The N-phenylpiperazine structures exhibit very extensive multiple receptor activities including the influencing of α1-adrenoceptors (α1-AR). Their antagonistic activity towards α1-AR is intensively applied in the therapy of cardiovascular system diseases - e. g. hypertension as well as in the treatment of benign prostatic hyperplasia. The limited ratio of selective effect on the specific subtypes of the α1-AR by certain drugs used in the practice (azosine-type structures) leads to multiple side effects which includes postural hypotension, syncope or first dose phenomena. The existence of multiple α1-AR subtypes holds promise for the discovery, projection and development of more specific selective drug molecules targeting only one α1-adrenoceptor subtype and making them free from side effects. Towards this aim wide-ranging modifications have been reported in the literature on the "basic" structure of the N-phenylpiperazine-based molecules. The present paper deals with the affinity features of (substituted) N-phenylpiperazines towards α1-ARs in which the structure is a connecting chain formed by (unsubstituted) ethane-1,2-diyl moiety bonded through certain atom or group (S, O, NH, NHCO-fragment, respectively) at the lipophilic part of the molecule.
