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RESEARCH PRODUCT

Reversibility and Diffusion in Mandelythiamin Decarboxylation. Searching Dynamical Effects in Decarboxylation Reactions

Juan-luis Pascual-ahuirMaite RocaIñaki Tuñón

subject

Models MolecularDecarboxylationDiffusionNon-equilibrium thermodynamicsThermodynamicsPhotochemistryDecarboxylationBiochemistryCatalysisCatalysisDiffusionMandelythiamin DecarboxylationColloid and Surface ChemistryReaction rate constantThiaminePhysics::Chemical PhysicsChemistrySolvationWaterGeneral ChemistrySolutionsDiffusion processMandelic AcidsQuantum TheoryThermodynamicsDecarboxylation ReactionsSolvent effects

description

Decarboxylation of mandelylthiamin in aqueous solution is analyzed by means of quantum mechanics/molecular mechanics simulations including solvent effects. The free energy profile for the decarboxylation reaction was traced, assuming equilibrium solvation, while reaction trajectories allowed us to incorporate nonequilibrium effects due to the solvent degrees of freedom as well as to evaluate the rate of the diffusion process in competition with the backward reaction. Our calculations that reproduce the experimental rate constant show that decarboxylation takes place with a non-negligible free energy barrier for the backward reaction and that diffusion of carbon dioxide is very fast compared to the chemical step. According to these findings catalysts would not act by preventing the backward reaction. GV/2012/053. ESTUDIO DEL MECANISMO DE REACCION Y DE LOS MOVIMIENTOS DINAMICOS DE LAS ENZIMAS ADN-METILTRANSFERASAS: CATALISIS Y INHIBICION

yearjournalcountryeditionlanguage
2012-06-19
10.1021/ja3026455http://hdl.handle.net/10234/159435