Glycosylium Ions in Superacid Mimic the Transition State of Enzyme Reactions.

The hydrolysis of glycosides is a biochemical transformation that occurs in all living organisms, catalyzed by a broad group of enzymes, including glycoside hydrolases. These enzymes cleave the glycosidic bond via a transition state with substantial oxocarbenium ion character, resulting in short-lived oxocarbenium ion-like species. While such transient species have been inferred through theoretical studies and kinetic isotope effect measurements, their direct spectroscopic characterization remains challenging.