H-1, C-13 and N-15 nuclear magnetic resonance analysis and chemical features of the two main radical oxidation products of 2'-deoxyguanosine: Oxazolone and imidazolone nucleosides
H-1, C-13 and N-15 nuclear magnetic resonance analysis and chemical features of the two main radical oxidation products of 2'-deoxyguanosine: Oxazolone and imidazolone nucleosides
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DOI：
10.1039/p29960000371
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发表时间：
1996-03-01
期刊：
影响因子：
--
通讯作者：
Cadet, J
中科院分区：
文献类型：
--
作者：
Raoul, S;Berger, M;Cadet, J
两个初级单电子氧化和(OH)- o -。-介导的2'-脱氧鸟苷1的分解产物是2,2-二氨基-4-[（2-脱氧- β -d -红-戊呋喃基）氨基]-2,5-二氢恶唑-5-酮3 （dZ）及其前体2-氨基-5-[（2-脱氧- β -d -红-戊呋喃基）氨基]- 4h -咪唑-4-酮2 （dIz）。本文用快原子轰击质谱法、紫外光谱法、红外光谱法以及H-1、C-13、N-15和O-17的一维和二维核磁共振谱法测定了dz3和diz2的结构。在中性水溶液中，加入一分子水，diz2水解为dz3 （t(1/2) = 147 min，温度37℃）。热碱（65℃，pH 13）处理diz2和dz3定量释放胍(t(1/2) = 3.3和3.1 min；后一种性质使我们能够建立一种特异性和敏感性的方法来检测两种修饰的核苷2和3。甲氧基胺与3',5'-二- o-乙酰基- dz 2a定量反应速度比与3',5'-二- o-乙酰基- dz 3a快速120倍，形成4个3,5-二- o-乙酰基-2-脱氧-d -红-戊糖-甲氧基胺异构体。
The two primary one-electron oxidation and (OH)-O-.-mediated decomposition products of 2'-deoxy-guanosine 1 are 2,2-diamino-4-[(2-deoxy-beta-D-erythro-pentofuranosyl)amino]-2,5-dihydrooxazol-5-one 3 (dZ) and its precursor, 2-amino-5-[(2-deoxy-beta-D-erythro-pentofuranosyl)amino]-4H-imidazol-4-one 2 (dIz). Here, we describe in detail the spectroscopic and chemical properties of both oxidative DNA lesions, The structures for dZ 3 and dIz 2 were determined by fast-atom bombardment mass spectrometry, UV spectroscopy, IR spectroscopy, together with H-1, C-13, N-15 and O-17 1D and 2D NMR spectroscopy. In neutral aqueous solution dIz 2 is hydrolysed to dZ 3 (t(1/2) = 147 min at 37 degrees C) with the incorporation of one molecule of water. Hot alkali treatment (65 degrees C; pH 13) of dIz 2 and dZ 3 quantitatively results in the release of guanidine (t(1/2) = 3.3 and 3,1 min; respectively), The latter property allowed us to develop a specific and sensitive method for the detection of the two modified nucleosides 2 and 3, Methoxyamine reacts quantitatively with 3',5'-di-O-acetyl-dIz 2a 120-times faster than with 3',5'-di-O-acetyl-dZ 3a to form four 3,5-di-O-acetyl-2-deoxy-D-erythro-pentose-methoxyamine isomers.