Spectral evolution of a photochemical protecting group for orthogonal two-color uncaging with visible light

J Am Chem Soc. 2013 Oct 23;135(42):15948-54. doi: 10.1021/ja408225k. Epub 2013 Oct 11.


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.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aminocoumarins / chemistry*
  • Color*
  • Coumarins / chemistry*
  • Cyclic AMP / chemistry
  • Hydrolysis
  • Light*
  • Molecular Structure
  • Photochemical Processes
  • gamma-Aminobutyric Acid / chemistry


  • Aminocoumarins
  • Coumarins
  • gamma-Aminobutyric Acid
  • Cyclic AMP