Fatty acids palmitoleic

Lipid standards (2°/o solutions in chloroform) a triacylglycerol (triolein), cholesterol ester (cholesterol linoleate), fatty acid (palmitoleic, oleic, etc.), fatty acid methyl ester (linolenic acid, methyl ester), a glycerophosphatide (phosphatidylcholine, phosphatidylethano-lamine, etc.), a diacylglycerol (diolein), and a monoacylglycerol (monoolein). 

Monounsaturated Fatty Acids Palmitoleic acid C16 1A cA-9-Hexadecenoic acid... 

Wnt proteins are also acylated. The Wnt3a protein is modified by thioester-linked palmitate at a conserved cysteine residue and also by an unsaturated fatty acid, palmitole-ic acid, which is oxyester-linked to a conserved serine residue (R. Takada, 2006). Porcupine (pore), a member of the MBOAT family, is required for the O-acylation of Wnt3a. It is not clear whether pore or another acyltransferase carries out the 5-acyl modification. 

Certain long-chain unsaturated fatty acids of metabolic significance in mammals are shown in Figure 23-1. Other C20, C22, and C24 polyenoic fatty acids may be derived from oleic, linoleic, and a-flnolenic acids by chain elongation. Palmitoleic and oleic acids are not essential in the diet because the tissues can introduce a double bond at the position of a saturated fatty acid. 

Figure 23-1. Structure of some unsaturated fatty acids. Although the carbon atoms in the molecules are conventionally numbered—ie, numbered from the carboxyl terminal—the co numbers (eg, co7 in palmitoleic acid) are calculated from the reverse end (the methyl terminal) of the molecules. The information in parentheses shows, for instance, that a-linolenic acid contains double bonds starting at the third carbon from the methyl terminal, has 18 carbons and 3 double bonds, and has these double bonds at the 9th, 12th, and 15th carbons from the carboxyl terminal. (Asterisks Classified as "essential fatty acids.")...

The tuft-forming green alga Cladophora glomerata synthesizes a wide variety of toxic fatty acids, including capric and palmitoleic acids, which have been demonstrated to be insecticidal and allelopathic (Dodds and Gudder 1992). 

Tran. -isomers are much rarer than cis-isomers. Many different positional isomers of monoenoic acids may be present in a single, natural lipid and this is not a comprehensive list. Palmitoleic and oleic acids are quantitatively the commonest unsaturated fatty acids in most organisms. Odd-chain monoenoic acids are minor components of animal lipids but are more significant in some fish and bacterial lipids. 

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 ... 

The second family of secreted proteins that is covalently lipidated is the family of Wnt proteins. They are also involved in numerous processes like proliferation of stem cells, specification of the neural crest, and the expanding of specific cell types. The correct regulation of this pathway is important for animal development. Willert and coworkers were the first to isolate an active Wnt molecule. Mass spectroscopy studies carried out with the isolated protein revealed that cysteine 93 is palmitoylated. Mutating this amino acid to alanine led to almost complete loss of the signaling activity. Later in 2006, a second lipidation was found on a serine in Wnt3a. " In this case, the hydroxyl side chain is acylated with palmitoleic acid. This unsaturated fatty acid seems to be crucial for the progression of the protein through the secretory pathway. The attachment of two different lipid chains may therefore serve different functions. ... 

P F]F2 adds across the double bond of c/ s-9,10-palmitoleic acid in a syn fashion (Scheme 14) to yield a mixture of racemic eryf/ ro-9,10-c// [ F]fluoropalmitic acid in 12-16% radiochemical yield. It was designed for the study of fatty-acid metabolism [89]. 

The lipid of morama beans is mainly ( 75%) unsaturated fatty acids, with the principal fatty acid being oleic acid (43%). The beans furthermore contain linoleic (22%) and palmitic acid (13%) as well as stearic, arachidic, linolenic, arachidonic, erucic, behenic, myristic, palmitoleic, and gadoleic acid in lower concentrations (Bousquet, 1982 Bower et ah, 1988 Engelter and Wehmeyer, 1970 Francis and Campbell, 2003 Ketshajwang et ah, 1998 Mitei et ah, 2008). The fatty acid composition resembles that of olive oil (Mitei et ah, 2008). A literature review of the fatty acid composition of morama beans is given in Table 5.3. Less than 5% of the fatty acids are present as free acids (Bower et ah, 1988 Dubois et ah, 1995), which means that the activity of lipases is negligible in dry morama beans. 

FIGURE 21-12 Routes of synthesis of other fatty acids. Palmitate is the precursor of stearate and ionger-chain saturated fatty acids, as well as the monounsaturated acids palmitoleate and oleate. Mammals cannot convert oleate to linoleate or a-linolenate (shaded pink), which are therefore required in the diet as essential fatty acids. Conversion of linoleate to other polyunsaturated fatty acids and eicosanoids is outlined. Unsaturated fatty acids are symbolized by indicating the number of carbons and the number and position of the double bonds, as in Table 10-1. 

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... 

Oxygen Requirement for I)esat,iirases The biosynthesis of palmitoleate (see Fig. 21-12), a common unsaturated fatty acid with a cis double bond in the A9 position, uses palmitate as a precursor. Can this be carried out under strictly anaerobic conditions Explain. 

PALMITOLE1C ACID. [CAS 373-49-9], Also called dr-9-hexadec-anoic acid, formula CH3 (CH2)5CH CH(CHi>7COOH. This is an unsaturated fatty acid found in nearly every fat, especially in marine oils (15-20%i. At room temperature, it is a colorless liquid. Insoluble in water soluble in alcohol and ether mp 1.0°C bp 140-141°C (5 millimeters pressure). Combustible. Palmitoleic acid is used in organic synthesis, and as a standard in chromatographic analysis. See also Vegetable Oils (Edible). 

Free fatty acids are separable by GC by the inclusion of phosphoric acid in the packing so, for HPLC analysis, the phosphoric acid or other equivalent strong acid is included in the mobile phase. On a SUPELCOSIL LC 18 column, a model mixture of free fatty acids was separated with a mobile phase containing tetrahydrofuran, acetonitrile, water, and phosphoric acid (6 64 30 0.1) at pH 2 (Fig. 1) (15). Oleic and elaidic acids, palmitoleic and palmitelaidic acids, and linoleic and linoelaidic acids were well separated, but margarine fatty acids presented a difficult problem. Ultraviolet detection of 220 nm was used to prepare this chromatogram. 

Fig. 1 HPLC of free fatty acids. Column SUPELCOSIL LC 18. 25 cm X 4.6-mm ID. (5fi) mobile phase tetrahydrofuran/acetonitrile/0.1% phosphoric acid, pH 2.2 (21.6 50.4 28.0) flow rate 1.5 ml/min temperature 35°C detection at 220 nm sample concentration 1-2 mg/ml per component. 16 1 (cis) = cis-9-hexadecenoic acid (cis-palmitoleic acid) 16 1 (trans) = trans-9-hexadecenoic acid (trans-palmitoleic acid) 18 0 = octadecanoic acid (stearic acid) 18 1 (cis) = cw-9-octadecenoic acid (oleic acid) 18 1 (trans) = trans-9-octadecenoic acid (elaidic acid) 18 2 (cis) = cis-9-cis-12-ctadecadienoic acid (linoleic acid) 18 2 (trans) = trans-9-trans-12-octadecadienoic acid (linolelaidic acid) 18 3 (cis) = cis-9-cis-2-cis-15-octadecatrienoic acid (linolenic acid).

Fig. 5 Chromatograms of the 2-nitrophenylhydrazides of a mixture of saturated and unsaturated long-chain fatty acids obtained with UV detection. Flow rate 1.2 ml/min. Eluent and column temperatures (a) methanol/water (86 14 v/v) and 50°C (b) acetonitrile/water (85 15 v/v) and 30°C. Peaks 1. capric 2. Laurie 3. myristoleic 4. eicosapentenoic 5. linolenic 6. myristic 7. docosahexenoic 8. palmitoleic 9. arachidonic 10. linoleic 11. eicosatrienoic 12. palmitic 13. oleic 14. margaric (internal standard) 15. stearic acid hydrazide. Each peak corresponds to 150 pmol.

To improve the separation of the derivatives of fatty acids with the same effective carbon number, e.g., palmitoleic (C16 1), linoleic (18 2), andmyristic (C14 0), Baty et al. (33) reported the preparation of the anthrylmethyl esters derivatives of several fatty acids (with 9-hydroxy-methylanthracene and the catalyst 2-bromo-l-methylpyridinium iodide (BMPI)) with a view to analysis by HPLC and LC-MS (with gradient elution on a ZORBAK 5-/zm Cl8 column) (see Chemical Structure 1). The excess reagents were evaporated under nitrogen at 50°C, and the de-rivatized acids were taken up in 1 ml of mobile phase prior to chromatography. This method did not allow the resolution of the C16 1, 08 2, and C14 0 esters, although HPLC data obtained for the other acids correlated well with that obtained by capillary gas-liquid chromatography. 

Unsaturated Fatty Acids1 Palmitoleic acid H H 1 1 CH3(CH2)5C=C(CH2)7C02H 16 1A9... 

The infamous fluoroacetic acid and the equally toxic naturally occurring even-numbered co-fhiorinated fatty acids were discussed in detail earlier (7), and several reviews are available (34,44, 66). Although not counted as being natural in the earlier survey (7), 4-fluorothreonine (837) is now considered to be a bona fide natural metabolite of Streptomyces cattleya (893), the stereochemistry of which has been confirmed by synthesis (894). In addition to the five oo-fluorinated fatty acids presented earlier (7), new studies of the seed oil of Dichapetalum toxicarium have uncovered 16-fluoro-palmitoleic acid (838), 18-fluorostearic acid (839), 18-fluorolinoleic acid (840), 20-fluoroarachidic acid (841), 20-fluoroeicosenoic acid (842), 18-fluoro-9,10-epoxystearic acid (843) (895), (Z)-16-fluorohexadec-7-enoic acid (844), (Z)-18-fluoroocta-dec-9-enoic acid (845), and (Z)-20-fluoroicos-9-enoic acid (846) (896). 

To identify the unsaturated fatty acids produced in the transformants that were able to grow without supplementation with palmitoleic or oleic acid, cells were grown at 30° C in YPD liquid medium to a density of 2 x 107 cells/ml, at which point the cells were pelleted and washed three times with water, and then extracted with methanol/chloroform (1 2). After solvent evaporation, the lipid residue was treated with 0.5 M KOH/methanol, and the resulting fatty acid... 

An expression construct consisting of the open reading frame of the TnFB A9Ds cDNA inserted into the yeast desaturase expression vector YEpOLEX was used to transform the olel strain of S. cerevisiae as described above. Many transformant colonies were obtained on medium lacking unsaturated fatty acids, indicating complementation of the olel mutation by the encoded T. ni desaturase. GC/MS analysis of the fatty acid methyl esters obtained from the transformants showed that the TnFBA9Ds cDNA encoded a A9 desaturase that produced oleic acid (Z9-18 Acid) and palmitoleic acid (Z9-16 Acid) (Liu et al., 1999). Quantitation of these unsaturated fatty acids under standard conditions as described above revealed about three times more of the former than the latter (Rosenfield et al., 2001). 

Fig. 1. Structures of (a) a saturated fatty acid (palmitate, C16 0) (b) a mono-unsaturated fatty acid with the double bond in the cis configuration (palmitoleate, C16 1) (c) a mono-unsaturated fatty acid with the double bond in the trans configuration (C18 1) and (d) a polyunsaturated fatty acid (linoleate, C18 2).

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