1(2H)-Pyrimidinyl, 3,4-dihydro-5-methyl-2,4-dioxo- | 63031-49-2

• 分子结构分类: 有机化合物 - 有机杂环化合物 - 二嗪类
• 英文名称: 1(2H)-Pyrimidinyl, 3,4-dihydro-5-methyl-2,4-dioxo-
• 英文别名: 5-methyl-2H-1λ2-pyrimidine-2,4(3H)-dione；thymine-5-yl radical；thymin-1-yl radical
• CAS: 63031-49-2
• 化学式: C₅H₅N₂O₂
• 分子量: 125.107
• InChiKey: BZHBJAKZRBJNMA-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  -0.26
• 重原子数：
  9.0
• 可旋转键数：
  0.0
• 环数：
  1.0
• sp3杂化的碳原子比例：
  0.2
• 拓扑面积：
  60.27
• 氢给体数：
  1.0
• 氢受体数：
  2.0

反应信息

• 作为产物：
  描述：

  胸腺嘧啶 在 过氧化苯甲酰 作用下， 以 水 为溶剂， 生成 1(2H)-Pyrimidinyl, 3,4-dihydro-5-methyl-2,4-dioxo-
  参考文献：
  名称：

  Photochemistry of protein and nucleic acid constituents: electron spin resonance and spin-trapping with 2-methyl-2-nitrosopropane

  摘要：

  我们回顾了最近对脂肪族和芳香族肽、DNA组分及其5-卤衍生物在水溶液中的直接紫外光解以及苯甲酰过氧化物与氨基酸、肽、脂肪酸和嘧啶在含二甲基亚砜的溶液中的光诱导反应的研究。2-甲基-2-亚硝基丙烷被用于自旋捕获和表征在水溶液或无极溶剂中光化学产生的自由基，其光波长范围为220-313 nm。脂肪族二肽和苯丙氨酸肽的直接光解主要产生脱羧自由基，而对酪氨酸肽来说，脱羧和去氨基自由基都被自旋捕获；对色氨酸二肽和三肽来说，主要产生去氨基自由基，而对长链多肽来说，观察到主链断裂。当嘧啶碱基被光解时，与在5,6-双键的C(5)位置加入氢原子或羟基自由基相一致的自由基可以被检测到。在5-氯、溴或碘尿嘧啶的光解中，一般的反应模式是碳-卤键的自由裂解，而对于5-氟尿嘧啶，α-氟自由基被自旋捕获。发现二苯甲酰过氧化物能够在氨基酸、肽和脂肪酸暴露在紫外光下（这些化合物不吸收）时诱导自由基产生，即λ=313±10 nm。最主要的反应是终端酸基的脱羧。这一过程可以通过从酸到光激发的过氧化物或其裂解产物的电子转移来解释。在这些条件下，嘧啶碱基，如胞嘧啶和胸腺嘧啶，可以被氧化以产生C(5)中心自由基。

  DOI：

  10.1139/v82-213

文献信息

• Radiation-induced free-radical formation in thymine derivatives: EPR/ENDOR of anhydrous thymine single crystals x-irradiated at 10 K
  作者：Einar Sagstuen、Eli O. Hole、William H. Nelson、David M. Close

  DOI：10.1021/j100182a019

  日期：1992.2

  Anhydrous single crystals of thymine have been X-irradiated at 10 K and studied using K-band EPR, ENDOR, and FSE spectroscopy. In addition to several radical pairs, five monoradicals were formed and stabilized at this temperature. It is demonstrated that the dominating radical pair species analyzed previously (Bergene, R.; Melo, T. B. Int. J. Radiat. Biol. 1973, 23, 255) consists of two radicals, each formed by net hydrogen abstraction from the methyl group. The five monoradicals were identified to be the O4-protonated thymine anion, the thymine-7-yl radical formed by net hydrogen abstraction from the methyl group, the 6-yl radical formed by net hydrogen addition to C5, the 5-yl radical formed by net hydrogen addition to C6, and the I-yl radical formed by net hydrogen abstraction from NI. Upon thermal annealing, the protonated anion decays before 60 K apparently with no successor, and the 6-yl radical decays slowly by storage at room temperature, most probably by a transformation into the 5-yl radical. Possible mechanisms for the formation of these radicals are discussed. These involve processes initiated by primary ionization followed by charge neutralization by protonation/deprotonation or by geminate recombination leading to the formation of hydrogen atoms by homolytic bond scission from molecules in (super)excited states.