Widely used competitive NMDA antagonist. More active form of AP5. Also agonist at quisqualate-sensitized AP6 site where it is less potent than the L-isomer, L-AP5 (Cat. No. 0107). Also available as part of the Mixed NMDA Receptor Tocriset™ or as a mixed isomer DL-AP5 (Cat. No. 3963).