Synthesis, 3D-pharmacophore modelling and 2D-QSAR study of new pyridine-3-carbonitriles as vasorelaxant active agents

Abstract

A new set of pyridine-3-carbonitriles (3a–v) conjugated with various five-membered ring systems at pyridinyl C-6 were designed and synthesized as vasorelaxant active agents. The majority of the new target derivatives exhibited noteworthy vasodilation efficacy and compounds 3b, 3k, 3l, 3m, 3o, 3p, 3s, 3u and 3v were the most potent analogues with IC₅₀ values = 220.7, 256.7, 164.1, 252.2, 229.8, 265.2, 247.9, 239.1 and 159.8 μM, respectively, which were superior to that of prazosin hydrochloride (IC₅₀ = 272.8 μM). Moreover, 3b, 3l, 3o and 3v displayed significant α₁-adrenergic receptor (α₁-AR) blocking efficiency ranging from 65.38 to 87.86% compared with 89.34% for prazosin hydrochloride. Furthermore, a 2D-QSAR study and 3D-pharmacophore model were introduced to carry out compare-fit study for the designed molecules with the generated hypothesis and creating a statistically significant model.