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HSP Application note #57

logP, logKow estimation accuracy


HSPiP Team Senior Developer, Dr. Hiroshi Yamamoto


If you have the Smiles or InChI molecular structure, you can estimate logP (logKow) very easily with HSPiP.

HSPiP(Hansen Solubility Parameters in Practice)

The first edition of HSPiP that appeared in November, 2008, greatly enhanced the usefulness of the Hansen solubility parameters (HSP).

The HSP values of over 1200++ chemicals and 500 polymers are provided in convenient electronic format and have been revised and updated using the latest data sources in the second edition (March, 2009).

A third edition of the HSPiP appeared in March, 2010. There are now 10,000 compounds in the HSP file which also includes data on density, melting point, boiling point, critical parameters, Antoine constants and much more. The user is able to carry out many different sorts of optimisations of solubility, evaporation, diffusion, adhesion, create their own datasets (automatically if required) and explore the huge range of applications for HSP in coatings, paints, nanoparticles, cosmetics, pharma, organic photovoltaics and much more.

The 3rd Edition v3.1 was released on 12 December 2010. Current users can upgrade free (now v3.1.09) by downloading the latest .msi installer from http://hansen-solubility.com

The 4th Edition v4.0.x was released on 2 Jan. 2013. The Current users can upgrade with free charge.

2013.1.28 The Visual How to manual of HSPiP. You can understand what HSPiP can do.
Please check the Functional Group List whether your targets are available with HSPiP.
How to purchase HSPiP
2013..1.2 The HSPiP ver. 4 include Power Tools for HSPiP power user.


Smiles(Simplified Molecular Input Line Entry Syntax)

SMILES is a string obtained by printing the symbol nodes encountered in a depth-first tree traversal of a chemical graph.
"Organic subset" of B, C, N, O, P, S, F, Cl, Br, and I, brackets can be omitted.
Branches are described with parentheses, as in CCC(=O)O for propionic acid
Double and triple bonds are represented by the symbols '=' and '#'
Ring closure labels are used to indicate connectivity between non-adjacent atoms in the SMILES

Pirika JAVA Demo Applet getting Smiles. Draw2Smiles is available here.
Now we have Power Tool "Draw 2 Smiles", GUI HTML5 software on HSPiP ver. 4.


Just input Smiles structure in TextField
Push calculate button
Get result.

If you want to know how to draw molecules, please refer to Power Tools applications. The full version of this estimation routine is implemented into Y-Predict Powert Tools in HSPiP ver. 4.

Program break molecule into functional groups and estimate properties.
Now I finished build new Y-MB ver. 3.1 and checking the accuracy.

I found the logP data for hormonally active agents (endocrine disrupting chemicals).


At first, I need to get the Smiles molecular structures. I searched in our HSPiP database. Almost all these compounds are already exist in our database and determined HCode (Hansen Code).
Once I get the Smiles molecular structures, I can easily get all estimated properties.

The only one molecule (HCode=21051) is out of the Line.

HCode 21051
HCode 20877
HCode 20927

HCode 20928
HCode 20929
HCode 20931

Compare with the similar compounds' logP, 3.18 is too small and predicted value 6.27 is very reasonable.

Above the HP, they listed SciQSAR and ScilogP estimation result. (I don't know which version they use)
But I can say, Y-MB ver. 3.1 have very good accuracy.

If you have other papers that list molecules and logP, please send me.
I will confirm my method.

If you are interested in logP and Hansen Solubility parameters, then please refer to this article.
If you are interested in hormonally active agents (endocrine disrupting chemicals), please refer to this article


Volatile Organic Compounds (VOC) Prediction Result.