title: Absolute configuration of the alpha (1B)-adrenoceptor antagonist (+)-cyclazosin.
abstract: (+)-Cyclazosin is a quinazoline derivative pharmacologically characterized as alpha(1b)-adrenoceptor selective ligand in binding assays and alpha(1B)-selective antagonist in isolated tissues. In this work, we determined the absolute configuration of (+)-cyclazosin by X-ray crystallographic analysis applied to the (R,R)-(+)-tartrate of (-)-2, which is the enantiomer of the specific synthetic precursor of (+)-cyclazosin. Results indicated that (+)-cyclazosin has an R and S configuration at its C4a and C8a atoms, respectively.
authors.affiliation: Department of Chemical Sciences, University of Camerino, Via S. Agostino 1, 62032 Camerino, Italy. dario.giardina@unicam.it
authors.forename: Dario
authors.initials: D
authors.lastname: Giardinà
authors.forename: Gianni
authors.initials: G
authors.lastname: Sagratini
authors.forename: Massimo
authors.initials: M
authors.lastname: Grelli
authors.forename: Ugo
authors.initials: U
authors.lastname: Gulini
authors.forename: Carlo
authors.initials: C
authors.lastname: Melchiorre
authors.forename: Luciano
authors.initials: L
authors.lastname: Antolini
mesh_terms: D058668:Adrenergic alpha-1 Receptor Antagonists; D018360:Crystallography, X-Ray; D006860:Hydrogen Bonding; D008968:Molecular Conformation; D011799:Quinazolines / Q000737:chemistry*; D011810:Quinoxalines / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D058668:Adrenergic alpha-1 Receptor Antagonists; D011799:Quinazolines; D011810:Quinoxalines; C080462:cyclazosin