Computer-aided design, synthesis and biological assay of p-methylsulfonamido phenylethylamine analogues

Class III antiarrhythmic agents selectively delay the effective refractory period (ERP) and increase the transmembrance action potential duration (APD). Based on our previous studies, a set of 17 methylsulfonamido phenylethylamine analogues were investigated by 3D-QSAR techniques of CoMFA and CoMSIA. The 3D-QSAR models proved a good predictive ability, and could describe the steric, electrostatic and hydrophobic requirements for recognition forces of the receptor site. According to the clues provided by this 3D-QSAR analysis, we designed and synthesized a series of new analogues of methanesulfonamido phenylethylamine (VIa–i). Pharmacological assay indicated that the effective concentrations of delaying the functional refractory period (FRP) 10 ms of these new compounds have a good correlation with the 3D-QSAR predicted values. It is remarkable that the maximal percent change of delaying FRP in μM of compound VIc is much higher than that of dofetilide. The results showed that the 3D-QSAR models are reliable.