title: Identification of RC-33 as a potent and selective σ1 receptor agonist potentiating NGF-induced neurite outgrowth in PC12 cells. Part 2: g-scale synthesis, physicochemical characterization and in vitro metabolic stability.
abstract: Strong pharmacological evidences indicate that σ1 receptors are implicated in the pathophysiology of all major CNS disorders. In the last years our research group has conducted extensive studies aimed at discovering novel σ1 ligands and we recently selected (R/S)-RC-33 as a novel potent and selective σ1 receptor agonist. As continuation of our work in this field, here we report our efforts in the development of this new σ1 receptor agonist. Initially, we investigated the binding of (R) and (S) enantiomers of RC-33 to the σ1 receptor by in silico experiments. The close values of the predicted affinity of (R)-RC-33 and (S)-RC-33 for the protein evidenced the non-stereoselective binding of RC-33 to the σ1 receptor; this, in turn, supported further development and characterization of RC-33 in its racemic form. Subsequently, we set-up a scaled-up, optimized synthesis of (R/S)-RC-33 along with some compound characterization data (e.g., solubility in different media and solid state characterization by thermal analysis techniques). Finally, metabolic studies of RC-33 in different biological matrices (e.g., plasma, blood, and hepatic S9 fraction) of different species (e.g., rat, mouse, dog, and human) were performed. (R/S)-RC-33 is generally stable in all examined biological matrices, with the only exception of rat and human liver S9 fractions in the presence of NADPH. In such conditions, the compound is subjected to a relevant oxidative metabolism, with a degradation of approximately 65% in rat and 69% in human. Taken together, our results demonstrated that (R/S)-RC-33 is a highly potent, selective, metabolically stable σ1 agonist, a promising novel neuroprotective drug candidate.
authors.affiliation: Medicinal Chemistry Laboratory, Department of Drug Sciences, Medicinal Chemistry and Pharmaceutical Technology Section (MCPTS), University of Pavia, Viale Taramelli 12, 27100 Pavia, Italy.
authors.forename: Daniela
authors.initials: D
authors.lastname: Rossi
authors.forename: Annamaria
authors.initials: A
authors.lastname: Marra
authors.forename: Pietro
authors.initials: P
authors.lastname: Picconi
authors.forename: Massimo
authors.initials: M
authors.lastname: Serra
authors.forename: Laura
authors.initials: L
authors.lastname: Catenacci
authors.forename: Milena
authors.initials: M
authors.lastname: Sorrenti
authors.forename: Erik
authors.initials: E
authors.lastname: Laurini
authors.forename: Maurizio
authors.initials: M
authors.lastname: Fermeglia
authors.forename: Sabrina
authors.initials: S
authors.lastname: Pricl
authors.forename: Stefania
authors.initials: S
authors.lastname: Brambilla
authors.forename: Nicoletta
authors.initials: N
authors.lastname: Almirante
authors.forename: Marco
authors.initials: M
authors.lastname: Peviani
authors.forename: Daniela
authors.initials: D
authors.lastname: Curti
authors.forename: Simona
authors.initials: S
authors.lastname: Collina
mesh_terms: D000818:Animals; D001713:Biphenyl Compounds / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D002627:Chemistry, Physical; D004285:Dogs; D006801:Humans; D051379:Mice; D008958:Models, Molecular; D015394:Molecular Structure; D020932:Nerve Growth Factor / Q000378:metabolism*; D016501:Neurites / Q000187:drug effects*; D016716:PC12 Cells; D010880:Piperidines / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D051381:Rats; D017480:Receptors, sigma / Q000819:agonists* / Q000378:metabolism; D000097605:Sigma-1 Receptor
chemical_list: D001713:Biphenyl Compounds; D020932:Nerve Growth Factor; D010880:Piperidines; D017480:Receptors, sigma; D000097605:Sigma-1 Receptor; C584299:1-(3-biphenyl-4-ylbutyl)piperidine