Chemical Behavior of Coenzyme PQQ toward Aminoguanidine: Redox Reaction and Adduct Formation
作者:Minae Mure、Kazumi Nii、Shinobu Itoh、Yoshiki Ohshiro
DOI:10.1246/bcsj.63.417
日期:1990.2
The reaction of coenzyme PQQ with aminoguanidine, which is known as an inhibitor of quinoprotein amine oxidases, was investigated in vitro. The redox reaction predominantly proceeded at pH 10.0 to give PQQH2 (quinol), whereas deactivation of PQQ occurred at pH 6.7 to give the triazine adduct. In the case of semicarbazide or acetohydrazide as the substrate, azo adduct formation was mainly observed even at pH 10.0. Importance of the C-5 carbinolamine-type intermediate a is discussed.
在体外研究了辅酶 PQQ 与氨基胍(醌蛋白胺氧化酶抑制剂)的反应。氧化还原反应主要在 pH 10.0 下进行,生成 PQQH2(对苯二酚),而 PQQ 的失活在 pH 6.7 下发生,生成三嗪加合物。在氨基脲或乙酰肼作为底物的情况下,即使在pH 10.0下也主要观察到偶氮加合物的形成。讨论了 C-5 甲醇胺型中间体 a 的重要性。