PMID- 25078723
OWN - NLM
STAT- MEDLINE
DCOM- 20151026
LR  - 20140820
IS  - 1520-5126 (Electronic)
IS  - 0002-7863 (Linking)
VI  - 136
IP  - 33
DP  - 2014 Aug 20
TI  - Superior photoprotective motifs and mechanisms in eumelanins uncovered.
PG  - 11626-35
LID - 10.1021/ja501499q [doi]
AB  - Human pigmentation is a complex phenomenon commonly believed to serve a 
      photoprotective function through the generation and strategic localization of 
      black insoluble eumelanin biopolymers in sun exposed areas of the body. Despite 
      compelling biomedical relevance to skin cancer and melanoma, eumelanin 
      photoprotection is still an enigma: What makes this pigment so efficient in 
      dissipating the excess energy brought by harmful UV-light as heat? Why has Nature 
      selected 5,6-dihydroxyindole-2-carboxylic acid (DHICA) as the major building 
      block of the pigment instead of the decarboxylated derivative (DHI)? By using 
      pico- and femtosecond fluorescence spectroscopy we demonstrate herein that the 
      excited state deactivation in DHICA oligomers is 3 orders of magnitude faster 
      compared to DHI oligomers. This drastic effect is attributed to their specific 
      structural patterns enabling multiple pathways of intra- and interunit proton 
      transfer. The discovery that DHICA-based scaffolds specifically confer uniquely 
      robust photoprotective properties to natural eumelanins settles a fundamental gap 
      in the biology of human pigmentation and opens the doorway to attractive advances 
      and applications.
FAU - Corani, Alice
AU  - Corani A
AD  - Department of Chemical Physics, Lund University , Box 124, 22100 Lund, Sweden.
FAU - Huijser, Annemarie
AU  - Huijser A
FAU - Gustavsson, Thomas
AU  - Gustavsson T
FAU - Markovitsi, Dimitra
AU  - Markovitsi D
FAU - Malmqvist, Per-Ake
AU  - Malmqvist PA
FAU - Pezzella, Alessandro
AU  - Pezzella A
FAU - d'Ischia, Marco
AU  - d'Ischia M
FAU - Sundstrom, Villy
AU  - Sundstrom V
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20140811
PL  - United States
TA  - J Am Chem Soc
JT  - Journal of the American Chemical Society
JID - 7503056
RN  - 0 (Indoles)
RN  - 0 (Melanins)
RN  - 12627-86-0 (eumelanin)
RN  - 4790-08-3 (5,6-dihydroxy-2-indolylcarboxylic acid)
SB  - IM
MH  - Humans
MH  - Indoles/*chemistry
MH  - Melanins/*chemistry
MH  - Molecular Structure
MH  - Photochemical Processes
MH  - Spectrometry, Fluorescence
EDAT- 2014/08/01 06:00
MHDA- 2015/10/27 06:00
CRDT- 2014/08/01 06:00
PHST- 2014/08/01 06:00 [entrez]
PHST- 2014/08/01 06:00 [pubmed]
PHST- 2015/10/27 06:00 [medline]
AID - 10.1021/ja501499q [doi]
PST - ppublish
SO  - J Am Chem Soc. 2014 Aug 20;136(33):11626-35. doi: 10.1021/ja501499q. Epub 2014 
      Aug 11.