Preparation of glucosamine hydrochloride from field crab shells

Abstract

Introduction: Glucosamine is an endogenous amino - mono - saccharide, a component that helps synthesize glycosaminoglycan that makes up cartilage tissue in the body. Glucosamine is synthesized by the body but that ability decreases with age, so it is necessary to supplement glucosamine from the outside. Glucosamine is mainly prepared by hydrolyzing chitin or chitosan in a hydrochloric acid environment. In Vietnam, there is a rich source of crustacean shells (shrimp shells, crab shells...) - the main source for extracting chitin and chitosan. Based on the above reality, we chose to research the topic: "Preparation of glucosamine hydrochloride from field crab shells". Subjects and methods: Chitosan was extracted from the shells of freshwater crabs collected at some markets in Hai Phong city. Preparation of Glucosamine hydrochloride (glu.HCl) by hydrolysis of chitosan in hydrochloric acid environment. The chemical structure of glu.HCl was determined by infrared spectroscopy (IR) and nuclear magnetic resonance spectroscopy (NMR). Survey of some factors affecting the preparation efficiency such as: reaction time, reaction temperature and concentration of reactants to find the optimal conditions of the reaction. Results:  The results of the study on the chemical structure of glu.HCl are consistent with the theory and some published references. The optimal conditions for the preparation of glu.HCl from chittosan were found: concentrated HCl acid 36%; reaction temperature 90 - 950C; reaction time 4 hours. The efficiency of the preparation of glu.HCl from chitosan reached 62.8%. Conclusion: The study isolated chitosan from crab shells with a deacetylation degree (DDA) of 81.73% and prepared glu.HCl from chitosan with a yield of 62.8%.