title: Chiral selectivity in the binding of [4]helicene derivatives to double-stranded DNA.
abstract: The interaction of a series of chiral cationic [4]helicene derivatives, which differ by their substituents, with double-stranded DNA has been investigated by using a combination of spectroscopic techniques, including time-resolved fluorescence, fluorescence anisotropy, and linear dichroism. Addition of DNA to helicene solutions results to a hypochromic shift of the visible absorption bands, an increase of fluorescence quantum yield and lifetime, a slowing down of fluorescence anisotropy decay, and a linear dichroism in flow-oriented DNA, which unambiguously points to the binding of these dyes to DNA. Both helicene monomers and dimeric aggregates, which form at higher concentration, bind to DNA, the former most probably upon intercalation and the latter upon groove binding. The binding constant depends substantially on the dye substituents and is, in all cases, larger with the M than the P enantiomer, by factors ranging from 1.2 to 2.3, depending on the dye.
authors.affiliation: Department of Physical Chemistry, University of Geneva, 30, quai Ernerst-Ansermet, 1211 Genève 4, Switzerland.
authors.forename: Oksana
authors.initials: O
authors.lastname: Kel
authors.forename: Alexandre
authors.initials: A
authors.lastname: Fürstenberg
authors.forename: Nathalie
authors.initials: N
authors.lastname: Mehanna
authors.forename: Cyril
authors.initials: C
authors.lastname: Nicolas
authors.forename: Benoît
authors.initials: B
authors.lastname: Laleu
authors.forename: Martin
authors.initials: M
authors.lastname: Hammarson
authors.forename: Bo
authors.initials: B
authors.lastname: Albinsson
authors.forename: Jerôme
authors.initials: J
authors.lastname: Lacour
authors.forename: Eric
authors.initials: E
authors.lastname: Vauthey
mesh_terms: D002942:Circular Dichroism; D004247:DNA / Q000737:chemistry*; D005453:Fluorescence; D005454:Fluorescence Polarization; D005456:Fluorescent Dyes / Q000737:chemistry*; D007364:Intercalating Agents / Q000737:chemistry; D015394:Molecular Structure; D013057:Spectrum Analysis; D013237:Stereoisomerism
chemical_list: D005456:Fluorescent Dyes; D007364:Intercalating Agents; D004247:DNA