Rational Design and Enantioselective Synthesis of (1<i>R</i>,4<i>S</i>,5<i>R</i>,6<i>S</i>)-3-Azabicyclo[3.3.0]octane-4,6-dicarboxylic Acid A Novel Inhibitor at Human Glutamate Transporter Subtypes 1, 2, and 3
作者:Lennart Bunch、Birgitte Nielsen、Anders A. Jensen、Hans Bräuner-Osborne
DOI:10.1021/jm0508336
日期:2006.1.1
The natural product kainic acid is used as template for the rational design of a novel conformationally restricted (S)-glutamic acid (Glu) analogue, (1R,4S,5R,6S)-3-azabicyclo[3.3.0]octane-4,6-dicarboxylic acid (1a). The target structure 1a was synthesized from commercially available (S)-pyroglutaminol, in an enantioselective fashion, in 14 steps. Pharmacological characterization of 1a at human glutamate transporter subtypes 1, 2, and 3 yielded K-i values of 127, 52, and 46 mu M, respectively. Furthermore, binding studies at native ionotropic Glu (iGlu) receptors revealed low affinity for (alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA)-preferring, iGlu receptors (IC50 > 100 mu M), whereas affinities for the KAIN-preferring iGlu receptors and the N-methyl-D-aspartate (NMDA)-preferrin- group of iGlu receptors were in the low micromolar range (IC50 = 14 and 2.9 mu M, respectively). At metabotropic Glu receptors (mGluR), EC50 values for 1a were > 1000 mu M for mGluR1 and 4, representing group I and III, respectively, and similar to 1000 mu M (agonist) for mGluR2, representing group II.