topological polar surface area

The public tpsa function computes the topological polar surface area for an input molecule. It uses a table of atomic surface areas and atomic smarts pattens. The function consists solely of the following SQL statement:

Select sum(atom_psa*ob.count_matches($1,smarts)) from oc.tpsa;

1. The ob.count_matches function uses the atomic_smarts column of the tpsa table to return how many of each type of atom occurs in the structure.
2. The (built-in)sum aggregate function sums up the atomic areas stored in the atom_psa column of the tpsa table.

For description of the methodology see: P. Ertl, B. Rohde, P. Selzer, Fast Calculation of Molecular Polar Surface Area as a Sum of Fragment-based Contributions and Its Application to the Prediction of Drug Transport Properties, J.Med.Chem. 43, 3714-3717, 2000