Component fatty acids

Nandanan et al. [35] reported the utilization of linseed oil as an MFA in nitrile rubber vulcanizates. Linseed oil not only acted as a plasticizer but also as the fatty acid component of the activator in the NBR vulcanizates. Use of linseed oil gave appreciable increase in properties like tensile strength, tear resistance, etc. while the viscosity of the compound was marginally lower than that of the control compound (which used di-octyl phthalate as the plasticizer). The vulcanizates containing linseed oil also exhibited increased cure rate as well as reduced leachability compared to the control at a dosage of 2-5 phr. This loading was seen to replace 6 phr DOP and 2 phr stearic acid in conventional NBR vulcanizates thereby reducing compound costs. 

Table 6.2 Main fatty acid components of vegetable oils (as percentage of total fatty acids)...

Lipid Fatty acid components Number of carbon atoms in fatty acid chain... 

The repertoire of chemicals that can be used for communication is limited by the biosynthetic ability of the insect. Compared to other insect orders, pheromone biosynthesis in Hymenoptera has received little study [191]. However, the biosynthetic origins of chemically diverse hymenopteran semiochemicals likely include aromatic, fatty acid, and terpenoid pathways as well as simple modifications of host-derived precursors. Notable recent studies include the biosynthesis of the fatty acid components (2 )-9-oxodec-2-enoic acid 52 and (2 )-9-hydroxydec-2-enoic acid of the honeybee queen mandibular pheromone from octadecanoic acid [192,193], and the aliphatic alcohol and ester... 

Figure 22.5 The three fatty acid components commonly used in liposome construction.

Conversely, the racemic film system appears to be solubilized by the achiral fatty acid component. At compositions of 10-33% palmitic acid, the ESP of the racemic system varies linearly with film composition, indicating that the monolayer in equilibrium with the racemic crystal is a homogeneous mixture of racemic SSME and palmitic acid. At compositions of less than 33% palmitic acid, the ESP is constant, indicating that three phases consisting of palmitic acid monolayer domains, racemic SSME monolayer domains, and racemic SSME crystals exist in equilibrium at the surface. 

Other workers began to study the structure of gramicidin. Christensen and coworkers12 isolated crystalline tryptophane and leucine from a hydrolysate. They found no evidence for a fatty acid component and established that phenylalanine, proline and hydroxyproline were absent from a hydrolysate. These workers isolated alanine diox-pyridate from a hydrolysate and also established that gramicidin contained a compound with vicinal hydroxy and amino groups. They speculated that this compound might be serine or isoserine and proposed that gramicidin contains two tryptophane, 2 leucine, 2 or 3 alanine and 1 hydroxyamino residues or a multiple of this composition. 

The suffix -anoic Indicates a saturated fatty acid component. 

The suffix -enoic indicates an unsaturated fatty acid component. 

Alicyclic hydrocarbons are saturated carbon chains that form ring structures. Naturally occurring alicyclic hydrocarbons are common (Chap. 1). For example, alicyclic hydrocarbons are a major component of crude oil, comprising 20-67 vol.%. Other examples of complex, naturally occurring alicyclic hydrocarbons include camphor (a plant terpene) and cyclohexyl fatty acids (components of microbial lipids). Anthropogenic sources of alicyclic hydrocarbons to the environment include fossil-fuel processing and oil spills, as well as the use of such agrochemicals as the pyrethrin insecticides (Chap. 1, and references therein). 

Unsaturated polyesters in which the alkene double bond resides in a fatty acid component such as oleic (IX) and linoleic (X) acids are referred to as alkyds or alkyd resins (Sec. 2-12a). 

Table 1. Hie fatty acid components of carp oil and tuna oil.

Since the phospholipids have cis-unsaturated fatty acid components there is a certain amount of fluidity to the bilayer. You can picture a sea of lipids moving in a transverse motion across the inside and outside faces. Note that the exterior of the membrane is composed of the polar portions of the biolipids while the interior of the membrane is highly nonpolar. 

Lipids The fatty acid components of the lipids entering hepatocytes also have several different fates (Fig. 23-15). Some are converted to liver lipids. Under most circumstances, fatty acids are the primary oxidative fuel in the liver. Free fatty acids may be activated... 

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 major, fatty acid component in these glycolipids is the C22 , acid, and no hydroxy acids were found. The sphingosine bases are represented by dihydroxy bases, among which, the preponderant one is the C,8 sphin-... 

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). 

Phospholipid-derived fatty acids are often used to identify bacteria by capillary GC analysis after liquid solvent extraction, concentration steps, and chemical derivatization to their methyl esters. Our initial investigations attempted to extract the intact phospholipids, but no significant recoveries were achieved using pure C02. Even if SFE conditions were developed that could extract intact phospholipids, an additional derivatization step would be required before GC analysis of the fatty acid components. For these reasons, chemical derivatization/SFE was investigated in an effort to eliminate the lengthy conventional liquid solvent extractions as well as to combine (and shorten) the extraction and derivatization steps. The derivatization/SFE procedure was performed on samples of whole bacteria using 0.5 mL of 1.5% TMPA in methanol. The static derivatization step was performed for 10 minutes at 80°C and 400 atm C02, followed by dynamic SFE for 15 minutes at a flow rate of ca. 0.5 mL/min of the pressurized C02. Extracts were collected in ca. 3 mL of methanol and immediately analyzed by capillary GC without any further sample preparation. 

The separation of individual fatty acid components from whole fatty acid distillates is achieved by fractional distillation.l8a,b However, fractional distillation cannot efficiently separate C,6-C 8 saturated from the corresponding unsaturated fatty acids. In such cases, the melting points vary considerably with the degree of unsaturation and this property is used for their separation via a number of industrial processes.I9a,b... 

A typical high-efficiency fractionation system (Fig. 36.14) consists of one continuous straight distillation and one, or preferably two fractionation columns.I0,17a,b This system is very efficient for the separation of low-boiling fatty acid components,6,10 a C12 fraction of 99.5 percent purity from coconut fatty acid or a C22 fraction of 95 percent purity from rapeseed fatty acid is readily obtained. 

The fatty acid content of the ovipositor tips of a variety of Lepidopteran species were determined by acid methanolysis followed by gas-liquid chromatography (GLC) (4.). In each case, unusual fatty acids corresponding to pheromone components were identified. For example, the tufted apple bud moth, Platynota idaeusalis, uses (E)—11—tetradecenyl acetate and alcohol as pheromone components (5.) and also contains (E) -11—tetradecenoic acid in its ovipositor tip. In several species, the fatty acid content of the rest of the insect also was determined. In each instance, the unusual fatty acid components were found only in the ovipositor tip or in the pheromone-producing gland located in the tip. 

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