Molecular simulation of the hydration Gibbs energy of barbiturates

• Tipo: Artigo em Revista Científica Internacional
• Data: 2010

Autores

Nuno M. Garrido (Autor) FEUP; Miguel Jorge (Autor) FEUP; António J. Queimada (Autor) FEUP; Ioannis G. Economou (Autor) FEUP; Eugénia A. Macedo (Autor) FEUP

Revista

Título: Fluid Phase Equilibria

Vol. 289 Nº 2

Páginas: 148-155

ISSN: 0378-3812

Editora: Elsevier

Indexação

ISI Web of Knowledge - 15 Citações

ISI Web of Science

Scopus - 16 Citações

Classificação Científica

FOS: Ciências da engenharia e tecnologias > Engenharia química

CORDIS: Ciências Físicas > Química > Química molecular

Outras Informações

ID Authenticus: P-003-898

DOI: 10.1016/j.fluid.2009.11.022

Abstract (EN): In the present work, molecular dynamics calculations of the Gibbs energy of hydration of 10 different substituted barbiturates in SPC/E water were performed using thermodynamic integration. Given that experimental determination of the Gibbs hydration energy for this class of compounds is currently unfeasible, computer simulations appear as the only alternative for the estimation of this important quantity. Several simulation parameters are discussed and optimized based on calculations for barbituric acid. It is concluded that accounting for electrostatic interactions with the Reaction-Field method can be up to two times faster than with Particle-Mesh-Ewald method, without loss of accuracy. Different number of solvent molecules and simulation lengths were also tested. Lennard-Jones and electrostatic contributions were scaled down to zero in an independent way. It is shown that the electrostatic contribution is dominant (representing approximately 90% of the total Gibbs energy of hydration) and that barbiturate intra-molecular interactions cannot be neglected. The importance of the electrostatic contribution is attributed to the formation of hydrogen bonds between the barbiturates and water, which play an important role in the solvation process. The influence of the different substituents and their contribution to the Gibbs energy of hydration was assessed. Finally, the Lennard-Jones contributions and the total hydration Gibbs energy can both be correlated against molecular weight or partition coefficient data for mono- and di-substituted barbiturates.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 8