Affinity and activity profiling of unichiral 8-substituted 1,4-benzodioxane analogues of WB4101 reveals a potent and selective α1B-adrenoceptor antagonist
作者:Laura Fumagalli、Marco Pallavicini、Roberta Budriesi、Marco Gobbi、Valentina Straniero、Michael Zagami、Giuseppe Chiodini、Cristiano Bolchi、Alberto Chiarini、Matteo Micucci、Ermanno Valoti
DOI:10.1016/j.ejmech.2012.09.049
日期:2012.12
Unichiral 8-substituted analogues of 2-[(2-(2,6-dimethoxyphenoxy)ethyl)aminomethyl]-1,4-benzodioxane (WB4101) were synthesized and tested for binding affinity at cloned human alpha(1a), alpha(1b)-and alpha(1d)-adrenoreceptor (alpha(1a)-, alpha(1b)-and alpha(1d)-AR) and at native rat 5-HT1A receptor and for antagonist affinity at MIA". affrand am-AR and at a2A/D-AR. Among the selected 8-substituents, namely fluorine, chlorine, methoxyl and hydroxyl, only the last caused significant decrease of alpha(1) binding affinity in comparison with the lead compound. Functional tests on the S isomers confirmed the detrimental effect of OH positioned in proximity to benzodioxane O(1). For the other three substituents (F, Cl, OMe), the alp and the am antagonist affinities were generally lower than the alpha(1a) and alpha(1d) binding affinities, but not the alpha(1B) antagonist affinity, which was similar and sensibly higher compared to alpha(1b) binding affinity in the case of F and OMe respectively. This trend confers significant alpha(1B)-AR selectivity, in particular, to the 8-methoxy analogue of (S)-WB4101, a new potent (pA(2) 9.58) alpha(1B)-AR antagonist. The S enantiomers of all the tested compounds were proved to act as al-AR inverse agonists in a vascular model. (C) 2012 Elsevier Masson SAS. All rights reserved.