SDZ EAA 494 [ 3-(2-carboxypiperazine-4-yl)-1-propenyl-1-phosphonic acid,4-(3-phosphonoprop-2-enyl)piperazine-2-carboxylic acid,D-CPP-ene,SDZ EAA 494, (E)-isomer,SDZ EAA 494, (R-(E))-isomer,SDZ EAA 494, (S-(E))-isomer,cppene ] N-methyl-D-aspartate receptor antagonist