Profiling two indole-2-carboxamides for allosteric modulation of the CB1 receptor. Academic Article uri icon


  • Allosteric modulation of G-protein coupled receptors (GPCRs) represents a novel approach for fine-tuning GPCR functions. The cannabinoid CB1 receptor, a GPCR associated with the CNS, has been implicated in the treatment of drug addiction, pain, and appetite disorders. We report here the synthesis and pharmacological characterization of two indole-2-carboxamides:5-chloro-3-ethyl-1-methyl-N-(4-(piperidin-1-yl)phenethyl)-1H-indole-2-carboxamide (ICAM-a) and 5-chloro-3-pentyl-N-(4-(piperidin-1-yl)phenethyl)-1H-indole-2-carboxamide (ICAM-b). Although both ICAM-a and ICAM-b enhanced CP55,940 binding, ICAM-b exhibited the strongest positive cooperativity thus far demonstrated for enhancing agonist binding to the CB1 receptor. Although it displayed negative modulatory effects on G-protein coupling to CB1, ICAM-b induced -arrestin-mediated downstream activation of extracellular signal-regulated kinase (ERK) signaling. These results indicate that this compound represents a novel class of CB1 ligands that produce biased signaling via CB1.

published proceedings

  • J Neurochem

altmetric score

  • 0.25

author list (cited authors)

  • Ahn, K. H., Mahmoud, M. M., Samala, S., Lu, D., & Kendall, D. A.

citation count

  • 28

complete list of authors

  • Ahn, Kwang H||Mahmoud, Mariam M||Samala, Sushma||Lu, Dai||Kendall, Debra A

publication date

  • March 2013