Seminar Series:
Friday, November 4, 2011 - 10:00am
Chemistry Building Rm 409


Two-Photon excitation (2PE) is a well-described optical process that involves the simultaneous absorption of two photons of light.  It has found applications in cell biology, biochemistry, and neuroscience.  Advantages of 2PE over standard single photon excitation include localization of excitation volume to as little as a femtoliter, or about the size of a bacterial cell, and deeper tissue penetration due to infrared irradiation wavelengths.  Photoremovable protecting groups (PPGs) that have sensitivity to 2PE-induced uncaging are valuable tools for probing cell physiology, but few reliable, well-described PPGs with 2PE-sensitivity exist in the literature.  Among those are the quinoline-based PPGs, including 8-bromo-7-hydroxyquinoline (BHQ).  BHQ has been previously used to synthesize caged forms of cellular second messengers and agents for selective gene expression and knock down.  Described here is the synthesis and photochemistry of caged forms of the neuromodulators serotonin and capsaicin with sensitivity to 2PE.  The reported compounds are significant improvements over other previously described caged serotonins and capsaicins that exist in the literature, which suffer from poor uncaging kinetics and lack 2PE sensitivity.