Presentation on theme: "Pool of the fragments is predefined inside the logP calculator program. A unique name and a calculated value is assigned to each fragments. logP of a molecule."— Presentation transcript:
Pool of the fragments is predefined inside the logP calculator program. A unique name and a calculated value is assigned to each fragments. logP of a molecule is calculated as the sum of the unique value of the appropiate fragments. logP calculation We implemented 120 fragments altogether. f1f1 f2f2 f3f3 f4f4 f5f5 f6f6 f7f7 f8f8 f9f9 f 10 f 11 f 12 f 13 f 14 logP=sum of f i values (i=1…14)
The value of fifi depends on the training set. The prevoious versions of the logP calculator has only one logP fragment set The latest version of the logP calculator was extended with two more fragments set. Training set based on the ref.2. Training set based on the Physprop database Training set based on the ref.1.
Teaching of the logP calculator is possible with the latest version of the logP calculator. fifi It means that the value offragments can be calculated from an external users training set. Multiple regression analysis User defined fragment set Users training set ….
This is the option panel of the logP calculator in the Marvins GUI. Three+1 frgament sets can be used. Weigthed combination of the 3(4) logP methods
Zwitterionic molecule is quasi-neutral at its isoelectric point. logP of zwitterion like molecules calculated at pH=pI logP of a neutral zwitterionic molecule = logD at pI. The logP=-2.83 because the logD=-2.83 at pH=5.98
Test result of the logP calculation References: 1.Viswanadhan, V. N.; Ghose, A. K.; Revankar, G. R.; Robins, R. K., J. Chem. Inf. Comput. Sci., 1989, 29, 163-172; 2.Klopman, G.; Li, Ju-Yun.; Wang, S.; Dimayuga, M.: J.Chem.Inf.Comput.Sci., 1994, 34, 752;