Zur Essentialität der Polyenfettsäuren

On the Essential Nature of Polyunsaturated Fatty Acids Several plant oils contain polyunsaturated fatty acids which cannot be synthesized by the human body. They have been recognized as essential nutrients, as characteristic symptoms are caused by deficient intake. The LCP-fatty acids are incorporated into structural lipids and cell membrans and influence directly their properties. LCP-fatty acids are precursors of prostaglandins, lencotrienes and eicosanoid mediators, which intern regulate numerous cell functions. The effects of LCP-fatty acids on pre- and postnatal growth and the nervous system are discussed in detail.     

Zur Chemie der cyclischen Fettsäuren

Cyclic Fatty Acids Following a review, the most important processes for preparing monomeric cyclic fatty acids are dealt with. In the alkali cyclization of triunsaturated fatty acids, formation of cyclizable isomers having a central cis-structure takes place preferentially compared to thermal ring closure. Compared to conjugated or isolated structure, cis/trans configuration of double bonds have stronger impact on distribution of isomers in cyclic acids formed. Isolated unsaturated trienoic fatty acids yield also bicyclic compounds having indanyl structure besides monocyclic compounds. Heterogeneous catalytic cyclization with Pd/C or Ni favours more extensive displacement of double bonds and disproportionation leading to formation of aromatics besides monoenoic and saturated fatty acids.     

Zur Kenntnis der Cashew-Öle II. Über einige Derivate der Hauptbestandteile des Schalenöls

Studies on Cashew Oils II: Some Derivatives of the Main Components of the Cashew Nut Shell Liquid Derivatives (esters and ethers) of the 3-pentadecyl-phenol, which were prepared by the hydrogenation of Cardanol and the addition of thiocyanogen to hydrogenated 2-carboxy-3-pentadecyl-phenol are described.     

Zur Kenntnis der optischen Aufheller II: Physikalische und chemische Vorgänge bei der Fluoreszenzlöschung und optischen Filterwirkung

The Optical Brighteners II. The Physical and Chemical Processes of the Fluorescence Extinction and the Optical Filter Effect The fluorescence extinction of the optical brighteners is an undesirable phenomenon in case of white textiles. There are different causes which can lead to the fluorescence extinction. The effect is shown in the statical or dynamical extinction mechanism or in an optical filter effect. It is also possible to depict the fluorescenceinfluence through the principle of self or extraneous extinction. The present work discusses the processes of fluorescence extinction and its form of appearance. The optical filter effect is also discussed.     

Großtechnische Feinfraktionierung von Kokos- und Palmkernfettsäuren aus der Sicht des Praktikers II

Technical Fine Fractionation of Coconut and Palm-Kernel Fatty Acids from Practical Viewpoint II The first part of this work reviewed the technological possibilities for the optimum separation of coconut and palm-kernel fatty acids. The present communication deals with the factors, such as plant design and processing, which are of major significance for the processing cost and processing behaviour. In this context, the influences of the quality of raw material and that of the residue, which is mainly composed of the unhydrolyzed oil, on the properties of fatty acid distillate were studied. Further discussions concern the corrosion behaviour of the currently available economical materials of construction and the permissible thermal stress from the viewpoint of product stability. In both cases, the effects of time as well as temperature were studied. Since hot fatty acids are prone to oxidative deterioration, severe loss of quality may occur if adequate precautions are not taken. In this respect, the experience gathered during the last decade on the use of pumps without stuffing box for the operation of falling film evaporators with forced circulation is reported. Finally, it is shown that the plants which are conceived and their mode of operation was worked out by the author easily fulfil the requirements concerning environmental safety with respect to waste water, air, and noise.     

Produkte der Dimerisierung ungesättigter Fettsäuren XI: Die Fraktion der alicyclischen Dimerfettsäuren

Products of Dimerisation of Unsaturated Fatty Acids XI: The Fraction of Alicyclic Dimeric Acids Dimeric fatty acids can be separated as their dimethylates by HPLC-chromatography [W. Link, G. Spiteller, Fat Sci. Technol. 92 , 135 (1990)]. The main fraction of dimeric fatty acids obtained by the dimerisation of linoleic acid consists of alicyclic unsaturated dimeric fatty acids with the molecular weights 588 and 590. The structures of these compounds remained unknown until now. This fraction was subjected to hydrogenation, epoxidation and dehydrogenation with SeO₂ and Pd/C. The investigation of the reaction products provided evidence that these dimeric acids are a mixture of the following compounds: Dimeric acids with a 6-ring and one double bond and dimeric acids with two 6-rings and a double bond could be identified. In both types of compounds the double bond can be either situated in the ring as well as outside the ring. In dimeric acids containing two rings this ring system can be condensed or separated by a C-chain. Besides dimeric acids with two 6-rings dimeric acids with one 6-ring and one 5-ring were found. Essential contributions to these deductions were obtained by an investigation of model compounds and model fractions.     

Rolle von Fett und Gallensäuren in der Pathogenese des Kolonkarzinoms

The Role of Fats and Gallic Acids in the Pathogenesis of the Colon Carcinoma A great number of epidermiological studies showed a positive correlation between certain nutritional habits, especially a high fat consumption and an increased incidence of colon carcinoma. By different criteria (strength of association, temporal sequence, independency on other associations, ability for prediction and coherence of the findings) it is checked, whether this correlation is based on a causal relation. A hypothesis for the pathogenesis of the colon carcinoma is presented which integrates epidemiological findings between fat consumption and incidence of colon carcinoma, microbiological findings about intestine flora and gallic acid metabolism, co- or procarcinogenic properties of gallic acids, findings about gallic acid pattern in faeces and incidence of colon carcinoma as well as findings about negative correlations between serum cholesterol level and carcinoma mortality. Clinical and therapeutical consequences from this hypothesis are discussed.     

Produkte der Dimerisierung ungesättigter Fettsäuren VI: Untersuchungen zur Kinetik der Bildung dimerer Fettsäuren

Products of Dimerisation of Unsaturated Fatty Acids VI: Kinetic Studies about the Formation of Dimeric Fatty Acids During the dimerisation reaction of a mixture of 60% oleic acid and 40% linoleic acid samples were collected in time intervals. The samples were converted into their dimethylates by diazomethane and separated by thin layer chromatography in one fraction of monomers and one of dimers. The monomeric fractions were further separated by GC, the dimeric fractions by HPLC. First linoleic acid reacts, either by cyclisation or by attacking another molecule of linoleic acid. Thus linoleic acid has already disappeared nearly completely at the end of the heating up period (after 60 min). The less linoleic acid is present, the more molecules of linoleic acid react with oleic acid molecules. The primary cyclic dimerisation products are slowly converted to aromatic compounds as well as cyclohexane derivatives. The oleic acid is transformed already in the heating up period into its isomer, elaidic acid and isomers thereof with double bonds in other positions of the chain. These products are converted slowly partly to stearic acid, partly to isostearic acids. Dimeric compounds of MW 592 (methylates) are produced as well by reaction of 2 molecules of oleic acid. They are slowly converted to open chain dimeric acids of MW 594 (methylates).     

Zur Kenntnis der Cashew-Öle I: Gewinnung und Analyse

Studies on Cashew Oils I: Preparation and Analysis The fatty acid composition of the cashew kernel oil, determined by gas chromatography, was found to be: palmitic acid 8.2%, palmitoleic acid 0.4%, stearic acid 4.2%, oleic acid 67.4% and linoleic acid 19.8%. The cashew nut shell liquid contains mainly mono- and dihydroxyalkylbenzenes and alkylphenolic acid. Owing to their large polarity differences, these components of the cashew nut shell liquid can be separated by partition between 80-90% methanol and low boiling petrol ether. The silicagel column chromatography can be employed for the preparative separation of these components.     

Produkte der Dimerisierung ungesättigter Fettsäuren V: Die Aromatenfraktion dimerer Fettsäuren

Products of Dimerisation of Unsaturated Fatty Acids V: The Aromatic Fraction of Dimeric Acids The aromatic fraction of dimeric fatty acid esters can be separated according to a decreasing grade of unsaturation by HPLC using an UV-recorder. Hydrogenation experiments of the collected fractions allowed the determination of the number of rings. If the aromatic fraction are oxidized with KMnO₄ using a phase-transfer catalyst benzene 1,2,4- and 1,3,5-tri-, 1,2,4,5-and 1,2,3,5-tetra- and the pentacarboxylic acid were obtained as main products. Consequently we have to conclude that the catalyst causes intramolecular extensive migration of alkyl chains. Finally 2,3-dihydrobenzofurantetracarboxylic acids with different position of the carboxylic groups were detected in the mixture of oxidation products.     

Zur Bildung von Kohlenwasserstoffen bei der Autoxidation gesättigter Fettsäuren und ihrer Methylester

Formation of Hydrocarbons in the Autoxidation of Saturated Fatty Acids and Their Methyl Esters Oxidation of heated fatty acids and their methyl esters lead to the formation of saturated and unsaturated hydrocarbons among other reactions. These substances could be detected even when the material under investigation was subjected to thermal stress in the absence of oxygen. Accordingly, the hydrocarbons are formed by thermal decomposition of fatty acids.     

Octadecadiensäuren im Butterfett II. Mitteilung: Identifizierung einiger nichtkonjugierbarer Fettsäuren

Octadecadienoic Acids in Butterfat II: Identification of a Few Nonconjugable Fatty Acids With the help of gas and thin-layer chromatography as well as by determining the position of double bonds with OsO₄, the following iso-linoleic acids in the butter fat were identified: cis,trans (or trans,cis): 11, 16 and/or 11, 15; 10, 16 and/or 10, 15; 9, 15 and/or 9, 16; 8, 16 and/or 8, 15 and/or 8, 12. trans,trans: 12, 16; 11, 16 and/or 11, 15; 10, 16 and/or 10, 15; 9, 16 and/or 9, 15 and/or 9, 13.