The rare caribbean spongeLeucosolenia canariensis: Phospholipid fatty acids and sterols

The phospholipid fatty acid composition of the Calcarean spongeLeucosolenia canariensis was studied, and no Δ^5,9 fatty acids were detected. These results are in contrast to the phospholipids from sponges belonging to the class Demospongiae where Δ5,9 fatty acids are predominant. Odd branched-chain fatty acids between 17 and 19 carbons accounted for 26% of the total fatty acids ofL. canariensis, while straight-chain fatty acids between 16 and 22 carbons accounted for 61% of the total fatty acid composition. The sterol composition ofL. canariensis is also reported, and only Δ^5,7,22 sterols were observed.     

Sterols and fatty acids of a whisk fernPsilotum nudum

The sterols and fatty acids ofPsilotum nudum were investigated. The 4,4-dimethyl- and 4α-methylsterol fractions contained 24β-methyl-Δ²⁵-unsaturated sterols,viz., cyclolaudenol and 24β-methyl-25-dehydrolophenol, respectively, as dominant sterols among the other components common in vascular plants. 24-Methylcholesterol (mixture of C-24 epimers) and sitosterol constituted the dominant sterols in the 4-demethylsterol fraction. This is the first identification of 24-methylene-5α-lanost-8-en-3β-ol, 24β-methyl-25-dehydrolophenol, codisterol, isofucosterol, 24-methylene-25-methylcholesterol and avenasterol in a fern. The major fatty acids were 16:0, 18:1, 18:2, 18:3 and 20:3. In addition, several C₂₀ fatty acids with various unsaturation were found to be present in low concentrations.     

Composition of the unsaponifiable oil fraction obtained from a number of cultivars of safflower

Composition of the unsaponifiable matter obtained from oil ex-tracted from six safflower cultivars (UC-1, Tara, S-541, S-202, S-317 and S-918) was determined. The composition of the fractions of sterols was related to fatty acid composition, and significant correlations were found between campesterol, Δ⁷-stigmastenol, oleic and linoleic acids. The composition of the fractions of terpenic alcohols and methyl sterols is also reported.     

Lipid Profiles of Tunisian Coriander (<Emphasis Type="Italic">Coriandrum sativum</Emphasis>) Seed

Coriander (Coriandrum sativum L.) seeds were harvested from the region of Korba (North-East Tunisia) in order to characterize their fatty acids, phytosterols, tocopherols and tocotrienols (tocols) profiles. Nine fatty acids, with petroselinic acid accounting for 76.6% of the total fatty acids, followed by linoleic, oleic and palmitic acids, accounting for 13.0, 5.4 and 3.4%, respectively, of the total fatty acids were identified. Neutral lipids (NLs) were mainly composed of triacylglycerols (98.4%). Polar lipids were mainly composed of phosphatidylcholine as the major phospholipid (PL) subclass, whereas digalactosyldiacylglycerol was the major galactolipid (GL). Total sterols content was estimated to be 36.93 mg/g oil. Stigmasterol accounted for 29.5% of the total sterols. Other representative sterols were β-sitosterol, Δ⁷-stigmasterol and Δ⁵, 24-stigmastadienol, which accounted for 24.8, 16.3 and 9.2%, respectively. Gamma-tocotrienol was the predominant tocol at 238.40 μg/g seed oil. This was equivalent to 72.8% of the total tocols followed by γ-tocopherol (8.06%) and α-tocopherol (7.6%).     

Composition of long-chain fatty compounds and sterols of four milled peat samples from Finnish peatlands

Four milled peat samples from three Finnish peatlands were studied in terms of their extract content and composition of fatty compounds and sterols using capillary g.c.-m.s. The extract yields obtained by CH₂Cl₂-acetone (9:1 v/v) ranged from 49 to 180 mg g⁻¹ of dry peat. The wax content of peat extracts varied between 43 and 55 wt %. The acidic part of extracts contained mainly long-chain fatty acids and ω-hydroxy acids with some α,ω-alkanedioic acids. The neutral extractives included predominantly primary alkanols with smaller amounts of n-alkanes and sterols. The extracts of all four peat samples were qualitatively similar but the milled peat Al with high heat value (27.1 MJ kg⁻¹) differed from the other peats in extract content and composition. The peat B with enhanced self-heating ability resembled the ordinary milled peats A2 and C in peat technological characteristics and extractive composition. Accordingly, the self-heating ability of milled peat in stockpiles does not correlate directly to the distribution pattern of long-chain fatty compounds and sterols.     

Differential incorporation of acetate and glucose in maturing douglas fir seeds

In order to discern the synthetic pathways of lipids in coniferous seeds, decoated maturing Douglas fir seeds were incubated with 2-¹⁴C-acetate and ul-¹⁴C-glucose for 3 hr in phosphate buffer at pH 6.0. About 52% of incorporated acetate was found in lipids, but only 9% of the absorbed glucose was converted to lipids. Distribution of incorporated radioactivity in lipid classes was similar for both substrates, 45% in polar lipids, 22% in diglycerides, 15% in triglcerides, 7% in sterol esters, 4% in each of fatty acids and monoglycerides, and 3% in sterols. High specific activity was found in free fatty acids, diglycerides, monoglycerides and polar lipids indicating a rapid turnover of the intermediates for reserve triglycerides and structural polar lipids. Degradation analyses showed that 50% of incorporated acetate and glucose in lipids were in fatty acid moiety. Acetate contributed more in sterols and other unsaponifiables than in glycerol, and the reverse was true for glucose. All the data indicated that acetate is the direct precursor of fatty acids and sterols. General synthetic pathways prevail in fir seeds. Methods for complete analysis of chemical and radio-chemical composition were presented and results discussed. Technical paper 2346 Oregon Agricultural Experiment Station.     

Localization of long-chain fatty acids and unconventional sterols in spherulous cells of a marine sponge

The first direct evidence is provided for the presence of unconventional lipids in a particular subcellular membrane system of a sponge. Spherulous cells were isolated from the variety of cell types present in the marine spongeAplysina fistularis by density gradient centrifugation. Spherulous cell plasma membrane was subsequently isolated by cell rupture followed by differential centrifugation and sucrose, or Percoll, density gradient ultracentrifugation. Plasma membrane isolates were identified and assessed for purity using [³H] concanavalin A plasma membrane marker, sodium dodecyl sulfate polyacrylamide gel electrophoresis and ratios of protein, sterol and phosphate. Plasma membrane isolates could not be assessed for purity by traditional enzymatic means. Spherulous cell plasma membrane was found to contain unusual lipids, including long-chain (C₂₄–C₃₀) fatty acids (16.8–27.2%) and unconventional 26-alkylated sterols (66.4–72.6%), in addition to more conventional fatty acids and sterols. Spherulous cell intracellular membranes were also found to contain long-chain fatty acids and unconventional sterols, although the relative importance of these unusual lipids apparently varies between intracellular membranes, with some containing approximately 50% long-chain acids. Part 19 of “Phospholipid Studies of Marine Organisms.” For Part 18 see Li, H., Duzgunes, N., Ayanoglu, E., and Djerassi, C.,Chem. Phys. Lipids, in press.     

The content and composition of sterols and sterol esters in low erucic acid rapeseed (Brassica napus)

The low temperature crystallization technique for the enrichment of “minor” components, such as sterols and sterol esters, from vegetable oils was applied to low erucic acid rapeseed oils. The recovery of free sterols and sterol esters was estimated by use of¹⁴C-cholesterol and¹⁴C-cholesterol oleate. 80% of the free sterols and 45% of the sterol esters were recovered in the liquid fraction, while in two studies total recoveries were 95% and 99%, respectively. This technique showed some selectivity toward the sterol bound fatty acids when compared to direct preparative thin layer chromatography (TLC) of the crude oil. Gas liquid chromatography (GLC) analysis of the free and esterified sterols as TMS-derivatives showed very little selectivity in the enrichment procedure. The fatty acid patterns of the sterol esters demonstrated, however, a preference in the liquid fraction for those sterol esters which have a high linoleic and linolenic acid content. The content of free sterols was 0.3–0.4% and that of sterol esters 0.7–1.2% of the rapeseed oils in both winter and summer types of low erucic acid rapeseed (Brassica napus) when the lipid classes were isolated by direct preparative TLC of the oils. The free sterols in the seven cultivars or breeding lines analyzed were composed of 44–55% sitosterol, 27–36% campesterol, 17–21% brassicasterol, and a trace of cholesterol. The esterified sterols were 47–57% sitosterol, 36–44% campesterol, 6–9% brassicasterol, and traces of cholesterol and Δ5-avenasterol. The fatty acid patterns of these esters were characterized by ca. 30% oleic acid and ca. 50% linoleic acid, whereas these acids constitute 60% and 20%, respectively, of the total fatty acids in the oil. Little or no variation in sterol and sterol ester patterns with locality within Sweden was observed for the one cultivar of summer rapeseed investigated by the low temperature crystallization technique.     

Acetate and mevalonate labeling studies with developingCuphea lutea seeds

Cuphea seeds contain large amounts of medium chain (C₈ to C₁₄) fatty acids, mainly as triacylglycerols. The biosynthesis of these lipids was studied in vivo by incubating developingCuphea lutea seeds with labeled acetate. Incorporation of label into triacylglycerols and into medium chain fatty acids occurred principally during the period of endogenous lipid deposition, but some label was encountered in these products even during seed dehydration. At this later stage palmitate and oleate were the dominant labeled fatty acids. During the period of rapid endogenous lipid deposition acyl lipids other than triacylglycerols were minor labeled components. The labeling patterns were consistent with the Kennedy pathway for triacylglycerol biosynthesis. The fatty acid composition of the acyl-CoA pool was similar to the total lipid fatty acid composition, but the acyl-ACP pool contained relatively more short chain acyl groups. Squalene was labeled from acetate throughout the period of seed development, but labeled sterols were not detected. Using [2-¹⁴C]mevalonic acid lactone as substrate, squalene was the principal labeled product. Small amounts of label were found in free sterols. However, in terms of mass, free sterol dominated over squalene. The possibility of two independent sites of isoprenoid biosynthesis in the developing embryo is discussed.     

Free,esterified and glucosidic sterols in cocoa butter

Sterol lipids of cocoa butter (cocoa beansLome Tongo) were fractionated into free sterols, steryl esters (SE), steryl glucosides and acylated steryl glucosides (ASG). 4-Desmethyl, 4-methyl and 4,4′-dimethyl sterols or triterpene alcohols, which were isolated as free sterols or which resulted from hydrolysis, were determined by thin layer chromatography-flame ionization detection and identified by gas chromatography and combined gas chromatography-mass spectroscopy. Free sterols comprise the main sterol fraction in cocoa butter. Esterified sterols amount to 11.5% of total sterols and glucosidic sterols to 16.3%. Fatty acids and D-glucose from hydrolysis of esters and glucosides were analyzed. The fatty acids of SE and ASG are richer in unsaturated fatty acids than cocoa butter total fatty acids.     

A comparison of the fatty acids and sterols of seeds of weedy and vegetable species ofAmaranthus spp.

The seeds of weedy and vegetable species ofAmaranthus were analyzed for sterols and fatty acids. The major sterol was spinasterol, which ranged from 46 to 54% by weight of the total sterol mixture. Δ⁻⁷ stigmasterol occurred in the next higher amount with lesser amounts of Δ⁻⁷ ergosterol, stigmasterol and 24-methylene-cycloartenol. There was little difference in the sterol composition of the vegetable species compared to the weedy species. The fatty acid compositions of the species were essentially all the same. Linoleic acid was present in the greatest amount, with lesser amounts of oleic, palmitic, stearic, myristic, linolenic, arachidic and lignoceric acids.     

Lipid and fatty acid characterization and metabolism in the sea anemonePhymactis clematis (Dana)

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.     

Tissue culture of cocoa beans (Theobroma cacao L.): Incorporation of acetate and laurate into lipids of cultured cells

Suspension cultures of cocoa bean tissue readily incorporated exogenous acetate into lipids. The distribution of radioactivity from acetate in individual lipid classes after 48 hr was 20, 5, 1, 15, 25, and 35% in triglycerides, diglycerides, free fatty acids, sterol esters, sterols and polar lipids, respectively. The labeled acetate was rapidly incorporated into various fatty acids within 2 hr. The [1-¹⁴C] saturated fatty acids declined slightly after 4 hr, whereas [1-¹⁴C] oleate declined significantly after 2 hr. There was a concomitant increase in [1-¹⁴C] linoleate. The radioactivity associated with linolenate was relatively high up to 4 hr, declined by 24 hr, and then increased again. The kinetics of fatty acid labeling suggested that biosynthesis of linolenic acid in cocoa bean suspension culture may occur via the desaturation of linoleic acid and the chain elongation of dodecatrienoic acid. The patterns of fatty acid radiolabeling following incubation of cells with [1-¹⁴C] laurate was consistent with this mechanism.     

Biosynthesis of lipids by bovine meibomian glands

Isolated bovine meibomian glands incorporated exogenous [1-¹⁴C] acetate into lipids. Thin layer chromatographic analysis of the lipids showed that wax esters and sterol esters contained 61% of the total label. Radio gas liquid chromatographic analysis of the acid and alcohol moieties of both ester fractions showed the label was distributed equally between the two portions of the ester in both cases. Cholesterol and 5-α-cholest-7-en-3β-ol were the major labeled sterols, and anteiso-C25, anteiso-C27 and anteiso-C23 were the most highly labeled alcohols. The major labeled fatty acids in the wax esters were anteiso-C15,n-C16, anteiso-C17 andn-C18∶1, whereas anteiso-C25 and anteiso-C27 were the major labeled acids in the sterol esters. The diester region with 6% of the total label contained labeled fatty acids and fatty alcohols each with anteiso-C25 as the major component and ω-hydroxy acids in whichn-C32∶1 was the major labeled component. The trigly ceride fraction which contained 8% of the total lipids was composed of labeled fatty acids similar to those found in both sterol and wax ester fractions. Chromatographic analyses of the labeled lipids derived from exogenous labeled isoleucine showed that anteiso-branched products were preferentially labeled. The labeled triglyceride fraction derived from [U-¹⁴C] isoleucine also contained esterified C15, C13, C11, C9, C7 and possibly shorter anteisobranched acids.     

Skin surface lipids of the dog

The skin surface lipid of the dog has been reported to contain a high proportion of diol diesters having a lower mobility on thin layer chromatography than diesters from other species in spite of containing similar fatty acid and diol components. In the present study, dog skin surface lipid was separated by preparative thin layer chromatography into sterol esters (42%), wax diesters (32%), free sterols (9%), polar lipids (7%), and unidentified components (10%). The diesters contained 1,2-diols, each esterified with one long chain fatty acid and one isovaleric acid moiety. The diols were principally branched chain C₂₁ and C₂₂ compounds while the long chain fatty acids esterified with them were mainly C₂₀ and C₂₁ branched compounds. The fatty acids from the sterol esters were mostly saturated, branched chain C₁₉ to C₂₃, together with 7% of straight chain monoenoic acids, principally C₂₁ and C₂₂. There were only trace amounts of free sterols other than cholesterol, while the esterified sterols contained 96% cholesterol and 4% lathosterol.     

Untersuchungen über die Lipide von Kartoffeln

Investigations on the Lipids of Potatoes Gas chromatographic investigations on the fatty acid composition of the total lipids of freeze-dried potato showed that 90% of the fatty acids consist of linolenic, linoleic, palmitic and stearic acids. In all, 31 different fatty acids were detected and identified. Noticeable amounts of odd-chain fatty acids and those having more than 20 C-atoms (up to C₃₀) were found. Eight different varieties of potato were investigated. Difference in the fatty acid composition of the individual varieties was not appreciable. Experiments on the group separation of lipids showed that they contain a large amount of phospholipids (especially lecithin and cephalin). Appreciable amounts of triglycerides were also found, however, the sterol esters, sterols and free fatty acids were present to a lesser extent.     

Lipophilic Extractives in Eucalyptus globulus Kraft Pulps. Behavior during ECF Bleaching

Abstract

The composition of E. globulus kraft pulp lipophilic extractives and their behaviour during an ECF (DEDED) bleaching sequence were investigated. Sterols; fatty acids, including several α‐ and ω‐hydroxyfatty acids; and long‐chain aliphatic alcohols are the major lipophilic extractives of the unbleached pulp. During the bleaching, about 80% of the aliphatic extractives are removed from pulp (ca. 70% of the sterols, 70% of the fatty acids, and 90% of the long‐chain aliphatic alcohols). The decrease of sterols is mainly due to the degradation of β‐sitosterol by chlorine dioxide, while the decrease of fatty acids and alcohols is essentially assigned to their extraction and elimination with the alkaline filtrates. The major chemical transformations in pulp extractives composition and structure occur in the last bleaching stages.     

The content and composition of sterols and sterol esters in sunflower and poppy seed oils

The composition and proportion of free sterols and sterol esters in crude sunflower and poppy seed oils were determined, using preparative thin layer chromatography followed by gas chromatography with cholesterol as an internal standard. Free sterols and sterol esters were also isolated in a liquid fraction obtained by low temperature crystallization (−80 C) of the oils and enriched with minor lipid classes. This enrichment procedure provided a liquid fraction suitable for studies of minor components in the oils. However, selectivity towards sterol esters was observed since sterols esterified to very long chain fatty acids (C₂₀–C₂₄) were preferentially retained in the precipitate. The proportions of free and esterified sterols were found to be 0.34 and 0.28%, respectively, in the sunflower oil, whereas the corresponding figures for poppy seed oil were 0.33% and 0.05%. Sunflower oil was characterized by a relatively high percentage of Δ7-sterols, preferentially obtained in the esterified fraction, and by very long chain saturated fatty acids of sterol esters. The sterols in poppy seed oil were composed almost entirely of campesterol, stigmasterol, sitosterol and Δ5-avenasterol, although their percentage distributions were remarkably different in the free and esterified fraction.     

The effect of lyophilization on the solvent extraction of lipid classes,fatty acids and sterols from the oysterCrassostrea gigas

The lipid class compositions of adult Pacific oysters [Crassostrea gigas (Thunberg)] were examined using latroscan thin-layer chromatography/flame-ionization detection (TLC/FID), and fatty acid compositions determined by capillary gas chromatography and gas chromatography/mass spectrometry (GC/MS). The fatty acid methyl esters were separated using argentation TLC and also analyzed as their 4,4-dimethyloxazoline derivatives using GC/MS. Major esterified fatty acids inC. gigas were 16∶0, 20∶5n−3, and 22∶6n−3. C₂₀ and C₂₂ nonmethylene interrupted (NMI) fatty acids comprised 4.5 to 5.9% of the total fatty acids. The NMI trienoic fatty acid 22∶3(7,13,16) was also identified. Very little difference was found in the proportions of the various lipid classes, fatty acids or sterols between samples of adult oysters of two different sizes. However, significant differences in some of the lipid components were evident according to the method of sample preparation used prior to lipid extraction with solvents. Lyophilization (freeze drying) of samples led to a significant reduction in the amounts of triacylglycerols (TG) extracted by solvents in two separate experiments (7.0 and 52.5% extracted). Extracts from lyophilized samples had less 16∶0, C₁₈ unsaturated fatty acids, and 24-ethylcholest-5-en-3β-ol, while C₂₀ and C₂₂ unsaturated fatty acids comprised a higher proportion of the total fatty acids. There was no significant change in the amounts of polar lipids, total sterols, free fatty acids or hydrocarbons observed in extracts from lyophilized samples relative to extracts from nonlyophilized samples. Addition of water to the freezedried samples prior to lipid extraction greatly improved lipid yields and resulted in most of the TG being extracted.     

The distribution of lipids and sterols in cell types from the marine spongePseudaxinyssa sp

The sponge Pseudaxinyssa sp., unique in sterol and fatty acid composition, was cellularly dissected into fractions enriched in each of the major cell types present in the sponge: microbial symbionts (cyanobacteria), small sponge cells (pinacocytes and choanocytes), and large sponge cells (archeocytes and cyanophytes). Three phototrophic microbial symbionts were also isolated from the cell fractions and grown in culture. An unsymmetrical distribution of fatty acids and sterols was observed for the sponge cells: small cells contained larger quantities of long chain fatty acids (greater than C24) and smaller quantities of sterols than were present in the larger sponge cells. Moreover, the rare sterols 24-isopropylcholesterol predominated in the smaller sponge cells, whereas its 22-dehydro analog predominated in the larger sponge cells. Long chain fatty acids and sterols were not detected in the cultured microbial symbionts. This constitutes the first report of lipid variability according to cell type for this most primitive group of Metazoa.