title: The role of different structural motifs in the ultrafast dynamics of second generation protein stains.
abstract: Engineering the properties of fluorescent probes through modifications of the fluorophore structure has become a subject of interest in recent times. By doing this, the photophysical and photochemical properties of the modified fluorophore can be understood and this can guide the design and synthesis of better fluorophores for use in biotechnology. In this work, the electronic spectra and fluorescence decay kinetics of four analogues of the fluorescent natural product epicocconone were investigated. Epicocconone is unique in that the native state is weakly green fluorescent, whereas the enamine formed reversibly with proteins is highly emissive in the red. It was found that the ultrafast dynamics of the analogues depends profoundly on the H-bonding effect of solvents and solvent viscosity though solvent polarity also plays a role. Comparing the steady state and time-resolved data, the weak fluorescence of epicocconone in its native state is most likely due to the photoisomerization of the hydrocarbon side chain, while the keto enol moiety also has a role to play in determining the fluorescence quantum yield. This understanding is expected to aid the design of better protein stains from the same family.
authors.affiliation: Department of Chemistry and Biomolecular Sciences Macquarie University , Sydney, NSW 2109, Australia.
authors.forename: Soumit
authors.initials: S
authors.lastname: Chatterjee
authors.forename: Peter
authors.initials: P
authors.lastname: Karuso
authors.forename: Agathe
authors.initials: A
authors.lastname: Boulangé
authors.forename: Philippe A
authors.initials: PA
authors.lastname: Peixoto
authors.forename: Xavier
authors.initials: X
authors.lastname: Franck
authors.forename: Anindya
authors.initials: A
authors.lastname: Datta
mesh_terms: D001578:Benzopyrans / Q000138:chemical synthesis / Q000737:chemistry*; D001688:Biological Products / Q000138:chemical synthesis / Q000737:chemistry*; D005453:Fluorescence; D005456:Fluorescent Dyes / Q000138:chemical synthesis / Q000737:chemistry*; D005663:Furans / Q000138:chemical synthesis / Q000737:chemistry*; D007659:Ketones / Q000138:chemical synthesis / Q000737:chemistry*; D007700:Kinetics; D015394:Molecular Structure; D011506:Proteins / Q000737:chemistry*
chemical_list: D001578:Benzopyrans; D001688:Biological Products; D005456:Fluorescent Dyes; D005663:Furans; D007659:Ketones; D011506:Proteins; C477464:epicocconone