Kono Y, Shibata H, Kodama Y, Sawa Y
Department of Bacteriology, Faculty of Medicine, Tottori University, Japan.
Biochem J. 1995 Dec 15;312 ( Pt 3)(Pt 3):947-53. doi: 10.1042/bj3120947.
N-Nitrosation of a model aromatic amine (2,3-diamino-naphthalene) by the N-nitrosating agent produced by nitrite in acidic solution was inhibited by a polyphenol, chlorogenic acid, which is an ester of caffeic acid quinic acid. Caffeic acid also inhibited the N-nitrosation, but quinic acid did not. 1,2-Benzenediols and 3,4-dihydroxybenzoic acid had inhibitory activities. Chlorogenic acid, caffeic acid, 1,2-benzenediols and 3,4-dihydroxybenzoic acid were able to scavenge the stable free radical, 1,1-diphenyl-2-picrylhydrazyl. Chlorogenic acid was found to be nitrated by acidic nitrite. The kinetic studies and the nitration observed only by bubbling of nitric oxide plus nitrogen dioxide gases indicated that the nitrating agent was nitrogen sesquioxide. The observations showed that the mechanism by which chlorogenic acid inhibited N-nitrosation of 2,3-diamino-naphthalene is due to its ability to scavenge the nitrosating agent, nitrogen sesquioxide. Chlorogenic acid may be effective not only in protecting against oxidative damage but also in inhibiting potentially mutagenic and carcinogenic reactions in vivo.
在酸性溶液中,由亚硝酸盐产生的N-亚硝化剂对模型芳香胺(2,3-二氨基萘)进行的N-亚硝化反应受到一种多酚——绿原酸的抑制,绿原酸是咖啡酸与奎尼酸的酯。咖啡酸也抑制N-亚硝化反应,但奎尼酸没有。1,2-苯二醇和3,4-二羟基苯甲酸具有抑制活性。绿原酸、咖啡酸、1,2-苯二醇和3,4-二羟基苯甲酸能够清除稳定自由基1,1-二苯基-2-苦基肼。发现绿原酸会被酸性亚硝酸盐硝化。动力学研究以及仅通过鼓入一氧化氮加二氧化氮气体观察到的硝化反应表明,硝化剂是三氧化二氮。观察结果表明,绿原酸抑制2,3-二氨基萘的N-亚硝化反应的机制是由于其清除亚硝化剂三氧化二氮的能力。绿原酸可能不仅在预防氧化损伤方面有效,而且在抑制体内潜在的致突变和致癌反应方面也有效。