设计并合成了一系列咪唑并[1,5- a ]喹啉衍生物作为中心苯并二氮杂pine受体(CBR)配体。大多数化合物在亚微摩尔和亚纳摩尔范围内都具有很高的CBR亲和力和K i值,并在其结构亲和力关系中进行了有趣的调节。特别是,氟衍生物7w(K i = 0.44 nM)导致了迄今为止所述的咪唑并[1,5- a ]喹啉衍生物中最有效的配体。总体而言,这些观察结果证实了以下假设:在与咪唑[1,5-]的位置4和5相互作用的CBR结合位点区域中存在一个明显饱和的亲脂性大袋。一个]喹啉核。体内生物学特性表明,化合物7a,c,d,l,m,q,r,w显示出抗焦虑和抗记忆删除活性,而没有经典的1,4-BDZ的令人讨厌的肌松反应副作用。此外,7l,q,r和8i降低大鼠脑切片中缺血样条件引起的乳酸脱氢酶(LDH)释放的作用表明这些咪唑并[1,5- a ]喹啉衍生物具有神经保护作用。
Further Studies on the Interaction of the 5-Hydroxytryptamine3 (5-HT3) Receptor with Arylpiperazine Ligands. Development of a New 5-HT3 Receptor Ligand Showing Potent Acetylcholinesterase Inhibitory Properties
摘要:
Novel arylpiperazine derivatives bearing lipophilic probes were designed, synthesized, and evaluated for their potential ability to interact with the 5-hydroxytryptamine(3) (5-HT3) receptor. Most of the new compounds show subnanomolar 5-HT3 receptor affinity. Ester 6bc showing a picomolar K-i value is one of the most potent 5-HT3 receptor ligands so far synthesized. The structure-affinity relationship study suggests the existence of a certain degree of conformational freedom of the amino acid residues interacting with the substituents in positions 3 and 4 of the quipazine quinoline nucleus. Thus, the tacrine-related heterobivalent ligand 6o was designed in an attempt to capitalize on the evidence of such a steric tolerance. Compound 6o shows a nanomolar potency for both the 5-HT3 receptor and the human AChE and represents the first example of a rationally designed high-affinity 5-HT3 receptor ligand showing nanomolar AChE inhibitory activity. Finally, the computational analysis performed on compound 6o allowed the rationalization of the structure-energy determinants for AChE versus BuChE selectivity and revealed the existence of a subsite at the boundary of the 5-HT3 receptor extracellular domain, which could represent a "peripheral" site similar to that evidenced in the AChE gorge.