1. A backbone amide protecting group for overcoming difficult sequences and suppressing aspartimide formation
- Author
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John Offer, Martin Quibell, George Papageorgiou, Abu-Baker M. Abdel-Aal, Fabienne Burlina, Richard Raz, Analyse, Interactions Moléculaires et Cellulaires (LBM-E2), Laboratoire des biomolécules (LBM UMR 7203), Université Pierre et Marie Curie - Paris 6 (UPMC)-Département de Chimie - ENS Paris, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Département de Chimie - ENS Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université Paris sciences et lettres (PSL), The National Institute for Medical Research, Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Département de Chimie - ENS Paris, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Département de Chimie - ENS Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)
- Subjects
Special Issue Articles ,Stereochemistry ,Acylation ,Fmoc SPPS ,010402 general chemistry ,O,N acyl transfer ,reductive amination ,01 natural sciences ,Biochemistry ,Reductive amination ,Hmb ,nitro reduction ,chemistry.chemical_compound ,Structural Biology ,Amide ,Drug Discovery ,Solid-Phase Synthesis Techniques ,Peptide bond ,Amino Acid Sequence ,backbone amide protection ,Protecting group ,Molecular Biology ,Nitrobenzenes ,Pharmacology ,Aspartic Acid ,Molecular Structure ,[CHIM.ORGA]Chemical Sciences/Organic chemistry ,010405 organic chemistry ,Chemistry ,aspartimide formation ,Organic Chemistry ,Special Issue Article ,General Medicine ,Amides ,difficult sequence ,0104 chemical sciences ,Intramolecular force ,Molecular Medicine ,Amine gas treating ,Peptides - Abstract
International audience; A backbone amide bond protecting group, 2-hydroxy-4-methoxy-5-nitrobenzyl (Hmnb), improved the synthesis of aggregation and aspartimide-prone peptides. Introduction of Hmnb is automated and carried out during peptide assembly by addition of 4-methoxy-5-nitrosalicylaldehyde to the peptidyl-resin and on-resin reduction to the secondary amine. Acylation of the hindered secondary amine is aided by the formation of an internal nitrophenol ester that undergoes a favourable O,N intramolecular acyl transfer. This activated ester participates in the coupling and generally gives complete reaction with standard coupling conditions. Hmnb is easily available in a single preparative step from commercially available material. Different methods for removing the amide protecting group were explored. The protecting group is labile to acidolysis, following reduction of the nitro group to the aniline. The two main uses of backbone protection of preventing aspartimide formation and of overcoming difficult sequences are demonstrated, first with the synthesis of a challenging aspartimide-prone test sequence and then with the classic difficult sequence ACP (65-74) and a 23-mer homopolymer of polyalanine.
- Published
- 2016