Studies on Reaction Mechanism of Carotenoids and Peroxynitrite In Vivo

过氧亚硝酸盐是体内一种强氧化剂，是超氧化物和一氧化氮的反应产物。过氧亚硝酸盐在低密度脂蛋白中可引起DNA链断裂、硝化和羟化的蛋白质修饰以及脂质过氧化。考察了叶黄素、辣椒素和岩藻黄质对过氧亚硝酸根的体外反应活性，并对过亚硝酸根清除反应产物进行了分析。硝基类胡萝卜素是从这些类胡萝卜素与过氧亚硝酸盐反应中分离出来的。这些类胡萝卜素抑制过亚硝酸根对酪氨酸的硝化作用。

Peroxynitrite, the reaction product of superoxide and nitric oxide, is a powerful oxidant in vivo. Peroxynitrite is known to induce DNA strand scission, protein modification by nitration and hydroxylation and lipid peroxydation in LDL. The in vitro reactivity of lutein, capsanthin and fucoxanthin toward peroxynitrite was investigated, and the reaction products produced by scavenging with peroxynitrite were analyzed. Nitro-carotenoids were isolated from the reaction of these carotenoids with peroxynitrite. These carotenoids inhibited the nitoration of tyrosin by peroxynitrite.