Fatty acids alternative names

The fatty acids are named by replacing the final -e of the name of the parent hydrocarbon by the suffix -oic. Thus, a saturated 18-carbon acid would be named octade-canoic after the parent octadecane. An 18-carbon acid with one double bond would be octadecenoic after octadecene. The position of the double bond is indicated by reference to the carboxyl carbon atom (carbon atom 1). Thus, 9-octadecenoic acid would have 18 carbon atoms and a double bond between carbon atoms 9 and 10. Similarily, 9,12,15-octadecatrienoic acid would have 18 carbon atoms and double bonds between carbon atoms 9 and 10,12 and 13, and 15 and 16.The names may be abbreviated by stating the number of carbon atoms followed by a colon, followed by the number of double bonds (A), the positions of which are stated as a superscript. Thus, octadeca-trienoic acid would be designated 18 3 . Alternatively it may be written 9,12, 15-18 3. Carbon atoms 2 and 3 are designated alpha (a) and beta (P), respectively, and the methyl carbon at the distal end of the chain as the omega (w) carbon atom. In nutritional work, the unsaturated acids are frequently named in relation to the terminal methyl as carbon atom 1. Under this system 9,12,15-octadecatrienoic acid would become (i)-3,6,9-octadecatrienoic acid, since carbon atoms 3, 6 and 9 correspond to carbon atoms 16,13 and 10 imder the former system.The abbreviated designation would be (0-3,6,9-18 3. It has become common practice to use n instead of double bonds is inchcated by the use of the prefixes cis and tram. Wms, a-linolenic acid would be all cis-9,12,15-octadecatrienoic, or more simply aU cis 9,12,15-18 3. 

In the liver, there is an alternative mechanism for regenerating CoA from acetyl-CoA two acetyl-CoA molecules react to form a 4-carbon compound called a ketone body. (Naming a class of molecules bodies is a quaint hangover from the past, but in reality these compounds embody the molecule of acetyl-CoA.) The enzyme in the hepatocyte that catalyzes the relevant reaction is hydroxymethylglutaryl CoA synthase. The consequent release of CoA from acetyl-CoA enables P-oxidation to continue rapidly. The ketone body that is formed first is acetoacetate, it is reduced to -hydroxybutyrate by NADH and the oxidation of NADH further stimulates flux via the fatty acid P-oxidation pathway. Recall that P-oxidation requires regeneration of NAD+ (Sec. 10.5). 

Until recently, P-oxidation of different fatty acids and fatty acid derivatives in peroxisomes was thought to be mediated by a single bifunctional protein containing both 2-enoyl-CoA hydratase and 3-hydroxyacyl-CoA dehydrogenase activities. " Recent studies have shown that there is an additional bifunctional protein alternatively called multifunctional protein 2 multifunctional enzyme 2, or D-bifunctional protein. " This newly identified bifunctional protein generates a D-3-hydroxyacyl-CoA, whereas the other bifunctional protein generates L-3-hydroxyacyl-CoA intermediates. Because of this remarkable difference in stereospecificity of the two bifunctional proteins, Hashimoto and coworkers suggested the names D-bifunctional protein (D-BP) and L-bifunctional protein (L-BP), respectively. ... 

All three fatty acids bound in triacylglycerols can be the same, and in this case we may speak about simple triacylglycerols (3-50). For example, the triacylglycerol with three identical acyls, derived from palmitic acid, is l,2,3-tripahnitoylglycerol or simply tripahnitoylglycerol, or tripalmitin to give it its trivial name. Three acyl residues derived from oleic acid are found in triolein and three stearic acid residues are found in tristearin. Alternatively, the two... 

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