scholarly journals 1-Octanol/Water Partition Coefficients of n-Alkanes from Molecular Simulations of Absolute Solvation Free Energies

2009 ◽  
Vol 5 (9) ◽  
pp. 2436-2446 ◽  
Author(s):  
Nuno M. Garrido ◽  
António J. Queimada ◽  
Miguel Jorge ◽  
Eugénia A. Macedo ◽  
Ioannis G. Economou
Keyword(s):  
Partition Coefficients ◽  
Molecular Simulations ◽  
Free Energies ◽  
Solvation Free Energies

scholarly journals Approaches for calculating solvation free energies and enthalpies demonstrated with an update of the FreeSolv database

2017 ◽  
Author(s):  
Guilherme Duarte Ramos Matos ◽  
Daisy Y. Kyu ◽  
Hannes H. Loeffler ◽  
John D. Chodera ◽  
Michael R. Shirts ◽  
...  
Keyword(s):  
Free Energy ◽  
Organic Molecules ◽  
Molecular Simulations ◽  
General Purpose ◽  
Free Energies ◽  
Energy Functions ◽  
Neutral Compounds ◽  
Aqueous Solvation ◽  
Solvation Free Energies

AbstractSolvation free energies can now be calculated precisely from molecular simulations, providing a valuable test of the energy functions underlying these simulations. Here, we briefly review “alchemical” approaches for calculating the solvation free energies of small, neutral organic molecules from molecular simulations, and illustrate by applying them to calculate aqueous solvation free energies (hydration free energies). These approaches use a non-physical pathway to compute free energy differences from a simulation or set of simulations and appear to be a particularly robust and general-purpose approach for this task. We also present an update (version 0.5) to our FreeSolv database of experimental and calculated hydration free energies of neutral compounds and provide input files in formats for several simulation packages. This revision to FreeSolv provides calculated values generated with a single protocol and software version, rather than the heterogeneous protocols used in the prior version of the database. We also further update the database to provide calculated enthalpies and entropies of hydration and some experimental enthalpies and entropies, as well as electrostatic and nonpolar components of solvation free energies.

scholarly journals Resolving solvophobic interactions inferred from experimental solvation free energies and evaluated from molecular simulations

2017 ◽  
Vol 667 ◽  
pp. 62-67 ◽  
Author(s):  
J. Wesley Barnett ◽  
Amna Bhutta ◽  
Sarah C. Bierbrier ◽  
Natalia da Silva Moura ◽  
Henry S. Ashbaugh
Keyword(s):  
Molecular Simulations ◽  
Free Energies ◽  
Solvophobic Interactions ◽  
Solvation Free Energies

Partition Coefficients of Methylated DNA Bases Obtained from Free Energy Calculations with Molecular Electron Density Derived Atomic Charges.

2018 ◽  
Author(s):  
Alejandro Lara ◽  
Maximiliano Riquelme ◽  
Esteban Vöhringer-Martinez
Keyword(s):  
Electron Density ◽  
Partition Coefficients ◽  
Dna Bases ◽  
Atomic Charges ◽  
Free Energies ◽  
Solvation Model ◽  
Minimal Basis ◽  
Methylated Dna ◽  
Implicit Solvation Model ◽  
Good Agreement

<div> <div> <div> <p>Partition coefficients serve in various areas as pharmacology and environmental sciences to predict the hydrophobicity of different substances. Recently, they have been also used to address the accuracy of force fields for various organic compounds and specifically the methylated DNA bases. In this study atomic charges were derived by different partitioning methods (Hirshfeld and Minimal Basis Iterative Stockholder) directly from the electron density obtained by electronic structure calculations in vac- uum, with an implicit solvation model or with explicit solvation taking the dynamics of the solute and the solvent into account. To test the ability of these charges to describe electrostatic interactions in force fields for condensed phases the original atomic charges of the AMBER99 force field were replaced with the new atomic charges and combined with different solvent models to obtain the hydration and chloroform solvation free energies by molecular dynamics simulations. Chloroform-water partition coefficients derived from the obtained free energies were compared to experimental and previously reported values obtained with the GAFF or the AMBER-99 force field. The results show that good agreement with experimental data is obtained when the polarization of the electron density by the solvent has been taken into account deriving the atomic charges of polar DNA bases and when the energy needed to polarize the electron den- sity of the solute has been considered in the transfer free energy. These results were further confirmed by hydration free energies of polar and aromatic amino acid side chain analogues. Comparison of the two partitioning methods Hirsheld-I and Minimal Basis Iterative Stockholder (MBIS) revealed some deficiencies in the Hirshfeld-I method related to nonexistent isolated anionic nitrogen pro-atoms used in the method. Hydration free energies and partitioning coefficients obtained with atomic charges from the MBIS partitioning method accounting for polarization by the implicit solvation model are in good agreement with the experimental values. </p> </div> </div> </div>

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