Discovery of an enantiopure N-[2-hydroxy-3-phenyl piperazine propyl]-aromatic carboxamide derivative as highly selectiveα_(1D/1A)-adrenoceptor antagonist and homology modelling

α_(1)-Adrenergic receptor(AR)blockers can be effective for the treatment of benign prostatic hyperplasia/lower urinary tract symptoms(BPH/LUTS),their usage is limited by cardiovascular-related side effects that are caused by the subtype nonselective nature or low selectivity of many current drugs.We previously reported that phenylpiperazine analogues with amide and propane linker were moderateα_(1D/1A)adrenoceptor antagonists and exhibited better anti-BPH effect than lead compound naftopidil(NAF)in vivo,however,with modestα_(1D/1A)-subtype selectivity.Herein,we replaced propane moiety with2-hydroxypropanol linker and synthesized twenty-seven racemic derivatives with modified aromatic and hetero aromatic groups.Of these new compounds,quinoline surrogate 17 exhibited extremely weak antagonistic affinity onα_(1B)in both cell-based calcium assay and tissue-based functional assay,so that elicited significantα_(1A/1B)andα_(1D/1B)selectivity.Intriguingly,the R enantiomer of 17 preferentially displayed superior anti-BPH effect in rat model compared with S-17,supporting ligand regulates the receptor in a highly stereospecific manner.Finally,the computer-aided modelling research was also performed in order to deeply understand the unique binding mode of R-17 in complex withα_(1A)and the subtype receptor selectivity for R-17 was also rationalized in this study.Taken together,our work enriched the diversity of phenylpiperazines for the treatment of BPH/LUTS,and provided a basis for discovery ofα_(1D/1A)-selective ligands.