A-Eleostearate

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. 

A hydroboration-protonolysis procedure for the conversion of conjugated enynes to dienes is far superior to partial hydrogenation over Lindlar s catalyst, in terms of stereoselectivity and yields280. Ratovelomanana and Linstrumelle reported the synthesis of methyl a-eleostearate (equation 163) and methyl punicate by employing this strategy280. 

Elemental uranium, crystal structures of, 25 409. See also Uranium (U) Elementary reaction, 21 336 Element/isotope ratios, in fine art examination/conservation, 11 419 Element mapping, in fine art examination/ conservation, 11 406 Element names/symbols, 17 386-387 transfermium, 17 387t Elements, in earth s crust, 26 23 a-Eleostearic acid, physical properties, 5 33t... 

Polyunsaturated fatty acids can also be prepared by Wittig reactions. Thus, Bergel-son and Shemyakin synthesized a-eleostearic acid [(9Z, 11ZT, 13 )-9,11,13-octadeca-trienoic acid 42] from (2 ,4 )-2,4-nonadienal 40 and phosphorane 4149). The intro-... 

The only conjugated dienoic fatty acid isolated from plant sources (the seed oil of Chilopsis linearis) is reported to be trans-lO, trans-12-octadecadienoic acid. In contrast, fatty acids with conjugated triene systems have been detected in various plant species. Tung oil is the commercial source of the most widespread fatty acid from this group, 9-cis, W-trans, I i-trans-octadecatrienoic (a-eleostearic) acid (1, 2). 

Hydrogenation of methyl p-eleostearate (methyl frani,fran5,fra s-9,ll,13-octadecatrienoate) with [Cr(CO)3(arene)] yields the diene products from 1,4-addition trans-9-cis- 2- and CK-10-fran5-13-oc-tadecadienoates). With a-eleostearate (methyl d5,fran5,fra i-9,ll,13-octadecatrienoate), stereoselective 1,4-reduction of the trans,trans-diene moiety yields linoleate (cis,cis-9,l2) accompanied by cm,Irani-1,4-dienes which are formed from the isomerization of a- to p-eleostearate. ... 

Oils containing Cjg polyene acids Calendula officinalis seed oil. Calendula oil (from marigold) is of interest because it contains about 58% of calendic acid (8fl0fl2c-18 3). This unusual acid is an isomer of a-eleostearic (9cllfl3f-18 3) present in tung oil, and calendula oil should also be a good drying oil. The presence of linoleic acid (30%) will add to the unsaturated nature of this oil (131-133). 

Figure 4 shows the peaks of the components in the gas chromatogram. The highest peak was the peak of a-eleostearic acid. Although both eleostearic and linolenic acids have three double bonds, the stmcture and the properties of eleostearic acid are different from linolenic acid which was contained in soybean or rapeseed biodiesel (Fig. 5) [13,17], Table 3 shows the fatty acid composition of tung biodiesel. The saturated fatty acid content of tung biodiesel was 14.1% and the unsaturated fatty acid content was 84.6%. The eontent of...

FIGURE 2.1 Schematic diagram of a-eleostearic acid and triacylglycerol biosynthesis in developing tung (Vernicia fordii) seeds. Eleostearic acid is synthesized from linoleic acid attached to endoplasmic reticulum (ER) phospholipids, primarily phosphatidylcholine (PC), then removed from the phospholipid pool and channeled into triacylglycerols through any of several coenzyme A (CoA)-dependent or -independent acyltransferase reactions. 

Conjugated octadecatrienoic acids are available in tung oil (a-eleostearic acid, 70-80%, Section 3.3.39), in oiticia oil (licanic acid, 80%, Section 3.3.22) and... 

The major fatty acid in oiticica, Mexican oiticica and poyoak Parinarium sherbroense) oils is a-licanic acid, a conjugated trienoic Cis fatty acid with a keto function at C4 (4-keto-18 3 9c t 3t) (Morrell and Davis, 1936). Hydroxy fatty acids (4%) have also been detected by GLC. Prior to GLC a-eleostearic acid had been reported (Sections 1.5 and 3.2.12). 

---