Studies of Unusual Amino Acids and Their Peptides. XII. The Chemistry of<i>N</i>-(Carboxymethyl)amino Acids. I. The Preparation, Properties, and Characterization of<i>N</i>-(Carboxymethyl)amino Acids and Their Esters
作者:Toshifumi Miyazawa
DOI:10.1246/bcsj.53.2555
日期:1980.9
N-Carboxymethyl(Cm-)amino acids and their mono- and diesters were prepared by several routes, and their physical and chiroptical properties were compared with those of the parent amino acids and their esters. The isolation procedure was improved for the preparation of the free Cm-amino acids obtained from the corresponding amino acids and bromoacetic acid; the aimed-at compounds were also obtained
N-羧甲基(Cm-)氨基酸及其单酯和二酯通过多种途径制备,并与母体氨基酸及其酯的物理和手性特性进行了比较。对相应氨基酸和溴乙酸制备游离Cm-氨基酸的分离步骤进行了改进;目标化合物也通过二苄基酯的催化氢解获得。Cm-氨基酸的单烷基酯的异构体对同样可通过苄基烷基酯获得。证明二酯适用于 Cm-氨基酸的 GLC 和 MS 分析。所有游离的 Cm-L-氨基酸及其 N-乙硫代碳硫酰衍生物的二环己基铵盐在 CD 测量中分别在 200-225 nm 和 335-350 nm 处显示出正 Cotton 效应;
Effects on Metal Binding of Circular NH- - -OC Intramolecular Hydrogen Bonding in Hydrophilic Pseudocavities of <i>p-tert</i>-Butylcalix[4]arenes Carrying Amino Acid Moieties
Calix[4]arenes bearing amino acid moieties were prepared by the reaction of carboxyl-protected amino acids with the acid chlorides of O-carboxymethylcalix[4]arenes. The binding ability toward metal ions was estimated by solvent extraction. These calixarenes showed selective extraction capability toward Na(+) and Ag(+) ions, which increased in the order 2a < 2b < 2d < 2c. The complexing ability was
通过使羧基保护的氨基酸与O-羧甲基杯[4]芳烃的酰氯反应,制备带有氨基酸部分的杯[4]芳烃。通过溶剂萃取来估计对金属离子的结合能力。这些杯芳烃显示出对Na(+)和Ag(+)离子的选择性萃取能力,并以2a <2b <2d <2c的顺序增加。络合能力还受溶剂性质的影响,并且在乙酸乙酯中的溶解度高于二氯甲烷。(1)H NMR研究表明2c与Na(+)离子的络合诱导了酰胺基团的方向从网状图案转变为环状NH---O = C 2c分子间氢键羰基会聚在Na(+)离子上的图形。CD光谱的测量也支持这种变化。
Dramatic Differences in the Effectiveness among Various Coupling Methods in the Synthesis of Peptides Containing α,α-Diphenylglycine
Both couplings of N-benzyloxycarbonyl-α,α-diphenylglycine (Z-Dph) with methyl esters of various amino acids (AA-OMe) and Z-AA with Dph-OMe by various methods can yield Z-Dph-AA-OMe and Z-AA-Dph-OMe, respectively. Yields of the dipeptides remarkably differ from over 90% to 0% depending on the coupling method employed.