Fatty acids, activation unsaturated

McPhail, L.C., Clayton, C.L. and Snyderman, R (1984). A potential messenger role for unsaturated fatty acids activation of Ca -dependent protein kinase. Science 224, 622-625. 

Phytoplanktonic microalgae, which are important sources of food in both oceans and fresh water habitats, use an activated form of chemical defense to reduce grazing by predators. Damaged microalgal cells convert unsaturated fatty acids into unsaturated aldehydes which affect reproductive outcomes in herbivorous cope-pods and other planktonic grazers.30 Representative products of these biotransformations include the C10 aldehydes 1 and 2 in the diatom Thalassiosira rotula, and Cg diene hydrocarbons and the trienoic acid aldehyde 3 in Asterionella formosa.31... 

Some fatty acids, especially unsaturated fatty acids, are well-known skin penetration enhancers. It is also known that many fatty acids possess antimicrobial activity. The topical activity of the anti-viral drug acyclovir is hampered by its inadequate permeability through the skin barrier. Some reports have shown that fatty acid extract of cod liver oil as well as the extract in the form of an ointment show effective antiviral properties against herpes simplex virus (HSV-1) (37). 

McPhail LC, Clayton CC, Snyderman R. A Potential 2nd messenger role for unsaturated fatty-acids—activation of Ca2+-dependent protein-kinase. Science 1984 224 622-625. 

See also Acetyl-CoA, Fats, Albumin, Fatty Acid Activation, Oxidation of Saturated Fatty Acids, Oxidation of Unsaturated Fatty Acids, Fatty Acid Biosynthesis Strategy, Palmitate Synthesis from Acetyl-CoA, Fatty Acid Desaturation, Essential Fatty Acids, Control of Fatty Acid Synthesis, Molecular Structures and Properties of Lipids (from Chapter 10)... 

Saturated fatty acids reach their cptimal effects with chains 12 carbons long. Mcmounsaturation increases the activity of long or greater) but not short ( chain fatty acids. Cis unsaturated fatty acids eure more active than trans acids. Adding a second double bond further increases activity while the addition of a third double bond does not substantially iirprove activity. 

On the basis of data obtained, it is possible to suggest that tolerance to water stress is determined by the cell antioxidant system protecting unsaturated C fatty acids and unsaturated very-long-chain fatty acids against modifications induced by the oxidative stress, for example activation of free radical processes [20]. Changes in the C fatty acids in the mitochondrial membrane lipids are noted for the first time. Just the unsaturation coefficient of C fatty acids was correlated with the highest rates of... 

Enzymes which catalyze peroxidation of unconjugated unsaturated fatty acids active the substrate by creating a radical cation which is easier to deprotonate than the parent olefinic substrate. The free radical so produced then reacts readily with molecular oxygen. 

Aktiplast T Combination of zinc salts of unsaturated fatty acids, activator and process aid... 

Figure 16.4 Long-chain and very long-chain fatty acid biosynthesis in mammals. The long-chain saturated fatty acids and unsaturated fatty acids of the n-10, n-7, and n-9 families (Top panel) can be synthesized from palmitic acid (Cl6 0) produced by the cellular fatty acid synthesis machinery. Long-chain fatty acids of the n-6 and n-3 famihes can only be synthesized from their respective precursors obtained from diets. The symbols of, , and stand for the involved activities of desaturation, elongation, and peroxisomal 3-oxidation, respectively, in the steps. Many isoforms of the genes corresponding to these activities were identified (see the review [34] for details).

Epidemiologic studies in Japan indicate an increased risk of stomach cancer owing to consumption of broiled fish and meats (116). In the United States, stomach cancer incidence has steadily declined since the 1940s, whereas consumption of broiled food has increased (108). In addition, the average human intake of PAHs is only 0.002 of that required to produce cancer in half of animals fed. Test results are often contradictory (117) and many components of food, such as vitamin A, unsaturated fatty acids, thiols, nitrites, and even saUva itself, tend to inhibit the mutagenic activity of PAHs (118—120). Therefore, the significance of PAHs in the human diet remains unknown (121,109). 

These oxazolines have cationic surface-active properties and are emulsifying agents of the water-in-oil type. They ate acid acceptors and, in some cases, corrosion inhibitors (see Corrosion). Reaction to oxazoline also is useful as a tool for determination of double-bond location in fatty acids (2), or for use as a protective group in synthesis (3). The oxazolines from AEPD and TRIS AMINO contain hydroxyl groups that can be esterified easily, giving waxes (qv) with saturated acids and drying oils (qv) with unsaturated acids. 

The principal mbbers, eg, natural, SBR, or polybutadiene, being unsaturated hydrocarbons, are subjected to sulfur vulcanization, and this process requires certain ingredients in the mbber compound, besides the sulfur, eg, accelerator, zinc oxide, and stearic acid. Accelerators are catalysts that accelerate the cross-linking reaction so that reaction time drops from many hours to perhaps 20—30 min at about 130°C. There are a large number of such accelerators, mainly organic compounds, but the most popular are of the thiol or disulfide type. Zinc oxide is required to activate the accelerator by forming zinc salts. Stearic acid, or another fatty acid, helps to solubilize the zinc compounds. 

The Goodyear vulcanization process takes hours or even days to be produced. Accelerators can be added to reduce the vulcanization time. Accelerators are derived from aniline and other amines, and the most efficient are the mercaptoben-zothiazoles, guanidines, dithiocarbamates, and thiurams (Fig. 32). Sulphenamides can also be used as accelerators for rubber vulcanization. A major change in the sulphur vulcanization was the substitution of lead oxide by zinc oxide. Zinc oxide is an activator of the accelerator system, and the amount generally added in rubber formulations is 3 to 5 phr. Fatty acids (mainly stearic acid) are also added to avoid low curing rates. Today, the cross-linking of any unsaturated rubber can be accomplished in minutes by heating rubber with sulphur, zinc oxide, a fatty acid and the appropriate accelerator. 

Mammals can add additional double bonds to unsaturated fatty acids in their diets. Their ability to make arachidonic acid from linoleic acid is one example (Figure 25.15). This fatty acid is the precursor for prostaglandins and other biologically active derivatives such as leukotrienes. Synthesis involves formation of a linoleoyl ester of CoA from dietary linoleic acid, followed by introduction of a double bond at the 6-position. The triply unsaturated product is then elongated (by malonyl-CoA with a decarboxylation step) to yield a 20-carbon fatty acid with double bonds at the 8-, 11-, and 14-positions. A second desaturation reaction at the 5-position followed by an acyl-CoA synthetase reaction (Chapter 24) liberates the product, a 20-carbon fatty acid with double bonds at the 5-, 8-, IT, and ITpositions. 

Eicosanoids, so named because they are all derived from 20-carbon fatty acids, are ubiquitous breakdown products of phospholipids. In response to appropriate stimuli, cells activate the breakdown of selected phospholipids (Figure 25.27). Phospholipase Ag (Chapter 8) selectively cleaves fatty acids from the C-2 position of phospholipids. Often these are unsaturated fatty acids, among which is arachidonic acid. Arachidonic acid may also be released from phospholipids by the combined actions of phospholipase C (which yields diacyl-glycerols) and diacylglycerol lipase (which releases fatty acids). 

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