Substituted 1,2,3,4-tetrahydroquinolin-6-yloxypropanes as β3-adrenergic receptor agonists: Design, synthesis, biological evaluation and pharmacophore modeling

In search of potent beta(3)-adrenergic receptor agonists, a series of novel substituted 1,2,3,4-tetrahydroquinolin-6-yloxypropanes has been synthesized and evaluated for their beta(3)-adrenergic receptor agonistic activity (ranging from -17.73% to 90.64% inhibition at 10 microM) using well established Human SK-N-MC neuroblastoma cells model. Four molecules viz. 11, 15, 22 and 23 showed beta(3)-AR agonistic IC(50) value of 0.55, 0.59, 1.18 and 1.76 microM, respectively. These four candidates have been identified as possible leads for further development of beta(3)-adrenergic receptor agonists for obesity and Type-II diabetes pharmacotherapy. The free OH and NH functions are found to be essential for beta(3)-adrenergic receptor agonistic activity. Among the synthesized beta(3)-adrenergic receptor agonists having 1,2,3,4-tetrahydroquinoline scaffold, the N-benzyl group is found to be superior over N-arylsulfonyl group. A putative pharmacophore model has been modeled considering the above four active molecules which distinguishes well between the active and inactive molecules.