Ligands for the sigma receptor and the mu-opioid receptor

Abstract

The sigma receptor is a unique receptor family with two subtypes: sigma-1 and sigma-2. In order to conduct structure-activity relationship studies (SAR), a series of specific 1-phenylpropyl-4-benzylpiperidine and 1-phenylpropyl-4- benzylpiperazine analogues were synthesized as sigma ligands. Sigma receptors binding assays were conducted for the piperidine analogues. The last chapter is concerned with the opioid receptors, which have three subtypes: mu, delta, and kappa. The [mu]-opioid receptor is believed to be the subtype with the most clinical importance. In order to obtain [mu]-opioid tetrapeptide ligand I-Dmt-D-Ala-Phe-Orn-NH₂ with high affinity and proper lipophilicity, mono-iodination reaction was studied on the 2,6-dimethyl-L-tyrosine residue.