Hexoses are fundamental monosaccharides with the general formula C₆H₁₂O₆, playing essential roles in energy metabolism, structural polysaccharides, and cellular recognition processes. Their multiple stereogenic centers generate a wide variety of stereoisomers, each with distinct physicochemical and biological properties. Crystallographic studies provide invaluable insights into their conformational preferences, hydrogen-bonding networks, polymorphic behavior, and responses to environmental conditions. This review compiles and critically examines the available crystallographic data for both aldo- and ketohexoses, including common sugars such as glucose, galactose, and mannose, as well as rare sugars like allose, psicose, and tagatose. Notable structural motifs, hydration states, and high-pressure transformations are discussed, alongside trends in hydrogen-bond organization and molecular packing. Special attention is given to rare structural features that may correlate with functional properties. By providing a systematic overview, this work serves as a reference framework for carbohydrate crystallography and a resource for applied research in pharmaceuticals, food science, and materials engineering
Zielińska-Pisklak et al. (Thu,) studied this question.