糖の親水性と疎水性-脂質膜に与える効果

抄録

Saccharides have been regarded as the strong hydrophilic solutes by virtue of their hydrogen bonding with water molecules. The oxygen positions of equatorial OH groups almost fit the oxygen positions of tridymite structure of water. Therefore, the degree of hydrophilicity is different from each saccharide, because of the different orientation of OH groups. On the contrary, the hydrophobic plane formed by the CH- and CH₂-groups is also different from each saccharide molecule and different hydrophobicities are observed for various monosaccharides, though they are considerably weak. The amphipathic character of saccharide molecule, that is, strong hydrophilicity and weak hydrophobicity, has been demonstrated by the studies of the interaction of lipid membranes with monosaccharides and cyclodextrins. The most hydrophilic monosaccharides stabilize the liposome membrane in frozen state, while the most hydrophobic cyclodextrins destruct the liposome membrane at room temperature by recognizing the lipid molecule and forming the inclusion complexes. Bile salts are also included in the cavity of, β-cyclodextrin and liberate the guest molecule by the exchange reaction.