Determination of the region in the μ opioid receptor involved in covalent binding of β-FNA

Morphinan alkaloids labeled with tritium: synthesis and applications

“…In constructing this ligand, Michael conjugate addition by a proximate nucleophilic opiate receptor function (cysteine and lysine) was designed to occur at the 6‐position. We were the first to prepare [15, 16‐ 3 H]β‐funaltrexamine for the initial work on this radioligand, and later investigators successfully employed it as well for study of the mu opiate receptor . One especially intriguing report was published by the Liu‐Chen group at Temple University School of Medicine .…”