Solvent-free synthesis of Ser–His dipeptide from non-activated amino acids and its potential function as organocatalyst

Short homopeptides (up to 3-mer) of serine and histidine, as well as Ser–His and His–Ser hetero-dipeptides, are produced from non-activated amino acids by using facile chemical vapor deposition and TiO2 nanoparticles as catalyst. The assessment of the formation of peptides is based on spectroscopic data such as in situ FT-IR and mass spectrometry. Evidence of the capability of Ser–His to promote hydrolysis of peptide bonds in hexaglycine is provided, contributing to the debate on the effectiveness of this dipeptide as an organocatalyst.