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Biologically relevant metal ion‐dependent hydroxyl radical generation An update
Author(s) -
Halliwell Barry,
Gutteridge John M.C.
Publication year - 1992
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(92)80911-y
Subject(s) - chemistry , hydroxyl radical , radical , hydroxylation , oxidizing agent , reactivity (psychology) , spin trapping , photochemistry , oxidative phosphorylation , metal , organic chemistry , biochemistry , enzyme , medicine , alternative medicine , pathology
Transition metal ions, especially iron, appear to be important mediators of oxidative damage in vivo. Iron(II) reacts with H 2 O 2 to give more‐reactive radicals. On the basis of ESR spin‐trapping data with DMPO, supported by aromatic hydroxylation studies and patterns of DNA base modification, it is concluded that hydroxyl radical (OH • ) is likely to be the major damaging species formed in Fenton Systems under biologically‐relevant conditions (which include iron concentrations no higher than the micromolar range). Although reactive oxo‐iron species (such as ferryl and perferryl) may also be important, chemical evidence for their formation and identity in biologically relevant Fenton systems is currently lacking. Studies at alkaline pH values show that iron(IV) and iron(V) species are highly oxidizing under those reaction conditions, with a pattern of reactivity different from that of OH • .