Pannala A S, Razaq R, Halliwell B, Singh S, Rice-Evans C A
International Antioxidant Research Centre, Department of Pharmacy, King's College, University of London, Chelsea, UK.
Free Radic Biol Med. 1998 Mar 1;24(4):594-606. doi: 10.1016/s0891-5849(97)00321-3.
Peroxynitrite is a cytotoxic species generated by the reaction between superoxide and nitric oxide. In this study the ability of hydroxycinnamate antioxidants to decrease peroxynitrite-mediated nitration of tyrosine was investigated. The results obtained show that all compounds were able to inhibit nitration of tyrosine. The potency of inhibitory activity was in the order; caffeic acid > or = chlorogenic acid > or = ferulic acid > p-coumaric acid > ocoumaric acid > m-coumaric acid. Trolox, which was included in the study for comparative purposes, had an activity between that of ferulic acid and p-coumaric acid. The data obtained suggest that hydroxycinnamates can act by one of two possible mechanisms: preferential nitration for monophenolates and electron donation by catecholates.
过氧亚硝酸根是超氧化物和一氧化氮反应生成的一种细胞毒性物质。在本研究中，对羟基肉桂酸类抗氧化剂减少过氧亚硝酸根介导的酪氨酸硝化作用的能力进行了研究。所得结果表明，所有化合物均能抑制酪氨酸的硝化作用。抑制活性的效力顺序为：咖啡酸≥绿原酸≥阿魏酸＞对香豆酸＞邻香豆酸＞间香豆酸。为作比较而纳入研究的Trolox，其活性介于阿魏酸和对香豆酸之间。所获数据表明，羟基肉桂酸类可通过两种可能的机制之一发挥作用：单酚盐的优先硝化作用和儿茶酚盐的电子供体作用。
