The mapping of the electrostatic potential is an established technique for investigation of biologically active compounds because it plays a key role in the initial steps of ligand-receptor interactions. The formatted checkpoint files of the compounds generated by the geometric optimization computation were used as input for CUBEGEN program interfaced with Gaussian 03 program to compute the MESP. The MESP isopotential surfaces was produced and superimposed onto the total electron density surface (0.0004 e/au 3 ). The electrostatic potential of the whole molecule is finally obtained by superimposing the electrostatic potentials upon the total electron density surface of the compound.