peroxidaci

Peroxidation refers to chemical processes in which peroxides and peroxyl radicals drive oxidation of substrates. In organic chemistry, peroxidation often involves hydroperoxide intermediates that generate reactive species and lead to further oxidation products such as alcohols, aldehydes, or ketones. In biochemistry, the term lipid peroxidation is commonly used to describe the oxidative degradation of polyunsaturated fatty acids within cell membranes, initiated by reactive oxygen species and propagated by radical chain reactions that produce lipid hydroperoxides and secondary reactive aldehydes.

The mechanism of peroxidation typically follows initiation, propagation, and termination steps. A radical abstracts a hydrogen or a peroxide homolytically cleaves to form radicals; peroxyl radicals then react with adjacent lipids to form new lipid radicals and hydroperoxides, sustaining a chain reaction. Lipid peroxidation can compromise membrane integrity and fluidity and yields reactive aldehydes such as malondialdehyde (MDA) and 4-hydroxynonenal (4-HNE), which can modify proteins and nucleic acids.

Biological systems counter peroxidation with antioxidants and enzymes, including glutathione peroxidase, catalase, and superoxide dismutase, as well as non-enzymatic defenses such as vitamins E and C and glutathione. Measuring lipid peroxidation products or peroxide values is common in studies of aging, disease, and food spoilage. In industry, peroxidation products, including hydroperoxides, serve as intermediates in polymerization and other syntheses; however, uncontrolled peroxidation poses safety risks, particularly with organic peroxides. Proper storage and handling are essential to prevent hazardous decomposition.