Engman L, Persson J, Vessman K, Ekström M, Berglund M, Andersson C M
Uppsala University, Department of Organic Chemistry, Sweden.
Free Radic Biol Med. 1995 Oct;19(4):441-52. doi: 10.1016/0891-5849(95)00035-v.
Diaryl tellurides were found efficiently to retard azo-initiated lipid peroxidation of linoleic acid in methanol. The most efficient compounds, 31 and 39, contained one and two hydroxyl groups, respectively, in the para positions and methyl groups in all four positions ortho to tellurium. As determined by the values of n.kinh, these materials were as effective retarders of lipid peroxidation as vitamin E. Contrary to the conventional antioxidants examined, diaryl tellurides were found to inhibit peroxidation for long times, seemingly with an autocatalytic mechanism. Diaryl tellurides were found to be partially oxidized during the peroxidation. The reduction of tellurium (IV) compounds to the divalent state during the conditions of the experiment is discussed. The reactivity of some diaryl chalcogenides toward 2,2-diphenyl-1-picrylhydrazyl (DPPH) in methanol was studied. All compounds investigated were less reactive than vitamin E. One of the most active organotellurium compounds, bis(4-aminophenyl) telluride, reacted considerably faster with DPPH than the corresponding selenide or sulfide. It was concluded that mechanisms involving both hydrogen atom transfer and electron transfer were operative in the reaction of organotellurides with DPPH.
已发现二芳基碲化物能有效抑制甲醇中偶氮引发的亚油酸脂质过氧化反应。最有效的化合物31和39在对位分别含有一个和两个羟基，且在碲的邻位的所有四个位置均含有甲基。根据n.kinh值测定，这些物质作为脂质过氧化反应的抑制剂与维生素E一样有效。与所检测的传统抗氧化剂不同，二芳基碲化物被发现能长时间抑制过氧化反应，似乎具有自催化机制。在过氧化过程中发现二芳基碲化物会部分被氧化。讨论了在实验条件下碲（IV）化合物还原为二价态的情况。研究了一些二芳基硫属元素化物在甲醇中对2,2-二苯基-1-苦基肼（DPPH）的反应活性。所有研究的化合物的反应活性均低于维生素E。最具活性的有机碲化合物之一双（4-氨基苯基）碲与DPPH的反应速度比相应的硒化物或硫化物快得多。得出的结论是，涉及氢原子转移和电子转移的机制在有机碲化物与DPPH的反应中起作用。
