Uric Acid as a Photosensitizer in the Reaction of Deoxyribonucleosides with UV Light of Wavelength Longer than 300 nm: Identification of Products from 2′-Deoxycytidine
作者:Toshinori Suzuki、Atsuko Ozawa-Tamura、Miyu Takeuchi、Yuriko Sasabe
DOI:10.1248/cpb.c21-00501
日期:2021.11.1
formed by cycloaddition of an amide group from uric acid. A 15N-labeled uric acid, uric acid-1,3-15N2, having two 14N and two 15N atoms per molecule, produced N4,5-cyclic amide-2′-deoxycytidine containing both 14N and 15N atoms from uric acid-1,3-15N2. Singlet oxygen, hydroxyl radical, peroxynitrous acid, hypochlorous acid, and hypobromous acid generated neither N4-hydroxy-2′-deoxycytidine nor N4
DNA 直接与波长短于 300 nm 的紫外线发生反应。尽管地表阳光几乎完全被大气吸收,因此几乎不包含这种短波长紫外线,但阳光是导致皮肤癌的主要原因。因此,内源性物质的光敏性必须参与皮肤癌的发展机制。尿酸是人体嘌呤的最终代谢产物,在细胞和体液中的浓度相对较高。2'-脱氧胞苷、2'-脱氧鸟苷、胸苷和2'-脱氧腺苷的中性混合溶液在尿酸存在下用波长大于300 nm的紫外光照射时,所有的核苷都被消耗掉。酸剂量依赖性方式。这些反应被自由基清除剂的添加所抑制,乙醇和叠氮化钠。2'-脱氧胞苷的两种产物被分离并鉴定为N 4 -羟基-2'-脱氧胞苷和N 4 ,5-环状酰胺-2'-脱氧胞苷,由来自尿酸的酰胺基团环加成形成。甲15 N-标记的尿酸,尿酸-1,3- 15 Ñ 2,具有两个14 N和2个15每分子N原子,产生Ñ 4,5-环含有酰胺-2'-脱氧胞苷14 N和15从尿酸-1,3- N原子15 ñ 2。单