Amide bond-containing monodisperse polyethylene glycols beyond 10 000 Da

2016 ◽  
Vol 14 (33) ◽  
pp. 7912-7919 ◽  
Author(s):  
Zihong Wan ◽  
Yu Li ◽  
Shaowei Bo ◽  
Ming Gao ◽  
Xuemeng Wang ◽  
...  

Monodisperse polyethylene glycols above 4000 Da, including the longest one to date (10 262 Da), can be prepared from oligoethylene glycol-containing ω-amino acids through solid phase synthesis.

1981 ◽  
Vol 46 (9) ◽  
pp. 2136-2139 ◽  
Author(s):  
Ivo Bláha ◽  
Viktor Krchňák ◽  
Milan Zaoral

p-Toluenesulfonyl-S-benzylcysteinyl-tyrosyl-phenylalanyl-glutaminyl-asparaginyl-S-benzylcysteinyl-NG-p-toluenesulfanylarginyl-prolyl-glycineamide (I) and S-benzylcysteinyl-tyrosyl-isoleucyl-glutaminyl-asparaginyl-S-benzylcysteinyl-leucyl-prolyl-glycine amide (III) were prepared by solid phase synthesis. After removal of the protecting groups, closure of the disulfide ring, and purification by continuous free-flow electrophoresis [arginine7, proline8]vasopressin (II) and [leucine7, proline8]oxytocin (IV) were obtained. The antidiuretic effect of II is markedly higher than its pressor effect; IV possesses c. 6% of the uterotonic and c. 10% of the galactogogous effect of oxytocin.


Molecules ◽  
2021 ◽  
Vol 26 (1) ◽  
pp. 197
Author(s):  
Iván Ramos-Tomillero ◽  
Marisa K. Sánchez ◽  
Hortensia Rodríguez ◽  
Fernando Albericio

Using the classical Ugi four-component reaction to fuse an amine, ketone, carboxylic acid, and isocyanide, here we prepared a short library of N-alkylated α,α-dialkylglycine derivatives. Due to the polyfunctionality of the dipeptidic scaffold, this highly steric hindered system shows an interesting acidolytic cleavage of the C-terminal amide. In this regard, we studied the structure-acid lability relationship of the C-terminal amide bond (cyclohexylamide) of N-alkylated α,α-dialkylglycine amides 1a–n in acidic media and, afterward, it was established that the most important structural features related to its cleavage. Then, it was demonstrated that electron-donating effects in the aromatic amines, flexible acyl chains (Gly) at the N-terminal and the introduction of cyclic compounds into dipeptide scaffolds, increased the rate of acidolysis. All these effects are related to the ease with which the oxazolonium ion intermediate forms and they promote the proximity of the central carbonyl group to the C-terminal amide, resulting in C-terminal amide cleavage. Consequently, these findings could be applied for the design of new protecting groups, handles for solid-phase synthesis, and linkers for conjugation, due to its easily modulable and the fact that it allows to fine tune its acid-lability.


1992 ◽  
Vol 57 (8) ◽  
pp. 1707-1718
Author(s):  
Wolfgang Voelter ◽  
Gerhard Breipohl ◽  
Chryssa Tzougraki ◽  
Eveline Jungfleisch-Turgut

The solid phase synthesis of an amidated somatostatin analogue based on the principle of differentiated acidolysis is described. The acid labile and smoothly cleavable t-Bumeoc moiety (1% TFA/DCM) is used for temporary Nα-protection of D- and L-amino acids and [4-[[[9H-fluoren-9-yl-methoxycarbonyl]amino](4-methoxyphenyl)methyl]-2-methylphenoxy]acetic acid, attached to an aminomethylated polystyrene resin is used as acid sensitive linker of the solid carrier which releases the peptide in its amide form by treatment with TFA. Its preparation is described in detail.


1998 ◽  
Vol 53 (7) ◽  
pp. 753-764 ◽  
Author(s):  
Hans-Jürgen Kohlbaua ◽  
Jochen Tschakert ◽  
Raed A. Al-Qawasmeh ◽  
Tanveer Ahmad Nizamì ◽  
Abdul Malik ◽  
...  

Abstract New isomeric trialkoxybenzylamine resins are developed coupling phthalimidomethyl-3,5-dimethoxyphenols to the Merrifield resin, followed by subsequent treatment with hydrazine. The generated benzylamine function allows DCC coupling w ith the carboxyl function of amino acids and peptides which are removed as amides after treatment with trifluoroacetic acid. These new trialkoxybenzylamine resins allow expeditious syntheses of peptide amides and glycopeptide amides as is demonstrated for muramyl peptides and analogues.


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