6-Methoxy-N-alkyl isatin acylhydrazone derivatives as a novel series of potent selective cannabinoid receptor 2 inverse agonists: design, synthesis, and binding mode prediction

J Med Chem. 2009 Jan 22;52(2):433-44. doi: 10.1021/jm801353p.


Recently, we discovered and reported a series of N-alkyl isatin acylhydrazone derivatives that are potent CB2 agonists. Here, we describe a novel series of selective CB2 inverse agonists resulting from introduction of a methoxy moiety in position 6 of the isatin scaffold. These novel 6-methoxy-N-alkyl isatin acylhydrazone derivatives exhibited high CB2 functional activity and selectivity at human CB2. Compound 16 (MDA77) had high activity (EC(50) = 5.82 nM) at CB2 and no activity at CB1. Compound 15 (MDA55) (K(i) = 89.9 nM, EC(50) = 88.2 nM at CB2) inhibited the effect of compound 1 (MDA7), a selective CB2 agonist, in an animal model of neuropathic pain. The molecular modeling study presented here represents a first study of CB2 based on the structure of beta(2)-adrenergic receptor. A ligand-based homology model of the CB2 binding site was developed, and on the basis of our results, we propose a general binding mode for this class of inverse agonists with CB2.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Crystallography, X-Ray
  • Hydrazones / chemical synthesis
  • Hydrazones / chemistry
  • Hydrazones / metabolism
  • Hydrazones / pharmacology*
  • Hydrogen Bonding
  • Isatin / chemistry*
  • Magnetic Resonance Spectroscopy
  • Models, Molecular
  • Molecular Structure
  • Protein Binding
  • Receptor, Cannabinoid, CB2 / agonists*
  • Receptor, Cannabinoid, CB2 / metabolism


  • Hydrazones
  • Receptor, Cannabinoid, CB2
  • Isatin