Abstract

This study of the oxidation and reduction of synthetic 3,4-dihydroxy-DL-phenylalanine melanin has demonstrated that (a) the electron exchange witn melanin particles is biphasic; (b) about 25% of the indole units are on the surface of melanin particles; (c) melanin exists predominantly in the quinonoid oxidized form, which is suitable for those interactions involved in the formation of charge transfer complexes; (d) the reduced form of melanin is slowly reoxidized by air.