ThesisAuthors: Hong, Lian (2006)
Melanin is a pigment that is ubiquitous in the biological world. In addition to its obvious function of adornment, melanin is believed to serve as a metal reservoir and sunscreen. This work examined the metal binding behavior, the chemical structures and the interaction with light of natural melanins isolated from several different sources.
Sepia eumelanin was used as a model to study the metal binding behavior of eumelanins. Infrared spectroscopic analysis suggests that Mg(II), Ca(II) and Zn(II) are mainly bound to carboxyl groups and Cu(II) binds to hydroxyl groups at pH --4. The effect of metal content on the aerobic reactivity was examined by analyzing the ability of melanin to nick DNA. Of the metals studied, Cu(ll)- and Fe(III)-loaded melanin showed the most damaging effects ... 
