MacroModel Example: Partition Coefficient Estimation

Below is an example of a command file for conducting log Poctanol,water calculations on a series of molecules. It is very similar to that used for multiple minimization of non-conformers.

 
logP.mae
logP-out.mae
 FFLD      11      1      0      1     1.0000     0.0000     0.0000     0.0000
 BDCO       0      0      0      0    41.5692 99999.0000     0.0000     0.0000
 SOLV       3      9      0      0     0.0000     0.0000     0.0000     0.0000
 LOGP       1      1      1      0     0.0000     0.0000     0.0000     0.0000
 BGIN       0      0      0      0     0.0000     0.0000     0.0000     0.0000
 READ       0      0      0      0     0.0000     0.0000     0.0000     0.0000
 AUTO       0     -1      0      0     0.0000     1.0000     0.0000     0.0000
 CONV       2      0      0      0     0.0500     0.0000     0.0000     0.0000
 MINI       1      0   5000      0     0.0000     0.0000     0.0000     0.0000
 END        0      0      0      0     0.0000     0.0000     0.0000     0.0000

SOLV: Specifies the first, or primary, solvent. Arg2 = 9 corresponds to octanol.

LOGP: Turns on partition coefficient estimation and specifies the second solvent. Arg2 = 1 corresponds to water.

AUTO: Necessary for the proper processing of LOGP calculations. Arg2 = −1 instructs AUTO not to make a list of comparison atoms, and arg6 = 1.0000 indicates that this is a serial calculation.

In the .log file produced when such a calculation is run, a report appears for each ligand processed:

 =====================================
 LOGP(octanol,water) Calculation for ligand #  1
 Ligand Name:  Case74C
 LOGP(octanol,water) =   1.41024
 =====================================

and a table appears at the end of the .log file:

=====================================
  LOGP(octanol,water) Results
 
 Ligand     Solvation Free Energies    LOGP(octanol,water)   Converged
             octanol         water
             kJ/mol.      kJ/mol.
     1        -26.99        -18.94          1.41            T
     2        -20.93        -12.48          1.48            T
     3        -20.02        -11.02          1.58            T
     4        -29.41        -16.19          2.32            T
...
    12        -16.84        -15.40          0.25            T
 =====================================

Here, T or F in the Converged column signifies whether or not the minimizations (one in each solvent for each molecule) converged. If they did not converge, the results should not be considered reliable.