L-AP3 is a potent antagonist of metabotropic glutamate receptor (mGluR), demonstrating inhibitory effects on D-phosphoserine and L-phosphoserine with IC50 values of 368 μM and 2087 μM, respectively.

L-AP3 inhibits D-phosphoserine and L-phosphoserine with K i s of 151 μM and 845 μM, respectively[1]. L-AP3 has agonistic activity in enhancing phospholipase D activity and decreasing CAMP formation in rat hippocampus[1]. L-AP3 may have selectivity for Group II subtypes since it inhibits [ 3 H]glutamate binding to mGlu3, receptors (K i 125 μM)[1]. L-AP3 is a potent inhibitor of sodium-dependent L-[ 3 H]glutamate uptake in cerebellar and cortical synaptosomes (39 and 110 μM, respectively)[1].

L-AP3 has anticonvulsant activity in animals. L-AP3 blocks audiogenic seizures in DBA/2 mice[1].