Structure, Chemistry, and Biosynthesis of the Melanins

Characterization of melanin extracted from apricot (Armeniaca sibirica) and its effect on hydrazine-induced rat hepatic injury

“…The positive controls also received gavage administration of bifendate (10 mg/kg) dissolved in sterile water at pH 7.4. The three experimental groups were allocated to gavage administration of MAKS at a low, medium, or high dose (10,20, and 30 mg/kg, respectively) 30 min prior to the same hydrazine treatment.…”

“…There are three general forms; black-brown eumelanin, pheomelanin (ranging from red to yellow brown), and black allomelanin. The structures of eumelanin and pheomelanin are still unclear, but basic structural models suggested by Nicolaus and Swan 20 have been widely adopted ( Fig. 1).…”

On the origin of the electrostatic surface potential of Aspergillus niger spores in acidic environments

“…Melanin from A. niger is believed to be associated with proteins and possibly also with carbohydrates (Swan, 1974). However, the mass fraction of the carbohydrates as estimated from the phenol-sulfuric acid method based on a glucose standard was relatively small (approx.…”

Solid‐state cross‐polarization magic angle spinning 13C and 15N NMR characterization of Sepia melanin, Sepia melanin free acid and Human hair melanin in comparison with several model compounds

“…1 Melanins also have importance in several nonbiological contexts. Insulating and semiconducting properties of melanins have been noted 2,3 and applications as ion-exchange resins 4 and redox polymers have been demonstrated. The polymerization patterns resulting from these different types of linkages appear to govern functionality.…”

“…A feature that has been observed by x-ray characterization is a 3.4Å spacing corresponding to the parallel stacking of aromatic units in randomly oriented local domains. 2,6,7 X-ray analysis has also been used to examine the structure of Sepia melanin, L-dopa and tyrosine synthetic melanins. 8,9 These studies showed that melanins have short to intermediate range order.…”