title: Synthesis and structural determination of stereoisomers of muscarinic ligands of the (3-propylthio-1,2,5-thiadiazol-4-yl)-1-azabicycloalkane type.
abstract: Methods for the synthesis of each of the four stereoisomers of 6-(3-propylthio-1,2,5-thiadiazol-4-yl)-1-azabicyclo[3.2.1]oc tane (10, 11, 12, and 13) and 3-(3-propylthio-1,2,5-thiadiazol-4-yl)-1-azabicyclo[2.2.1]he ptane (18, 19, 20, and 21), and the two stereoisomers of 3-(3-propylthio-1,2,5-thiadiazol-4-yl)-1-azabicyclo[2.2.2]oc tane (27 and 28) were developed. The relative configuration of the compounds was determined on the basis of previously described 1H NOE experiments, and the absolute configuration of 6-(3-propylthio-1,2,5-thiadiazol-4-yl)-1-azabicyclo[3.2.1]oc tanes (10, 11, 12, and 13) and 3-(3-propylthio-1,2,5-thiadiazol-4-yl)-1-azabicyclo[2.2.2]oc tane (27 and 28) was determined by single crystal X-ray crystallography. Optical purity was determined by capillary electrophoresis (CE) using chiral selectors as trimethyl-beta-cyclodextrin and heparin dissolved in the running buffer. All the 3-(3-propylthio-1,2,5-thiadiazol-4-yl)-1-azabicycles had low nanomolar affinity for muscarinic receptors as determined by displacement of radiolabelled oxotremorine-M (3H-Oxo-M) and pirenzepine (3H-Pz) from cortical rat brain homogenates. The binding assay discriminated between diastereomers, but only a minor degree of enantioselectivity was observed in the binding assays.
authors.affiliation: Novo Nordisk A/S, Maaloev Denmark.
authors.forename: P H
authors.initials: PH
authors.lastname: Olesen
authors.forename: P
authors.initials: P
authors.lastname: Sauerberg
authors.forename: T G
authors.initials: TG
authors.lastname: Petersen
authors.forename: S
authors.initials: S
authors.lastname: Treppendahl
authors.forename: B
authors.initials: B
authors.lastname: Bentzen
authors.forename: J
authors.initials: J
authors.lastname: Deeter
authors.forename: J S
authors.initials: JS
authors.lastname: Ward
authors.forename: C H
authors.initials: CH
authors.lastname: Mitch
authors.forename: S V
authors.initials: SV
authors.lastname: Lehmann
mesh_terms: D000818:Animals; D001667:Binding, Competitive / Q000187:drug effects; D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000138:chemical synthesis* / Q000494:pharmacology; D018678:Cholinergic Agents / Q000138:chemical synthesis* / Q000494:pharmacology; D018360:Crystallography, X-Ray; D066298:In Vitro Techniques; D008024:Ligands; D008566:Membranes / Q000378:metabolism; D018721:Muscarinic Agonists / Q000378:metabolism; D018727:Muscarinic Antagonists / Q000378:metabolism; D010095:Oxotremorine / Q000378:metabolism; D010890:Pirenzepine / Q000378:metabolism; D051381:Rats; D013237:Stereoisomerism
chemical_list: D019086:Bridged Bicyclo Compounds, Heterocyclic; D018678:Cholinergic Agents; D008024:Ligands; D018721:Muscarinic Agonists; D018727:Muscarinic Antagonists; D010890:Pirenzepine; D010095:Oxotremorine