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.     

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.     

Die Extraktion der Gesamtlipoide von Hefen

Extraction of Total Lipids from Yeast Investigations on solubility of lipids in dimethylsulfoxide (DMSO) and use of DMSO in admixture with chloroform for the extraction of yeast lipids are reported. DMSO denatures protein and, in contrast to methyl alcohol containing extraction solvents, forms no methyl esters when free fatty acids are present and furthermore inactivates enzymes e. g. lipase.     

Hydrierung von Lipiden als Hilfsmittel zur Identifizierung und Quantifizierung von Phosphatiden aus Membransystemen des Herzmuskels

Hydrogenation of Lipids for Identification and Quantification of Phosphatides from Pellicle Systems of Cardiac Muscle. It was the aim of our research to show that hydrogenation of lipids is an auxiliary technique in phospholipid analysis of cardiac membranes. This is of interest if a preliminary overview on lipid fractions containing highly unsaturated fatty acids is needed. The fatty acids and the diglycerides from phospholipids were hydrogenated according to the procedure described by Appelqvist (A simple and convenient procedure for the hydrogenation of lipids on the micro- and nanomole scale, J. Lipid Res. 13 (1972), 146) with platinum oxide as a catalyst. The lipids (fatty acid methyl esters or acetylated diglycerides) were taken to dryness in a test-tube under nitrogen and flushed with hydrogen. The catalyst, suspended in methanol was injected through a septum. For identification purposes thin-layer chromatography on silica gel and on silica gel impregnated with silver nitrate was combined with gas chromatography before and after hydrogenation. After hydrogenation the fatty acid profile is much simpler and the fatty acid methyl esters can easily be differentiated from dimethyl acetals, as the latter are more volatile. Diacylglycerides and alkenylacylglycerides were also separated by thin-layer chromatography in individual subclasses before they were analysed by gaschromatography. Hydrogenating the lipids makes it possible to circumvent in part difficulties which arise often with polyunsaturated fatty acids. As the chain length of C20 and C22 are mainly represented by C20:4 , the arachidonic acid and C22:6 the docosahexaenoic acid, both fatty acids can be assessed after hydrogenation. The fatty acid profile of phosphatidylcholine and phophatidylethanolamine of cardiac muscle from rat, guinea pig and pig was determined. Each sample was analysed before and after hydrogenation. The fatty acids with the same chain length were summed up and compared to the corresponding chain length after hydrogenation.     

Diesterwachse und ungewöhnliche Fettsäuren aus Bürzeldrüsenlipiden

Diester Waxes and Unusual Fatty Acids in Lipids of Sebaceous Gland Systematic investigations of lipids of sebaceous gland of birds have shown close relationship between the structure of these lipids and the individual species in the natural system of birds. In almost all the species studied so far the lipids of sebaceous gland consist of wax esters which are made up of unusual fatty acids and alcohols. Thus in the group of passeriformes (sparrows) 3-methyl substituted fatty acids, in the group of strigiformes (owls) 2-propyl and 2-butyl substituted fatty acids, and in the group of columbiformes (pigeons) 3-hydroxy fatty acids are found as constituents of the wax esters. Diester waxes are found in galliformes (hens), columbiformes, limicolae (snipes) and in some members of passeriformes. Unusual constituents of these waxes are alkanediols, 3-hydroxy fatty acids, and alkylhydroxymalonic acids. The structures were elucidated by a combination of GLC and mass spectrometry. Some of the mass spectra are discussed.     

Plant waxes

The surface of plants is covered with a complex mixture of lipids, often in crystalline form, called plant waxes. The chemistry, biosynthesis, catabolism and function of plant waxes are reviewed. The most common components are hydrocarbons, wax esters, free fatty alcohols and acids. Ketones, secondary alcohols, diols, aldehydes, terpenes and flavones are also found. The major function of the wax appears to be protection of the organism from water loss and other hazards of the environment. The alkanes are formed from fatty acids either by elongation followed by decarboxylation or by head-to-head condensation between two biochemically dissimilar fatty acids followed by specific decarboxylation of one of them. Fatty acyl-CoA is reduced to the aldehyde which in turn is reduced to the alcohol. The alcohol is then esterified with acyl moieties from acyl-CoA or phospholipids. Plant waxes undergo very little catabolism in plants but animals can degrade them to a limited extent and microorganisms readily degrade them. One of six papers to be published from the Symposium on Natural Waxes, presented at the AOCS Meeting, San Francisco, April 1969.     

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.     

Lipids in soil

As much as 20% of soil humus occurs in the form of lipids. High values are characteristic of Podzol soils and highmoor peats. Lipids of the following types are known to be present: paraffin hydrocarbons, phospholipids, fats, waxes, fatty acids, and terpenoids. A long list of compounds have been reported; the identification of many of them require confirmation using modern analytical techniques. Some of the lipids known to occur in soil have phytotoxic properties; these may have a depressing effect on seed germination and on root and shoot growth. Waxes and similar materials may be responsible for the difficultly wettable condition of certain sands.     

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.     

吕宋芒果中香味成分分析

用GC—MS方法分析测定了吕宋芒果提取液的香味成分,共测得51个组成成分,其主要成分为萜烯类（45．22％）、高级脂肪酸（14．94％）、醛酮类（1．11％）和少量醇、酯、内酯、烷烃类等。萜烯类中,异松油烯的含量最高,达31．84％。     

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.     

Massenspektrometrische Identifizierung von verzweigtkettigen Fettsäuren und Alkoholen aus Bürzellipiden

Mass Spectrometric Identification of Branched Chain Fatty Acids and Alcohols from Preen Gland Lipids The preen gland lipids of some birds were isolated, the waxes separated and resolved into fatty acid and alcohol fractions. The alcohols were oxidised with chromic acid to form the corresponding fatty acids. After methylation with methanolic HCl, the fatty acid methyl esters were investigated by capillary gas chromatography-mass spectrometry. The fatty acids possess mainly mono-, di- and trimethyl branched structures, the branching positions being located preferentially on C–2/–3/–4/–6, C–2,4/–2,6/–2,8/–3,7 C–2,4,6/–2,6,10 and C–6/C–10 or C–14. The mass spectrometric fragmentations which are significant for the structure elucidation of these fatty acid methyl esters are discussed in detail. The investigations indicate a correlation between the composition of the birds to defined orders of the natural system (chemotaxonomy).     

The specific refraction of fatty oils

Summary It is shown that atomic and group refractions, obtained from data on hydrocarbons, may be used in calculating the Lorenz-Lorentz molar refraction of fatty acid esters. By assuming that the various atomic and group refractions are additive in mixtures of fatty acid esters, a relation between the iodine value, the saponification value, and the specific refraction of fatty oils is derived. The validity of this relation is confirmed by comparing the calculated and the experimentally determined specific refractions of a number of fatty oils and their hydrogenation products. From this relation a diagram for the graphical-statistical analysis of glycerides of nonconjugated, nonpolymerized, straight-chain fatty acids is developed.     

Wechselwirkungen zwischen Aromastoffen und Lipiden 1. Mitteilung: Sorption einiger leichtflüchtiger Stoffe an reine Lipide

Interactions Between Aroma Substances and Lipids 1. Sorption of Some Volatile Substances in Pure Lipids Ethyl acetate, n-hexane, ethanol, and acetone are sorbed much better by liquid lipids than by solid ones. The sorption capacity of liquid lipids increases in the order triglyceride, free fatty acid, fatty acid methyl ester, and also with decreasing chain length of the fatty acid residues. Oleic acid derivatives sorb more than stearic acid ones. The sorbed amounts decrease in the order ethyl acetate, ethanol or hexane, acetone. This holds for the sorption of small amounts (some mmol/kg) measured by the retention volumes in gas chromatography, and for the sorption of greater amounts, which was measured by gravimetry. The sorption is a physical one. The sorption heats are 25–35 KJ/mol. Stronger binding is observed between phenol and esters and between n-butylamine or pyridine and free acids.     

Lipids of the earthwormLumbricus terrestris

The lipid composition of the earthwormLumbricus terrestris has been reexamined under conditions intended to avoid enzymatic and chemical alterations during storage, extraction, and fractionation procedures. The simple lipids included aliphatic hydrocarbons, steryl esters, glycerides, and at least nine different sterols, all though to be derived from the diet. Free fatty acids, previously considered to be major components of worm lipids, comprised only 0.3% of the total lipid weight. Phospholipids included (in order of relative abundance) phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, and phosphatidylinositol, as well as sphingomyelin. Glycolipids included cerebrosides and sulfatides containing both glucose and galactose, and gangliosides containing glucosamine and sialic acid. The fatty acid compositions of these lipid classes appeared to be a mixture of what are considered typical plant, bacterial, and animal acids. Several fatty acids found in the worms, includingcis-vaccenic and eicosapentaenoic acids, were essentially absent from the dietary components, and it is concluded that these acids were synthesized in the worms. The earthworm derives much of its lipid adventitiously, but exerts at least some control over its tissue lipid composition.     

The lipids of the common house cricket,Acheta domesticus L. I. Lipid classes and fatty acid distribution

The lipids of the common house cricket,Acheta domesticus L., have been examined with the following results. The fatty acids associated with the lipid extracts do not change significantly from the third through the eleventh week of the crickets' postembryonic life. The major fatty acids are linoleic (30–40%), oleic (23–27%), palmitic (24–30%), and stearic acids (7–11%). There are smaller amounts of palmitoleic (3–4%), myristic (∼1%), and linolenic acids (<1%). The fatty acid composition of the cricket lipids reflects but is not identical to the fatty acids of the dietary lipids: linoleic (53%), oleic (24%), palmitic (15%), stearic (3%), myristic (2%), and linolenic acid (2%). The amount of triglycerides present in the crickets increases steadily from the second through the seventh or eighth week of postembryonic life, then drops sharply. Other lipid classes, such as hydrocarbons, simple esters, diglycerides, monoglycerides, sterols, and free fatty acids remain about constant. The composition of the fatty acids associated with the tri-, di-, and monoglycerides and the free fatty acid fraction are all about the same. The fatty acids associated with the simple esters are high in stearic acid. Postdoctoral Research Associate, Department of Chemistry, University of Michigan, 1965–1967.     

Proportions of C18∶1n−7 and C18∶1n−9 fatty acids in canola seedcoat surface and internal lipids

Lipids of canola seedcoats (Brassica napus L. andB. rapa L.) were prepared by surface washing and by complete extraction of seed coats with toluene. The major fatty acyl-containing triacylglycerols, wax esters and free fatty acids were separated by thin-layer chromatography prior to transesterification and analysis by gas-liquid chromatography. The proportion of C18∶1n−7 to C18∶1n−9 was higher in the extracted lipids than in the surface-washed lipids for all three classes.     

Die Dünnschicht-Chromatographie auf dem Fettgebiet XXI: Die DC-Analyse der Lipoide mit Hilfe eines Flammenionisationsdetektors

The Thin-Layer Chromatography in the Field of Fats XXI: TLC-Analysis of Lipids with a Flame Ionization Detector Mixtures of lipids are initially resolved on a thin-layer of adsorbent spread over the internal surface of a narrow quarz tube. The lipids thus separated are then directly evaporated (or pyrolyzed) from the adsorbent one after the other by means of a moving furnace which encircles the tube chromatogram. The volatile products arising from the individual lipid zones are carried over to a flame ionization detector with the help of a carrier gas (nitrogen) which flows through the tube chromatogram opposite to the direction of movement of the pyrolytic furnace. Application of this method in the quantitative analysis of mixtures of various model substances like sterol esters, tri-, di- and monoglycerides, free fatty acids, fatty alcohols, free sterols as well as phospholipids is reported.     

Oberflächenlipide und Lipidpolymere von Pflanzen

Surface Lipids and Lipid Polymers of Plants The protective skin of higher plants, or cuticle, consists of a lipid coating and the characteristic polymer lipids cutin and suberin. The lipid coating contains hydrocarbons, wax, triterpenes, sterols and sometimes aldehydes and ketones. Cutin, an estolid, unsoluble in water and organic solvents, is built up by hydroxylated fatty acids with 16 and 18 C-Atoms. Suberin is in its constitution very similar to cutin. Its characteristic compounds are hydroxylated dicarbonic acids. To the degradation of cutin and suberin by men and animals some references have been given.     

Lipid composition of the sponge Verongia aerophoba from the Canary Islands

The fatty acid composition of the lipids from the sponge Verongia aerophoba was investigated and 60 acids were identified. Two of them were new and their structures were elucidated by gas chromatography‐mass spectrometry. These acids were identified as 20‐methylhexacosanoic and Δ5, 9, 22‐nonacosatrienoic. Only 13 sterols were present, and aplysterol predominated. In the volatile fraction 13 compounds were identified, mainly fatty acids, their esters and hydrocarbons, while in the n‐butanol fraction we found mainly free fatty acids and free amino acids.