Oleic moieties

Scheme 2.7 Two possible routes for the dimerisation of oleic moieties [2]...

Homogeneous and heterogenous catalysts which selectively or partially hydrogenate fatty amines have been developed (50). Selective hydrogenation of cis and trans isomers, and partial hydrogenation of polyunsaturated moieties, such as linoleic and linolenic to oleic, is possible. 

As shown in Table 1, the acyl moiety of cardiolipin is comprised almost entirely of unsaturated fatty acids. Other membrane phospholipids such as phosphatidyl choline and phosphatidyl ethanolamine contain 1(M0 mol of saturatedfatty acids such as palmitic acid (Ci6 0) and stearic acid (Ci8 0) per 100 mol of total fatty acids. In particular,linoleic acid (Cl8 2) is the most abundant polyunsaturated fatty acid consisting of 80 mol%, linolenic acid (Cl8 3) 8 mol%, and oleic acid (Ci8 i) 6 mol%. Therefore, by using a commercially available cardiolipin purified from bovine heart mitochondria, we characterized auto-oxidation products by reverse phase HPTLC and reverse phase HPLC. 

This structure shows a triglyceride with three identical saturated fatty acids. Tripalmitin, in which all fatty acids are palmitic acid (n = 14), provides one example of a fat. Triolein is an oil containing only oleic acid moieties esterified to glycerol. In contrast to these two examples, it is by no means necessary that the three fatty acid groups be derived from only one fatty acid. For example, we might have a triglyceride that contains one saturated fatty acid, say palmitic acid, one monounsaturated fatty acid, say oleic acid, and one polyunsaturated fatty acid, perhaps arachidonic acid. 

Table 1 shows an example of markup, generated using the OSCAR 3 system. The abstract of a polymer research paper has been parsed by OSCAR and the resulting markup for the first sentence of the abstract is shown in-line with the text (Table IB). The first chemical entity encountered in the sentence is oleic acid , which has been marked up as type = CM (Chemical Moiety) and a number of other annotations, such as in-line representations of chemical structure (InChl, SMILES) have been attached. 

The change from one oleic acid moiety in OOLc,c to one elaidic acid moiety (OElLc,c) affects retention time to the same extent as a corresponding change from linoleic acid with both double bonds in cis configuration in OOLc,c to linoleic acid with both double bonds in trans configuration (OOLt,t). 

Studies on the chemical structure of olive wax esters have shown that the homologues present in olive-pomace oil are almost entirely esters of oleic acid with long chain alkanol constituting the homologous series C40, C42, C44, C46. Odd-chain esters identified in the oil were esters of oleic acid with C23, C25, C27 alcohols. Gas chromatography and mass spectrometry analysis has shown that each carbon chain of the esters in made up of a single isomer in which the acyl moiety is that of oleic acid (Bianchi el al., 1994). Thus, for example, ester C44 was found to be made up of the couple acid-alcohol Cl8 1 and C26, whereas other possible isomers such as C16 l-C28 were not detected. This is unusual if it is compared with the composition of epicuticular ester fractions of oil seeds for which, in cases studied, each ester chain was composed of several positional isomers of the ester group. 

Disaturated-2-Unsaturated Mixed Acid Triacyigiycerois In this section, we consider the polymorphic behavior of a series of Sat.Unsat.Sat.TAGs, in which the sn-2 acid moieties are oleic, ricinoleic, and linoleic acids and the even-numbered saturated acids (palmitic, stearic, arachidic and behenic acids) are placed at the sn-l and sn-3 positions. 

Free radicals from certain halogenated xenobiotics Incorporate Into phospholipid. Trudell et al. (81,82) have shown that free radicals from carbon tetrachloride and halothane add to the double bonds of fatty acyl chains of phospholipids In the membrane surrounding cytochrome P-450. Oleic acid moieties were converted... 

Phosphatidylcholines, or lecithins, are zwitterionic over a wide pH range because of the presence of a quaternary ammonium group and a phosphate moiety. Phosphatidylcholines are the most abundant phospholipids in animal tissues and typically contain palmitic, stearic, oleic, linoleic, or arachidonic acid, usually with saturated fatty acids in the sn- position and unsaturated fatty acids at sn-2. 

Figure 1. Phospholipid classes. Phospholipid classes are categorized by the polar head group (X) covalently attached to the sn-3 carbon of the glycerol backbone by a phosphodiester bond. The sn-1 aliphatic chain (R,) is usually a saturated long-chain moiety (e.g., palmitic or stearic acids), while the sn-2 aliphatic chain (Rj) usually contains long-chain unsaturated aliphatic moieties (e.g., oleic, linoleic, orarachidonic acids).

The structure of 1-oleyltyrosol [41] was determined by simple chemical and spectroscopic methods. The nature of the fatty add moiety was deduced, besides spectroscopic considerations, by alkaline hydrolysis that allowed to isolate oleic acid. Alkaline hydrolysis allowed to isolate also tyrosol thereby determining the phenolic component. 

Figure 2. Reaction of soybean oil with DEAD. In Structure 2 we have arbitrarily placed an unreacted oleic acid moiety on position 2 of glycerol. In reality, we have a miKture of differentfatty acid moieties in soybean oil.

Since 1970, a new class of cyano compounds has been isolated from certain seed oils that are of interest as some members, like cyanogenic glycosides, liberate HCN on enzymic or mild chemical hydrolysis All the authenticated compounds occur in several genera of the Sapindaceae (soapberry) family " and they can comprise up to 50% v/v of the extract, e.g. in kusum seed oil. These cyanolipids are mono- or di-esters of mono- or dihydroxy-nitriles and 4 types are known (Figure 22). The chain length of the fatty acid moiety, which may be saturated or not (e.g. commonly from oleic acid), can be C14 to C22 with C18 and C20 predominant and the double bond in type 3 can be Z or E, but structural variations are few. After hydrolysis the a-hydroxynitriles derived from types 1 and 4 are cyanogenic. In many plant species one type occurs to the virtual exclusion of the others thus type 1 accumulates in Allophyllus and Paullina spp, whereas type 2 is characteristic of... 

Reviews of fungal fatty acid composition (, 7, ) reveal that their primary constituents are 12- to 20-carbon chain length unbranched compounds, with even-numbered chains predominant. Both saturated and unsaturated compounds occur, with palmltolelc (C-16 l), oleic (C-18 l), llnolelc (C-18 2) and llnolenlc (C-18 3) acids the most common unsaturated moieties ( ). As with most naturally occurring fatty acids (9), monounsaturated compounds usually contain a els oleflnlc bond and polyunsaturated acids have methylene-interrupted els double bonds. Although rare In occurrence and subjected to limited study, branched chains, hydroxy, oxo and epoxy acids are also synthesized ( 5). Lists of the structures of unusual fatty acids which can be employed In structure activity studies are presented In detail elsewhere (9-14). 

As an example, the mass spectrum of the DMOX derivative of oleic acid is given in Figure 1. DMOX derivatives give prominent peaks characteristic of the DMOX moiety at m/z 113 (McLafFerty rearrangement ion) and 126. The gap of 12 amu between m/z 196 and 208 locates the double bond in the example in Figure 1. 

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