Preparation of glucosamine by acid hydrolysis of chitin under microwave irradiation

Abstract

Glucosamine or 2-amino-2-deoxy-D-glucose is a natural monosaccharide. Glucosamine has been used extensively in the fields of nutrition, pharmacy, and cosmetics. Usually, glucosamine is obtained by complete hydrolysis of chitin using strong mineral acid at high temperature. Although acid hydrolysis has several disadvantages as caramel formation and low selectivity, this method is still interesting because it is simple and easy. Recently, microwave irradiation has been widely used in organic chemical reactions because of its ability to reduce both energy consumption and reaction time. In this study, preparation of glucosamine by acid hydrolysis of chitin using irradiation microwave was compared to conventional heating. The result showed that using conventional heating with hydrochloric acid 8 N, 95°Cof temperature process, ratio of chitin and HCl in 1:4 (w/v), and reaction time of 120 minutes yielded 58.8%. Whilst chitin hydrolysis using microwave irradiation with the power of 400 watts and for 25 minutes of reaction time yielded 67.1%. FTIR analysis showed that the glucosamine product from chitin hydrolysis using both conventional heating and microwave irradiation have similar structure with standard glucosamine. Glucosamine from Merck with the purity of 99% was used as the standard.