that the two-carbon side chain length was optimum for NMDA receptor affinity. Substitution on the ring was found to be counterproductive in the case of sterically demanding dimethyl groups and of no consequence in the case of an H-bonding hydroxyl group. Replacement of the phosphonic acid group by either a carboxylic acid or a tetrazole group was unproductive. The potent bicyclic NMDA antagonists were
二
氮杂双环氨基酸膦酸酯15 [2-(8,9-dioxo-2,6-diazabicyclo [5.2.0] non-1(7)-en-2-yl)ethyl]
膦酸被确定为有效的N
MDA拮抗剂。它包含
α-氨基酸生物甾体
3,4-二氨基-3-环丁烯-1,2-二酮和一个用于构象刚性的附加环。在[3H] CPP结合测定,受激[3H]
TCP结合测定和N
MDA诱导的小鼠致死性模型中,化合物15与CGS-19755(5)一样有效。在大鼠大脑中动脉永久闭塞后,静脉内单次推注剂量的化合物15使梗塞组织的大小减少了57%。结构-活性关系(
SAR)研究表明六元和八元环衍
生物的活性降低,并且两个碳的侧链长度最适合N
MDA受体的亲和力。发现在空间上需要二甲基的情况下,环上的取代会适得其反,而在氢键结合的羟基的情况下则无济于事。用
羧酸或
四唑基团取代
膦酸基是无用的。有效的双环N
MDA拮抗剂有效地合成了他们的非手性性质和容易从