Synthesis of bivalent β2-adrenergic and adenosine A1 receptor ligands

Research in the area of simutaneously targeting more than one G protein-coupled receptor (GPCR) has increased in recent times. By exploiting the cross talk between the beta(2)-adrenergic (beta(2)AR) and adenosine A(1) receptors (A(1)AR) on adenylate cyclase activity, we synthesized a series of bivalent agonists for both GPCRs to generate responses from more than one receptor. We have demonstrated a relationship between the various beta(2)-adrenergic and A(1) adenosine bivalent parameters of linker and bifunctionality by using data that are drawn from in vitro assays. The hexyl-linked 12e (K-i, 311 nM) and butyl-linked 12c (K-i, 863 nM) bivalent compounds displayed reasonable binding affinities for the PAR when compared with the control (-)isoproterenol (K-i, 136 nM), and both compounds also exhibited a persuasive bifunctional trend for both receptors at various drug concentrations. The bivalent compound 12e was also found to have significant EC50 potency (6 nM) at the beta(2)AR in DDT cells.