Imidazopyridine Cb2 Agonists: Optimization Of Cb2/Cb1 Selectivity And Implications For In Vivo Analgesic Efficacy

A new series of imidazopyridine CB2 agonists is described. Structural optimization improved CB2/CB1 selectivity in this series and conferred physical properties that facilitated high in vivo exposure, both centrally and peripherally. Administration of a highly selective CB2 agonist in a rat model of analgesia was ineffective despite substantial CNS exposure, while administration of a moderately selective CB2/CB1 agonist exhibited significant analgesic effects. (C) 2011 Elsevier Ltd. All rights reserved.