Synthesis of Polypeptide Having Defined Terminal Structures Through Polymerization of Activated Urethane-Derivative of γ-Benzyl-l-glutamate

Abstract

A new synthetic method of polypeptide having defined terminal structures was established with using an acyclic urethane of α-amino acid as a monomer. The urethane derivative presented herein is N-(4-nitrophenoxycarbonyl)-γ-benzyl-l-glutamate, of which polymerization behavior in N,N-dimethylacetamide (DMAc) in the presence of various amines was examined. The polymerization was accelerated remarkably by adding butylamine so that it proceeded smoothly at 30 °C to afford the corresponding polycondensate, poly(γ-benzyl-l-glutamate) (poly(BLG)). Detailed structural analysis of the obtained poly(BLG) with MALDI−TOF mass spectrometry revealed that butylamine was incorporated into the terminal of poly(BLG) and the other terminal was endowed with amino group.

Facile Synthesis of High Molecular Weight Polypeptides via Surface-Initiated Vapor Deposition Polymerization

“…It is also worth noted that PD distribution of synthetic PBLG resemble that of polycondensates, with typical PD ≧ 2.0. termination step leading to a 5-membered lactam structure which was formed by intramolecular nucleophilic attack of the terminal amine group to the benzyl ester in the side chain. 25 The MALDI-TOF mass data shown were in good agreement with the assumption. The major products of the synthetic PBLG has a primary amine chain end and even the lactam structure can be hydrolyzed by alkaline to generate primary amine which is capable of grafting the block copolypeptides on resin beads in the future.…”

Amino‐Acid‐Based Block Copolymers by RAFT Polymerization

“…Such characteristic self‐assembled structures and the potential applications of polymers derived from amino acids have motivated researchers to design and develop new synthetic routes to a variety of amino‐acid‐based polymers using assorted polymerization techniques 26–36. In particular, recent synthetic developments in this field, such as the polycondensation of urethane derivatives of α‐amino acids37–40 and the phosgene‐free synthesis of N ‐carboxy‐α‐amino acid anhydrides,41–43 can lead to the facile synthesis of well‐defined polymers containing amino acid moieties in the main chain with novel structures and architectures.…”

Useful synthetic method of polypeptides with well‐defined structure by polymerization of activated urethane derivatives of α‐amino acids

“…16 Also, we previously reported selective synthesis of NCA and polypeptides through N-(4-nitrophenyloxycarbonyl) amino acid. [17][18][19][20][21][22] Recently, we have developed newly synthetic route for production of NCA through intramolecular cyclization of N-(phenyloxycarbonyl) amino acids under heating in moderately polar solvents, such as 2-butanone, tetrahydrofuran (THF), and acetonitrile to give the corresponding NCA, without the use and production of any toxic compounds. 23 In this study, we report the polypeptides synthesis with well-defined terminal structure, using N-(phenyloxycarbonyl) amino acid as precursor of NCA in the presence of amine, and approaching for the synthesis of block copolypeptides.…”