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 IC50 0.63 muM on IMR-32 assay. Compound 2a showed analgesic efficacy in the rat formalin-induced pain model by intrathecal and oral administration. (C) 2001 Elsevier Science Ltd. All rights reserved.
Structure–activity study of l-amino acid-based N-type calcium channel blockers
amino acid residue of 1a, compound 12a, that include N-(t-butoxycarbonyl)-L-cysteine, was found to be a potent N-type calcium channel blocker with an IC(50) of 0.61 microM. Thus, L-cysteine was selected as a potential structural motif for further modification. Optimization of C- and N-terminals of L-cysteine using S-cyclohexylmethyl-L-cysteine as a central scaffold led to potent and selective N-type