Dissemin is shutting down on January 1st, 2025

Published in

Wiley, Angewandte Chemie, 2(125), p. 639-642, 2012

DOI: 10.1002/ange.201207730

Wiley, Angewandte Chemie International Edition, 2(52), p. 611-614, 2012

DOI: 10.1002/anie.201207730

Links

Tools

Export citation

Search in Google Scholar

5(4H)-Oxazolones as Intermediates in the Carbodiimide-and Cyanamide-Promoted Peptide Activations in Aqueous Solution

This paper was not found in any repository, but could be made available legally by the author.
This paper was not found in any repository, but could be made available legally by the author.

Full text: Unavailable

Green circle
Preprint: archiving allowed
Orange circle
Postprint: archiving restricted
Red circle
Published version: archiving forbidden
Data provided by SHERPA/RoMEO

Abstract

The formation of biopolymers in prebiotic environments is still unresolved regarding nucleic acids and functional peptides. Peptide function especially requires proper folding and hence sufficient lengths. In 1969, Cavadore and Previero1 observed that the EDC-mediated (EDC=1-ethyl, 3-(3-dimethylaminopropyl)carbodiimide hydrochloride) α-amino acid polymerization in water is significantly improved when N-acylated amino acids are introduced as initiators. Obviously, EDC is highly unlikely to have been abiotically formed but there are indications in the literature that underivatized carbodiimide HN[DOUBLE BOND]C[DOUBLE BOND]NH is involved as an intermediate in reactions of cyanamide,2 a prebiotically plausible reagent, and dicyandiamide is reported to behave similarly as carbodiimides.3 The behavior of N-acylamino acids as polymerization initiators was explained in the original work1 by an inhibition of activation owing to the greater acidity of free α-amino acids (pKA≈2.3) compared to C-terminal carboxy groups in peptides (pKA≈3.7). However, alternative explanations could be proposed.