Cannabidiol–recent advances. 17 Jul Dr D The antinociceptive effect of 2-chloro-2′-C-methyl-N6-cyclopentyladenosine (2′-Me-CCPA), a highly selective adenosine A1 receptor agonist, in the rat. Cannabidiol displays unexpectedly high potency as an antagonist of CB1 and CB2 receptor agonists in vitro