Unsaturated fatty adds

Prostaglandins are important derivatives of unsaturated fatty adds. Below we have drawn the structure of prostaglandin E2 as an illustration of the general structure of the prostaglandins. 

Hydrogenase Reduction of carbonyl groups, Unsaturated fatty adds,... 

Unsaturated fatty adds have one or more double bonds. Humans can synthesize only a few of the unsaturated fatty acids de novo the rest must be made from essential fatty acids in the diet transported from the intestine in chylomicrons. Two important essential fatty acids are linolenic and linoleic adds. 

Saturated-, unsaturated fatty adds, triglyceride from interesterification products silicalite-1 2-Heptanone/ acetone [191]... 

Table 11.4 Content of some unsaturated fatty adds in triacyl-glycerol in muscle of a fish, a bird and a ruminant and in green...

Craven PA, DeRubertis FR (1988) Role of activation of protein kinase C in the stimulation of colonic epithelial proliferation by unsaturated fatty adds. Gastroenterology 95 676-85... 

Data dted by Garke (24) indicate that fatty add content may be a good indication of lipid fractionation by SFE. He found that saturated fatty adds were reduced 72% and unsaturated fatty adds reduced by 63% compared to the unextracted control. Cholesterol was reduced by 76% to an average of 41.6 mg/100 g in the extracted meat residue (24). 

The coenzyine especially participates in gluconeogeiiesis, production of neural hormones, bile acids, unsaturated fatty adds, and porphyrins. 

Unusual features of vitamin E substances as observed by various investigators include (1) the vitamin may be involved in aging mechanisms by protecting unsaturated fatty adds and membranes against free radicals ... 

Palmitate can serve as a precursor for both longer and unsaturated fatty adds. Chain elongation takes place in both the endoplasmic reticulum and mitochondria. In the latter, this is a simple reversal of the /3-oxidation reaction sequence, except that the step that would normally require FADH2 requires NADPH instead. This system is designed for the elongation of short-chain acids. There is no activity with palmitate. 

Yokoyama, M. T., Davis, C.L. 1971. Hydrogenation of unsaturated fatty adds by Treponema (borrelia) strain B25, a rumen spirochete. J. Bacteriol. 107, 519-527. 

The elimination is known to be a cis removal of H and OH and the double bond is exclusively trans ( ). Only later in the nonconjugated unsaturated fatty adds do we get Z-alkenes. Finally, in this cycle, the double bond is reduced using another molecule of NADPH to give the saturated side chain. 

Gonjugated unsaturated fatty adds are made simply by stopping the acylation cycle at that stage and hydrolysing the thiol ester linkage between the unsaturated acyl chain and AGP. They always have the E (trans) configuration and are the starting points for other biosynthetic pathways. 

In saturated fatty acids, the chain is extended and flexible (i.e., the carbon atoms rotate freely around the longitudinal axis). Unsaturated fatty adds, however, have fixed 30° bends... 

Gerwick and co-workers have applied the BIRD sandwich sequence for a rapid and accurate determination of Vhh couplings in higher order spin systems present in the spectra of unsaturated fatty adds. Furihata and Seto have proposed new pulse sequences, /hr- and /cR-resolved-HMQC for determination of the Vrr coupling in strongly coupled spin systems. The authors have increased the accuracy of information on H-H /-splittings... 

Warwel S, Sojka M, Rosch M (1993) Synthesis of Dicarboxylic Adds by Transition-Metal Catalyzed Oxidative Cleavage of Terminal-Unsaturated Fatty Adds. 164 79 - 98... 

The hydrocarboxylation of an unsaturated fatty add ester is carried out in a single organic phase. As product, the monoester of a dicarboxylic add is formed. When this produd is treated with aqueous sodium hydroxide solution this add is converted into a water-soluble sodium salt. In the following separator the water-insoluble palladium catalyst is extracted from the aqueous phase by addition of an organic solvent. When the aqueous product phase is addified with aqueous hydrochloride solution the released carboxylic acid forms a second organic phase and can easily be separated. The catalyst-containing solvent phase passes a distillation step, thus recycling the solvent to the separator and the palladium catalyst to the reactor. 

What is important though is that the double bonds are separated by one and only one single bond. Remember the unsaturated fatty add, linoleic acid, that you met in Chapter 3 Another fatty acid with even more unsaturation is arachidonic acid. None of the four double bonds in this structure are conjugated since in between any two double bonds there is an sp carbon. This means there is no p orbital available to overlap with the ones from the double bonds. The saturated carbon atoms insulate the double bonds from each other. 

See also / -Oxidation of Saturated Fatty Add Unsaturated Fatty Add Oxidation, Oxidation of Odd-Numbered Fatty Acids, Peroxisomal / -Oxidation, Fatty Acids... 

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