Synthesis and photophysical characterization of novel 2-hydrazinylpyridine based fluorophores

ORGN 763

Sudath Hapuarachchi1, Gilbert Montano2, Charles B. Shuster2, and Jeffrey B. Arterburn, jarterbu@nmsu.edu1. (1) Department of Chemistry & Biochemistry, New Mexico State University, MSC 3C, P. O. Box 30001, Las Cruces, NM 88003, (2) Department of Biology, New Mexico State University, PO Box 30001 MSC 3AF, Las Cruces, NM 88003
Fluorescent molecules have proven to be extremely useful for labeling biomolecules and staining cellular targets for optical imaging. The development of target-specific fluorescent probes from receptor ligands and small molecules identified through chemical biology has great promise for visualizing biochemical and biological events. These applications depend on identifying probes that exhibit the same physicochemical and biological properties of the parent ligand, particularly water solubility, cell membrane permeability and receptor binding characteristics. This challenge has stimulated the development of new fluorescent cores that exhibit favorable photophysical properties and are suitable for conjugation to small molecules using bio-orthogonal coupling methodologies. We have developed a new class of neutral triazaborolopyridinium dyes derived from 2-hydrazinylpyridine (HPY). These compounds exhibit favorable absorption and emission properties and large Stokes shifts that are affected by substitutions on pyridine, hydrazone or boron. Cellular imaging and membrane permeability were demonstrated using HeLa cells.