Publication Details (including relevant citation information):
Sorensen, Ulrik S., Bleisch, Thomas J., Kingston, Anne E., Wright, Rebecca A., Johnson, Bryan G., Schoepp, Darryle D., Ornstein, Paul L. Bioorganic & Medicinal Chemistry 2003 11 (2) 197-205
Abstract: The major excitatory neurotransmitter in the central nervous system, (S)-glutamic acid (1), activates both ionotropic and metabotropic excitatory amino acid receptors. Its importance in connection to neurological and psychiatric disorders has directed great attention to the development of compounds that modulate the effects of this endogenous ligand. Whereas L-carboxycyclopropylglycine (L-CCG-1, 2) is a potent agonist at, primarily, group II metabotropic glutamate receptors, alkylation of 2 at the alpha-carbon notoriously result in group II mGluR antagonists, of which the most potent compound described so far, LY341495 (12), displays IC50 values of 23 and 10 nM at the group II receptor subtypes mGlu2 and mGlu3, respectively. In this study we synthesized a series of structural analogues of 12 in which the xanthyl moiety is replaced by two substituted-phenyl groups. The pharmacological characterization shows that these novel compounds have very high affinity for group II mGluRs when tested as their racemates. The most potent analogues demonstrate Ki values in the range of 5-12 nM, being thus comparable to LY341495 (12).