Multi-faceted Reactivity of Alkyltellurophenols Towards Peroxyl Radicals: Catalytic Antioxidant Versus Thiol-Depletion Effect
作者:Riccardo Amorati、Luca Valgimigli、Peter Dinér、Khadijeh Bakhtiari、Mina Saeedi、Lars Engman
DOI:10.1002/chem.201300451
日期:2013.6.3
ortho arrangement. In the presence of thiols, hydroxyaryl alkyl tellurides act as catalytic antioxidants towards both hydroperoxides (mimicking the glutathione peroxidases) and peroxyl radicals. The high efficiency of the quenching of the peroxyl radicals and hydroperoxides could be advantageous under normal cellular conditions, but pro‐oxidative (thiol depletion) when thiol concentrations are low.
羟芳基烷基碲化物在有机溶液和水性双相体系中都是有效的抗氧化剂。他们以非常规的方式与ROO做出反应。在303 K时速率常数高达10 7 M -1 s -1的自由基,性能优于普通酚。反应通过氧原子转移到碲,然后氢原子转移到生成的RO进行。酚羟基的自由基。反应速率不反映环取代基的电子性质,并且由于反应发生在溶剂笼中,因此当OH和TeR基团具有邻位时,淬灭更为有效安排。在硫醇的存在下,羟芳基烷基碲化物作为对氢过氧化物(模仿谷胱甘肽过氧化物酶)和过氧自由基的催化抗氧化剂。在正常的细胞条件下,过氧自由基和氢过氧化物的高效淬灭可能是有利的,但是当硫醇浓度低时,会促进氧化(巯基耗竭)。