(-) -Dizocilpine maleate ((-) -MK-801 maleate) is a less active (-) -enantiomer of Dizocilpine. (-) -Dizocilpine maleate is a selective and non-competitive N-methyl-D-aspartate (NMDA) receptor antagonist with a Ki of 211.7 nM. (-) -Dizocilpine maleate has antidepressant effects[1][2].