipide festgestellt werden. Die zu Vergleichszwecken analysierten Blätter bzw. das Holz von Kaffeepflanzen ergaben bei ähnlicher Zusammensetzung Werte von 5,10 resp. 3,02 mg/g Trockengewicht. Die Möglichkeit einer Hemmwirkung dieser Fettsäuren auf das Pflanzenwachstum wird diskutiert.

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Summary The saturated fatty acids in soils from coffee plantations of Arusha (Tanzania), Campinas (Brazil) and Sukamade (Java) were investigated. All fatty acids ranging from C₁₂ to C₃₄ could be identified using GLC. The total content counted for 0.07–0.26 mg/g dry matter. With increasing age of the coffee plantation an accumulation of the fatty acids and total lipids was found. The analysis of coffee leaves and coffee wood showed fatty acids from 5.10 to 3.02 mg/g dry weight respectively. The occurrence of phytotoxic properties of fatty acids is discussed. re]19760730

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Institut für Pflanzenbiologie der Universität Zürich     

Fatty Acid Compositions of Corynebacterium simplex Grown on 1-Alkenes

The utilization of 1-alkenes by Corynebacterium simplex ATCC 6946 was studied with respect to the characteristic fatty acid profiles resulting from the growth at the expense of these substrates.

It was indicated that the synthetic pathways of the cellular fatty acids in Corynebact. simplex grown on various n-alkanes or 1-alkenes changed markedly according to the chain lengths of the substrates. From shorter chain hydrocarbons (C₁₂, C₁₄) the fatty acids were found to be synthesized mainly via de novo synthesis pathway in a similar manner to those from glucose, while chain elongation and intact incorporation occurred to a very small extent. On the other hand, an intact incorporation mechanism was preferential in the cells grown on longer ones (C₁₆, C₁₈). When n-pentadecane or 1-pentadecene was used as the substrate, these three mechanisms seemed to operate simultaneously.     

Separation of some mono-, di- and tri-unsaturated fatty acids containing 18 carbon atoms by high-performance liquid chromatography and photodiode array detection

Positional and geometric isomers of mono-, di- and tri-unsaturated fatty acids containing 18 carbon atoms were separated on commercially available reversed-phase columns in gradient systems composed of acetonitrile and water, utilizing photodiode array detection. The biological samples were hydrolyzed with 2 M NaOH for 35–40 min at 85–90°C. After cooling, the hydrolysates were acidified with 4 M HCl and the free fatty acids were extracted with dichloromethane. The organic solvent was removed in a gentle stream of argon. The fatty acids were determined after pre-column derivatization with dibromacetophenone in the presence of triethylamine. The reaction components were mixed and reacted for 2 h at 50°C. Separations of derivatized fatty acids were performed on two C₁₈ columns (Nova Pak C₁₈, 4 μm, 250×4.6 mm, Waters) by binary or ternate gradient programs and UV detection at 254 and 235 nm. The geometric and positional isomers of some unsaturated fatty acids were substantially retained on the C₁₈ columns and were distinct from some saturated fatty acids, endogenous substances in biological samples or background interference. Only slight separation of critical pairs of cis-9 C_18:1/cis-11 C_18:1 and cis-6 C_18:1/trans-11 C_18:1 was obtained. A ternate gradient program can be used for complete fractionation of a mixture of conjugated linoleic acid isomers (CLA) from cis-9, cis-12 and trans-9, trans-12 isomers of C_18:2. The CLA isomers in the effluent were monitored at 235 nm. The CLA isomers were differentiated from saturated and unsaturated fatty acids using a photodiode array detector. The utility of the method was demonstrated by evaluating the fatty acid composition of duodenal digesta, rapeseed and maize oils.     

Fatty acids and aldehydes of brain phospholipids during fetal and infant development in man

Abstract— Brains of human fetuses III, V, VI, VII months) newborn and infants (3, 7 and 13 months old) were investigated and the contents of total lipid, neutral- and phospholipid fractions were estimated. Fatty acids as well as fatty aldehydes of the phosphatides were analysed by gas chromatography. The results showed, that during this period of development the C₁₆-compounds in the fatty acid and aldehyde fractions decrease, while the total C₁₈-derivatives increase. However, the C₁₈-monoenoic fatty acids decrease from the third fetal month until birth and increase during myelination. The same pattern was found for the C₁₈-monoenoic aldehydes. The amounts of C₂₀- and C₂₂-polyenoic fatty acids were relatively constant. Only trace amounts of aldehydes with chain lengths other than C₁₆- and C₁₈-saturated and C₁₈-monoenoic comnniinds were found.     

Biosynthesis of saturated very long chain fatty acids by purified membrane fractions from leek epidermal cells

Elongation of fatty acids by microsomal fractions obtained from leek epidermal cells was measured by the incorporation of [1-¹⁴C]stearate, [1-¹⁴C]stearyl CoA, and [1-¹⁴C]stearyl ACP in the presence of malonyl CoA and NADPH. Stearoyl CoA appears to be the primer of the elongase (s) rather than stearoyl ACP. There are at least two elongases, the first elongating C₁₈ to C₂₀, the second synthesizing C₂₂ to C₃₀ fatty acids from C₂₀. The main site of the elongase (s) is a subcellular fraction enriched in endoplasmic reticulum. The plasma membrane-enriched fraction, which contains large amounts of saturated very long chain fatty acids, synthesizes only minor amounts of them.