title: Inclusion excluded: Chiroptical sensing of the external surface of sulfated cyclodextrins.
abstract: It is shown that the heparin antagonist bis-aminoquinoline derivative surfen interacts with sulfated cyclodextrins in a unique fashion. Analysis of the UV spectroscopic data revealed exceptionally strong association (K(a) ∼ 10(7) M(-1)) of several surfen molecules to the external surface of the cyclodextrin hosts. H-bonded to the sulfate groups in 1:1 stoichiometry, the drug molecules form a chiral layer around the macrocycles. Due to the steric proximity, dipole-dipole coupling occurs between the adjacent aminoquinoline rings that accounts for the large UV hypochromism and the induced exciton couplet in the circular dichroism spectra.
authors.affiliation: Research Group of Chemical Biology, Institute of Organic Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences, POB 289, H-1519, Budapest, Hungary. Electronic address: zsila.ferenc@ttk.mta.hu.
authors.forename: Ferenc
authors.initials: F
authors.lastname: Zsila
mesh_terms: D002942:Circular Dichroism; D003505:Cyclodextrins / Q000737:chemistry*; D055096:Optical Devices; D013056:Spectrophotometry, Ultraviolet; D013237:Stereoisomerism; D013431:Sulfates / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D003505:Cyclodextrins; D013431:Sulfates
keywords: Circular dichroism; Exciton coupling; Hypochromism; Sulfated cyclodextrin; Surfen