Fluorescent characterization of vanillin aurone

Abstract

Since their discovery, fluorescent molecules have been used for a variety of purposes such as fluorescent tags in antibody assays, anterograde tracing in neuroscience studies, production of lasers, fluorescent cell imaging and many other areas. Fluorophores are powerful visualization tools and thus the development of novel, small organic fluorophores is in great demand. One such small organic fluorophore is derived from an aurone, 2-benzylidenebenzofuran-3(2H)-one, a molecule with the general structure of a benzylidene attached to a benzofuran at the second position. An aurone with a methoxy group at the 3’ position and a hydroxyl group at the 4’ position is termed vanillin aurone after the synthesis of the molecule by addition of vanillin to benzofuranone through an acid catalyzed Aldol condensation. In this study we evaluate the fluorescent capabilities of the vanillin aurone through a series of fluorescent titrations in various solvent environments assessing it’s solvatochromic behavior. Weakly polar, aprotic solvents amplify the fluorescent intensity of the molecule and blue shift the peak emission wavelength. To better understand the solvatochromic trends, extinction coefficients were determined in different solvents. These data point to another explanation for the fluorescent disparities independent of differences in photon absorption efficiency. As computational simulations show a promising interaction between the vanillin aurone and the active site of the ATP binding domain of YME1L AAA+, this protein has been used as a model system supporting vanillin aurone binding to ATPases. This binding to a family of proteins ubiquitous in cells provides an avenue for future, potential therapeutic development.