Synthesis, α-adrenoceptors affinity and α1-adrenoceptor antagonistic properties of some 1,4-substituted piperazine derivatives
作者:Marona、Kubacka、Filipek、Siwek、Dybala、Szneler、Pociecha、Gunia、Waszkielewicz, Anna M.
DOI:10.1691/ph.2011.1543
日期:——
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-phenoxyethyl)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 α1- and α2-receptors by radioligand binding assays on rat cerebral cortex using [3H]prazosin and [3H]clonidine as specific radioligand, respectively. Furthermore α1-antagonistic properties were checked for most promising compounds (1–5 and 10) by means of inhibition of phenylephrine induced contraction in isolated rat aorta. Antagonistic potency stayed in agreement with radioligand binding results. The most active compounds (1–5) displaced [3H]prazosin from cortical binding sites in low nanomolar range (Ki = 2.1–13.1 nM). Compound 10 showed slightly lower affinity for α1-adrenoceptor (Ki = 781 nM). Compounds 2–5 displayed the strongest antagonistic activity with pA2 values ranging from 8.441 to 8.807. Compound 1 gave a pA2 value of 7.868, while compound 10 showed the weakest antagonistic potency, giving a pA2 value of 6.374. 1-[3-(2-Chloro-6-methylphenoxy)propyl]-4-(2-methoxyphenyl)piperazine hydrochloride (5) showed the best α1- affinity properties with a Ki(α1) value of 2.1 nM and it was 61.05 fold more selective toward α1 than α2-receptors. The best properties showed 1-[3-(2,6-dimethylphenoxy)propyl]-4-(2-methoxyphenyl)piperazine hydrochloride (4) with a Ki(α1) value of 2.4 nM, a 142.13 fold better selectivity to α1- over α2-adrenoceptors and the best antagonistic potency (pA2 = 8.807). It is worth to emphasized that all most promising compounds possessed an 1-(o-methoxyphenyl)piperazine moiety which probably plays an important role in the affinity to α-adrenoceptors.
合成了一系列不同的 1,4 取代哌嗪衍生物 (1-11)。其中包括 1-(取代的苯氧基烷基)-4-(2-甲氧基苯基)哌嗪衍生物(1-5)、1,4-双(取代的苯氧基乙基)哌嗪衍生物(6-8)和 1-(取代的苯氧基)-3-(取代的苯氧基烷基哌嗪-1-基)丙-2-醇衍生物(9-11)。通过在大鼠大脑皮层分别使用[3H]哌唑嗪和[3H]氯尼丁作为特异性放射性配体进行放射性配体结合试验,评估了所有化合物对α1-和α2-受体的亲和力。此外,通过抑制离体大鼠主动脉中由苯肾上腺素引起的收缩,检测了最有希望的化合物(1-5 和 10)的α1-拮抗特性。拮抗效力与放射性配体结合结果保持一致。活性最强的化合物(1-5)在低纳摩尔范围内(Ki = 2.1-13.1 nM)将[3H]哌唑嗪从皮质结合位点移出。化合物 10 对 α1 肾上腺素受体的亲和力稍低(Ki = 781 nM)。化合物 2-5 显示出最强的拮抗活性,pA2 值在 8.441 到 8.807 之间。化合物 1 的 pA2 值为 7.868,而化合物 10 的拮抗效力最弱,pA2 值为 6.374。1-[3-(2- 氯-6-甲基苯氧基)丙基]-4-(2-甲氧基苯基)哌嗪盐酸盐(5)显示出最佳的 α1 亲和性,Ki(α1) 值为 2.1 nM,它对α1 受体的选择性比对α2 受体的选择性高 61.05 倍。性能最好的是 1-[3-(2,6-二甲基苯氧基)丙基]-4-(2-甲氧基苯基)哌嗪盐酸盐(4),其 Ki(α1) 值为 2.4 nM,对α1-的选择性比对α2-肾上腺素受体的选择性高 142.13 倍,拮抗效力最好(pA2 = 8.807)。值得强调的是,所有最有前途的化合物都具有 1-(邻甲氧基苯基)哌嗪分子,这可能对α-肾上腺素受体的亲和力起着重要作用。