Rational Design, Synthesis and Pharmacological Evaluation of the (2 R )‐ and (2 S )‐Stereoisomers of 3‐(2‐Carboxypyrrolidinyl)‐2‐methyl Acetic Acid as Ligands for the Ionotropic Glutamate Receptors

In this paper we describe the rational design, synthesis and pharmacological evaluation of two new stereoisomeric ( S )‐glutamate (Glu) analogues. The rational design was based on hybrid structures of the natural product kainic acid, a synthetic analogue CPAA and the high‐affinity Glu analogue SYM2081. Pharmacological evaluation of the two stereoisomers revealed that one stereoisomer showed a subtype selectivity profile with low micromolar affinity for GluK1 and GluK3 and a 10‐ to 15‐fold lower affinity for GluK2. The other stereoisomer displayed full selectivity for the KA over AMPA and NMDA receptors (GluK1–3: 0.39, 0.51 and 0.099 µ M , respectively).