2,2,4,4-Tetraethyl-3-hydroxy-1,5-dimethylimidazolidine

• 分子结构分类: 有机化合物 - 有机杂环化合物 - 唑烷类
• 英文名称: 2,2,4,4-Tetraethyl-3-hydroxy-1,5-dimethylimidazolidine
• 英文别名: 2,2,4,4-tetraethyl-3-hydroxy-1,5-dimethylimidazolidine
• 化学式: C₁₃H₂₈N₂O
• 分子量: 228.378
• InChiKey: MHCLRQFXCLKYAH-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  3.5
• 重原子数：
  16
• 可旋转键数：
  4
• 环数：
  1.0
• sp3杂化的碳原子比例：
  1.0
• 拓扑面积：
  26.7
• 氢给体数：
  1
• 氢受体数：
  3

反应信息

• 作为反应物：
  描述：

  2,2,4,4-Tetraethyl-3-hydroxy-1,5-dimethylimidazolidine 在 manganese(IV) oxide 作用下， 生成 3,4-dimethyl-2,2,5,5-tetraethylperhydroimidazol-1-yloxy
  参考文献：
  名称：

  Room-temperature electron spin relaxation of nitroxides immobilized in trehalose: Effect of substituents adjacent to NO-group

  摘要：

  Trehalose has been recently promoted as efficient immobilizer of biomolecules for room-temperature EPR studies, including distance measurements between attached nitroxide spin labels. Generally, the structure of nitroxide influences the electron spin relaxation times, being crucial parameters for room-temperature pulse EPR measurements. Therefore, in this work we investigated a series of nitroxides with different substituents adjacent to NO-moiety including spirocyclohexane, spirocyclopentane, tetraethyl and tetramethyl groups. Electron spin relaxation times (T-1, T-m) of these radicals immobilized in trehalose were measured at room temperature at X- and Q-bands (9/34 GHz). In addition, a comparison was made with the corresponding relaxation times in nitroxide-labeled DNA immobilized in trehalose. In all cases phase memory times T-m, were close to 700 ns and did not essentially depend on structure of substituents. Comparison of temperature dependences of T-m at T = 80-300 K shows that the benefit of spirocyclohexane substituents well-known at medium temperatures (similar to 100-180 K) becomes negligible at 300 K. Therefore, unless there are specific interactions between spin labels and biomolecules, the room temperature value of T-m in trehalose is weakly dependent on the structure of substituents adjacent to NO-moiety of nitroxide. The issues of specific interactions and stability of nitroxide labels in biological media might be more important for room temperature pulsed dipolar EPR than differences in intrinsic spin relaxation of radicals. (C) 2016 Elsevier Inc. All rights reserved.

  DOI：

  10.1016/j.jmr.2016.02.014
• 作为产物：
  描述：

  3,4-dimethyl-2,2,5,5-tetraethylperhydroimidazol-1-yloxy 在 维生素 C 作用下， 以 aq. phosphate buffer 为溶剂， 反应 2.0h， 生成 2,2,4,4-Tetraethyl-3-hydroxy-1,5-dimethylimidazolidine
  参考文献：
  名称：

  Sterically shielded spin labels for in-cell EPR spectroscopy: Analysis of stability in reducing environment

  摘要：

  Electron paramagnetic resonance (EPR) spectroscopy is a powerful and widely used technique for studying structure and dynamics of biomolecules under bio-orthogonal conditions. In-cell EPR is an emerging area in this field; however, it is hampered by the reducing environment present in cells, which reduces most nitroxide spin labels to their corresponding diamagnetic N-hydroxyl derivatives. To determine which radicals are best suited for in-cell EPR studies, we systematically studied the effects of substitution on radical stability using five different classes of radicals, specifically piperidine-, imidazolidine-, pyrrolidine-, and isoindoline-based nitroxides as well as the Finland trityl radical. Thermodynamic parameters of nitroxide reduction were determined by cyclic voltammetry; the rate of reduction in the presence of ascorbate, cellular extracts, and after injection into oocytes was measured by continuous-wave EPR spectroscopy. Our study revealed that tetraethyl-substituted nitroxides are good candidates for in-cell EPR studies, in particular pyrrolidine derivatives, which are slightly more stable than the trityl radical.

  DOI：

  10.3109/10715762.2014.979409

文献信息

• Sterically shielded spin labels for in-cell EPR spectroscopy: Analysis of stability in reducing environment
  作者：A. P. Jagtap、I. Krstic、N. C. Kunjir、R. Hänsel、T. F. Prisner、S. Th. Sigurdsson

  DOI：10.3109/10715762.2014.979409

  日期：2015.1.2

  Electron paramagnetic resonance (EPR) spectroscopy is a powerful and widely used technique for studying structure and dynamics of biomolecules under bio-orthogonal conditions. In-cell EPR is an emerging area in this field; however, it is hampered by the reducing environment present in cells, which reduces most nitroxide spin labels to their corresponding diamagnetic N-hydroxyl derivatives. To determine which radicals are best suited for in-cell EPR studies, we systematically studied the effects of substitution on radical stability using five different classes of radicals, specifically piperidine-, imidazolidine-, pyrrolidine-, and isoindoline-based nitroxides as well as the Finland trityl radical. Thermodynamic parameters of nitroxide reduction were determined by cyclic voltammetry; the rate of reduction in the presence of ascorbate, cellular extracts, and after injection into oocytes was measured by continuous-wave EPR spectroscopy. Our study revealed that tetraethyl-substituted nitroxides are good candidates for in-cell EPR studies, in particular pyrrolidine derivatives, which are slightly more stable than the trityl radical.
• Room-temperature electron spin relaxation of nitroxides immobilized in trehalose: Effect of substituents adjacent to NO-group
  作者：Andrey A. Kuzhelev、Rodion K. Strizhakov、Olesya A. Krumkacheva、Yuliya F. Polienko、Denis A. Morozov、Georgiy Yu. Shevelev、Dmitrii V. Pyshnyi、Igor A. Kirilyuk、Matvey V. Fedin、Elena G. Bagryanskaya

  DOI：10.1016/j.jmr.2016.02.014

  日期：2016.5

  Trehalose has been recently promoted as efficient immobilizer of biomolecules for room-temperature EPR studies, including distance measurements between attached nitroxide spin labels. Generally, the structure of nitroxide influences the electron spin relaxation times, being crucial parameters for room-temperature pulse EPR measurements. Therefore, in this work we investigated a series of nitroxides with different substituents adjacent to NO-moiety including spirocyclohexane, spirocyclopentane, tetraethyl and tetramethyl groups. Electron spin relaxation times (T-1, T-m) of these radicals immobilized in trehalose were measured at room temperature at X- and Q-bands (9/34 GHz). In addition, a comparison was made with the corresponding relaxation times in nitroxide-labeled DNA immobilized in trehalose. In all cases phase memory times T-m, were close to 700 ns and did not essentially depend on structure of substituents. Comparison of temperature dependences of T-m at T = 80-300 K shows that the benefit of spirocyclohexane substituents well-known at medium temperatures (similar to 100-180 K) becomes negligible at 300 K. Therefore, unless there are specific interactions between spin labels and biomolecules, the room temperature value of T-m in trehalose is weakly dependent on the structure of substituents adjacent to NO-moiety of nitroxide. The issues of specific interactions and stability of nitroxide labels in biological media might be more important for room temperature pulsed dipolar EPR than differences in intrinsic spin relaxation of radicals. (C) 2016 Elsevier Inc. All rights reserved.