Strukturaufklärung cyclischer Fettsäuremethylester III: Über das Auftreten bicyclischer Fettsäuremethylester in cyclisiertem Leinöl

Elucidation of Structure of Methyl Esters of Cyclic Fatty Acids III: Occurrence of Methyl Esters of Bicyclic Fatty Acids in Cyclised Linseed Oil In the study of aromatic methyl esters in alkali-cyclised linseed oil two hitherto unknown methyl esters of fatty acids were isolated by preparative gas chromatography. The structures of these compounds were elucidated by UV-, IR-, nuclear resonance and mass spectrometry and they were found to be the methyl esters of ω-(methyl-indanyl)-octanoic and ω-(ethyl-indanyl)-heptanoic acids. The indane ring system is substituted in 4,5-position.     

Untersuchungen über die Struktur dimerer Fettsäuren II: Herstellung und Strukturaufklärung von Diels-Alder-Dimeren aus 9t, 11t-Octadecadiensäure-methylester

Investigations on the Structure of Dimeric Fatty Acids, Part II: Preparation and Structure Determination of Diels-Alder Dimers from Methyl-9^t,11^t-Octadecadienoate From the reaction product resulting from 6 hrs of treatment of methyl-9^t,11^t-octadecadienoate at 250°C under argon 35% by weight of dimers were obtained. The thin-layer chromatogram of the dimers showed the presence of four components, which could be isolated in preparative scale as colourless liquids. All these components exhibited a refractive index n_D²⁰ = 1.4762 ± 0.0002, iodine value 86 ± 1 and mol weight 588. The mass spectra corresponded to those of tetrasubstituted cyclohexene derivatives. Hence, the product is a mixture of various positional isomers. The complete hydrogenation of the dimers could be accomplished only after the addition of a small quantity of perchloric acid. This behaviour appears to be typical for cyclohexenoic dimers with long chain rests.     

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.     

Neuartige Imidazoline und ihre Derivate aus Fettsäuren und Hydroxyalkylaminen

Novel Imidazolines and Their Derivatives from Fatty Acids and Hydroxyalkylamines Epoxides, derived from terminal and internal olefins, were reacted with ethylenediamine to give N-(vic.-hydroxyalkyl)-ethylenediamines and condensed with fatty acids and aromatic as well as aliphatic mono- and dicarboxylic acids to give 2-imidazolines. Quaternation of the 2-imidazolines yields imidazolinium salts, which, according to their structure, show strong microbiocide properties; they are also of interest as textile auxiliary.     

Fettsäuren-Zusammensetzung von Fischölkapseln

Fatty Acid Composition of Fish Oil Capsules The proven nutritional essentially of ω-fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) as well as their positive effect w.r.t. prevention and therapy of cardiovascular disease, have increased the significance of fish consumption as well as the intake of fish oil capsules from both marketing and medical points of view. Consequently, we analysed 26 fish oil preparation via GC, w.r.t. fatty acid composition as well as EPA- and DHA-content respectively. The aim was to identify the origin and provenance of the respective fish oils and thier possible blending will other edible fats and oils. The results of our investigations show that 23 samples could be considered as being composed of fish oils or fish oil concentrates. The remaining 3 were identified as being fish oil fatty acid ethylesters. An admixture with other edible oils could not be detected. Most of the fish oil capsules(= 20 products), as well as those specified as being salmon oil capsules, contained about 30% ω-3-fatty acids in a ratio between EPA:DHA of about 3:2. This ratio corresponds with those of a fish oil concentrate from Japan. Higher concentrations of ω-fatty acids of about 50% were found in the three capsules containing fish oil fatty acid ethylesters. The EPA:DHA ratio amounted in this case to about 3:2.     

Strukturaufklärung cyclischer Fettsäure-methylester I: Zusammensetzung von Gemischen aromatischer Fettsäure-methylester aus den Cyclisierungs- und Aromatisierungsprodukten von Leinöl- und Holzöl-Fettsäure-methylestern,Linolsäure und Linolsäure-methylester

Structure Determination of Methyl Esters of Cyclic Fatty Acids I: Composition of Mixtures Containing Methyl Esters of Aromatic Fatty Acids Obtained from Products of Cyclisation and Aromatisation of Linoleic Acid, Methyl Linoleate and Methyl Esters of Linseed and Tung Oil Fatty Acids The composition of methyl ester mixtures of aromatic fatty acids obtained by alkaline cyclisation and catalytic aromatisation of linoleic acid and methyl linoleate was determined. All the isomeric o-alkyl substituted methyl esters of aromatic fatty acids (I) (n = 0 to 11) could be identified by IR-, UV-, mass-spectrometry, gas-chromatography and by comparison with synthetic substances. The distribution of isomers in mixtures obtained by various procedures was determined by gas-chromatography. o-dodecyl phenol was found to be a by-product in the catalytic aromatisation of free linoleic acid.     

Regioselektive C-H-Funktionalisierung von Fettsäuren und Fettsäuremethylestern

Regioselective C-H-Functionalization of Fatty Acids and their Methyl Esters Fatty acids and thier methyl esters can be chlorinated preferentially at the terminal methylene groups with N-alkylchloroamines in sulfuric acid. With capric acid and its methyl ester the optimal reaction conditions for the selective chlorination were elaborated and then transferred to longer fatty acids up to stearic acid. The influence of the solvent, the temperature and the nature of different chlorinating reagents on the selectivity was studies. The capillary GC/MS-analysis of the isomeric chlorinated fatty acids is described.     

Fettsäuremuster und Tokopherolgehalte im Öl verschiedener Sonnenblumensorten aus weltweitem Anbau

Fatty Acid Pattern and Tocopherol Contents of Oils from Different Varieties of Sunflower in the Worldwide Cultivation The material available for investigation comprised 9 varieties from two harvests from 6 locations having greatly differing climate. Furthermore, the material from freely flowering plants and that from isolated plants, which were pollinated within the varieties, were investigated. The fatty acid composition is distinctly dependent on the location; linoleic acid content is negatively correlated with oleic acid content, being high in cold regions and low in warm regions. The tocopherol content of the oil varies both with location and variety in isolated plants, whereas in freely flowering plants the differences in tocopherol content between the varieties disappear. Correlations are found between tocopherol content of the oil and oil content of the seed, yet differentiation should be made whether the variations in oil content are due to genetic differences or due to regional factors. Varietal differences in oil content are positively correlated in both years and regional differences are negatively correlated with the tocopherol content of the oil.     

Strukturaufklärung cyclischer Fettsäuremethylester V: Massenspektrometrie isomerer Phenylundecansäure-methylester

Elucidation of Structure of the Methyl Esters of Cyclic Fatty Acids V: Mass-Spectrometry of Isomeric Methyl Esters of Phenyl Undecanoic Acid Isomeric phenyl undecanoic acids obtained by the Friedel-Crafts reaction of benzene with 10-undecenoic acid were investigated as methyl esters using capillary gas-chromatography – mass spectrometry (GC-MS). The isomers could be identified as methyl esters of (5-), 6-, 7-, 8-, 9- and 10 phenyl undecanoic acids. The fragmentation due to electron bombardment is discussed.     

Strukturaufklärung cyclischer Fettsäuremethylester IV: Über das Auftreten von ω-Phenylalkancarbonsäure-methylestern in cyclisiertem Holz- und Leinöl

Structure Elucidation of Methyl Esters of Cyclic Fatty Acids IV: Occurrence of Methyl Esters of ω-Phenyl Alkanoic Acids in Cyclised Tung and Linseed Oil Methyl esters of cyclic fatty acids (CFA-Me) obtained from alkali cyclised tung and linseed oil were oxidized by performic acid. A series of fractions containing methyl esters of various aromatic fatty acids were obtained by column chromatographic separation of the oxidation products. Whereas the initial fractions consisted of methyl esters of ω-(o-alkylphenyl)alkanoic acids (AFA-Me), the later fractions were found to contain a homologous series of unsubstituted ω-phenyl alkanoic esters. The main component in cyclised tung and linseed oil is the methyl ester of 9-phenyl nonanoic acid. The formation of methyl esters of aromatic fatty acids is discussed.     

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).     

Oxidatives Verfahren zur Herstellung kurzkettiger Carbonsäuren aus ungesättigten Fettsäuren

Oxidative Procedure for Production of Short-Chain Carbon Acids from Unsaturated Fatty Acids For decades, the oxidation of oleic acid to acelaic and pelargonic acid has been carried out in industrial scale by ozone. The high costs of ozone production are a problematical point in this procedure. Thanks to the high selectivity the procedure is today still economic. Efforts to replace the ozone oxidation by an oxygen one haven't yet led to a procedure which can be applied in industry. In this work the oxygen oxidation of oleic acid with aldehyds as intermediary carrier of oxygen is reported.     

Massenspektrometrische Untersuchung von dimeren Fettsäuren aus einem thermisch und oxydativ belasteten Bratfett

Mass Spectrometric Investigation of Dimeric Fatty Acids from Frying Fats Subjected to Thermal and Oxidative Action Methyl esters of dimers from peanut oil subjected to thermal and oxidative action in an industrial frying plant were isolated by column chromatography and investigated by mass spectrometry. Di-unsaturated bicyclic and tetra-unsaturated acyclic structures were found to be the main components of the dimers. Dimers of very similar composition were synthesized. The mechanism of dimer formation is discussed.     

Untersuchungen zur kontinuierlichen Hydrierung von Ölen und Fettsäuren III Kinetik der Härtung freier Fettsäuren des Sojaöls

Investigations of the Continuous Hydrogenation of Oils and Fatty Acids III: Kinetic of Free Fatty Acid Hardening of Soya Bean Oil The kinetic of continuous hardening of free fatty acids of soya bean oil was investigated in a reactor with solid porous catalyst using the trickling procedure. Under the given arrangement and continuous hydrogen excess (continuous phase) hydrogenation of fatty acids follows the kinetic I. order. Temperature influences are much stronger using Ni-catalyst in ihe phase of equalized properties than using fresh catalyst. Pressure influences the reaction rate in both cases in a positive way. Its effect however in connection with temperature rise is much stronger with catalyst in the phase of equalized properties, that is the catalyst with lower activity.     

Kristallstrukturuntersuchungen an Fettalkoholen und Fettsäuren mit Elektronen- und Röntgenbeugung I

Studies on Crystal Structures of Fatty Alcohols and Fatty Acids Using Electron and X-Ray Diffraction I For the homologous series of even numbered saturated fatty alcohols from dodecanol (C₁₂H₂₅OH) up to hexacosanol (C₂₆H₅₃OH) the almost orthorhombic unit cells of the β₀₁-modifications could be shown by using electron and X-ray diffraction. Fouriersynthesis based on hkO-reflexes showed the presence of a β₀₂-form which has half the edge length c compared to the β₀₁-modification. Moreover, the eight γ₃- to γ₁₀-modifications of the various alcohols were detected. Unit cell parameters and the chain tilt were determined for all crystal structures. By X-ray diffraction, stearic acid was shown to exhibit five β_n-(n = 2, 4, 5, 8) and seven γ₂- to γ₈-forms. The β_n-forms consist of molecules tilted over the short subcell a_s-axis, whereas in γ_n-forms the molecular chains are tilted over the b_s-axis. All the modifications of alcohols and fatty acids studied have an orthorhombic subcell, while the neighbouring molecules in monomolecular layers are turned to each other at an angle of about 90°.     

Bestimmung aromatischer Fettsäuren in hydrierten cyclischen Fettsäuren

Determination of Aromatic Fatty Acids in Hydrogenated Cyclic Fatty Acids Small amounts of aromatic fatty acids, besides hydrogenated cyclic fatty acids, in an urea non-adduct from hydrogenated fatty acids can not be determined by gas chromatography. A direct determination by UV-spectroscopy is also inaccurate, since the strong end absorption of the carbonyl group makes an evaluation of the aromatic band in the range of 260 to 275 nm difficult. After reducing the acids or esters with lithium aluminium hydride to the corresponding alcohols, a proper quantitative determination of aromatic fatty acids can be carried out even at low concentrations of the latter.