R-HA-966

**R-HA-966** is the R-(+)-enantiomer of HA-966 (3-amino-1-hydroxypyrrolid-2-one), a small molecule antagonist and low-efficacy partial agonist at the glycine site of the NMDA (N-methyl-D-aspartate) receptor. Unlike the S-(-)-enantiomer, which is sedative with gamma-butyrolactone-like effects, R-HA-966 is centrally active, neuroprotective, anticonvulsant, and acts specifically at the NMDA receptor glycine modulatory site, thus antagonizing glycine-potentiated NMDA responses without fully blocking the receptor. It exhibits potential activity in conditions involving excitotoxicity, such as tremors of extrapyramidal origin, and blocks mesolimbic dopaminergic activation induced by psychostimulants in preclinical studies. Developed by Merck as a research compound, it has no established therapeutic approval but has been used in animal models and early clinical studies[1][2][3][4][5][6][8][10].

Other names

(R)-(+)-HA-966(+)-HA-9663-amino-1-hydroxypyrrolid-2-one (R-enantiomer)(R)-3-amino-1-hydroxy-pyrrolidin-2-one