title: NMR studies of the inclusion complex between beta-cyclodextrin and paroxetine.
abstract: A 1H and 13C NMR study on the inclusion complex of paroxetine with beta-cyclodextrin was carried out in order to define the stoichiometry of the association and its strength. Proton and carbon chemical shift measurements of paroxetine and beta-cyclodextrin were performed at several molar ratios and temperatures, allowing the determination of a 1:1 stoichiometry and an association constant value of the order of 2 x 10(3) for the paroxetine-beta-cyclodextrin complex. Overhauser effects in the rotating frame were also measured, and the experimental interproton distance constraints have been used for molecular model building of the complex. The obtained model indicates that the benzodioxolyl moiety of paroxetine is deeply inserted in the cavity of the cylindrical structure of beta-cyclodextrin, while the fluoro-phenyl ring lays above the wider rim.
authors.affiliation: Biomolecular Structure Research Center and Department of Molecular Biology, University of Siena, via Fiorentina 1, 53100 Siena, Italy. andrea.bernini@unisi.it
authors.forename: Andrea
authors.initials: A
authors.lastname: Bernini
authors.forename: Ottavia
authors.initials: O
authors.lastname: Spiga
authors.forename: Arianna
authors.initials: A
authors.lastname: Ciutti
authors.forename: Maria
authors.initials: M
authors.lastname: Scarselli
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Bottoni
authors.forename: Paolo
authors.initials: P
authors.lastname: Mascagni
authors.forename: Neri
authors.initials: N
authors.lastname: Niccolai
mesh_terms: D005615:Freezing; D008956:Models, Chemical; D008958:Models, Molecular; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D017374:Paroxetine / Q000737:chemistry*; D012996:Solutions; D013816:Thermodynamics; D047392:beta-Cyclodextrins / Q000737:chemistry*
chemical_list: D012996:Solutions; D047392:beta-Cyclodextrins; D017374:Paroxetine; C031215:betadex