Walling C, Partch R E, Weil T
Department of Chemistry, University of Utah, Salt Lake City, Utah 84112.
Proc Natl Acad Sci U S A. 1975 Jan;72(1):140-2. doi: 10.1073/pnas.72.1.140.
Added substrates, acetone and t-butyl alcohol, strongly retard the decomposition of H(2)O(2) brought about by ferric ethylenediaminetetraacetate (EDTA) at pH 8-9.5. Their relative effectiveness and the kinetic form of the retardation are consistent with their interruption of a hydroxyl radical chain that is propagated by HO. attack both upon H(2)O(2) and on complexed and uncomplexed EDTA. Similar retardation is observed with decompositions catalyzed by ferric nitrilotriacetate and hemin, and it is proposed that such redox chains may be quite a general path for transition metal ion catalysis of H(2)O(2) decomposition.
添加的底物丙酮和叔丁醇能强烈抑制在pH 8 - 9.5条件下由乙二胺四乙酸铁(EDTA)引发的过氧化氢(H₂O₂)分解。它们的相对效能以及抑制的动力学形式与它们对由羟基自由基(HO·)引发的自由基链的中断相一致,该自由基链通过HO·对H₂O₂以及络合态和未络合态的EDTA的攻击而传播。在用次氮基三乙酸铁和血红素催化的分解反应中也观察到了类似的抑制现象,并且有人提出,这种氧化还原链可能是过渡金属离子催化H₂O₂分解的一种相当普遍的途径。