Hexadecanoic acid, fatty acids

Z,Z,Z,)-9,12,15-octadecatrienoic acid). Fish oils contain esters of eicosanoic and docosanoic acids with four to six double bonds separated by single methylene groups, eg, (i7//-Z)-4,7,10,13,16,19-docosahexaenoic acid [6217-54-5] in menhaden oil (4). The fatty acid with conjugated double bonds in tung oil is a-eleostearic acid [506-23-0] ((F,Z,F)-9,ll,13-octadecatrienoic acid) the predominant fatty acid in oiticica oil is licanic acid [17699-20-6] (4-oxo-(F,Z,F)-9,ll,13-octadecatrienoic acid). In all oils, other fatty acids including palmitic acid [57-10-3] (hexadecanoic acid), stearic acid [57-11-4] (octadecanoic acid), and oleic acid [112-80-1] ((Z)-9-octadecenoic acid) also are present. 

In total, 185 substances were found in the wing-sac liquid of male S. bilineata from a Costa Rican population. For a more detailed analysis the relative peak area of thirteen focus compounds was compared (Table 14.1). Of these nine were male-specific substances (indole, indol-3-carboxaldehyde, indole-3-carboxylic acid, 2-aminoacetophenon, anthranilic acid, SHJOH-dipyrrolofl -aT -dJpyrazine-5,10-dione (pyrocoll), indolo[2,l-b]quinazoline-6,12-dione (tryptanthrin), 2,6,10-trimethyl-3-oxo-6,10-dodecadienolide, and a compound C15H24O2 of unknown structure), three were fatty acids (tetradecanoic acid, hexadecanoic acid, and octadecanoic acid), and one a steroid (cholesterol). On average, the cumulative peak area of these substances made up 62.5 20.7% of the whole chromatogram area. 

Hexadecanoic Palmitic C16 0 Most common saturated fatty acid in plants and animals... 

The traditional major source for the nonionic surfactant industry is fatty acid triglycerides from both animal and vegetable sources as the saturated or unsaturated acids. The saturated acids include lauric acid (w-dodecanoic), myristic acid (n-tetradecanoic), palmitic acid ( -hexadecanoic),and stearic acid (n-octadecanoic). The unsaturated acids include oleic acid (Z-9-octadecenoic) and linoleic acid (Z,Z-9,12-octadecadienoic). Of the 200 non-ionic surfactants... 

From the muscle tissue of the bivalve Barnea dilatata japonica, a galac-tocerebroside has also been isolated, but here, the major fatty acid component is hexadecanoic acid (92.3%), and the major sphingosine base is C,8 2 sphingosine.130... 

The lipid composition in all of these oligosylceramides is similar. The major fatty acids are hexadecanoic and octadecanoic acid, and the major sphingosine base is octadeca-4-sphingenine. 

The hepatopancreas of H. schlegelii was found to contain an unusual cerebroside, a mannosylceramide, isolated from the monohexosylceramide fraction by t.l.c. on borate-impregnated silica gel.265 Its structure was shown to be /3-D-mannosylceramide, whose major sphingosine base is 4-sphingenine, and the fatty acids constitute a mixture of normal (77% of the total acids) and a-hydroxy acids, with hexadecanoic acid preponderant (43.7% of the total acids).265... 

Despite the large variety of potential fatty acid components in natural-occurring phosphodiglycerides, only three major fatty acid derivatives of synthetic phospholipids are commonly used in liposome preparation (1) myristic acid (w-tetradecanoic acid containing 14 carbons), (2) palmitic acid (w-hexadecanoic acid containing 16 carbons), and (3) stearic acid (w-octadccanoic acid containing 18 carbons) (Fig. 334). 

Total fatty acids were liberated by subjecting Salmonella minnesota Re lipopolysaccharide (or free lipid A) to acidic (4 N HC1, 5 h, 100°C) followed by alkaline (1 N NaOH, 1 h, 100°C) hydrolysis. After extraction (chloroform), the free fatty acids were converted into their methyl esters (diazomethane) and analysed by combined gas-liquid chromatography/mass spectrometry. Alternatively, the fatty acids of lipid A are transesterified by treatment of lipopolysaccharide with methanolic HC1 (2 N HC1 in water-free CHaOH, 18 h, 85°C). By these procedures the following fatty acids were identified (in approximate amounts relative to 2 moles glucosamine) dodecanoic (12 0, 1.1 mole), tetradecanoic (14 0, 0.8 mole), hexadecanoic (16 0, 0.9 mole), 2-hydroxytetradecanoic (2-OH-l4 0, 0.1 mole), and 3-hydroxytetradecanoic acid (3-OH-14 0, 4 moles). In total, therefore, approximately 7 moles of fatty acids are present per mole of lipid A backbone. The stereochemistry of the hydroxylated fatty acids was determined by gas-liquid chromatography of their diastereomeric methoxyacyl-L-phenylethylamide derivatives (24). It was found that 2-hydroxyte-tradecanoic acid possesses the-Ts), and the predominating 3-hydroxytetradecanoic acid the (R) configuration. 

Fluorescence Of Monolayers Containing Pyrene-Labeled Probes. A fluorescence probe method was also used as a complementary technique to study the thermodynamics of SA film formation. Mixed monolayers containing the fluorescence probe pyrene hexadecanoic acid, Py-C16, in host fatty acids of different lengths were prepared by adsoiption from solutions containing mostly the host fatty acid and a small fraction of Py-C16 (approximately 1 to 5 mol %). All monolayers were prepared under equilibrium adsoiption conditions. For fluorescence measurements only A1 substrate was used because when glass is used an impurity fluorescence from glass interferes with the pyrene fluorescence. 

Bjostad and Roelofs (1983) were the first to determine correctly how the major pheromone component for a particular moth was biosynthesized. This was done by looking for possible fatty acid intermediates and by monitoring the incorporation of radiolabeled precursors into pheromone components. They showed that glands of the cabbage looper, Trichoplusia ni, utilize acetate to produce the common fatty acids octadecanoate and hexadecanoate which undergo All desaturation to produce Zll-18 acid and Zll-16 acid. But the main pheromone component was Z7-12 OAc, which presumably was made from Z7-12 acid. To demonstrate how the fatty acid precursor Z7-12 acid was produced, [3H-16]-Z1 l-16 acid was applied to glands and monitored for incorporation. It was incorporated into both Z7-... 

Quantitative changes in lipid compounds on the silk and cuticle of females correlate significantly with changes in female sexual receptivity in spiders. For example, female T. atrica attach a contact sex pheromone to their web (Trabalon et al., 1997,2005 Prouvost et al., 1999). This pheromone consists of a complex mixture of saturated hydrocarbons, methyl esters (methyl tetradecanoate, methyl pentadecanoate, methyl hexadecanoate, and methyl octadecanoate) and their fatty acids (tetradecanoic, pentadecanoic, hexadecanoic, and cis,cis-9,12-octadecadienoic acids). The female uses cuticular compounds, which are applied to the silk in substantial amounts during web construction. Modification of chemical profiles makes the female attractive to males (Trabalon et al., 2005). Receptive females are different to unreceptive ones with respect to three fatty acids (hexadecanoic, octadeca-dienoic and octadecenoic acids) and three methyl esters (linoleate, oleate, and stearate) present on both the web and the cuticle. Our combined results from chemical analyses and behavioral assays demonstrate clearly that these contact compounds are quantitatively correlated with the behavior of spiders. 

Palmitic acid Hexadecanoic acid CH3(CH2)14C02H Fatty adds from oils and fats... 

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