scholarly journals The application of ketimine derivatives of amino acids to peptide synthesis

1976 ◽  
Vol 29 (7) ◽  
pp. 1591 ◽  
Author(s):  
AP Hope ◽  
B Halpern
Keyword(s):  
Amino Acids ◽  
Acetic Acid ◽  
Amino Acid ◽  
Biologically Active ◽  
Amino Acid Esters ◽  
Protecting Group ◽  
Active Peptides ◽  
Biologically Active Peptides ◽  
Derivatives Of ◽  
Acid Esters

N-(2-Hydroxyarylmethy1ene)amino acids have been coupled with amino acid esters to form sterically pure N-protected dipeptide esters. The protecting group can be removed by means of 80% acetic acid under conditions which leaves the t-butyloxycarbonyl protecting group intact. Biologically active peptides which are C-terminal partial sequences of substance P were prepared and were shown to have the expected vasodilator, spasmogenic and venoconstrictor properties.

Dimedone (5,5-Dimethylcyclohexane-1,3-dione) as a protecting agent for amino groups in peptide synthesis

1964 ◽  
Vol 17 (11) ◽  
pp. 1282 ◽  
Author(s):  
B Halpern ◽  
LB James
Keyword(s):  
Amino Acid ◽  
Peptide Synthesis ◽  
Amino Acid Esters ◽  
Protecting Group ◽  
Amino Groups ◽  
Active Esters ◽  
Optically Pure ◽  
Derivatives Of ◽  
Protected Peptides ◽  
Acid Esters

The reaction of dimedone (5,5-dimethylcyclohexane-1,3-dione) with amino-acid "active" esters leads to optically pure enamine derivatives. The dimedone derivatives of amino acid esters could also be converted by way of their hydrazides to the corresponding azides. The thiophenyl ester and azide derivatives have been used directly for peptide synthesis. The protecting group can easily be removed from the N-protected peptides by means of aqueous bromine, with the formation of 2,2-dibromodimedone and the hydrobromide of the corresponding peptide ester.

scholarly journals Protonation Equilibria of Biologically Active Ligands in Mixed Aqueous Organic Solvents

2014 ◽  
Vol 2014 ◽  
pp. 1-18
Author(s):  
Ahmed A. El-Sherif ◽  
Mohamed M. Shoukry ◽  
Abeer T. Abd Elkarim ◽  
Mohammad H. Barakat
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Organic Solvents ◽  
Biologically Active ◽  
Amino Acid Esters ◽  
Nonaqueous Media ◽  
Protonation Equilibria ◽  
Dna Constituents ◽  
Equilibrium Concentrations ◽  
Acid Esters

The review is mainly concerned with the protonation equilibria of biologically active ligands like amino acids, peptides, DNA constituents, and amino acid esters in nonaqueous media. Equilibrium concentrations of proton-ligand formation as a function of pH were investigated. Also, thermodynamics associated with protonation equilibria were also discussed.

scholarly journals Dipeptidesterkomplexe von Platin(II) durch Peptidsynthese an N-koordinierten α-Aminosäuren / Dipeptide Ester Complexes of Platinum (II) from Reaction of N-coordinated α-Amino Acids with Amino Acid Esters

1972 ◽  
Vol 27 (10) ◽  
pp. 1140-1145 ◽  
Author(s):  
Bernhard Purucker ◽  
Wolfgang Beck
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Infrared Spectra ◽  
Coupling Agent ◽  
Metal Ion ◽  
Amino Acid Esters ◽  
Protecting Group ◽  
New Compounds ◽  
Acid Esters

Complexes of the type trans-X2Pt (NH2CHRCOOH)2 (X = Cl, Br, J; R = H, CH3, CH(CH3)2, CH2OH) react with amino acid esters (GlyOCH3, GlyOC2H5) and N,N′-dicyclohexylcarbodiimide as coupling agent to form the corresponding dipeptide ester derivatives trans-X2Pt (NH2CHRC (O) NHCH2CO2R′) 2. In these reactions the metal ion acts as N-terminal protecting group. The infrared spectra of the new compounds are reported.

scholarly journals Synthesis of Derivatives of closo-Dodecaborate Anion Based on Amino Acid Esters

2021 ◽  
Vol 66 (11) ◽  
pp. 1616-1620
Author(s):  
A. V. Burdenkova ◽  
A. P. Zhdanov ◽  
I. N. Klyukin ◽  
N. A. Selivanov ◽  
A. Yu. Bykov ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Amino Acids ◽  
Amino Acid ◽  
Nmr Spectroscopy ◽  
Amino Acid Esters ◽  
Substitution Reactions ◽  
Multinuclear Nmr Spectroscopy ◽  
Esi Mass Spectrometry ◽  
Derivatives Of ◽  
Acid Esters

Abstract This work proposes a new method for the synthesis of N-borylated amino acids based on nucleophilic substitution reactions in the [B12H11IPh]– anion. Esters of glycine and L-phenylalanine were used as nucleophiles. The structure of the products has been determined by multinuclear NMR spectroscopy, IR spectroscopy, and ESI mass spectrometry.

AMINO ACID DISTRIBUTION IN BIOLOGICALLY ACTIVE PEPTIDES

1960 ◽  
Vol 38 (4) ◽  
pp. 477-481 ◽  
Author(s):  
Saul B. Needleman ◽  
R. Quentin Blackwell ◽  
Leonard S. Fosdick
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Biologically Active ◽  
Amino Acid Distribution ◽  
Chi Square ◽  
Active Peptides ◽  
Biologically Active Peptides ◽  
Unusual Occurrence ◽  
Specific Peptide

A group of biologically active peptides were examined for possible favored chain positions exhibited by some of the 21 constituent amino acids as well as for the unusual occurrence of specific peptide linkages. High levels of significance were revealed for certain amino acid couplets when they were subjected to chi-square analyses.

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