title: Synthesis and photophysics of a new family of fluorescent 9-alkyl-substituted xanthenones.
abstract: 9-Alkyl xanthenones with different aliphatic pendant groups have been easily prepared by means of nucleophilic addition of the corresponding Grignard derivative to a tert-butyldimethylsilyl ether (TBDMS)-protected 3,6-dihydroxy-xanthenone. The photophysical behavior of the new dyes has been explored by using absorption, steady-state-, and time-resolved fluorescence measurements. We determined the equilibrium constants, visible spectral characteristics, fluorescence quantum yield, and decay times. Remarkably, they retain similar fluorescent properties of fluorescein including the characteristic phosphate-mediated excited-state proton-transfer (ESPT) reaction. 6-Hydroxy-9-isopropyl-3H-xanthen-3-one (5) was investigated in living cells; it presented a good permeability and efficient accumulation inside the cytosol. For the first time, we reported that the requirement of an aryl group at C-9 is no longer needed and new fluorescent sensors can be therefore easily developed.
authors.affiliation: Department of Organic Chemistry, University of Granada, Fuentenueva Campus, 18071 Granada (Spain), Fax: (+34) 958248437.
authors.forename: Ángela
authors.initials: Á
authors.lastname: Martínez-Peragón
authors.forename: Delia
authors.initials: D
authors.lastname: Miguel
authors.forename: Rocío
authors.initials: R
authors.lastname: Jurado
authors.forename: José
authors.initials: J
authors.lastname: Justicia
authors.forename: José M
authors.initials: JM
authors.lastname: Alvarez-Pez
authors.forename: Juan M
authors.initials: JM
authors.lastname: Cuerva
authors.forename: Luis
authors.initials: L
authors.lastname: Crovetto
mesh_terms: D000818:Animals; D002460:Cell Line; D002463:Cell Membrane Permeability; D005456:Fluorescent Dyes / Q000138:chemical synthesis* / Q000737:chemistry / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D051379:Mice; D008856:Microscopy, Fluorescence; D061848:Optical Imaging; D055620:Optical Phenomena; D010006:Osteoblasts / Q000378:metabolism; D011522:Protons; D014966:Xanthenes / Q000138:chemical synthesis* / Q000737:chemistry / Q000378:metabolism
chemical_list: D005456:Fluorescent Dyes; D011522:Protons; D014966:Xanthenes
keywords: biosensors; dyes/pigments; fluorescence; photochemistry; photophysics