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Lipid peroxidation
Lipid peroxidation, or lipid oxidation, is a complex chemical process that leads to oxidative degradation of lipids, resulting in the formation of peroxide and hydroperoxide derivatives. It occurs when free radicals, specifically reactive oxygen species (ROS), interact with lipids within cell membranes, typically polyunsaturated fatty acids (PUFAs) as they have carbon–carbon double bonds. This reaction leads to the formation of lipid radicals, collectively referred to as lipid peroxides or lipid oxidation products (LOPs), which in turn react with other oxidizing agents, leading to a chain reaction that results in oxidative stress and cell damage.
In pathology and medicine, lipid peroxidation plays a role in cell damage which has broadly been implicated in the pathogenesis of various diseases and disease states, including ageing, whereas in food science lipid peroxidation is one of many pathways to rancidity.
The chemical reaction of lipid peroxidation consists of three phases: initiation, propagation, and termination.
In the initiation phase, a pro-oxidant hydroxyl radical (OH•) abstracts the hydrogen at the allylic position (–CH2–CH=CH2) or methine bridge (=CH−)[clarification needed] on the stable lipid substrate, typically a polyunsaturated fatty acid (PUFA), to form the lipid radical (L•) and water (H2O).
In the propagation phase, the lipid radical (L•) reacts with molecular oxygen (O2) to form a lipid hydroperoxyl radical (LOO•). The lipid hydroperoxyl radical (LOO•) can further abstract hydrogen from a new PUFA substrate, forming another lipid radical (L•) and now finally a lipid hydroperoxide (LOOH).
The lipid hydroperoxyl radical (LOO•) can also undergo a variety of reactions to produce new radicals.[citation needed]
The additional lipid radical (L•) continues the chain reaction, whilst the lipid hydroperoxide (LOOH) is the primary end product. The formation of lipid radicals is sensitive to the kinetic isotope effect. Reinforced lipids in the membrane can suppress the chain reaction of lipid peroxidation.
The termination step can vary, in both its actual chemical reaction and when it will occur. Lipid peroxidation is a self-propagating chain reaction and will proceed until the lipid substrate is consumed and the last two remaining radicals combine, or a reaction which terminates it occurs. Termination can occur when two lipid hydroperoxyl radicals (LOO•) react to form peroxide and oxygen (O2).[clarification needed] Termination can also occur when the concentration of radical species is high.[citation needed]
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Lipid peroxidation AI simulator
(@Lipid peroxidation_simulator)
Lipid peroxidation
Lipid peroxidation, or lipid oxidation, is a complex chemical process that leads to oxidative degradation of lipids, resulting in the formation of peroxide and hydroperoxide derivatives. It occurs when free radicals, specifically reactive oxygen species (ROS), interact with lipids within cell membranes, typically polyunsaturated fatty acids (PUFAs) as they have carbon–carbon double bonds. This reaction leads to the formation of lipid radicals, collectively referred to as lipid peroxides or lipid oxidation products (LOPs), which in turn react with other oxidizing agents, leading to a chain reaction that results in oxidative stress and cell damage.
In pathology and medicine, lipid peroxidation plays a role in cell damage which has broadly been implicated in the pathogenesis of various diseases and disease states, including ageing, whereas in food science lipid peroxidation is one of many pathways to rancidity.
The chemical reaction of lipid peroxidation consists of three phases: initiation, propagation, and termination.
In the initiation phase, a pro-oxidant hydroxyl radical (OH•) abstracts the hydrogen at the allylic position (–CH2–CH=CH2) or methine bridge (=CH−)[clarification needed] on the stable lipid substrate, typically a polyunsaturated fatty acid (PUFA), to form the lipid radical (L•) and water (H2O).
In the propagation phase, the lipid radical (L•) reacts with molecular oxygen (O2) to form a lipid hydroperoxyl radical (LOO•). The lipid hydroperoxyl radical (LOO•) can further abstract hydrogen from a new PUFA substrate, forming another lipid radical (L•) and now finally a lipid hydroperoxide (LOOH).
The lipid hydroperoxyl radical (LOO•) can also undergo a variety of reactions to produce new radicals.[citation needed]
The additional lipid radical (L•) continues the chain reaction, whilst the lipid hydroperoxide (LOOH) is the primary end product. The formation of lipid radicals is sensitive to the kinetic isotope effect. Reinforced lipids in the membrane can suppress the chain reaction of lipid peroxidation.
The termination step can vary, in both its actual chemical reaction and when it will occur. Lipid peroxidation is a self-propagating chain reaction and will proceed until the lipid substrate is consumed and the last two remaining radicals combine, or a reaction which terminates it occurs. Termination can occur when two lipid hydroperoxyl radicals (LOO•) react to form peroxide and oxygen (O2).[clarification needed] Termination can also occur when the concentration of radical species is high.[citation needed]