New-generation azaindole-adamantyl-derived synthetic cannabinoids

Purpose: This work reports the synthesis and pharmacological and analytical data for a new series of recently identified azaindole-adamantyl-derived synthetic cannabinoids (SCs). Methods: Each SC was synthesised using an efficient and divergent synthesis, and assessed by electron ionisation mass spectrometry (EIMS). The cannabimimetic activity of each compound was conducted using a fluorometric imaging plate reader (FLIPR) assay. Results: The described EIMS method and retention time by gas chromatography were able to effectively differentiate each of the analogues regardless of the bicyclic core. For the first time in these SC structures, the bicyclic ring system was shown to have an impact on the cannabimimetic activities in the fluorometric assay of membrane potential. Analogues ranged from moderately potent at both CB₁ and CB₂ (e.g., AP4AIC EC₅₀ = 160 nM and EC₅₀ = 64 nM, respectively) to not active at either cannabinoid receptor (AP4AICA, AP5AICA, and APIC). Conclusions: Further investigation into receptor selectivity surrounding these bicyclic cores could prove useful for future therapeutic applications.