SRC's  WsKow Program

WsKow estimates the water solubility (WSol) of an organic compound using the compounds log octanol-water partition coefficient (Kow). WsKow requires only a chemical structure to estimate Wsol. Structures are entered into WsKow through SMILES (Simplified Molecular Input Line Entry System) notations.

The following journal article describes the estimation methodology:

Meylan, W.M. P.H. Howard and R.S. Boethling. 1996. Improved method for estimating water solubility from octanol/water partition coefficient. Environ. Toxicol. Chem. 15: 100-106.

The newest version of WsKow runs under Windows (3.1, 95, 98, 2000, NT) making the estimation of water solubility more convenient and accurate. Methods for chemical structure input now support SMILES notations as well as chemical structures produced in popular chemical drawing programs. Enhanced features of the Windows version include batch-mode data entry and user functions.

Example Entry / Results (for 2-Nitrotoluene)

A total of 1,450 compounds (941 solids/509 liquids) that had measured values for K_ow, MP, and water solubility were used in the development of the linear regressions used by WsKow. The correlation coefficient for the method was 0.93 and it had a mean error of 0.47. The method was evaluated using a separate validation set of 817 chemicals (482 solids/335 liquids) with measured water solubilities and estimated log Kow values (from SRC's LogKow program) with a resulting correlation coefficient of 0.90 and a mean error of 0.48.