5-Carboxamido-5-formamido-2-iminohydantoin, in Addition to 8-oxo-7,8-Dihydroguanine, Is the Major Product of the Iron-Fenton or X-ray Radiation-Induced Oxidation of Guanine under Aerobic Reducing Conditions in Nucleoside and DNA Contexts
作者:Omar R. Alshykhly、Aaron M. Fleming、Cynthia J. Burrows
DOI:10.1021/acs.joc.5b00689
日期:2015.7.17
ine (cyclo-dG), and the free base guanine (Gua). Reactions conducted with ascorbate or N-acetylcysteine as a reductant under aerobic conditions identified d2Ih as the major lesion formed. Studies were conducted to identify the role of O2 and the reductant in product formation. From these studies, mechanisms are proposed to support d2Ih as a major oxidation product detected under aerobic conditions
外源性和内源性产生的活性氧会攻击DNA的碱基和糖部分,显示对2'-脱氧鸟苷(dG)位点反应的偏好。在目前的工作中,dG被HO •通过Fe(II)-Fenton反应或X射线水分解而被氧化。中观察到的氧化的损害包括-8-氧代-7,8- dihydroguanine(的2'-脱氧核苷的狗),spiroiminodihydantoin(DSP),5- guanidinohydantoin(DGH),恶唑酮(DZ),5-甲酰胺基-5-甲酰胺基-2- -亚氨基乙内酰脲(d2Ih),5',8-cyclo-2'-脱氧鸟苷(cyclo-dG)和游离碱鸟嘌呤(Gua)。在有氧条件下用抗坏血酸或N-乙酰半胱氨酸作为还原剂进行的反应确定d2Ih为形成的主要病变。进行研究以鉴定O 2和还原剂在产物形成中的作用。从这些研究中,提出了机制以支持d2Ih作为有氧条件下在还原剂存在下检测到的主要氧化产物。然后,这些核苷观察