title: Preliminary spectroscopic studies on the neuromelanic pigment of human substantia nigra nucleus.
abstract: The neuromelanic pigment obtained from human mid-brain Substantia Nigra Nucleus was studied by I.R. spectroscopy and compared with synthetic dopamine melanin. Natural neuromelanin and synthetic dopamine melanin show very similar features in two characteristic I.R. absorption regions: 1400 cm-1, typical of phenolic OH groups, and 3200 cm-1 band, typical of aminic groups. Natural mid-brain neuromelanin shows a different absorption in the I.R. region at 3000 cm-1 and in the 1300-900 cm-1 range probably due to the presence of lipidic residues bound to the molecule. The results of the U.V. spectroscopic analysis suggest a correlation between the optical density of human neuromelanic pigment and the different ages of the subjects providing the specimens.
mesh_terms: D000328:Adult; D000368:Aged; D004298:Dopamine / Q000032:analysis; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008543:Melanins / Q000032:analysis*; D008875:Middle Aged; D013055:Spectrophotometry, Infrared; D013056:Spectrophotometry, Ultraviolet; D013378:Substantia Nigra / Q000032:analysis*
chemical_list: D008543:Melanins; C014121:neuromelanin; D004298:Dopamine