Neuroactive flavonoids: new ligands for the Benzodiazepine receptors

Flavonoids isolated from plants used as tranquilizers in folkloric medicine have a selective affinity, for central benzodiazepine receptors (BDZ-Rs) and some of them possess a pharmacological profile compatible with a partial agonist action. Synthetic derivatives of the common flavone nucleus, give rise to high affinity ligands when electronegative groups are introduced in carbons 6 and/or 3′. Representative compounds such as 6,3′-dinitroflavone and, 6-bromo-3′-nitroflavone exhibit a high affinity for the BDZ-Rs (Ki = 1.5 to 30 nM) and have anxiolytic effects not associated with myorelaxant, sedative or amnesic actions.