28
1 Melanin Chemistry
54. R. Edge, M. d’Ischia, E.J. Land, A. Napolitano, S. Navaratnam, L. Panzella, A. Pezzella, C.A.
Ramsden, P.A. Riley, Dopaquinone redox exchange with dihydroxyindole and dihydroxyindole carboxylic acid. Pigment Cell Res. 19, 443–450 (2006)
55. C. Jímenez-Cervantes, F. Solano, T. Kobayashi, K. Urabe, V.J. Hearing, J.A. Lozano,
J.C. García-Borrón, A new enzymatic function in the melanogenic pathway. The 5,6dihydroxyindole-2-carboxylic acid oxidase activity of tyrosinase-related protein-1 (TRP1). J.
Biol. Chem. 269, 17993–18000 (1994)
56. T. Kobayashi, K. Urabe, A. Winder, C. Jímenez-Cervantes, G. Imokawa, T. Brewington, F.
Solano, J.C. García-Borrón, V.J. Hearing, Tyrosinase related protein 1 (TRP1) functions as a
DHICA oxidase in melanin biosynthesis. EMBO J. 13, 5818–5825 (1994)
57. C. Olivares, C. Jímenez-Cervantes, J.A. Lozano, F. Solano, J.C. García-Borrón, The 5,6dihydroxyindole-2-carboxylic acid (DHICA) oxidase activity of human tyrosinase. Biochem.
J. 354, 131–139 (2001)
58. S. Ito, N. Suzuki, S. Takebayashi, S. Commo, K. Wakamatsu, Neutral pH and copper ions
promote eumelanogenesis after the dopachrome stage. Pigment Cell Melanoma Res. 26, 817–
825 (2013)
59. A. Napolitano, M.G. Corradini, G. Prota, A reinvestigation of the structure of melanochrome.
Tetrahedron Lett. 26, 2805–2808 (1985)
60. G. Prota, Melanins melanogenesis and melanocytes: looking at their functional significance
from the chemist’s viewpoint. Pigment Cell Res. 13, 283–293 (2000)
61. A. Pezzella, A. Napolitano, M. d’Ischia, G. Prota, Oxidative polymerisation of 5,6dihydroxyindole-2-carboxylic acid to melanin: a new insight. Tetrahedron 52, 7913–7920
(1996)
62. P. Palumbo, M. d’Ischia, G. Prota, Tyrosinase-promoted oxidation of 5,6-dihydroxyindole2-carboxylic acid to melanin. Isolation and characterization of oligomer intermediates,
Tetrahedron 43, 4203–4206 (1987)
63. P. Meredith, T. Sarna, The physical and chemical properties of eumelanin. Pigment Cell Res.
19, 572–594 (2006)
64. M. d’Ischia, A. Napolitano, A. Pezzella, P. Meredith, T. Sarna, Chemical and structural
diversity in eumelanins: unexplored bio-optoelectronic materials. Angew. Chem. Int. Ed.
48, 3914–3921 (2009)
65. A. Pezzella, D. Vogna, G. Prota, Atropoisomeric melanin intermediates by oxidation of the
melanogenic precursor 5,6-dihydroxyindole-2-carboxylic acid under biomimetic conditions.
Tetrahedron 58, 3681–3687 (2002)
66. L. Panzella, A. Pezzella, A. Napolitano, M. d’Ischia, The first 5,6-dihydroxyindole tetramer
by oxidation of 5,5’,6,6’-tetrahydroxy-2,4’-biindolyl and an unexpected issue of positional
reactivity en route to eumelanin-related polymers. Org. Lett. 9, 1411–1414 (2007)
67. A. Pezzella, L. Panzella, A. Natangelo, M. Arzillo, A. Napolitano, M. d’Ischia, 5,6Dihydroxyindole tetramers with anomalous interunit bonding patterns by oxidative coupling
of 5,5’,6,6’-tetrahydroxy-2,7’-biindolyl: emerging complexities on the way toward an
improved model of eumelanin buildup. J. Org. Chem. 72, 9225–9230 (2007)
68. M. d’Ischia, A. Napolitano, A. Pezzella, E.J. Land, C.A. Ramsden, P.A. Riley, 5,6Dihydroxyindoles and indole-5,6-diones. Adv. Heterocycl. Chem. 89, 1–63 (2005)
69. A. Napolitano, O. Crescenzi, G. Prota, Copolymerisation of 5,6-dihydroxyindole and 5,6dihydroxyindole-2-carboxylic Acid in melanogenesis: isolation of a cross-coupling produc.
Tetrahedron Lett. 34, 885–888 (1993)
70. A. Napolitano, O. Crescenzi, K. Tsiakas, G. Prota, Oxidation chemistry of 5,6-dihydroxy-2methylindole. Tetrahedron 49, 9143–9150 (1993)
71. K. Glass, S. Ito, P.R. Wilby, T. Sota, A. Nakamura, C.R. Bowers, J. Vinther, S. Dutta, R.
Summons, D.E.G. Briggs, K. Wakamatsu, J.D. Simon, Direct chemical evidence for eumelanin
pigment from the Jurassic period. Proc. Natl. Acad. Sci. 109, 10218–10223 (2012)
72. S. Ito, K. Wakamatsu, K. Glass, J.D. Simon, High-performance liquid chromatography estimation of cross-linking of dihydroxyindole moiety in eumelanin. Anal. Biochem. 434, 221–225
(2013)
1 Melanin Chemistry
54. R. Edge, M. d’Ischia, E.J. Land, A. Napolitano, S. Navaratnam, L. Panzella, A. Pezzella, C.A.
Ramsden, P.A. Riley, Dopaquinone redox exchange with dihydroxyindole and dihydroxyindole carboxylic acid. Pigment Cell Res. 19, 443–450 (2006)
55. C. Jímenez-Cervantes, F. Solano, T. Kobayashi, K. Urabe, V.J. Hearing, J.A. Lozano,
J.C. García-Borrón, A new enzymatic function in the melanogenic pathway. The 5,6dihydroxyindole-2-carboxylic acid oxidase activity of tyrosinase-related protein-1 (TRP1). J.
Biol. Chem. 269, 17993–18000 (1994)
56. T. Kobayashi, K. Urabe, A. Winder, C. Jímenez-Cervantes, G. Imokawa, T. Brewington, F.
Solano, J.C. García-Borrón, V.J. Hearing, Tyrosinase related protein 1 (TRP1) functions as a
DHICA oxidase in melanin biosynthesis. EMBO J. 13, 5818–5825 (1994)
57. C. Olivares, C. Jímenez-Cervantes, J.A. Lozano, F. Solano, J.C. García-Borrón, The 5,6dihydroxyindole-2-carboxylic acid (DHICA) oxidase activity of human tyrosinase. Biochem.
J. 354, 131–139 (2001)
58. S. Ito, N. Suzuki, S. Takebayashi, S. Commo, K. Wakamatsu, Neutral pH and copper ions
promote eumelanogenesis after the dopachrome stage. Pigment Cell Melanoma Res. 26, 817–
825 (2013)
59. A. Napolitano, M.G. Corradini, G. Prota, A reinvestigation of the structure of melanochrome.
Tetrahedron Lett. 26, 2805–2808 (1985)
60. G. Prota, Melanins melanogenesis and melanocytes: looking at their functional significance
from the chemist’s viewpoint. Pigment Cell Res. 13, 283–293 (2000)
61. A. Pezzella, A. Napolitano, M. d’Ischia, G. Prota, Oxidative polymerisation of 5,6dihydroxyindole-2-carboxylic acid to melanin: a new insight. Tetrahedron 52, 7913–7920
(1996)
62. P. Palumbo, M. d’Ischia, G. Prota, Tyrosinase-promoted oxidation of 5,6-dihydroxyindole2-carboxylic acid to melanin. Isolation and characterization of oligomer intermediates,
Tetrahedron 43, 4203–4206 (1987)
63. P. Meredith, T. Sarna, The physical and chemical properties of eumelanin. Pigment Cell Res.
19, 572–594 (2006)
64. M. d’Ischia, A. Napolitano, A. Pezzella, P. Meredith, T. Sarna, Chemical and structural
diversity in eumelanins: unexplored bio-optoelectronic materials. Angew. Chem. Int. Ed.
48, 3914–3921 (2009)
65. A. Pezzella, D. Vogna, G. Prota, Atropoisomeric melanin intermediates by oxidation of the
melanogenic precursor 5,6-dihydroxyindole-2-carboxylic acid under biomimetic conditions.
Tetrahedron 58, 3681–3687 (2002)
66. L. Panzella, A. Pezzella, A. Napolitano, M. d’Ischia, The first 5,6-dihydroxyindole tetramer
by oxidation of 5,5’,6,6’-tetrahydroxy-2,4’-biindolyl and an unexpected issue of positional
reactivity en route to eumelanin-related polymers. Org. Lett. 9, 1411–1414 (2007)
67. A. Pezzella, L. Panzella, A. Natangelo, M. Arzillo, A. Napolitano, M. d’Ischia, 5,6Dihydroxyindole tetramers with anomalous interunit bonding patterns by oxidative coupling
of 5,5’,6,6’-tetrahydroxy-2,7’-biindolyl: emerging complexities on the way toward an
improved model of eumelanin buildup. J. Org. Chem. 72, 9225–9230 (2007)
68. M. d’Ischia, A. Napolitano, A. Pezzella, E.J. Land, C.A. Ramsden, P.A. Riley, 5,6Dihydroxyindoles and indole-5,6-diones. Adv. Heterocycl. Chem. 89, 1–63 (2005)
69. A. Napolitano, O. Crescenzi, G. Prota, Copolymerisation of 5,6-dihydroxyindole and 5,6dihydroxyindole-2-carboxylic Acid in melanogenesis: isolation of a cross-coupling produc.
Tetrahedron Lett. 34, 885–888 (1993)
70. A. Napolitano, O. Crescenzi, K. Tsiakas, G. Prota, Oxidation chemistry of 5,6-dihydroxy-2methylindole. Tetrahedron 49, 9143–9150 (1993)
71. K. Glass, S. Ito, P.R. Wilby, T. Sota, A. Nakamura, C.R. Bowers, J. Vinther, S. Dutta, R.
Summons, D.E.G. Briggs, K. Wakamatsu, J.D. Simon, Direct chemical evidence for eumelanin
pigment from the Jurassic period. Proc. Natl. Acad. Sci. 109, 10218–10223 (2012)
72. S. Ito, K. Wakamatsu, K. Glass, J.D. Simon, High-performance liquid chromatography estimation of cross-linking of dihydroxyindole moiety in eumelanin. Anal. Biochem. 434, 221–225
(2013)