4-Aminophenyl 2-acetamido-2-deoxy-a-D-galactopyranoside HCl is an oligosaccharide that is composed of glucose, galactose, and two amino acids. It has a molecular weight of 496.34 g/mol and a chemical formula of C14H20N2O8. This compound is synthesized by the click modification of 2,5-diaminopyridine with D -galactopyranosyl chloride. The methylation and glycosylation reactions are also performed to produce this compound.