Acyl fatty acid chains

Fig. 3. The stmcture of the nodulation (Nod) factors of i bium meliloti 2011 (44), where is 2 or 3, R is —H or—COCH, and R is C 2 as shown, C gT, or ie, a fatty acid chain having from 1 to 3 double bonds. The A/-acetyl glucosamine residues and an acyl moiety, R, are present ia all...

The preparation of fatty acids substituted within an aliphatic chain is necessary to prepare dermatological pharmaceuticals. The unsaturated acyl fatty acids are the intermediate and can be produced by Kao Corporation starting from low-cost saturated compounds applying whole... 

Typical weight per cent chain length distributions based on 20 80 tallow coconut fatty acid chain distribution specified for sodium acyl isethionate specified for the Monsavon bar [9], and the purely coconut fatty acid source for SCI. 

The leaving group is the enolate anion of acetyl-CoA, and the reaction thus cleaves off a two-carbon fragment from the original fatty acyl-CoA. Since the nucleophile is coenzyme A, the other product is also a coenzyme A ester. In fact, the reaction generates a new fatty acyl-CoA, shorter by two carbons, which can re-enter the P-oxidation cycle. Most natural fatty acids have an even number of carbons, so the process continues until the original fatty acid chain is cleaved completely to acetyl-CoA fragments. 

Palmitate and stearate serve as precursors of the two most common monounsaturated fatty acids of animal tissues palmitoleate, 16 1(A9), and oleate, 18 1(A9) both of these fatty acids have a single cis double bond between C-9 and C-10 (see Table 10-1). The double bond is introduced into the fatty acid chain by an oxidative reaction catalyzed by fatty acyl-CoA desatu-rase (Fig. 21-13), a mixed-function oxidase (Box 21-1). Two different substrates, the fatty acid and NADH or NADPH, simultaneously undergo two-electron... 

It is an acyl-CoA of the type mentioned in Section 1 and can also be formed from acetate, ATP, and coenzyme A. Although the human diet contains some acetic acid, the two major sources of acetyl-CoA in our bodies are the oxidative decarboxylation of pyruvate (Eq. 10-6) and the breakdown of fatty acid chains. Let us consider the latter process before examining the further metabolism of acetyl-CoA. 

At the end of this sequence, the P-oxoacyl-CoA derivative is cleaved (Fig. 17-1, step e) by a thiolase (see also Eq. 13-35). One of the products is acetyl-CoA, which can be catabolized to C02 through the citric acid cycle. The other product of the thiolytic cleavage is an acyl-CoA derivative that is two carbon atoms shorter than the original acyl-CoA. This molecule is recycled through the P oxidation process, a two-carbon acetyl unit being removed as acetyl-CoA during each turn of the cycle (Fig. 17-1). The process continues until the fatty acid chain is completely degraded. 

Fatty acid chains are taken apart two carbon atoms at a time by (3 oxidation. Biosynthesis of fatty acids reverses this process by using the two-carbon acetyl unit of acetyl-CoA as a starting material. The coupling of ATP cleavage to this process by a carboxylation-decarboxylation sequence, the role of acyl carrier protein (Section H,4), and the use of NADPH as a reductant (Section I) have been discussed and are summarized in Fig. 17-12, which gives the complete sequence of... 

Condensation step in fatty acyl-CoA elongation regulates fatty acid chain length... 

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