Mutual Relationships of Nanoconfined Hexoses: Impacts on Hydrodynamic Radius and Anomeric Ratios

Although all hexose sugars share the same chemical formula, C₆H₁₂O₆, subtle differences in their stereochemical structures lead to their various biological roles. Due to their prominent role in metabolism, hexose sugars are commonly found in nanoconfined environments. The complexity of authentic nanoconfined biological environments makes it challenging to study how confinement affects their behavior. Here, we present a study using a common model system, AOT reverse micelles, to study hexose sugars in nanoconfinement. We examine how reverse micelles affect the hexoses, how the hexoses affect reverse micelle formation, and the differences between specific hexoses: glucose, mannose, and galactose. We find that addition of glucose, mannose or galactose to reverse micelles that already contain water leaves their size smaller or nearly unchanged. Introducing aqueous hexose solution yields reverse micelles smaller than those prepared with the same volume of water. We use ¹H NMR to show how the nanoconfined environment impacts hexose sugars' anomeric ratios. Nanoconfined mannose and galactose display smaller changes in their anomeric ratios compared to glucose. These conclusions may provide insights about the biological roles of each hexose when studied under a more authentic nanoconfined system.