描述了动力学和机理研究,详细研究了由Ferryl络合物[Fe IV(O)(N4Py)] 2+氧化衍生自20种天然氨基酸的底物的过程。在相同条件下,用Ferryl配合物处理通式为Ac-AA-NHtBu的底物([Ac-AA-NHtBu] = 10 mM,[Fe] = 1 mM,1:1 H 2 O / CH 3CN),并获得伪一阶速率常数。由这些数据计算出的相对速率常数说明了反应性最强的五种底物。以降低的反应性顺序是从Cys,Tyr,Trp,Met和Gly衍生的那些。通过在伪一级条件下改变底物浓度来确定这些底物的二级速率常数。衍生自其他天然氨基酸的底物没有表现出显着的反应性,以不到未添加底物的对照反应的速率的十倍的速率加速了ferryl复合物的分解。Ferryl分解速率在D 2 O / CD 3中发生了变化CN用于Cys,Tyr和Trp底物,分别具有4.3、29和5.2的氘动力学同位素效应,与电
Preparation of N-acetyl, tert-butyl amide derivatives of the 20 natural amino acids
摘要:
N-Acetyl-AA(amino acid)-NHtBu derivatives of all 20 naturally occurring amino acids have been synthesized. Syntheses were performed via solution-phase methodology with yields that allow for access to gram quantities of substrates, in most cases. Syntheses include the coupling of a hindered amine, tert-butylamine, with each amino acid, either directly or in two steps using an activated ester isolated as an intermediate. The introduction of protecting groups was necessary in some cases. The development of synthetic sequences to access challenging substrates, such as the one derived from asparagine, are discussed.
Preparation of N-acetyl, tert-butyl amide derivatives of the 20 natural amino acids
作者:A. R. Ekkati、A. A. Campanali、A. I. Abouelatta、M. Shamoun、S. Kalapugama、M. Kelley、Jeremy J. Kodanko
DOI:10.1007/s00726-009-0279-y
日期:2010.3
N-Acetyl-AA(amino acid)-NHtBu derivatives of all 20 naturally occurring amino acids have been synthesized. Syntheses were performed via solution-phase methodology with yields that allow for access to gram quantities of substrates, in most cases. Syntheses include the coupling of a hindered amine, tert-butylamine, with each amino acid, either directly or in two steps using an activated ester isolated as an intermediate. The introduction of protecting groups was necessary in some cases. The development of synthetic sequences to access challenging substrates, such as the one derived from asparagine, are discussed.
Oxidation of the Natural Amino Acids by a Ferryl Complex: Kinetic and Mechanistic Studies with Peptide Model Compounds
作者:Ahmed I. Abouelatta、Ashley A. Campanali、Anil R. Ekkati、Mark Shamoun、Suneth Kalapugama、Jeremy J. Kodanko
DOI:10.1021/ic900527c
日期:2009.8.17
Trp substrates, giving deuteriumkineticisotope effects of 4.3, 29, and 5.2, respectively, consistent with electron-transfer, proton-transfer (Cys and Trp), or hydrogenatomabstraction (Tyr) mechanisms. Decomposition rates for [FeIV(O)(N4Py)]2+ in the presence of the Met and Gly substrates were identical in H2O/CH3CN versus D2O/CD3CN solvents. A deuteriumkineticisotopeeffect of 4.8 was observed with
描述了动力学和机理研究,详细研究了由Ferryl络合物[Fe IV(O)(N4Py)] 2+氧化衍生自20种天然氨基酸的底物的过程。在相同条件下,用Ferryl配合物处理通式为Ac-AA-NHtBu的底物([Ac-AA-NHtBu] = 10 mM,[Fe] = 1 mM,1:1 H 2 O / CH 3CN),并获得伪一阶速率常数。由这些数据计算出的相对速率常数说明了反应性最强的五种底物。以降低的反应性顺序是从Cys,Tyr,Trp,Met和Gly衍生的那些。通过在伪一级条件下改变底物浓度来确定这些底物的二级速率常数。衍生自其他天然氨基酸的底物没有表现出显着的反应性,以不到未添加底物的对照反应的速率的十倍的速率加速了ferryl复合物的分解。Ferryl分解速率在D 2 O / CD 3中发生了变化CN用于Cys,Tyr和Trp底物,分别具有4.3、29和5.2的氘动力学同位素效应,与电