部分モル体積補正を伴う溶媒和の3D-RISM-KH分子理論からのオクタノール水分配係数

オクタノール水係数係数は、化合物の疎水性/親水性特性を記述するために広く使用されている重要な物理化学的特性です。パーティション係数は、水からオクタノールへの化合物の移動自由エネルギーに関連しています。ここでは、統計的メカニカル、3D-RISM-KH分子溶媒和理論に基づいて、パーティション係数を予測するための新しいプロトコルを導入します。It was shown recently that with the compound-solvent correlation functions obtained from the 3D-RISM-KH molecular theory of solvation, the free energy functional supplemented with the correction linearly related to the partial molar volume obtained from the Kirkwood-Buff/3D-RISM theory, also called the "universal correction" (UC), provides accurate prediction of the hydration free energy of small compounds, compared to explicit solvent molecular dynamics [パーマー、D。S。;J. Phys。：condens。Matter 2010、22、492101]。ここでは、UCがそれに応じてリパラメトリ化されているため、この理論は、非極性溶媒（1-オクタノール）の溶媒和自由エネルギーの実験データとも優れた一致を提供し、オクタノール水パーティション係数を正確に予測することを報告します。Kovalenko-Hirata（KH）およびGaussian Fluctuation（GF）溶媒和自由エネルギー（GF）機能の性能は、UCの有無にかかわらず、多様な官能基を持つ小さな化合物の大きなライブラリでテストされています。オクタノール水パーティション係数の実験データとの最良の一致は、KH-UC溶媒和自由エネルギー機能で得られます。

The octanol-water partition coefficient is an important physical-chemical characteristic widely used to describe hydrophobic/hydrophilic properties of chemical compounds. The partition coefficient is related to the transfer free energy of a compound from water to octanol. Here, we introduce a new protocol for prediction of the partition coefficient based on the statistical-mechanical, 3D-RISM-KH molecular theory of solvation. It was shown recently that with the compound-solvent correlation functions obtained from the 3D-RISM-KH molecular theory of solvation, the free energy functional supplemented with the correction linearly related to the partial molar volume obtained from the Kirkwood-Buff/3D-RISM theory, also called the "universal correction" (UC), provides accurate prediction of the hydration free energy of small compounds, compared to explicit solvent molecular dynamics [ Palmer , D. S. ; J. Phys.: Condens. Matter 2010 , 22 , 492101 ]. Here we report that with the UC reparametrized accordingly this theory also provides an excellent agreement with the experimental data for the solvation free energy in nonpolar solvent (1-octanol) and so accurately predicts the octanol-water partition coefficient. The performance of the Kovalenko-Hirata (KH) and Gaussian fluctuation (GF) functionals of the solvation free energy, with and without UC, is tested on a large library of small compounds with diverse functional groups. The best agreement with the experimental data for octanol-water partition coefficients is obtained with the KH-UC solvation free energy functional.