Oleic acid, transformations

These reactions, which are believed to occur predominantly inter-molecularly, are capable of producing intermediates which hold some potential as precursors for important chemical products. For example, metathesis of olive oil, which consists chiefly of triglycerides of oleic acid, produces the glyceride of 9-octadecene-l,l8-dioic acid from which can be obtained, after saponification, acidification, and low-temperature crystallization, the free acid, which can be transformed by intramolecular condensation to civetone. 

Giant vesicles have been the subject of several international meetings and specialized literature (Luisi and Walde, 2000 Fischer et al., 2000). There are several reasons for this interest. One is that, because of their size, they can be observed by normal optical microscopy, without using the much more expensive and indirect electron microscopy. Figure 10.7 shows, as an example, the transformations brought about by the addition of a water-insoluble precursor (oleic anhydride) to oleic acid giant vesicles (Wick et al., 1995). 

Figure 10.11 The use of ferritin as a label for the mechanism of growth of vesicles (adapted from Berclaz et al, 2001a b). Schematic representation of the possible vesicle formation and transformation processes when oleate, and oleic acid, are added to pre-formed vesicles which have been labelled, (a) The situation if only de novo vesicle formation occurs, (b) Growth in size of the pre-formed and labeled vesicles which may lead to division, either yielding vesicles that all contain marker molecules (case i, a statistical redistribution of the ferritin molecules) or also yielding vesicles that do not contain markers (case ii). Compare all this with Figure 10.9.

Oxidation of oleic acid to 10-hydroxyoctadecanoic acid by a gram-positive bacterium was described with a transformation yield of 65% at a concentration of 50 g oleic acid after 72 h in a medium containing Tween 80 [232]. The hydroxy fatty acid can be converted to 4-dodecanolide, an important coconut-fruity like lactone, by -oxidation with yeasts, affording a total lactone yield of about 20% from oleic acid [222, 232]. 

Finally, the yeast Yarrowia lipolytica is able to transform ricinoleic acid (12-hydroxy oleic acid) into y-decalactone, a desirable fruity and creamy aroma compound however, the biotransformation pathway involves fi-oxidation and requires the lactonisation at the CIO level. The first step of fi-oxidation in Y. lipolytica is catalysed by five acyl-CoA oxidases (Aox), some of which are long-chain-specific, whereas the short-chain-specific enzymes are also involved in the degradation of the lactone. Genetic constructions have been made to remove these lactone-degrading activities from the yeast strain [49, 50]. A strain displaying only Aox2p activity produced 10 times more lactone than the wild type in 48 h but still showed the same growth behaviour as the wild type. 

In the mid-sixties, Atlas Chemical Industries investigated the reaction of epoxides with isohexides. Transformation of isosorbide (3) by ethylene oxide affords polyoxyethylene isosorbide (62), which was treated with oleic acid to afford the corresponding diesters (63), and these were further transformed into epoxidized products167 (64) (see Scheme 12). On treating all three iso-... 

To identify the unsaturated fatty acids produced in the transformants that were able to grow without supplementation with palmitoleic or oleic acid, cells were grown at 30° C in YPD liquid medium to a density of 2 x 107 cells/ml, at which point the cells were pelleted and washed three times with water, and then extracted with methanol/chloroform (1 2). After solvent evaporation, the lipid residue was treated with 0.5 M KOH/methanol, and the resulting fatty acid... 

An expression construct consisting of the open reading frame of the TnFB A9Ds cDNA inserted into the yeast desaturase expression vector YEpOLEX was used to transform the olel strain of S. cerevisiae as described above. Many transformant colonies were obtained on medium lacking unsaturated fatty acids, indicating complementation of the olel mutation by the encoded T. ni desaturase. GC/MS analysis of the fatty acid methyl esters obtained from the transformants showed that the TnFBA9Ds cDNA encoded a A9 desaturase that produced oleic acid (Z9-18 Acid) and palmitoleic acid (Z9-16 Acid) (Liu et al., 1999). Quantitation of these unsaturated fatty acids under standard conditions as described above revealed about three times more of the former than the latter (Rosenfield et al., 2001). 

Iron-platinum alloy nanoparticles are very promising candidates for future data storage systems. They become available by simultaneous reduction of platinum acetylacetonate and the decomposition of Fe(CO)5 in oleic acid and oleyl amine.The composition of FexPti x can be varied between X = 0.48 and x = 0.7. The particles exhibit disordered fee structure. They are superparamagnetic at room temperature. Aimealing at 550-600 °C transforms the fee structure into a face-centered tetragonal (fet) one. These have been shown to be suited for storage devices owing to their room temperature coercivity. The exact transition temperature depends on the stoichiometry. 

Takeuchi, Y. et al. Effects of oleic acid/propylene glycol on rat abdominal stratum comeum lipid extraction and appearance of propylene glycol in the dermis measured by Fourier transform infrared/attenuated total reflectance (FT-IR/ATR) spectroscopy. Chemical and Pharmaceutical Bulletin 4/(8) 1434-1437, 1993. 

Using diffuse reflectance Fourier transform infrared spectroscopy, Adhikari et al. studied the binding of oleic acid (88), triacylglycerol (89), and phosphatidylcholine (90) on silica gel at room temperature. Their interpretation was that oleic acid and triacylglycerols bind to silica surface hydroxyls via hydrogen bonding interactions between the carboxylate and ester carbonyls of these molecules, respectively. In contrast, phospholipids hydrogen bond to silica surface hydroxyls via the phosphate... 

Alkenes may also be transformed into vicinal dicarbonyl compounds. The treatment of alkenes with selenium dioxide, although possible, does not give satisfactory yields [509]. Better results are obtained when unsaturated compounds such as oleic acid are oxidized with potassium permanganate buffered with acetic anhydride [861],... 

If you ve encountered date pits, you know their usual fate—they are promptly discarded. But wait a nutritional study of date pits has documented their exceptional nutrient density, especially of protein, dietary fiber, and omega oils composed mainly of oleic acid, the same omega-9 monounsaturated fat famous in olive oil. Date pits may offer an inexpensive nutrient and oil source from what is currently a waste material. Simply through extraction or pulp processing of the pits, some future entrepreneur will recover those inedible pits and transform them into useful food products ... 

Naturally-occurring fatty acids, such as oleic acid, could serve as feedstocks for metathesis-centered transformations. For example, workers at Dow Chemical Company explored the use of Grubbs first-generation catalyst (23) to promote ethenolysis of methyl oleate (equation 11.18) to form C10 alkenes, which might serve as feedstocks for some of the processes that have already been mentioned in this section.49... 

Peterlin, P., Arrigler, V., Kogej, K., Svetina, S., and Walde, P. (2009) Growth and shape transformations of giant phospholipid vesicles upon interaction with an aqueous oleic acid suspension. Chemistry and Physics of Lipids, 159 (2), 67-76. 

The methatesis of vegetable oils with ethylene is a very interesting way to obtain new unsaturated structures to be transformed into new polyols via the epoxidation - alcoholysis route. Trioleine was used as a model compound (the triester of glycerol with oleic acid), the methatesis reaction with ethylene being catalysed by a special ruthenium catalyst [72]. The resulting triglyceride, with terminal double bonds, after removal of the 1-decene formed, is transformed into polyols by epoxidation, followed by alcoholysis with methanol (reactions 17.27 and 17.28). 

Several yeasts are able to assimilate fatty acids. In the /I-oxidation pathway of unsaturated fatty acids, NADPH-dependent 2,4-dienoyl-CoA reductase is needed for double-bond hydrogenation. The respective 2,4-dienoyl-CoA reductase has been partially purified from oleate-grown Candida tropicalis. It catalyzes one step in the degradation of oleic acid, namely the transformation of 2-trc/ s--4-c s-decadienoyl-CoA to 3-ttww-decadienoyl-CoA87. 

The cis-trans conversion of mono-unsaturated fatty acids is an equilibrium reaction. Oleic and elaidic acids can be transformed into each other the equilibrium mixture consists of 67 % elaidic acid and 33 % oleic acid, the equilibrium ratio being practically independent on the isomerization temperature (10). This, of course, limits the hardening effect of fatty-oil isomerization processes to a certain extent. 

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