title: Spectral evolution of a photochemical protecting group for orthogonal two-color uncaging with visible light.
abstract: Caged compounds are molecules rendered functionally inert by derivatization with a photochemical protecting group. We describe the design logic behind the development of a diethylaminocoumarin (DEAC) caging chromophore, DEAC450, that absorbs blue light strongly (ε450 = 43,000 M(-1) cm(-1)) and violet light 11-fold more weakly. The absorption minimum is in the wavelength range (340-360 nm) that is traditionally used for photolysis of many widely used nitroaromatic caged compounds (e.g., 4-carboxymethoxy-5,7-dinitroindolinyl(CDNI)-GABA). We used this chromophore to synthesize DEAC450-caged cAMP and found this probe was very stable toward aqueous hydrolysis in the electronic ground state but was photolyzed with a quantum efficiency of 0.78. When DEAC450-cAMP and CDNI-GABA where co-applied to striatal cholinergic interneurons, the caged compounds were photolyzed in an chromatically orthogonal manner using blue and violet light so as to modulate the neuronal firing rate in a bidirectional way.
authors.affiliation: Department of Neuroscience, Mount Sinai School of Medicine , New York, New York 10029, United States.
authors.forename: Jeremy P
authors.initials: JP
authors.lastname: Olson
authors.forename: Matthew R
authors.initials: MR
authors.lastname: Banghart
authors.forename: Bernardo L
authors.initials: BL
authors.lastname: Sabatini
authors.forename: Graham C R
authors.initials: GC
authors.lastname: Ellis-Davies
mesh_terms: D049933:Aminocoumarins / Q000737:chemistry*; D003116:Color; D003374:Coumarins / Q000737:chemistry*; D000242:Cyclic AMP / Q000737:chemistry; D006868:Hydrolysis; D008027:Light; D015394:Molecular Structure; D055668:Photochemical Processes; D005680:gamma-Aminobutyric Acid / Q000737:chemistry
chemical_list: D049933:Aminocoumarins; D003374:Coumarins; D005680:gamma-Aminobutyric Acid; D000242:Cyclic AMP