Docosenoic acids oxidation

Only a few specific kinds of lipids can be identified on the basis of the characteristic features of the FA profile and the presence of specific biomarkers. For example, oils obtained from the seeds of Brassicaceae, such as rapeseed oil, are characterized by abundant amounts of uncommon FA such as gondoic (Z-11 -eicosenoic) acid and erucic (Z-13-docosenoic) acid and, after ageing their oxidation products. Other examples are reported in Table 7.2 and in Chapter 1. 

Meadowfoam is composed of unique long-ehain fatty aeids with 5-eieosenoie acid (62%) as the major fatty aeid. The other main eomponents are 5,13-doeosa-dienoic acid (19%), 5-docosenoic acid (3%) and 13-docosenoic acid (10%). The A5 unsaturation provides an excellent chemical moiety for synthetic modifications to the oil or fatty acids by providing a site at which a carboxylate stabilized carbocation can form. In addition, the A5 unsaturation has enhanced resistance to oxidative degradation (8) as evidenced by the high OSI of the oil (246.9 h at 110°C) or its methyl ester (69.4 h at 90°C). 

The two most common naturally occurring c/s docosenoic acids are erucic acid (c/s 22 1 n-9) found in the seed oil of the Brassica family and ceto-leic acid (c/s 22 1 n-11) found mainly in marine oils (Ackman et ai, 1971a). The cetoleic acid in fish oils is derived by oxidation of the corresponding alcohol present in small Crustacea which form part of the food chain for marine life (Nenenzel, 1970 Pascal and Ackman, 1976). To date, no longterm studies have been reported in which these two docosenoic fatty acids were fed in purified form. When a comparison was made between a HEAR... 

It should be mentioned that the heavy investment in research on rapeseed not only yielded valuable information about the crop itself but also produced a body of scientific information which greatly helped in the understanding of fat metabolism and interspecies differences in metabolic pathways. The role of the chain shortening process and peroxisomal oxidation was made clearer by studies on docosenoic acid metabolism. Valuable information was obtained from experiments which dealt with the effects of erucic acid on adrenal gland activity and prostaglandin biosynthesis. Some excellent research was done also on the effect of erucic acid on cardiac mitochondrial respiratory activity. Moreover, some interesting theories were... 

Very-long-chain fatty acids as erucic acid (A -docosenoic acid, C22 l), polyunsaturated fatty acids, methyl-branched fatty acids, dicarboxylic fatty acids, prostaglandins, and the cholesterol side chain in bile acid synthesis are preferentially or exclusively oxidised in peroxisomes. Peroxisomal P-oxidation starts with introduction of a A2,3-double bond catalysed by acyl-CoA oxidase, which consumes O2 and produces H2O2 (Foerster et al. 1981). 

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