Lipids predominant metabolic pathways

By far the most predominant metabolic pathway for water-soluble azo dyes is cleavage of the azo linkage by azoreductase of the liver and extrahepatic tissue or by intestinal microflora in the body [25,26], Oxidative metabolism occurs for lipid-soluble dyes, e.g., solvent dyes. Three oxidation pathways are known for such dyes (1) C-(ring-)hydroxylation, (2) A-hydroxylation at a primary or secondary amino group or (3) by stepwise oxidation of the methyl groups of dimethylamino compounds (demethylation). All three oxidative degradation ways leave the azo bond intact. For further details of the mechanisms, see [27,28],... 

Fig. 4.6. Predominant metabolic pathways of the major classes of lipids in cestodes. (After Frayha Smyth, 1983.)...

Two forms of ACP have been purified from spinach and barley leaf, but, only one ACP Isoform predominates In spinach seed tissue (2, 3). Oleic acid Is the major product of fatty acid synthesis by Isolated chloroplasts (4). The regulation of plant lipid metabolism Is believed to Involve the export of oleic acid from Its site of synthesis (plastld) to sites of complex lipid metabolism (eg. ER). This pathway requires the Initial release of oleic acid from ACP by oleoyl-ACP thloesterase (5). In addition, the oleoyl moiety may also enter glycerollpld synthesis within the plastld through the action of acyl-ACP acyl-transferase (6). The preferred substrate for both the thloesterase and glycerol—3-phosphate acyl transferase reactions Is 18 1-ACP (6,7). 

---