General Protocol to Obtain D‐Glucosamine from Biomass Residues: Shrimp Shells, Cicada Sloughs and Cockroaches

A general protocol is developed to obtain D‐glucosamine from three widely available biomass residues: shrimp shells, cicada sloughs, and cockroaches. The protocol includes three steps: (1) demineralization, (2) deproteinization, and (3) chitin hydrolysis. This simple, general protocol opens the door to obtain an invaluable nitrogen‐containing compound from three biomass residues, and it can potentially be applied to other chitin sources. White needle‐like crystals of pure D‐glucosamine are obtained in all cases upon purification by crystallization. Characterization data (NMR, IR, and mass spectrometry) of D‐glucosamine obtained from the three chitin sources are similar and confirm its high purity. NMR investigation demonstrates that D‐glucosamine is obtained mainly as the α‐anomer, which undergoes mutarotation in aqueous solution achieving equilibrium after 440 min, in which the anomeric glucosamine distribution is 60% α‐anomer and 40% β‐anomer.