Investigations on the 4-quinolone-3-carboxylic acid motif. 3. Synthesis, structure-affinity relationships, and pharmacological characterization of 6-substituted 4-quinolone-3-carboxamides as highly selective cannabinoid-2 receptor ligands.

Serena Pasquini, Alessia Ligresti, Claudia Mugnaini, Teresa Semeraro, Lavinia Cicione, Maria De Rosa, Francesca Guida, Livio Luongo, Maria De Chiaro, Maria Grazia Cascio, Daniele Bolognini, Pietro Marini, Roger Guy Pertwee, Sabatino Maione, Vincenzo Di Marzo, Federico Corelli

Research output: Contribution to journalArticlepeer-review

34 Citations (Scopus)


A set of quinolone-3-carboxamides 2 bearing diverse substituents at position 1, 3, and 6 of the bicyclic nucleus was prepared. Except for six compounds exhibiting K-i > 100 nM, all the quinolone-3-carboxamides 2 proved to be high affinity CB2 ligands, with K-i values ranging from 73.2 to 0.7 nM and selectivity [SI = K-i(CB1)/K-i(CB2)] varying from > 14285 to 1.9, with only 2ah exhibiting a reverse selectivity (SI < 1). In the formalin test of peripheral acute and inflammatory pain in mice, 2ae showed analgesic activity that was antagonized by a selective CB2 antagonist. By contrast, 2e was inactive per se and antagonized the effect of a selective CB2 agonist. Finally, 2g and 2p exhibited CB2 inverse agonist-like behavior in this in vivo test. However, two different functional assays carried out in vitro on 2e and 2g indicated for both compounds an overall inverse agonist activity at CB2 receptors.

Original languageEnglish
Pages (from-to)5915-5928
Number of pages14
JournalJournal of Medicinal Chemistry
Issue number16
Early online date27 Jul 2010
Publication statusPublished - 26 Aug 2010


  • Amides
  • Analgesics
  • Animals
  • CHO Cells
  • Cricetinae
  • Cricetulus
  • Drug Inverse Agonism
  • Humans
  • Ligands
  • Mice
  • Pain Measurement
  • Quinolones
  • Radioligand Assay
  • Receptor, Cannabinoid, CB2
  • Stereoisomerism
  • Structure-Activity Relationship

Cite this