Document Type


Peer Reviewed


Publication Date


Scholarship Domain(s)

Scholarship of Discovery


As humans age, fluorescent retinoid pigments accumulate in the retinal pigment epithelial (RPE) cells responsible for photoreceptor support. These fluorophores are of interest because they seem to contribute to diseases of the retina, particularly age-related macular degeneration, which is a leading cause of blindness in older adults in the United States and currently has no cure. One well-characterized fluorophore, A2E, can be oxidized by visible light and then generate harmful oxidative species capable of inducing programmed cell death in RPE cells. Further characterization of the redox behavior of A2E could ultimately aid the development of macular degeneration treatments designed to mitigate the harmful effects of oxidized A2E. The purpose of this project was to estimate the reduction potential of A2E experimentally. A2E was synthesized by combining all-trans-retinal and ethanolamine in a 2:1 molar ratio, and separation was achieved by gravity chromatography followed by reverse phase HPLC. The presence of A2E was confirmed by measuring its absorbance spectrum. Linear sweep polarographic analyses of A2E were carried out using either tetrabutylammonium hexafluorophosphate (TBAHFP) or sodium chloride as the supporting electrolyte. Trials with TBAHFP solution produced one-wave polarograms, while trials with sodium chloride solution yielded two-wave polarograms. However, the polarograms obtained for A2E solutions were very similar to those produced by control solutions, indicating the need for procedural modifications.


Honors Capstone Project completed in 2013 for Olivet Nazarene University.