Comments on 'Crystal growth, spectral, optical, and thermal characterization of glycyl-L-alanine hydrochloride (GLAH) single crystal'

Abstract

The authors of the title paper (J Therm Anal Calorim 2012,110:873–878) report to have grown a dipeptide hydrochloride crystal namely glycyl-l-alanine hydrochloride by the slow evaporation of an aqueous solution containing stoichiometric amounts of l-alanine and glycine and an excess of hydrochloric acid. In this letter, we prove that no such dipeptide hydrochloride can be crystallized simply by mixing two amino acids in aqueous hydrochloric acid.