New Serotonin 5-HT<sub>1A</sub> Receptor Agonists Endowed with Antinociceptive Activity <i>in Vivo</i>
作者:Margarita Valhondo、Isabel Marco、Mar Martín-Fontecha、Henar Vázquez-Villa、José A. Ramos、Reinhard Berkels、Thomas Lauterbach、Bellinda Benhamú、María L. López-Rodríguez
DOI:10.1021/jm400766k
日期:2013.10.24
We report the synthesis of new compounds 4-35 based on two different openings (A and B) of the chromane ring present in the previously identified 5-HT1A receptor (5-HT1AR) ligand 3. The synthesized compounds were assessed for binding affinity, selectivity, and functional activity at the 5-HT1AR Selected candidates resulting from B opening were also evaluated for their potential antinociceptive effect in vivo and pharmacokinetic properties in vitro. Analogue 19 [2-(4-[2-(2-ethoxyphenoxy)ethyl]amino}butyl)tetrahydro-1H-pyrrolo[1,2-c]imidazole-1,3(2H)-dione] has been characterized as a high-affinity and potent 5-HT1AR agonist (K-i = 2.3 nM; EC50 = 19 nM). Pharmacokinetic studies indicated that compound 19 displays a good metabolic stability in human liver microsomes (t(1/2) similar to 3 h and CLint = 3.5 mL/min/kg, at 5 mu M), and a low level of protein binding (25%, at 5 mu M). Interestingly, 19 (3 mg/kg, ip, and 30 mg/kg, po) caused significant attenuation of formalin-induced behavior in early and late phases of the mouse intradermal formalin test of pain, and this in vivo effect was reversed by the selective 5-HT1AR antagonist WAY-100635. Thus, the new 5-HT1AR agonist identified in this work, 19, exhibits oral analgesic activity, and the results herein represent a step toward identifying new therapeutics for the control of pain.