A-834,735 is a drug developed by Abbott Laboratories that acts as a potent cannabinoidreceptorfull agonist at both the CB1 and CB2 receptors, with a Ki of 12 nM at CB1 and 0.21 nM at CB2. Replacing the aromatic 3-benzoyl or 3-naphthoyl group found in most indole derived cannabinoids with the 3-tetramethylcyclopropylmethanone group of A-834,735 and related compounds imparts significant selectivity for CB2, with most compounds from this group found to be highly selective CB2 agonists with little affinity for CB1. However, low nanomolar CB1binding affinity is retained with certain heterocyclic 1-position substituents such as (N-methylpiperidin-2-yl)methyl (cf. AM-1220, AM-1248), or the (tetrahydropyran-4-yl)methyl substituent of A-834,735, resulting in compounds that still show significant affinity and efficacy at both receptors despite being CB2 selective overall.[1][2][3][4][5]
^Dart M, Frost J, Tietje K, Daza A, Grayson G, Fan Y, et al. (2006). "1-Alkyl-3-keto-indoles: identification and in vitro characterization of a series of potent cannabinoid ligands". 2006 Symposium on the Cannabinoids. Burlington, VT: International Cannabinoid Research Society.