depended upon the substituent on the aromatic ring. A chlorine atom produced a marked drop in activity (K(i) > 100 nM), while a m-methoxy group gave a compound with nanomolar affinity (K(i) = 3 nM). The most potent compounds were the heterocyclic derivatives with pyrimidine, pyrazine, pyridazine, or pyridine moieties (compounds 9r, 9t, 9u, 9x, respectively). K(i) values for 9a and 9r were determined
芳基
哌嗪9的新衍
生物是根据ML 10302(在胃肠系统中有效的5-HT(4)受体激动剂)设计的。通过将许多可得的芳基
哌嗪或杂芳基
哌嗪与2-
溴乙基
4-氨基-5-氯-2-甲氧基苯甲酸酯缩合来合成化合物。他们在结合测定中评估了最近克隆的人5-HT(4(e))同工型,在C6神经胶质细胞中稳定表达,[[3] H] GR 113808作为放射性
配体。亲和力值(K(i))取决于芳环上的取代基。
氯原子的活性显着下降(K(i)> 100 nM),而间甲氧基生成的化合物具有纳摩尔摩尔亲和力(K(i)= 3 nM)。最有效的化合物是具有
嘧啶,
吡嗪,
哒嗪或
吡啶部分的杂环衍
生物(分别为化合物9r,9t,9u,9x)。确定了5-HT(4(a)),5-HT(4(b)),5-HT(4(c))和5-HT(4( d))在COS细胞中瞬时表达的受体同工型。结果表明这些化合物不是选择性的。他们在稳定表达5-HT(4(e))受体的