Biological Perspectives and the Problem of Melanin Structure

6- dihydroxyindole 1 may have physiological significance and may play an important role in photoprotection (95PP650). Indolic melanin precursors have been shown to possess redox properties that may modify some important processes such as radical attack on biomolecules. For example, 5,6-dihydroxyindole 1 (and 

Overall, the generation and distribution of surface pigments based on the 5,6-dihydroxyindole structure is clearly associated with survival benefit, perhaps including its role in camouflage or sexual display as well as radiation protection. Animals in which melanogenesis is deficient or absent (as in albinism) appear to be disadvantaged. 

Mercier, I. Parikh, and A. S. Dreiding, Helv. Chim. Acta, 45, 640 (1962). 

69MI50 H. J. Roth and U. Volkmann, Arch. Pharm. Ber. Dtsch. Pharm. Ges., 

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