6-Amino-3-Pyridinols: Towards Diffusion-Controlled Chain-Breaking Antioxidants

摘要

Peroxyl radicals (LOO~·) are the chain-propagating species in the rate-determining step of lipid peroxidation [Eq.(1)]. LOO~·+L-H→~(k_p)LOOH + L~· (1) Chain-breaking antioxidants, most commonly substituted phenols (ArOH) such as 1-3, inhibit peroxidation by transferring their phenolic H atom to the propagating radical [Eq. (2)] at a rate (k_(inh)[ArOH]) faster than that of chain LOO~· + ArOH→~(k_mb) LOOH + ArO~· (2) propagation (k_p[L-H]). The best-known example of a phenolic antioxidant is α-tocopherol (α-TOH, 2), the most potent form of vitamin E, nature's primary defense against radical chain oxidation. recently, considerable effort has been devoted to the development of peroxyl-radical-trapping antioxidants more effective than α-TOH, since the peroxidation of lipids in vivo has been suggested to be a major factor in the development of several degenerative diseases.