HA-966

**HA-966** is a small molecule researched primarily as a neuropharmacological tool compound. It acts as a selective antagonist (and low-efficacy partial agonist) at the glycine modulatory site of the N-methyl-D-aspartate (NMDA) receptor complex. HA-966 shows **neuroprotective, anticonvulsant, anxiolytic, antinociceptive, and sedative/hypnotic effects** in animal models. Its pharmacology is enantio-specific: the (R)-(+)-enantiomer is a selective glycine/NMDA receptor antagonist accounting for its anticonvulsant action, while the (S)-(-)-enantiomer acts primarily as a potent sedative and muscle relaxant and displays GHB-like but not GABA~B~ergic effects. It was historically explored in pilot clinical studies for treating tremors of extrapyramidal origin, but is not in current clinical development. Structurally, HA-966 is a **cyclized derivative of norvaline hydroxamate** and resembles cyclic GABA.

Other names

3-amino-1-hydroxy-pyrrolidin-2-one1-hydroxy-3-amino-pyrrolidone-2