Polyunsaturated fatty secondary products

The high concentration of polyunsaturated fatty acids in cellular and subcellular membranes makes them particularly susceptible to free radical damage. In addition, mitochondrial membranes contain flavins as a part of their basic structure, potentially contributing C>2 resulting in free radical damage. The process of uncontrolled lipid peroxidation can result in the loss of essential polyunsaturated fatty acids, and the formation of toxic hydroperoxides and other secondary products. The loss of essential fatty acids may then result in loss of membrane integrity and loss of function. Extensive oxidation can also lead to rupture of... 

Additionally, key secondary oxidation products contribute distinctive aromas characteristic to certain fish species. In salmon, co-oxldatlon of polyunsaturated fatty acids of fish oils with salmon-specific carotenoid pigments leads to the formation of a characterizing cooked salmon flavor compound, and changes the ratio of carbonyl compounds formed compared to that for pure fish oil. 

Abstract. The significance of free radical oxidation of phospholipids in tissues of animals with experimental atherosclerosis was investigated. By using modem physico-chemical methods an elevated content of polyunsaturated fatty acids and other lipids peroxides was discovered in the blood and the aorta of rabbits with experimental atheromatosis. The human blood demonstrated a low level of protective enzymatic systems and a high content of products secondary to peroxidal oxidation of the lipids. The mechanism accounting for the action of lipids peroxides on the vascular wall resulting in the formation of atheromatous plaques is considered. 

Central among the toxic responses to oxidative stress is the induction of apop-totic death (Curtin et al, 2002 Fleury et al, 2002 Polster and Fkskum, 2004 Ryter et al, 2007). While it is clear that it can be an initiator as well as a signaling event within the apoptotic process, the specific mechanisms underlying these remain uncertain. Likely, these responses could be related to the damage of cellular components e.g. DNA, lipids, and polysaccharides. One potential pathway by which ethanol-mediated oxidative stress may elicit apoptosis of neurons is associated with the oxidation of polyunsaturated fatty acids within mitochondria (Ramachandran et al, 2001, 2003). Among the variety of oxidation products of these fatty acids are toxic/pro-apoptotic aldehydes, the most potent being 4-hydrox-ynonenal (Esterbauer et al, 1990 Uchida et al., 1993). This compound readily induces apoptotic death of neurons (Lovell and Markesbery, 2006 Dwivedi et al., 2007) and is produced in neurons secondary to ethanol-related oxidative stress (Ramachandran et al, 2001, 2003)... 

The large number of precursors of volatile decomposition products affecting the flavor of oils has been discussed in Chapter 4. Only qualitative information is available on the relative oxidative stability of hydroperoxides, aldehydes and secondary oxidation products. As observed with the unsaturated fatty ester precursors, the stability of hydroperoxides and unsaturated aldehydes decreases with higher unsaturation. Different hydroperoxides of unsaturated lipids, acting as precursors of volatile flavor compounds, decompose at different temperatures. Hydroperoxides of linolenate and long-chain n-3 PUFA decompose more readily and at lower temperatures than hydroperoxides of linoleate and oleate. Similarly, the alkadienals are less stable than alkenals, which in turn are less stable than alkanals. The short-chain fatty acids produced by oxidation of unsaturated aldehydes will further decrease the oxidative stability of polyunsaturated oils. For secondary products, dimers are less stable than dihydroperoxides, which are less stable than cyclic peroxides. 

Algae Industrially used for single cell algae (Chlorella), -carotene (Dunaliella), or polyunsaturated fatty acids (PUFAs). Chlorella is another genus used as health food. Chlorella is a preferred algal expression host Plant cells Production of the anticancer plant secondary metabolite <75... 

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