Fenton chemistry prevention

Interestingly, Stait and Leake (1994) have reported that while ascorbic acid prevents oxidation of native LDL by macrophages and metal ions, confirming earlier reports (Jialal and Grundy, 1991 Jialal et al, 1990 Retsky et aL, 1993), ascorbic acid exerts a prooxidant effect when added to oxidized LDL incubated with metal ions. The mechanism underlying this effect of ascorbic acid may involve stimulation of lipid peroxidation in LDL via breakdown of preformed lipid hydroperoxides with reduced metal ions, rather than production of hydroxyl radicals by Fenton chemistry (see above). However, stimulation of LDL oxidation by ascorbic acid appears to occur only in extensively oxidized LDL mildly oxidized LDL is protected against further metal ion-dependent oxidation because ascorbic acid completely destroys preformed lipid hydroperoxides (Retsky and Frei, 1995). 

Effect of Methoxylation on the Ability of Desferrithiocin Analogues to Prevent Fenton Chemistry... 

Although both GPx and Cat are very efficient in removing H202, HO can still be formed in abundance (Fenton and Haber-Weiss chemistry). To partially offset the influence of transition metal ions on free radical production, there are numerous metal-binding proteins which prevent these reactions from taking place these include, among others, ferritin, transferrin, ceruloplasmin, and metallotheinein (Table 2). 

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