Excitatory amino acid agonists. Enzymic resolution, x-ray structure, and enantioselective activities of (R)- and (S)-bromohomoibotenic acid
作者:Jan J. Hansen、Birgitte Nielsen、Povl Krogsgaard-Larsen、Lotte Brehm、Elsebet O. Nielsen、David R. Curtis
DOI:10.1021/jm00130a005
日期:1989.10
confirmed the expected preference of the enzyme for the S form of the substrate 4. (S)- and (RS)-Br-HIBO were potent neuroexcitants on cat spinal neurones in vivo, while (R)-Br-HIBO was a very weak excitant. Correspondingly, the S enantiomer of Br-HIBO (IC50 = 0.34 microM) was considerably more potent than the R form (IC50 = 32 microM) as an inhibitor of [3H]-(RS)-alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic
α-氨基-4-溴-3-羟基-5-异恶唑丙酸的对映异构体(4-溴高同戊烯酸,Br-HIBO,1)是一类对中心(S)-谷氨酸受体有选择性和强效激动剂的对映体,通过使用固定的氨酰基酶经(RS)-α-(乙酰氨基)-4-溴-3-甲氧基-5-异恶唑丙酸(4)的立体选择性酶水解,制备了对映体过量高于98.8%的对映体。通过X射线晶体学分析确定了Br-HIBO对映异构体的绝对构型,这证实了酶对底物4的S形式的预期偏爱。(S)-和(RS)-Br-HIBO是有效的神经兴奋剂在猫的脊神经元体内,而(R)-Br-HIBO是非常弱的兴奋剂。相应地,Br-HIBO的S对映体(IC50 = 0。作为[3H]-(RS)-α-氨基-3-羟基-5-羟基-4-甲基-4-异恶唑丙酸([3H] AMPA的抑制剂),R型(IC50 = 32 microM)比R型(IC50 = 32 microM)更有效。 )在体外与大鼠脑突触膜结合