Peptide Synthesis in Aqueous Solution. V. Properties and Reactivities of (<i>p</i>-Hydroxyphenyl)benzylmethylsulfonium Salts for Direct Benzyl Esterification of<i>N</i>-Acylpeptides
Some (p-hydroxyphenyl)benzylmethylsulfonium salts were prepared. These compounds generated a benzyl cation and converted not only N-acylamino acids but also N-acylpeptides into their corresponding benzyl esters without causing the racemization.
Impact of Azaproline on Amide Cis<i>−</i>Trans Isomerism: Conformational Analyses and NMR Studies of Model Peptides Including TRH Analogues
作者:Wei-Jun Zhang、Anders Berglund、Jeff L.-F. Kao、Jean-Pierre Couty、Marvin C. Gershengorn、Garland R. Marshall
DOI:10.1021/ja020994o
日期:2003.2.1
motif in both proteins and peptides. Four residues, making almost a complete 180 degree-turn in the direction of the peptide chain, define the beta-turn. Several types of the beta-turn are defined according to Phi and Psi torsional angles of the backbone for residues i + 1 and i + 2. One special type of beta-turn, the type VI-turn, usually contains a proline with a cis-amide bond at residue i + 2. In an
β-转角是蛋白质和肽中经过充分研究的基序。四个残基在肽链的方向上几乎完全旋转了 180 度,定义了 β 转角。根据残基 i + 1 和 i + 2 骨架的 Phi 和 Psi 扭转角定义了几种类型的 β 转角。 一种特殊类型的 β 转角,即 VI 型转角,通常包含带有顺式的脯氨酸残基 i + 2 上的 -酰胺键。在氮杂氨基酸中,氨基酸的 α-碳变为氮。核磁共振研究表明,含有氮杂脯氨酸 (azPro) 的肽在晶体和有机溶剂中更喜欢 VI 型β-转角。使用 GB/SA 水溶剂化模型的 MC/MD 模拟探索了含水系统中含 azPro 肽的构象偏好。azPro 的顺式-酰胺构象异构体的构象偏好的增加被清楚地看到,但与先前的建议相比,反式构象异构体的稳定性增加相对较小。为了根据晶体结构和 NMR 在有机溶剂中的实验数据测试计算的有效性,合成了 [azPro(3)]-TRH 和 [Phe(2), azPro(3)]-TRH,及其构象偏好由
Acylated cyanamide compounds
申请人:Regents of the University of Minnesota
公开号:US04940816A1
公开(公告)日:1990-07-10
Acylated cyanamide compounds useful for ethanol deterrence of the formula RCONHCN, wherein R is a lipophilic acyl group or is derived from an (N-substituted)-alpha-aminoacyl group.
Acylated cyanamide composition for treating ethanol ingestion
申请人:Regents of the University of Minnesota
公开号:US04726941A1
公开(公告)日:1988-02-23
Acylated cyanamide compounds useful for ethanol deterrence of the formula RCONHCN, wherein R is a lipophilic acyl group or is derived from an (N-substituted)-alpha-aminoacyl group.
Acylated cyanamide compounds useful for ethanol deterrence of the formula RCONHCN, wherein R is a lipophilic acyl group or is derived from an (N-substituted)-alpha-aminoacyl group.