(+/-)-Citalopram (1, 1-(3-(dimethylamino)propyl)-1-(4-fluorophenyl)-1,3-dihydroisobenzofuran-5-carbonitrile), and its eutomer, escitalopram (S-(+)-1) are selective serotonin reuptake inhibitors (SSRIs) that are used clinically to treat anxiety and depression. To further explore structure-activity relationships at the serotonin transporter (SERT), a series of (+/-)-4- and 5-substituted citalopram analogues were designed, synthesized, and evaluated for binding at the SERT, dopamine transporter (DAT) and norepinephrine transporter (NET) in native rodent tissue. Many of these analogues showed high SERT binding affinities (K-i = 1-40 nM) and selectivities over both NET and DAT. Selected enantiomeric pairs of analogues were synthesized and both retained enantioselectivity as with S- and wherein S > R at the SERT. In addition, the enantiomeric pairs of 1 and 5 were tested for binding at the homologous bacterial leucine transporter (LeuT), wherein low affinities and the absence of enantioselectivity suggested distinctive binding sites for these compounds at SERT as compared to LeuT. These novel ligands will provide molecular tools to elucidate drug-protein interactions at the SERT and to relate those to behavioral actions in vivo.
(+/−)-Citalopram(1, 1-(3-(二
甲基氨基)丙基)-
1-(4-氟苯基)-1,3-二氢异苯并呋喃-5-腈),及其eutomer(纯对映体),艾司
西酞普兰(S-(+)-1)是选择性5-羟
色胺再摄取
抑制剂(SSRIs),临床上用于治疗焦虑和抑郁。为了进一步探索5-羟
色胺转运体(
SERT)处的构效关系,设计、合成了(+/-)-4-和5-取代的
西酞普兰类似物,并在啮齿类动物的
天然组织中评估了它们对
SERT、
多巴胺转运体(
DAT)和
去甲肾上腺素转运体(NET)的结合能力。许多这些类似物显示出高
SERT结合亲和力(K-i = 1-40 nM),并且对NET和
DAT具有选择性。合成了一些对映体类似物,其中S-和R-对映体在
SERT处均保持了对映选择性,且S > R。此外,1和5的对映体对在同源的细菌亮
氨酸转运体(LeuT)上的结合能力也被测试,结果显示低亲和力和缺乏对映选择性,这表明这些化合物在
SERT上的结合位点与LeuT相比是独特的。这些新型
配体将为阐明药物与蛋白质在
SERT处的相互作用提供分子工具,并将这些作用与体内行为反应相关联。