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The free radical theory of aging states that organisms age because cells accumulate free radical damage over time. [1] A free radical is any atom or molecule that has a single unpaired electron in an outer shell. [2] While a few free radicals such as melanin are not chemically reactive, most biologically relevant free radicals are highly ...
Mechanistic evidence was provided by Denham Harman's free radical theory of aging, created in the 1950s. This theory stated that organisms age over time due to the accumulation of damage from free radicals in the body. [4] It also showed that metabolic processes, specifically the mitochondria, are prominent producers of free radicals. [4]
[10] [13] [14] Upon the exposure to light, the aroma 3-methyl-2,4-nonanedione (MND) is formed from furan fatty acids in the reaction with singlet oxygen, which has a hay-like odor and is found, for example, in green tea. [15] [16] Furan fatty acids act as radical scavengers. In the example, two hydroxyl radicals are trapped to form a dioxoenoic ...
For example, Tokunagayusurika akamusi is a species of midge fly whose larvae live as obligate scavengers at the bottom of lakes and whose adults almost never feed and only live up to a few weeks. Most scavenging animals are facultative scavengers that gain most of their food through other methods, especially predation.
Free radical toxicity induced by xenobiotics and the subsequent detoxification by cellular enzymes (termination). Effects of ROS on cell metabolism are well documented in a variety of species. [ 19 ] These include not only roles in apoptosis (programmed cell death) but also positive effects such as the induction of host defence [ 36 ] [ 37 ...
The mitochondrial theory of ageing has two varieties: free radical and non-free radical. The first is one of the variants of the free radical theory of ageing. It was formulated by J. Miquel and colleagues in 1980 [1] and was developed in the works of Linnane and coworkers (1989). [2] The second was proposed by A. N. Lobachev in 1978. [3]
Galvinoxyl is a commercially available radical scavenger. [1] It finds use both as a probe for studying radical reactions and as an inhibitor of radical polymerization.It may be synthesized by oxidation of the parent phenol with lead dioxide or potassium hexacyanoferrate(III).
Pentaerythritol tetrakis(3,5-di-tert-butyl-4-hydroxyhydrocinnamate): A primary antioxidant consisting of sterically hindered phenols with para-propionate groups. Primary antioxidants (also known as chain-breaking antioxidants) act as radical scavengers and remove peroxy radicals (ROO•), as well as to a lesser extent alkoxy radicals (RO•), hydroxyl radicals (HO•) and alkyl radicals (R•).