title: Free energy surface for Brønsted acid-catalyzed glucose ring-opening in aqueous solution.
abstract: Car-Parrinello-based molecular dynamics coupled with metadynamics simulations were used to determine the mechanism and associated free energy surface for opening the ring structure of cyclic glucopyranose in acidic aqueous solutions. The ring-opening process is initiated by the protonation of the ring oxygen atom and the breakage of the C1-O5 bond. The barrier for this process is about 25 kcal/mol, in good agreement with experimental measurements. Moreover, the glucose cyclic conformation is found to be more stable than the open chain form. The barrier for proton-catalyzed ring-opening in aqueous solution appears to be largely solvent induced due to the high affinity of water molecules for protons.
authors.affiliation: Department of Chemical Engineering, University of Arkansas , Fayetteville, Arkansas 72701, United States.
authors.forename: Xianghong
authors.initials: X
authors.lastname: Qian
mesh_terms: D000143:Acids / Q000737:chemistry*; D000447:Aldehydes / Q000737:chemistry; D002244:Carbon / Q000737:chemistry; D005947:Glucose / Q000737:chemistry*; D006859:Hydrogen / Q000737:chemistry; D008956:Models, Chemical; D008968:Molecular Conformation; D056004:Molecular Dynamics Simulation; D010100:Oxygen / Q000737:chemistry; D012996:Solutions / Q000737:chemistry; D012997:Solvents / Q000737:chemistry; D013816:Thermodynamics; D014867:Water / Q000737:chemistry*
chemical_list: D000143:Acids; D000447:Aldehydes; D012996:Solutions; D012997:Solvents; D014867:Water; D002244:Carbon; D006859:Hydrogen; D005947:Glucose; D010100:Oxygen