A DFT study of inclusion complexes of the antituberculosis drugs pyrazinamide and isoniazid with cucurbit[7]uril

Complexation behavior of the antituberculosis drugs pyrazinamide and isoniazid with cucurbit[7]uril are investigated with B3LYP, M06-2X, and WB97x-D based density functional theories with 6-31G and 6-31G++ basis set in vacuum and in water. Complexation, interaction and deformation energies, geometries, chemical reactivity, thermodynamic parameters have been investigated. The obtained results clearly indicate that the formed complexes are energetically favored. The most reactive sites in the complexes were identified by molecular electrostatic potential map. Finally, charge transfer between the donor and acceptor orbital of pyrazinamide, isoniazid and cucurbit[7]uril plays an important role to stabilize the inclusion complexes.