Lipid composition of millet (Pennisetum americanum) seeds

The composition of lipids extracted from a sample of millet seeds by each of 8 solvent systems is reported. Lipid components were separated by silicic acid column and thin layer chromatography (TLC) and quantitated by analysis of fatty acid methyl esters by gas liquid chromatography (GLC), with heptadecanoic acid as internal standard. Best results were obtained by extraction with hot water-saturated butanol. Lipids extracted amounted to 7.2% of the seed dry weight and consisted of 85% neutral lipids, 12% phospholipids and 3% glycolipids. Neutral lipids contained mostly (85%) triacylglycerols and small amounts of mono- and diacylglycerols, sterols and free fatty acids. Sterols consisted of campesterol, stigmasterol and 2 unidentified sterols, occurring in the same proportions in free and esterified forms. Ten glycolipid and 10 phospholipid components were separated and characterized. Contrary to previously published observations, lysophosphatidylcholine was the major phospholipid (42%) in millet seeds; smaller amounts of phosphatidylcholine (24%), lysophosphatidylethanolamine (21%) and trace amounts of phosphatidylglycerol, phosphatidic acid, phosphatidylserine and phosphatidylinositol also were present. The major glycolipids were esterified sterol glycoside, sterol glycoside, monogalactosyldiacylglycerol, digalactosyldiacylglycerol and cerebrosides (ceramide monohexosides).     

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.     

表面活性剂复配体系的分析

介绍了一种使用经典的分析技术定量测定液体皂、皂胶、洗衣皂及香皂中存在的皂类、脂肪酸、非离子表面活性剂及除肥皂以外的阴离子表面活性剂和两性表面活性剂混合物的分析方法。这种方法克服了分析混合表面活性剂系统时常常会碰到的问题。     

Combination of thin layer chromatography and gas chromatography in the analysis on a microgram scale of lipids from wheat flour and wheat flour doughs

Lipids were extacted on a microgram scale from 3 to 6 mg flour or from freeze-dried dough by percolation. The impure extract was separated into 12 nonpolar and 14 polar lipids by TLC. Then the fatty acid composition of most of these lipids was determined by gas chromatography. The microscale method renders possible qualitative and quantitative determination of the composition of the lipids in minute quantities of flour and dough. The selectivity of different extraction solvents was studied. In both flour and dough the fatty acid composition of a given component is identical in the free and bound lipid fractions. In dough, the quantity of free lipids is less than in flour; the extent of the decrease depends on the atmosphere in which it is mixed. During mixing, the carotenoid pigments, α-monoglycerides and the free linoleic acid and linolenic acid are oxidized. Oxidation is apparently a function of the concentration of oxygen and of lipoxidase.     

Lipid metabolism ofAgaricus bisporus (Lange) sing.: I. Analysis of sporophore and mycelial lipids

The lipid components of four strains ofAgricus bisporus (Lange) Sing., the cultivated mushroom, were analyzed. Both sporophore and mycelial samples were obtained from beds in normal production. A method for obtaining mycelium free of compost was developed. Neutral lipids were separated from polar lipids by silicic acid column chromatography. Each fraction was separated by thin layer chromatography. Fatty acid methyl esters were analyzed by gas liquid chromatography and mass spectrometry. Sporophore extracts contained free sterol, free fatty acid, triglycerides, phosphatidyl choline and phosphatidyl ethanolamine. High amounts of linoleic acid were found in both neutral and polar lipid fractions. Mycelial extracts contained free fatty acids, triglycerides, phosphatidylcholine and phosphatidyl ethanolamine. No free sterol could be detected. Linoleic acid was also present in large amounts. Paper 3798 in the Journal Series of The Pennsylvania Agricultural Experiment Station.     

Wechselwirkungen zwischen Aromastoffen und Lipiden 2. Mitteilung: Sorption ausgewählter Aromastoffe an Kakaobutter

Interactions Between Aroma Compounds and Lipids, 2. Sorption of Some Selected Aroma Compounds on Cocoa Butter The specific retention volumes and retention indices of 30 aroma compounds on cocoa butter have been determined at some temperatures between 90° and 130° C or between 130° and 170° C. The linear correlations between the logarithms of the specific retention volumes or the retention indices and the boiling points proved to be the best ones of several correlations. They can serve for the estimation of the reversible sorbed amounts of not tested aroma compounds. Possibilities of extrapolation to other temperatures are discussed. The retention values depend on the relation of aroma compound to cocoa butter. Another linear relationship exists between the sorption heats and the boiling points.     

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.     

Lipids of cultured hepatoma cells: I. Effect of serum lipid levels on cell and media lipids

Minimal deviation hepatoma cells were cultured as monolayers to confluency in roller flasks containing modified Swim's medium, supplemented with decreasing amounts of serum, lipid-free serum, and lipid-free serum containing added fatty acids. Good cell growth was observed until serum levels fell below 5% of the medium. Media containing lipid-free serum or lipid-free serum plus linoleic or palmitic acids did not support good growth. Lipids were extracted from cells; media, obtained during the first and last half of the incubation period, resolved into neutral and phospholipid fractions; fatty acid composition of each fraction analyzed by gas liquid chromatography; and lipid class distributions compared by thin layer chromatography. The data showed that the media contained more neutral lipids and phospholipids after incubation than initially, indicating that minimal deviation hepatoma cells excreted lipids into the media. The class composition of the excreted lipids resembled that of the serum. A comparison of media, cells, and serum fatty acid compositions indicated that the lipids secreted into the media were of cellular origin. Although some differences were noted, in general, cells grown on the nine different media had the same ca. neutral lipid and phospholipid class and fatty acid compositions. In contrast, dramatic differences were observed in the class and fatty acid compositions of the serums from that of the cells and media. These results indicate that exogenous serum lipids had little influence on cellular class and fatty acid compositions of the minimal deviation hepatoma cells. This neoplasm did not contain detectable levels of glyceryl ether diesters, indicating that this compound is not characteristic of all tumors. Lipid class profiles and fatty acid compositions of cells grown on various media suggest that the minimal deviation hepatoma cells can synthesize most, if not all, neutral lipid and phosphoglyceride classes found in liver. Presented at the AOCS Meeting, New Orleans, April 1973.     

Chemie der Fischlipide

Chemistry of Fish Lipids The muscle (‘meat’) of freshwater fishes and marine fishes contains 1–25% lipids which are predominantly triglycerides; phospholipids are generally present in rather small proportions. The lipids in the muscle of typical freshwater fishes contain considerable proportions of oleic and linoleic acids, whereas the lipids of most marine fishes contain relatively large amounts of highly unsaturated fatty acids having 20 and 22 carbon atoms. The fatty acid patterns of lipids in the muscle of freshwater predatory fishes resembles to a greater extent that of marine fishes than herbivorous freshwater fishes. In the meat of sharks, alkyldiacylglycerols occur in addition to small amounts of alk-1-enyldiacylglycerols (neutral plasmalogens). In the muscle lipids of marine fishes from depths of more than 1000 m, wax esters predominate. As a rule, the liver of marine fishes, especially of sharks, is rich in alkoxylipids, wax esters, steryl esters, vitamin A esters and hydrocarbons.     

The thermodynamic state of water in cellulose acetate membranes

Using experimental sorption data and corresponding experimental results from calorimetric investigations, the state of water in cellulose acetate (CA) membranes is discussed by applying a theoretical treatment of sorption reported previously (1–3). The sorption of water can be attributed to a gain in surface energy at the polymer/vapor interface. Using differential thermodynamic potentials of sorbed water together with experimentally determined heat capacities of sorbed water, the thermodynamic potentials G, H, and S of sorbed water are estimated for the temperature interval ?40 to + 40°C. At constant temperature, each thermodynamic potential depends on the water content. The resulting distribution function of G indicates that the sorbed water exists in different states. Comparing the Gibbs free energy of sorbed water with that of ice or liquid water at the same temperature leads to the conclusion that none of the sorbed water freezes to ice within the temperature interval used. Based on the Gibbs free energy of water in electrolyte solutions and the distribution function of G for sorbed water, partition coefficients of salts within CA membranes may be estimated. The results are in good agreement with experimentally determined partition coefficients which are available from the literature. As the partition coefficient of a salt is directly related to the salt rejection of the membrane, this provides a method of estimating the desalination performance of a membrane from its water sorption isotherm.     

Lipid composition of rice (Oryza sativa L.) bran

The composition of lipids of bran from three varieties of rice is reported. Lipids extracted amounted to 21.9–23.0% of the bran dry weight and consisted of 88.1–89.2% neutral lipids, 6.3–7.0% glycolipids and 4.5–4.9% phospholipids. Neutral lipids consisted mostly of triacylglycerols (83.0–85.5%), monoacylglycerols (5.9–6.8%) and small amounts of diacylglycerols, sterols and free fatty acids. Three glycolipids and eight phospholipids were separated and characterized. Acylated steryl glucoside and digalactosyldiacylglycerol were the main glycolipids, while monogalactosylmonoacylglycerol was present in small amounts. The major phospholipids were phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol and phosphatidic acid. Phosphatidylglycerol, lysophosphatidylcholine, lysophosphatidylethanolamine and acyl-phosphatidylethanolamine were present in small quantities.     

The lipid composition of the spleen and intestinal and popliteal lymph nodes in the sheep

Lipids were isolated from the spleen, intestinal lymph nodes and popliteal lymph nodes, tissues of potential importance in the metabolism of lymph or lymphocytes, of the sheep. The most abundant lipid classes were the triacylglycerols, free cholesterol and phospholipids, especially phosphatidylcholine, phosphatidylethanolamine and sphingomyelin. In each lipid class, the amounts of the essential fatty acids were lower than in the corresponding lipids of lymph or plasma. The triacylglycerols of each tissue resembled those of adipose tissue in structure, rather than those of lymph or plasma. Also, the structures of the phosphatidylcholines were distinctive. The results are discussed in terms of the metabolism of lipids in lymph. It does not appear probable that lymphoid tissue can supply appreciable amounts of lipid to lymph.     

Über trans-Lipoide: Die Lipoide des Hühnerei-Dotters

Trans Lipids: The Egg Yolk Lipids of the Hen The feeding of hens with a trans-containing edible fat resulted in an increase in the trans fatty acids of the egg yolk lipids to the extent of 10%, which completely disappeared within 14 days after stopping the trans-containing feed. The fatty acids in the triglyceride fractions contained in each case more trans unsaturated fatty acids than those in the corresponding phosphatide fractions. The gas chromatographic analysis of the fatty acid methyl esters showed that the triglycerides contained more oleic acid than the phosphatide fatty acids whereas stearic as well as polyunsaturated components were concentrated predominently in the phosphatides. The analysis of the fatty acid methyl esters from triglyceride and phosphatide fractions after feeding of trans-containing fat showed distinct changes in both the groups, thus for example a reduction of oleic acid in the neutral fat analogous to that in the total lipids as against its increase in phosphatides. The amount of linoleic acid in the phosphatide fatty acids increased while it remained constant in triglyceride fatty acids.     

Dietary induced alterations in the fatty acids of rat bone marrow

Weanling rats were fed fat free diets supplemented with 10% added fatty acids so that dietary effects on bone marrow fatty acids could be determined. The addition or deletion of linoleic acid from the fatty acid supplement resulted in alterations of the fatty acid patterns of bone marrow lipids but to a lesser degree than in erythrocyte lipids. With myristic acid supplementation, increased amounts of stearic acid were found in the lipid fractions, the difference between the bone marrow and erythrocyte lipids being less marked than when linoleic acid was fed. The activities of the bone marrow lipases varied with the dietary treatment. When linoleic acid was fed, higher rates of hydrolysis were observed with saturated fatty acid substrates. The reverse occurred when saturated fatty acids were fed.     

Die Hautoberflächenlipide bei der Psoriasis vulgaris (Ps) -Cholesterin- und Wachsester,Triglyceride und Fettalkohole

The Skin-Surface Lipids in Psoriasis vulgaris (Ps) - Cholesterol Esters, Wax Esters, Triglycerides and Fatty Alcohols The composition of waxes and cholesterol esters, triglycerides and alcohols of hair lipids from subjects with psoriasis vulgaris and control group was determined by gas liquid chromatography. The amount of palmitoleic acid was lower in the lipid group of the waxes and cholesterol esters in psoriasis vulgaris. Triglycerides show two different changes in the fatty acid pattern by psoriasis: 1) the composition of shorter chain fatty acids was distinct lower but 2) patients with a heavy psoriasis show an increase of the shorter chain fatty acids especially lauric acid and a decrease of the longer chain fatty acids. The analysis of the alcohols indicates that psoriatic patients possess a higher content of alcohols with 12,13 and 14 carbonatoms than normal subjects.     

Biosynthesis of fatty acids from acetate in soybean suspension cultures

Suspension cultures of finely divided soybean cells established from callus were incubated with sodium [1(14)C] acetate for periods up to 86 hr. Lipids and fatty acids were analyzed for radioactivity in samples harvested at logarithmic time periods. Incorporation of acetate into cell lipid was directly proportional to the logarithm of time up to 32 hr, after an initial lag of 4-6 hr. Most of the lipid radioactivity was found in the phospholipid fraction, and all common soybean fatty acids became labeled within 6 hr. The order of labeling and distribution of radioactivity with time were essentially the same as in tissues from intact growing plants. These results support the concept of sequential desaturation of oleic acid in the cells. It was concluded that valid studies of the biosynthesis of common lipids in the soybean can be carried out for extended periods of time by use of undifferentiated cells in suspension cultures.     

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.     

Präparative Schichtchromatographie phosphatidhaltiger Lipide

Preparative Layer Chromatography of Lipids Containing Phosphatides According to the method described by H. Halpaap, the separations of microgram amounts of lipids containing phosphatides on precoated silicagel plates have been scaled up to milligram level using 2 mm precoated layers. Following this procedure the composition of lipid mixtures containing phosphatides, such as those from soybean and some commercial preparations, was determined by gravimetry. In order to check the fractionation by preparative layer chromatography, the isolated fractions were re-chromatographed on thin-layer plates, following the dry transfer technique. This simple technique combined with gas chromatography was employed for the determination of fatty acid composition of bile lipid fractions.     

Solvent solubility parameter and flour moisture effects on lipid extractability

Lipids were extracted with a series of solvent systems whose solubility parameter (δ) values ranged from 7.27 to 12.92 (hexane and its aqueous azeotrope, benzene, acetone and its azeotrope and 2-propanol and its azeotrope) from a flour with 1.2%, 7.2% or 13.8% moisture content (MC). The extracted total lipids (TL) were fractionated into nonpolar lipids (NL) and polar lipids (PL) by silicic acid column chromatography. NL and PL were further subfractionated by thin layer chromatography (TLC). PL were separated into glycolipids (GL) and phospholipids (PhL). TL, NL and PL extractabilities were affected by both flour MC and by the nature and composition of extractants: the overall solvent effects were substantially more pronounced than the flour MC effects. Free fatty acid and digalactosyldiglyceride (DGDG) extractabilities increased for all extractants, in general, as flour MC increased. Significant linear relations between the δ values of extractants and the average amounts of TL, PL, GL and PhL from flours with 3 MC were found. The high correlation (r=0.981) between δ and extractability of TL was primarily caused by PL; extractabilities of monoglycerides (among NL) and all classes of GL and PhL were significantly (at the 0.01 level) linearly related to the δ values at all 3 flour MC levels. The present study indicated no selective binding between flour proteins and a specific PL class. Among PL, DGDG showed a clear-cut breaking point in irreversible restoration of breadmaking characteristics. Thus, the present study confirms the significant role of PL to breadmaking, resulting primarily from the contribution of DGDG. Presented in part at the AOCS Meeting, San Francisco, 1979.     

Wirkung langkettiger Monoensäuren auf die Lipide in Nebennieren und Blutserum von Schweinen

Action of Long-Chain Monoenoic Acids on the Lipids of Adrenals and Blood Serum of Pigs The influence of soybean oil and rapeseed oil diets with varying fat content and erucic acid content on the lipids of adrenals and blood serum of pigs was studied. The content of total lipids, free sterols and sterol esters is influenced by the composition of the diet. The composition of the sterols is found to be the same in all lipid samples examined. The fatty acid composition of triglycerides of adrenals showed a characteristic dependence on the dietary fat, whereas no influence was observed in sterol esters, the typical transition lipids, due to large fluctuations between the individual animals. Moreover, independent of the type of feed, large differences were observed in the triglycerides and sterol esters of blood serum. Significant alterations by feeding rapeseed oil did not occur in adrenals and blood serum.