Synthesis and Physicochemical Properties of Glycolipids Bearing Oligosaccharide Headgroups

Glycolipids, amphiphiles that bear oligosaccharides as their hydrophilic headgroups, are of importance both scientifically and technically. This review describes recent advances in our understanding of the molecular correlations in phase behavior of aqueous glycolipids. In the first part, we discuss how headgroup stereochemistry affects the phase behavior of glycolipids both in the two- and three- dimensional systems. In the second part, we discuss effects of alkyl chain structure on phase behavior of phytanyl-chained glycolipid/water systems. Physical properties of glycolipid/water systems strongly depend on the inter-headgroup interactions that is related to factors such as stereochemistry (conformation) and size of headgroups, type of sugar residues involved, alkyl chain structure, etc. Thus, apart from the conventional concept likeghydrophilic/lipophilic balanceh, explicit accounts of headgroup interactions are crucial to control a particular glycolipid/water system concerned. This makes marked contrast to the conventional amphiphile/water systems where the inter-headgroup interactions are in most cases simply repulsive.