Structure-activity study and analgesic efficacy of amino acid derivatives as N-type calcium channel blockers.

Abstract The synthesis and structure–activity relationship (SAR) study of a novel series of N-type calcium channel blockers are described. l -Cysteine derivative 2a was found to be a potent and selective N-type calcium channel blocker with IC 50 0.63 μM on IMR-32 assay. Compound 2a showed analgesic efficacy in the rat formalin-induced pain model by intrathecal and oral administration.