2-amino-4-mercaptobutanoate | 52993-49-4

• 分子结构分类: 有机化合物 - 有机酸及其衍生物 - 羧酸及其衍生物
• 英文名称: 2-amino-4-mercaptobutanoate
• 英文别名: 19-homocysteinate；DL-homocysteinate；3-amino-4-hydroxy-4-oxobutane-1-thiolate
• CAS: 52993-49-4
• 化学式: C₄H₈NO₂S
• 分子量: 134.179
• InChiKey: FFFHZYDWPBMWHY-UHFFFAOYSA-M

计算性质

• 辛醇/水分配系数(LogP)：
  -2.1
• 重原子数：
  8
• 可旋转键数：
  2
• 环数：
  0.0
• sp3杂化的碳原子比例：
  0.75
• 拓扑面积：
  67.2
• 氢给体数：
  2
• 氢受体数：
  4

反应信息

• 作为反应物：
  描述：

  2-amino-4-mercaptobutanoate 在 azide radical 作用下， 以 水 为溶剂， 生成
  参考文献：
  名称：

  Kinetics of One-Electron Oxidation of Thiols and Hydrogen Abstraction by Thiyl Radicals from .alpha.-Amino C-H Bonds

  摘要：

  One-electron oxidation of cysteine, homocysteine, and glutathione by azide radical in alkaline solution (pH 10.5), where both the amino and the SH groups are deprotonated, has been investigated by pulse radiolysis. Reducing alpha-aminoalkyl radicals ((.)CR), which are formed via intramolecular rearrangement of thiyl radicals, were detected using methylviologen as oxidant in the kinetic analysis. The general scheme of the reactions is sketched. Thiyl radicals either equilibrate with RSSR(.-) in reaction 5, RS(.) + RS(-) = RSSR(.-), or undergo intramolecular transformation via equilibrium 6, RS(.) = (.)CR. At pH 10.5, equilibrium 6 is completely shifted to the right, resulting in alpha-aminoalkyl radical formation. The rate constants in the reaction scheme for cysteine, homocysteine, and glutathione were measured. With the rate constants obtained, the decay kinetics of RSSR(.-) into (.)CR was simulated, and it agreed with that measured at 420 nm. At pH 10.5, the first-order rate constants for the transformation (k(6)) were determined to be 2.5 x 10(4), 1.8 x 10(5) and 2.2 x 10(5) s(-1) for cysteine, homocysteine, and glutathione, respectively. The rate constants for intermolecular hydrogen abstraction by thiyl radicals from alpha-amino C-H bonds of alanine and glycine were determined at the same pH to be 7.7 x 10(5) and 3.2 x 10(5) M(-1) s(-1), respectively. Thermodynamic estimation places the reduction potential E degrees(H2NC(CO2-)CH3)(.), H+/H2NCH(CO2-)CH3) at ca. 1.22 V, which implies a rather weak tertiary C-H bond in the anion of alpha-amino acids. Thus, an intramolecular hydrogen abstraction mechanism for the transformation of thiyl radical to alpha-amino carbon-centered radical is postulated. Molecular geometry plays an important part in deciding the transformation rates (k(6)) of different thiyl radicals.

  DOI：

  10.1021/ja00105a048
• 作为产物：
  描述：

  L-高胱氨酸 以 水 为溶剂， 生成 、 2-amino-4-mercaptobutanoate
  参考文献：
  名称：

  Kinetics of One-Electron Oxidation of Thiols and Hydrogen Abstraction by Thiyl Radicals from .alpha.-Amino C-H Bonds

  摘要：

  One-electron oxidation of cysteine, homocysteine, and glutathione by azide radical in alkaline solution (pH 10.5), where both the amino and the SH groups are deprotonated, has been investigated by pulse radiolysis. Reducing alpha-aminoalkyl radicals ((.)CR), which are formed via intramolecular rearrangement of thiyl radicals, were detected using methylviologen as oxidant in the kinetic analysis. The general scheme of the reactions is sketched. Thiyl radicals either equilibrate with RSSR(.-) in reaction 5, RS(.) + RS(-) = RSSR(.-), or undergo intramolecular transformation via equilibrium 6, RS(.) = (.)CR. At pH 10.5, equilibrium 6 is completely shifted to the right, resulting in alpha-aminoalkyl radical formation. The rate constants in the reaction scheme for cysteine, homocysteine, and glutathione were measured. With the rate constants obtained, the decay kinetics of RSSR(.-) into (.)CR was simulated, and it agreed with that measured at 420 nm. At pH 10.5, the first-order rate constants for the transformation (k(6)) were determined to be 2.5 x 10(4), 1.8 x 10(5) and 2.2 x 10(5) s(-1) for cysteine, homocysteine, and glutathione, respectively. The rate constants for intermolecular hydrogen abstraction by thiyl radicals from alpha-amino C-H bonds of alanine and glycine were determined at the same pH to be 7.7 x 10(5) and 3.2 x 10(5) M(-1) s(-1), respectively. Thermodynamic estimation places the reduction potential E degrees(H2NC(CO2-)CH3)(.), H+/H2NCH(CO2-)CH3) at ca. 1.22 V, which implies a rather weak tertiary C-H bond in the anion of alpha-amino acids. Thus, an intramolecular hydrogen abstraction mechanism for the transformation of thiyl radical to alpha-amino carbon-centered radical is postulated. Molecular geometry plays an important part in deciding the transformation rates (k(6)) of different thiyl radicals.

  DOI：

  10.1021/ja00105a048

文献信息

• Kinetics of One-Electron Oxidation of Thiols and Hydrogen Abstraction by Thiyl Radicals from .alpha.-Amino C-H Bonds
  作者：Rong Zhao、Johan Lind、Gabor Merenyi、Trygve E. Eriksen

  DOI：10.1021/ja00105a048

  日期：1994.12

  One-electron oxidation of cysteine, homocysteine, and glutathione by azide radical in alkaline solution (pH 10.5), where both the amino and the SH groups are deprotonated, has been investigated by pulse radiolysis. Reducing alpha-aminoalkyl radicals ((.)CR), which are formed via intramolecular rearrangement of thiyl radicals, were detected using methylviologen as oxidant in the kinetic analysis. The general scheme of the reactions is sketched. Thiyl radicals either equilibrate with RSSR(.-) in reaction 5, RS(.) + RS(-) = RSSR(.-), or undergo intramolecular transformation via equilibrium 6, RS(.) = (.)CR. At pH 10.5, equilibrium 6 is completely shifted to the right, resulting in alpha-aminoalkyl radical formation. The rate constants in the reaction scheme for cysteine, homocysteine, and glutathione were measured. With the rate constants obtained, the decay kinetics of RSSR(.-) into (.)CR was simulated, and it agreed with that measured at 420 nm. At pH 10.5, the first-order rate constants for the transformation (k(6)) were determined to be 2.5 x 10(4), 1.8 x 10(5) and 2.2 x 10(5) s(-1) for cysteine, homocysteine, and glutathione, respectively. The rate constants for intermolecular hydrogen abstraction by thiyl radicals from alpha-amino C-H bonds of alanine and glycine were determined at the same pH to be 7.7 x 10(5) and 3.2 x 10(5) M(-1) s(-1), respectively. Thermodynamic estimation places the reduction potential E degrees(H2NC(CO2-)CH3)(.), H+/H2NCH(CO2-)CH3) at ca. 1.22 V, which implies a rather weak tertiary C-H bond in the anion of alpha-amino acids. Thus, an intramolecular hydrogen abstraction mechanism for the transformation of thiyl radical to alpha-amino carbon-centered radical is postulated. Molecular geometry plays an important part in deciding the transformation rates (k(6)) of different thiyl radicals.