Anhydrogalactoses

Anhydrogalactoses are a group of carbohydrate derivatives formed by the removal of a molecule of water from galactose. Galactose is a monosaccharide, a simple sugar. When two galactose units undergo dehydration, they can form a disaccharide with an anhydro linkage. More commonly, anhydrogalactoses refer to the cyclic forms of galactose that result from intramolecular dehydration. These can occur in solution or during certain chemical reactions.

One prominent example is levoglucosan, which is technically an anhydroglucose, but the concept applies to galactose as well. In the context of galactose, intramolecular dehydration can lead to the formation of fused ring structures. These anhydrogalactoses can be found as constituents of certain polysaccharides, particularly those derived from marine algae, such as agar and carrageenan. In these complex carbohydrates, galactose units are often linked together with anhydro bridges. The presence and specific arrangement of these anhydrogalactose units contribute to the unique gelling and thickening properties of these biopolymers. Research into anhydrogalactoses is relevant to food science, biotechnology, and the study of carbohydrate chemistry.