Theoretical studies on the conformational properties and pharmacophoric pattern of several bipyridine cardiotonics

Conformational features of two bipyridine cardiotonics viz., amrinone and milrinone have been examined by an ab initio(STO-3-21 G level) method. The calculated results suggest a twisted conformation for both molecules. Molecular electrostatic potential calculations have been carried out on various conformers of these molecules to visualize their pharmacophoric patterns. The results suggest that the twisted conformers of these molecules are responsible for their observed cardiotonic properties.