Molecular Alignment and 3D-QSAR Modeling

For 3D-QSAR analyses, 47 compounds were selected as the training set for model construction, and the remaining 11 compounds were selected as the test set for model validation. 

The steric and electrostatic potential fields for CoMFA were calculated at each lattice intersection of a regularly spaced grid of 2.0 A. The lattice was defined automatically, and was extended 4 A units past Van der Waals volume of aU molecules in X, Y, and Z directions. An sp carbon atom with Van der Waals radius 

CoMSIA similarity indices descriptors were derived according to Klebe et al. [18] with the same lattice box used for the CoMFA. CoMSIA similarity indices (Ap) for a molecule j with atoms i at a grid point q are determined as follows  

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