Potential transformation of catecholamines to melanins in the presence of polysaccharides
Catecholamines (CATs) like epinephrine, norepinephrine or dopamine readily undergo oxidation, particularly in the presence of redox-sensitive cations like Cu (II) or Fe (III). We have reasoned that anionic polysaccharides (PS) could have the potential to bring CATs and cations like Cu (II) in close proximity and as such promote the oxidation of the CATs. Such pro-oxidizing capabilities are in contrast with the anti-oxidant properties attributed to anionic PS. The oxidation of CATs leads to the generation of chromophores followed by a cyclization, further oxidation and polymerization to pigments known as melanins. We have used UV- Vis spectroscopy, RP-HPLC and size exclusion chromatography (SEC) as analytical tools to monitor the kinetics of the oxidation of the CATs and further transformation to melanin-like pigments. SEC proved to be the best tool as it allows one to observe (a) the unreacted CAT molecule, (b) the chromophore initially generated, (c) the PS and (d) possible PS/melanin complexes. ^
Biology, Cell|Chemistry, Molecular|Chemistry, Biochemistry
Paola Andrea Forero Bello,
"Potential transformation of catecholamines to melanins in the presence of polysaccharides"
ETD Collection for Tennessee State University.