Cannabilactones: a novel class of CB2 selective agonists with peripheral analgesic activity

J Med Chem. 2007 Dec 27;50(26):6493-500. doi: 10.1021/jm070441u. Epub 2007 Nov 27.


The identification of the CB2 cannabinoid receptor has provided a novel target for the development of therapeutically useful cannabinergic molecules. We have synthesized benzo[ c]chromen-6-one analogs possessing high affinity and selectivity for this receptor. These novel compounds are structurally related to cannabinol (6,6,9-trimethyl-3-pentyl-6 H-benzo[ c]chromen-1-ol), a natural constituent of cannabis with modest CB2 selectivity. Key pharmacophoric features of the new selective agonists include a 3-(1',1'-dimethylheptyl) side chain and a 6-oxo group on the cannabinoid tricyclic structure that characterizes this class of compounds as "cannabilactones." Our results suggest that the six-membered lactone pharmacophore is critical for CB2 receptor selectivity. Optimal receptor subtype selectivity of 490-fold and subnanomolar affinity for the CB2 receptor is exhibited by a 9-hydroxyl analog 5 (AM1714), while the 9-methoxy analog 4b (AM1710) had a 54-fold CB2 selectivity. X-ray crystallography and molecular modeling show the cannabilactones to have a planar ring conformation. In vitro testing revealed that the novel compounds are CB2 agonists, while in vivo testing of cannabilactones 4b and 5 found them to possess potent peripheral analgesic activity.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Analgesics / chemical synthesis*
  • Analgesics / chemistry
  • Analgesics / pharmacology
  • Animals
  • Binding, Competitive
  • Chromones / chemical synthesis*
  • Chromones / chemistry
  • Chromones / pharmacology
  • Crystallography, X-Ray
  • Lactones / chemical synthesis*
  • Lactones / chemistry
  • Lactones / pharmacology
  • Male
  • Mice
  • Models, Molecular
  • Molecular Conformation
  • Prosencephalon / metabolism
  • Radioligand Assay
  • Rats
  • Rats, Sprague-Dawley
  • Receptor, Cannabinoid, CB1 / metabolism
  • Receptor, Cannabinoid, CB2 / agonists*
  • Receptor, Cannabinoid, CB2 / metabolism
  • Spleen / metabolism
  • Synaptosomes / metabolism


  • 3-(1,1-dimethyl-heptyl)-1-9-dihydroxy-benzo(c)chromen-6-one
  • 3-(1,1-dimethyl-heptyl)-1-hydroxy-9-methoxy-benzo(c)chromen-6-one
  • Analgesics
  • Chromones
  • Lactones
  • Receptor, Cannabinoid, CB1
  • Receptor, Cannabinoid, CB2