ABSTRACT
Chitosan, a copolymer of glucosamine and N-acetylglucosamine units linked by one to four glucosidic bonds, is commercially obtained from chitin, which is one of the most abundant natural amino polysaccharide. Chitosan could be converted by using proper reagents into a number of O-alkyl and O-acyl derivatives. Chitosan also behaves as a moderately basic cationic polyelectrolyte, which readily forms salts with acids. In addition, the presence of the primary amino group in chitosan offers further possibilities for modications such as N-acylation, N-alkylation, and N-alkylidenation. Therefore, numerous varieties of chitosan derivatives can be synthesized from this nature’s abundant polymer.
