Amino acid derivatives of 1,2,5-thiadiazol-3-yl-piperazine related to (+)-WAY-100135 and WAY-100635 are potent 5-HT 1A receptor agonists and antagonists, which have selective affinity for 5-HT 1A receptors versus α 1 and dopamine (D 2 , D 3 , and D 4 ) receptors. ... Amino acid derivatives of 1,2,5-thiadiazol-3-yl-piperazine related to (+)-WAY-100135 and WAY-100635 are potent 5-HT 1A receptor agonists and antagonists, which have selective affinity for human ...