| Autor: |
Farmer, P. J., Stark, K. B., Gallas, J. M., Zajac, G. W., Golab, J. T., Eisner, M., Gidanian, S., McIntire, T. |
| Předmět: |
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| Zdroj: |
Pigment Cell Research; Aug2004, Vol. 17 Issue 4, p446-446, 1p |
| Abstrakt: |
Spectroscopic simulations of a leading structural model for melanin, the pigment responsible for coloration and photo protection in humans and animals, were done. In direct continuation of an earlier study (Stark et al. J Phys Chem, B 2003;307:361) on possible monomer and dimer subunits of eumelanin, we have performed Density Functional Theory (DFT) calculations on a recent structural model for eumelanin based upon higher oligomers of neutral 5,6-indolequinone. This paper further reports on our semi-empirical spectroscopic simulations for the higher oligomer (tetramers through hexamers) energy-minimized structures. A linear combination of the oligomeric spectra reproduces several features of the experimental spectrum. This result strongly supports the assumption that melanin is constituted of substructures such as those considered in this study. In addition, the effect of stacking on the theoretical spectra has been investigated and the existing model has been chemically modified in order to incorporate different oxidation states of melanin. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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