RESUMO
Synthetic cannabinoid (SC) designer drugs based on indole and indazole scaffolds and featuring l-valinamide or l-tert-leucinamide side chains are encountered with increasing frequency by forensic researchers and law enforcement agencies and are associated with serious adverse health effects. However, many of these novel SCs are unprecedented in the scientific literature at the time of their discovery, and little is known of their pharmacology. Here, we report the synthesis and pharmacological characterization of AB-FUBINACA, ADB-FUBINACA, AB-PINACA, ADB-PINACA, 5F-AB-PINACA, 5F-ADB-PINACA, ADBICA, 5F-ADBICA, and several analogues. All synthesized SCs acted as high potency agonists of CB1 (EC50 = 0.24-21 nM) and CB2 (EC50 = 0.88-15 nM) receptors in a fluorometric assay of membrane potential, with 5F-ADB-PINACA showing the greatest potency at CB1 receptors. The cannabimimetic activities of AB-FUBINACA and AB-PINACA in vivo were evaluated in rats using biotelemetry. AB-FUBINACA and AB-PINACA dose-dependently induced hypothermia and bradycardia at doses of 0.3-3 mg/kg, and hypothermia was reversed by pretreatment with a CB1 (but not CB2) antagonist, indicating that these SCs are cannabimimetic in vivo, consistent with anecdotal reports of psychoactivity in humans.
Assuntos
Agonistas de Receptores de Canabinoides/farmacologia , Drogas Desenhadas/farmacologia , Indazóis/farmacologia , Indóis/farmacologia , Animais , Temperatura Corporal/efeitos dos fármacos , Agonistas de Receptores de Canabinoides/síntese química , Agonistas de Receptores de Canabinoides/química , Antagonistas de Receptores de Canabinoides/farmacologia , Linhagem Celular Tumoral , Estudos de Coortes , Drogas Desenhadas/síntese química , Drogas Desenhadas/química , Relação Dose-Resposta a Droga , Avaliação Pré-Clínica de Medicamentos , Frequência Cardíaca/efeitos dos fármacos , Humanos , Indazóis/síntese química , Indazóis/química , Indóis/síntese química , Indóis/química , Masculino , Potenciais da Membrana/efeitos dos fármacos , Camundongos , Estrutura Molecular , Ratos Wistar , Receptor CB1 de Canabinoide/agonistas , Receptor CB1 de Canabinoide/antagonistas & inibidores , Receptor CB1 de Canabinoide/genética , Receptor CB1 de Canabinoide/metabolismo , Receptor CB2 de Canabinoide/agonistas , Receptor CB2 de Canabinoide/antagonistas & inibidores , Receptor CB2 de Canabinoide/genética , Receptor CB2 de Canabinoide/metabolismoRESUMO
Synthetic cannabinoid (SC) designer drugs featuring bioisosteric fluorine substitution are identified by forensic chemists and toxicologists with increasing frequency. Although terminal fluorination of N-pentyl indole SCs is sometimes known to improve cannabinoid type 1 (CB1) receptor binding affinity, little is known of the effects of fluorination on functional activity of SCs. This study explores the in vitro functional activities of SC designer drugs JWH-018, UR-144, PB-22, and APICA, and their respective terminally fluorinated analogues AM-2201, XLR-11, 5F-PB-22, and STS-135 at human CB1 and CB2 receptors using a FLIPR membrane potential assay. All compounds demonstrated agonist activity at CB1 (EC50 = 2.8-1959 nM) and CB2 (EC50 = 6.5-206 nM) receptors, with the fluorinated analogues generally showing increased CB1 receptor potency (â¼2-5 times). Additionally, the cannabimimetic activities and relative potencies of JWH-018, AM-2201, UR-144, XLR-11, PB-22, 5F-PB-22, APICA, and STS-135 in vivo were evaluated in rats using biotelemetry. All SCs dose-dependently induced hypothermia and reduced heart rate at doses of 0.3-10 mg/kg. There was no consistent trend for increased potency of fluorinated SCs over the corresponding des-fluoro SCs in vivo. Based on magnitude and duration of hypothermia, the SCs were ranked for potency (PB-22 > 5F-PB-22 = JWH-018 > AM-2201 > APICA = STS-135 = XLR-11 > UR-144).