Linolenic add

Interestingly, the first biosynthetic experiments with [3H]linolenic add and the terrestrial plant Senecio isatideus (Asteraceae) as a model system for the biosynthesis of algal pheromones were unsuccessful. If, however, labeled dodeca-3,6,9-trienoic add is administered, a rapid transformation into ectocarpene takes place (36). Nevertheless, the C12 add ultimately derives from linolenic acid via three /3-oxidations, since labeled tetradeca-5,8,11-trienoic acid, which requires only one /3-oxidation, is converted into labeled ectocarpene albeit with very low effidency (37). 

Essential fatty acids are fatty acids that have to be supplied in the diet. Without exception, these are all polyunsaturated fatty acids the C20 fatty acid arachidonic add (20 4 5,8,11,14) and the two Cis acids linoleic add (18 2 9,12) and linolenic add (18 3 9,12,15). The animal organism requires arachidonic acid to synthesize eicosanoids... 

Fig.4.16. Separation of some 2-naphthacyl esters of fatty adds. A, C, adds B, C adds. Peaks 1 = oleic add 2 = linoleic add 3 a-Unolenic add 4 = 7-linolenic add 5 = dihomo-7-linolenic add 6 = arachidonic add 7 = 2-naphthacyl bromide. (From ref. 40 with permission of the American Chemical Society, Washington.)...

Poumes-Ballihaut, C., Langelier, B., Houher, F.,Alessandri, J., Dinand. G.. Latge, C., and Guesnet, P. (2001) Comparative Bioavailability of Dietary a-Linolenic Add and Docosahexaenoic Acid in the Growing Rat, Lipids 36,793 00. 

The human body does not have the enzyme to make (0-3 and (o-6 fatty adds. Therefore, an appropriate amount must be consumed in the food to maintain health. Linoleic and a-linolenic adds were considered vitamins (vitamin F) at a certain point in the history of science, but the term essential fatty acid is the accepted version today. There are no such essential compounds among monounsatuiated or saturated fatty acids. 

In this chapter, an explanation of the method is provided, with examples from real samples. The currently proposed mechanism for diagnostic ion formation is explained. Initial results are also presented to show the promising nature of this method for the analysis of longer chain conjugated FAME, conjugated linolenic adds, and trans monoene fatty adds. 

The biohydrogenation of linolenic (n-3) acid is usually shown proceeding to ds-9, trans-, cis- 5, then to trans-, cis- 5, then to trans-W monoene, and ending as stearic acid. Griinari and Bauman (25) proposed that linolenic add also could be converted to a trans- 0, cis- 2, dr-15 triene, which subsequently would be hydrogenated to a trans- 0, dr-15 diene, then to a tram- Q monene, and finally to stearic acid. A few early studies (27, 28) su ested the formation of cis-9, trans- 1... 

The activity of the microbial isomerase or isomerases (Fig. 1.1.) is key to the production of CLA. An isomerase is solely responsible for movement of the methylene-interrupted double bonds in hnoleic and linolenic adds to conjugated positions. Subsequent action of a reductase reduces or eliminates double bonds, but serves no function in rearrangement of double bonds to conjugated positions. Thus, it is the study and regulation of the isomerases that is needed to maximize the quantity of specific CLA isomers. 

Except for eicosanoic acid, the proportions of all fatty acids in egg yolk lipids were significantly (P < 0.01) influenced by the dietary CLA (59). The proportions of myristic, palmitic, and stearic acids, and CLA cis-9,trans- CLA and transit),cis-f2 CLA) in egg yolk lipids were increased by dietary CLA, but those of palmitoleic, oleic, linoleic, and linolenic, arachidonic acids, and DHA were decreased. These changes in fatty acid composition of yolk lipids are similar to those reported by Chamruspollert and Sell (60), although the total CLA concentration observed in the current research when a 5% CLA diet was fed (8.5-8.6%) was less than the 11.2% reported by those authors. The decrease in the concentrations of linoleic and linolenic acids in yolk lipids of hens fed CLA likely reflects the relatively low concentration of these fatty acids in the CLA source compared with soybean oil. Decreases in arachidonic acid and DHA in yolk lipids from hens fed CLA also could be related to the low concentration of dietary linoleic and linolenic acids, which serve as precursors to the formation of arachidonic acid and DHA. Another possibility is that CLA may compete with Unoleic and/or linolenic add for A6-desaturase, the rate-limiting step for the conversion of these fatty acids into arachidonic acid and/or DHA in liver microsomes (48). Feeding CLA increased the concentration of stearic acid in yolk lipids. 

The amount of co-3 fatty acids required is still under discussion. At first, due to the activity of desaturases, the biological effects of a-linolenic acid and EPA in the diet were thought to be very different. In view of the platelet aggregation, a tenfold amount of a-linolenic acid is necessary to yield the effect of EPA [1] (Fig. 2). From this experience - in contrast to o)-6 fatty acids - we might need two different requirement figures for (o-3 fatty acids, a greater one for a-linolenic add and a lower for EPA. That demands the use of a o)-3 fatty acid equivalent doses when formulating recommendations. 

Lamptey MS and Walker BL (1976) A possible essential role for dietary linolenic add in the development of the young rat. J Nitrition 106 86-93... 

Tinoco J, Babcock R, Hincenbergs I, Medwadowski B, Miljanich P and Williams MA (1979) Linolenic add deficiency. Lipids 14 166-173... 

Green, A.G. and Marshall, D.R. (1984) Isolation of induced mutants in linseed Linum usitatissimum) having reduced linolenic add content. Euphytica 33, 321-328. 

Fatty acid composition (wt%). Grape seed oil from V. vinifera is rich in linoleic acid, an essential fatty acid for man and animals. The level of linoleic acid is remarkably constant at about 70% of the total fatty acid in many different varieties and growing conditions (Table 7.7). The low levels of linolenic add (about 0.5%) make the oil resistant to revision flavors due to oxidation of this fatty acid oils such as canola, rapeseed and soy are susceptible to such flavor development. In this respect grapeseed oil is similar to corn, sunflower or safflower oils. 

Nakahara, T., Yokocki, T., Kamisaka, Y. and Suzuki, O. (1992) Gamma-linolenic add from genus Mortierella in Industrial Applications of Single Cell Oils, eds. D.J. Kyle and C. Ratledge, American Oil Chemists Society, Champaign, IL, pp. 61-97. 

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