Bioactivation of 6,7-Dimethyl-2,4-di-1-pyrrolidinyl-7<i>H</i>-pyrrolo[2,3-<i>d</i>]pyrimidine (U-89843) to Reactive Intermediates That Bind Covalently to Macromolecules and Produce Genotoxicity<sup>1</sup>
作者:Zhiyang Zhao、Kenneth A. Koeplinger、Guy E. Padbury、Michael J. Hauer、Gordon L. Bundy、Lee S. Banitt、Theresa M. Schwartz、David C. Zimmermann、Philip R. Harbach、Judy K. Mayo、C. Sidney Aaron
DOI:10.1021/tx960092z
日期:1996.1.1
U-89843 is a novel pyrrolo[2,3-d]pyrimidine antioxidant with prophylactic activity in animal models of lung inflammation. During preclinical safety evaluation, U-89843 was found to give a positive response in the in vitro unscheduled DNA synthesis (UDS) assay, an assay which measures DNA repair following chemically-induced DNA damage in metabolically competent rat hepatocytes. Incubation of [14C]U-89843
U-89843是一种新型的吡咯并[2,3-d]嘧啶类抗氧化剂,在肺部炎症的动物模型中具有预防作用。在临床前安全性评估过程中,发现U-89843在体外非计划DNA合成(UDS)分析中给出了阳性反应,该分析可测量代谢性大鼠肝细胞中化学诱导的DNA损伤后的DNA修复。[14C] U-89843与肝微粒体的孵育导致放射性物质通过NADPH依赖性过程与大分子共价结合。已经显示,在由细胞色素P450 2C11催化的反应中,U-89843在大鼠体内和体外均经过C-6甲基羟基化作用,生成U-97924。合成的U-97924具有化学反应性,在水溶液中会发生二聚作用。通过添加亲核试剂(例如甲醇,谷胱甘肽和N-乙酰基半胱氨酸)可显着抑制U-97924的二聚化。U-97924的相应甲醇,谷胱甘肽和N-乙酰半胱氨酸加合物的表征支持了涉及通过U-97924脱水形成的反应性亚胺类物质的反应途径的假说。在存在还原型谷胱甘