(2,5-Dioxoimidazolidin-4-ylidene)aminocarbonylcarbamic Acid as a Precursor of Parabanic Acid, the Singlet Oxygen-Specific Oxidation Product of Uric Acid
作者:Sayaka Iida、Yorihiro Yamamoto、Akio Fujisawa
DOI:10.1021/acs.joc.9b00163
日期:2019.3.15
we identified that parabanic acid (PA) and its hydrolysate, oxaluric acid (OUA), are the singlet oxygen-specific oxidation products of uric acid (UA). In this study, we investigated the PA formation mechanism by using HPLC and a time-of-flight mass spectrometry technique and identified unknown intermediates as (2,5-dioxoimidazolidin-4-ylidene)aminocarbonylcarbamic acid (DIAA), dehydroallantoin, and
先前,我们确定了对羟基苯甲酸(PA)及其水解产物草酸(OUA)是尿酸(UA)的单线态氧特异性氧化产物。在这项研究中,我们通过使用HPLC和飞行时间质谱技术研究了PA的形成机理,并鉴定了未知的中间体,如(2,5-dioxoimidazolidin-4-ylidene)氨基羰基氨基甲酸(DIAA),脱氢丙氨酸和4-羟丙氨酸(4-HAL)。DIAA是生产PA的关键,它的形成途径使用18 O 2和H 2 18来表征。O.已确认将两个氧原子结合到DIAA中:来自单重态氧的5-氧合氧和来自水的羧酸氧。分离出的DIAA和4-HAL以化学计量获得PA。提出了一个可行的反应方案,其中有两条途径从DIAA分支出来,并讨论了PA作为生物形成单线态氧的内源性探针的潜力。