JWH-424 is a drug from the naphthoylindole family, which acts as a cannabinoid agonist at both the CB1 and CB2receptors, but with moderate selectivity for CB2, having a Ki of 5.44nM at CB2 vs 20.9nM at CB1. The heavier 8-iodo analogue is even more CB2 selective, with its 2-methyl derivative having 40x selectivity for CB2. However the 1-propyl homologues in this series showed much lower affinity at both receptors, reflecting a generally reduced affinity for the 8-substituted naphthoylindoles overall.
^Valerie Smith, John Huffman, Jenny Wiley and Billy Martin. EFFECTS OF HALOGEN SUBSTITUENTS UPON CB1 AND CB2 RECEPTOR AFFINITIES IN THE SERIES OF N-ALKYL-3-(8-HALO-1-NAPTHOYL)INDOLES. (2007) 17th Annual Symposium on the Cannabinoids, Burlington, Vermont, International Cannabinoid Research Society, Page 72.
^John W. Huffman, et al. STRUCTURE-ACTIVITY RELATIONSHIPS AT THE CB1 AND CB2 RECEPTORS FOR 1-ALKYL-3-(1-NAPHTHOYL-4 AND 8-HALOGEN SUBSTITUTED) INDOLES (2009) 19th Annual Symposium on the Cannabinoids, Burlington, Vermont, International Cannabinoid Research Society, Page 2.