Fatty acids, conjugated unsaturated

Plant oils are excellent sources of some valuable compounds such as unsaturated fatty acids, phytosterols, squalene, pigments, antioxidants, vitamins, waxes, glycolipids, and lipoproteins. Plant oils could be employed for technological uses as biodiesel, lubricants, surfactants, emulsifiers, biopolymers, and so on. Vegetable oils also can serve as appropriate sources for the production of valuable compounds having applications in food, pharmaceutical, medical, and environmental fields. Attention has been focused on various types of value-added fatty acids (polyunsaturated fatty acids, conjugated fatty... 

Measurement of Unsaturation. The presence of double bonds in a fatty acid side chain can be detected chemically or through use of instmmentation. Iodine value (IV) (74) is a measure of extent of the reaction of iodine with double bonds the higher the IV, the more unsaturated the oil. IV may also be calculated from fatty acid composition. The cis—trans configuration of double bonds may be deterrnined by infrared (59) or nmr spectroscopy. Naturally occurring oils have methylene-intermpted double bonds that do not absorb in the uv however, conjugated dienes maybe deterrnined in an appropriate solvent at 233 nm. 

We focused our attention on Tall oil, a by-product of the paper industry, whenever this is prepared according to the KRAFT process. Said material consists of a mixture of highly unsaturated fatty acids (many of which with conjugated diene systems) and terpene derived rosin acids. The rosin acids have the molecular formula C20H30O2 and thus belong to the diterpenes (pimaric and abietic acids). Tall Oil has an iodine number equal to approximately 170 gl2/100 g. 

Unsaturated fatty acids are the preponderant fatty acids of cucurbit oils, and in some seeds conjugated triene comprises one-third of this unsaturation. Table I shows the fatty acid distribution in oils of cucurbit seeds (1 ). More recent determinations (7, 27, 3U 33) are in close agreement with these results. Occasionally a species... 

Additionally, it should be observed that the thermal oxidability and oxidative polymerization of the unsaturated fatty acids follows the trend linolenic > linoleic > oleic > > palmitoleic (Martinenghi, 1963). The oxidation involves, as first step, the abstraction of a hydrogen atom in allylic position to the double bonds. Certainly, this process is favoured in the case of fatty acids with two or more unconjugated double bonds where the formation of a free radical by allylic hydrogen abstraction leads quite necessarily to double bonds slippage with formation of conjugated double bonds ... 

To characterize phospholipid oxidation during apoptosis, cellular phospholipids were metabolically labeled at sn-2 position with a natural unsaturated florescent fatty acid containing four conjugated double bonds, cw-parinaric acid (cw-PnA) (Kagan et al, 1998 Tyurina et al, 2001). Oxidative desttuction of any part of the conjugated double bond system of... 

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