Glucosamine is an amino sugar and a prominent precursor in the biochemical synthesis of glycosylated proteins and lipids. Glucosamine is part of the structure of two polysaccharides, chitosan and chitin. Glucosamine is one of the most abundant monosaccharides. Glucosamine is formed by replacing one hydroxyl group of glucose with an amino group and is easily soluble in water and hydrophilic solvents. Glucosamine usually exists in microbial, animal derived polysaccharides and bound polysaccharides in the form of N-neneneba acetyl derivatives (such as chitin) or N-nenenebb sulfate and N-acetyl-3-O-lactate ether (cell wall acid).