Un saturated fatty acids

A typical lipid in foodstuffs is the triestcr formed from glycerol and oleic acid, which is the most abundant lipid in olive oil. Oleic acid is a mo no-un saturated fatty acid —it has one Z douhle bond in the middle of the Cjg chain. This bond gives the molecule a marked kink in the middle. The compound actually present in olive oil is the triester, also kinked. 

SATURATED AND MONO-UN SATURATED FATTY ACID BIOSYNTHESIS IN BRAIN RELATION TO DEVELOPMENT IN NORMAL AND DYSMYELINATING MUTANT MICE... 

The saturated fatty acids that are present in significant quantities in milk fat are molecules with un-branched hydrocarbon chains, which vary in length from 4 to 18 carbon atoms. These fatty acids account for approximately 70 to 75% of the total fatty acids. The most important saturated fatty acid from a quantitative viewpoint is 16 0, which accounts for about 25 to 30% of the total, while two other fatty acids, 14 0 and 18 0 have values in the region 10 to 13% (Table 1.2). The amounts of the short-chain fatty acids, 4 0 and 6 0, are reasonably high when their proportions are expressed as molar percentages (approximately 10 and 5%, respectively—Table 1.2) appreciable amounts of medium-chain length fatty acids (Cs to C12) are also present. 

A method for the complete structural analysis of complex mixrnres of methyl esters of saturated and un-samrated fatty acids has been performed by 2-D TLC. Adsorbent silica gel impregnated with a 10% solution of dodecane was used for the first direction with acetonitrile-acetone (1 1, v/v) as eluent. The silica gel for the second direction was impregnated with a 20% AgNOs and dipropyl ether-hexane (2 3, v/v) was used as eluent. In this way, complete separation of a standard mixture of the methyl esters of six saturated, nine monoethylenic, and three polyenic esters were achieved. 

Fatty acids, both saturated and unsaturated, have found a variety of applications. Brassilic acid (1,11-un-decanedicarboxylic acid [BA]), an important monomer used in many polymer applications, is prepared from erucic acid (Scheme 2), obtained from rapeseed and crambe abyssinica oils by ozonolysis and oxidative cleavage [127]. For example, an oligomer of BA with 1,3-butane diol-lauric acid system is an effective plasticizer for polyvinylchloride. Polyester-based polyurethane elastomers are prepared from BA by condensing with ethylene glycol-propylene glycol. Polyamides based on BA are known to impart moisture resistance. 

In special cases, a selective fluid/fluid extraction is of interest. Ethanol extracts free fatty acids (above a level of 3%) from triacylglycerols in crude oils - this is a suitable way to treat oils with exceptionally high amounts of free acids. At a given temperature, furfural can extract only the polyunsaturated triacylglycerols. On the other hand, propane under pressure preferentially solubilizes the saturated triacylglycerols and leaves behind the unsaturated ones, together with un-saponifiable matter. Pressurized propane is uti-... 

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