Peptide Synthesis: Coupling Methods

Abstract

Peptide‐bond formation requires activation of a carboxyl group followed by aminolysis of the activated carbonyl. The reagents and methods employed for activation, the intermediates and activated forms generated and their aminolysis are described. Rationalization of the strategy employed to avoid isomerization during coupling is presented. Approaches for minimizing aggregation that interferes with coupling are also given.

Exploring the Formulation and Approaches of Injectable Hydrogels Utilizing Hyaluronic Acid in Biomedical Uses

“…Te reaction depends initially on the process of activating the carboxylic group [64], in addition to the creation of an amide or ester bond in two stages; initially, the reaction between the reactant and the carboxylic functional group of the hyaluronic acid produces a reactive moiety, the amino group of the reagent acts as the nucleophile and the nucleophile reacts with the carboxyl group and forms the ammonium hydrogel. Te hydrogel prepared following these reactions was characterized by improved stability and mechanical properties [65][66][67].…”

Crosslinking method of hyaluronic-based hydrogel for biomedical applications

“…The amino group or alcohol group is implied as the nucleophile in these reactions. 23,24 The fabrication of hybrid hydrogels from arginine-based poly(ester amide) and HA precursors (Arg-PEA and HA-AEMA) was achieved by photo-crosslinking. Synthesis of HA-AEMA was carried out by dissolving HA in 100 mL 1-ethyl-3-(3-dimethyl aminopropyl)-1-carbodiimide hydrochloride (EDC; 15 mmol); N-hydroxysuccinimide (NHS; 15 mmol) and AEMA (10 mmol) were added to solution to form amide bonds.…”

Cross-Linking Method-Based Nanogels for Biomedical Applications

“…A characteristic common to the action mechanism of all these amide reagents is the carboxyl group activation. The use of PEG diamine as cross-linking agents is of great interest, as well as the amino group is revealed as the nucleophile attack [35,36]. In recent research, the amidation reaction of polymers have carboxylic acids groups such as hyaluronic acid (HA) are take placed using N-hydroxysuccinimide (NHS) as a crosslinker for formation of amide bonds (see Fig.…”