Benzamides derived from 1,2-diaminocyclopropane as novel ligands for human D 2 and D 3 dopamine receptors
作者:Donglai Yang、Slaheddine Kefi、Valérie Audinot、Mark-J. Millan、Michel Langlois
DOI:10.1016/s0968-0896(99)00281-3
日期:2000.2
Benzamides (3a-f) derived from 4-amino-5-chloro-2-methoxybenzoic acid and either cis or trans 1,2-diamino cyclopropane were synthesised and were evaluated in binding assays employing, bovine striatal D-2 receptors, recombinant human hD(2) and hD(3) receptors expressed in CHO cells and rat, cortical 5-HT3 and striatal 5-HT4 receptors. The cis and trans isomers of the derivatives were isolated and characterised. The results demonstrated the superiority of the cis conformers over the trans conformers in dopamine receptor binding assays (K-i hD(2) = 13.4 and 6.9 nM and K-i hD(3) = 17.7 and 4.5 nM for the cis-3b and cis-3f compounds, respectively; K-i hD(2) = 816 and >1000 nM and K-i hD(3) = 469 and >1000 nM for the corresponding trans-3b and trans-3f compounds respectively). The cis compounds are folded: the benzamide group and the basic nitrogen atom were in a syn relationship. Compound 3f can be superimposed with a conformation of the tropane derivative, BRL 25594, having the benzyl group in an axial position to give a suitable fit, indicating that both compounds may have a common binding site in the dopamine receptor. (C) 2000 Elsevier Science Ltd. All rights reserved.