A new method of quaternizing amines and its use in amino acid and peptide chemistry

1976 ◽  
Vol 54 (20) ◽  
pp. 3310-3311 ◽  
Author(s):  
Francis C. M. Chen ◽  
N. Leo Benoiton
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Methyl Iodide ◽  
New Method ◽  
Hydroxyl Groups ◽  
Amino Groups ◽  
Small Peptides ◽  
Peptide Chemistry ◽  
Selective Reagent ◽  
Derivatives Of

Methyl iodide and potassium bicarbonate in methanol is presented as a mild, efficient, and selective reagent for the quaternization of amino groups. It does not attack hydroxyl groups. Its use with amino acids, derivatives of lysine, and small peptides is described.

scholarly journals The sequence of amino acids in insulin isolated from islet tissue of the cod (Gadus callarias)

1968 ◽  
Vol 110 (2) ◽  
pp. 289-296 ◽  
Author(s):  
K. B. M. Reid ◽  
P T Grant ◽  
A. Youngson
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Sequences ◽  
Small Peptides ◽  
Islet Tissue ◽  
Complete Digestion ◽  
The Individual ◽  
Derivatives Of

1. S-Aminoethylcysteinyl derivatives of the A and B chains of cod insulin were prepared from the individual S-sulpho chains. 2. Studies on small peptides derived from the S-aminoethylated peptide chains by treatment with trypsin allowed the amino acid sequences in the region of the cysteinyl residues of the A and B peptide chains to be defined. 3. The six amide groups in cod insulin were located by complete digestion of small peptides from the A and B chains with aminopeptidase followed by amino acid analyses. 4. The results, together with previous studies on the oxidized A and B chains, define the sequences of the 51 amino acids that constitute cod insulin.

scholarly journals Well-Defined Construction of Functional Macromolecular Architectures Based on Polymerization of Amino Acid Urethanes

Biomedicines ◽  
2020 ◽  
Vol 8 (9) ◽  
pp. 317
Author(s):  
Takeshi Endo ◽  
Atsushi Sudo
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Primary Amines ◽  
Amino Groups ◽  
Molecular Weights ◽  
Antifouling Coatings ◽  
Onium Salts ◽  
Polypeptide Synthesis ◽  
Produce Amino Acid ◽  
Derivatives Of

Polypeptide synthesis was accomplished using the urethane derivatives of amino acids as monomers, which can be easily prepared, purified, and stored at ambient temperature without the requirement for special precautions. The urethanes of amino acids are readily synthesized by the N-carbamoylation of onium salts of amino acids using diphenyl carbonate (DPC). The prepared urethanes are then efficiently cyclized to produce amino acid N-carboxyanhydrides (NCAs). Thereafter, in the presence of primary amines, the ring-opening polymerization (ROP) of NCAs is initiated using the amines, to yield polypeptides with controlled molecular weights. The polypeptides have propagating chains bearing reactive amino groups and initiating chain ends endowed with functional moieties that originate from the amines. Aiming to benefit from these interesting characteristics of the polypeptide synthesis using the urethanes of amino acids, various macromolecular architectures containing polypeptide components have been constructed and applied as biofunctional materials in highly efficient antifouling coatings against proteins and cells, as biosensors for specific molecules, and in targeted drug delivery.

N-Methylamino Acids in Peptide Synthesis. II. A New Synthesis of N-Benzyloxycarbonyl, N-Methylamino Acids

1973 ◽  
Vol 51 (12) ◽  
pp. 1915-1919 ◽  
Author(s):  
John R. McDermott ◽  
N. Leo Benoiton
Keyword(s):  
Amino Acids ◽  
Methyl Iodide ◽  
Peptide Synthesis ◽  
Side Chains ◽  
Butyl Group ◽  
New Synthesis ◽  
Derivatives Of

Reaction of N-benzyloxycarbonyl derivatives of aliphatic amino acids, and threonine, aspartic, and glutamic acids whose side-chains were protected with the t-butyl group, gave the corresponding N-methylamino acid derivatives in good yields. The methionine derivative could be obtained by using only one mol of methyl iodide. Derivatives of threonine, and aspartic and glutamic acids whose side-chains were not protected could not be methylated. Analysis of the crude products of methylation in three cases showed that they contained 0–1% of racemized material.

N-DICHLOROACETYL DERIVATIVES OF SERINE AND THREONINE AND OF THEIR ESTERS AND SODIUM SALTS

1960 ◽  
Vol 38 (7) ◽  
pp. 1135-1140 ◽  
Author(s):  
I. Levi ◽  
A. E. Koller ◽  
G. Laflamme ◽  
J. W. R. Weed
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Antitumor Activity ◽  
Amino Acid Ester ◽  
Amino Group ◽  
Sodium Salts ◽  
Sarcoma 37 ◽  
Walker Carcinoma ◽  
Derivatives Of ◽  
Dichloroacetyl Chloride

The N-dichloroacetyl derivatives of DL-serine and DL-threonine were prepared by the Schotten–Baumann reaction from the amino acids and dichloroacetyl chloride. Negative ninhydrin tests coupled with elementary analyses indicated that only the amino group was acylated. The ester derivatives of these compounds were prepared either by esterification of the N-dichloroacetyl-DL-amino acid with diazomethane or by the reaction of the amino acid ester with dichloroacetyl chloride in the presence of triethylamine. The sodium salts and the esters were tested for antitumor activity against sarcoma 37 in mice and Walker carcinoma 256 in rats. In both cases regression of the tumors was obtained.

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