Development of pharmacophores for inhibitors of the rapid component of the cardiac delayed rectifier potassium current

Blockade of cardiac-delayed rectifier potassium current (IKr) is an important mechanism for Class III antiarrhythmic effect. We developed pharmacophores for IKr inhibitors starting from structures of known blockers. To obtain the pharmacophores, DISCO module of SYBYL was used. Conformations required for DISCO computations were provided by Multisearch type conformational analyses. A common five-point three-dimensional relationship was identified for the most active compounds, whereas a four-point pharmacophore forming a subset of the former one, could be developed for less potent agents.