Potent, non-competitive excitatory amino acid transporter (EAAT) blocker. Preferentially inhibits glutamate-induced [3H]D-aspartate release (IC50 = 1.2 μM) rather than [3H]L-glutamate uptake (IC50 = 16.9 μM). Moderately selective; displays no affinity for NMDA and metabotropic glutamate receptors, and low affinity for AMPA and kainate receptors (IC50 values are 35 and 45 μM respectively).