ORIGINAL ARTICLES Department of Bioorganic Chemistry, Chair of Organic Chemistry1; Department of Pharmacodynamics2; Department of Cytobiology and Histochemistry, Laboratory of Pharmacobiology3, Faculty of Pharmacy Medical College; Faculty of Chemistry4, Jagiellonian University Krakow, Poland Synthesis, ␣-adrenoceptors affinity and ␣1-adrenoceptor antagonistic properties of some 1,4-substituted piperazine derivatives H. Marona 1, M. Kubacka 2, B. Filipek 2, A. Siwek 3, M. Dybała 3, E. Szneler 4, T. Pociecha 1, A. Gunia 1, A. M. Waszkielewicz 1 Received March 24, 2011, accepted April 25, 2011 Dr. Anna M. Waszkielewicz, Department of Bioorganic Chemistry, Chair of Organic Chemistry, Faculty of Pharmacy, Jagiellonian University Medical College, 9 Medyczna Street, 30-688 Krakow, Poland
[email protected] Pharmazie 66: 733–739 (2011) doi: 10.1691/ph.2011.1543 A series of different 1,4-substituted piperazine derivatives (1–11) was synthesized. It comprised 1- (substituted-phenoxyalkyl)-4-(2-methoxyphenyl)piperazine derivatives (1–5); 1,4-bis(substituted-phenoxy- ethyl)piperazine derivatives (6–8) and 1-(substituted-phenoxy)-3-(substituted-phenoxyalkylpiperazin-1- yl)propan-2-ol derivatives (9–11). All compounds were evaluated for affinity toward ␣1- and ␣2-receptors by radioligand binding assays on rat cerebral cortex using [3H]prazosin and [3H]clonidine as specific radioli- gand, respectively. Furthermore ␣1-antagonistic properties were checked for most promising compounds (1–5 and 10) by means of inhibition of phenylephrine induced contraction in isolated rat aorta. Antago- nistic potency stayed in agreement with radioligand binding results. The most active compounds (1–5) 3 displaced [ H]prazosin from cortical binding sites in low nanomolar range (Ki = 2.1−13.1 nM).