SYNTHESIS AND NEUROBIOLOGICAL ACTIONS OF PYRROLIDINE-2,3-DICARBOXYLICACIDS (PRDA) - CONFORMATIONALLY RESTRICTED ANALOGS OF L-ASPARTATE

Four stereoisomers of PRDAs 1 similar to 4, a novel aspartate analogue incorporating a pyrrolidine ring, were synthesized in an enantiomeric ally pure form starting from a chiral synthon, 5-amino-5,6-dihydropyro ne. Electrophysiological experiments of 1 similar to 4 in newborn rat spinal cords showed a variety of depolarizing activities. The conforma tional studies of PRDAs and their activity profile suggested that the gauche and the anti conformers about two carboxylic acid groups of Asp could be active forms to NMDA and non-NMDA receptors, respectively.