Formation of a diimino-imidazole nucleoside from 2′-deoxyguanosine by singlet oxygen generated by methylene blue photooxidation
作者:Toshinori Suzuki、Marlin D Friesen、Hiroshi Ohshima
DOI:10.1016/s0968-0896(03)00124-x
日期:2003.5
compound, which we recently isolated and characterised from the reaction mixture of 2'-deoxyguanosine with reagent HOCl and a myeloperoxidase-H(2)O(2)-Cl(-) system. The yield of dD was increased by D(2)O and decreased by azide. dD was not generated from 8-oxo-7,8-dihydro-2'-deoxyguanosine. These results indicate that dD is generated by (1)O(2) directly from 2'-deoxyguanosine, but not via 8-oxo-7,8-dihydro-2'-deoxyguanosine
单线态氧((1)O(2))能够诱导遗传毒性,致癌和诱变作用。以前有报道说(1)O(2)与2'-脱氧鸟苷的反应是DNA成分中(1)O(2)的主要靶标,导致形成多种氧化产物,包括8- oxo-7,8-dihydro-2'-deoxyguanosine和spiroiminodihydantoin,氨基咪唑酮和二氨基恶唑酮核苷。除了这些产品之外,我们还报告了一种新型的二亚氨基咪唑核苷,2,5-二亚氨基-4-[(2-脱氧-β-D-赤型戊呋喃糖基)氨基] -2H,5H-咪唑(dD), 2'-脱氧鸟苷与(1)O(2)的反应是通过在有氧条件下在亚甲基蓝存在下用可见光照射而产生的。它的鉴定是基于与真实化合物相同的色谱和光谱数据,我们最近从2'-脱氧鸟苷与试剂HOCl和髓过氧化物酶-H(2)O(2)-Cl(-)的反应混合物中进行了分离和表征系统。dD的产率由D(2)O增加,而叠氮化物则降低。dD不是由8-oxo-7