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Bottom-Up Approach to Eumelanin Photoprotection: Emission Dynamics in Parallel Sets of Water-Soluble 5,6-Dihydroxyindole-Based Model Systems.

Corani, Alice LU ; Huijser, Annemarie LU ; Iadonisi, Alfonso; Pezzella, Alessandro; Sundström, Villy LU and d'Ischia, Marco (2012) In The Journal of Physical Chemistry Part B 116(44). p.13151-13158
Abstract
The molecular mechanisms by which the black eumelanin biopolymers exert their photoprotective action on human skin and eyes are still poorly understood, owing to critical insolubility and structural heterogeneity issues hindering direct investigation of excitation and emission behavior. Recently, we set up strategies to obtain water-soluble 5,6-dihydroxyindole (DHI)-based polymers as useful models for disentangling intrinsic photophysical properties of eumelanin components from aggregation and scattering effects. Herein, we report the absorption properties and ultrafast emission dynamics of two separate sets of DHI-based monomer-dimer-polymer systems which were made water-soluble by means of poly(vinyl alcohol) or by galactosyl-thio... (More)
The molecular mechanisms by which the black eumelanin biopolymers exert their photoprotective action on human skin and eyes are still poorly understood, owing to critical insolubility and structural heterogeneity issues hindering direct investigation of excitation and emission behavior. Recently, we set up strategies to obtain water-soluble 5,6-dihydroxyindole (DHI)-based polymers as useful models for disentangling intrinsic photophysical properties of eumelanin components from aggregation and scattering effects. Herein, we report the absorption properties and ultrafast emission dynamics of two separate sets of DHI-based monomer-dimer-polymer systems which were made water-soluble by means of poly(vinyl alcohol) or by galactosyl-thio substitution. Data showed that dimerization and polymerization of DHI result in long-lived excited states with profoundly altered properties relative to the monomer and that glycosylation of DHI imparts monomer-like behavior to oligomers and polymers, due to steric effects hindering planar conformations and efficient interunit electron communication. The potential of S-glycation as an effective tool to probe and control emission characteristics of eumelanin-like polymers is disclosed. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
The Journal of Physical Chemistry Part B
volume
116
issue
44
pages
13151 - 13158
publisher
The American Chemical Society
external identifiers
  • wos:000310768600001
  • pmid:23072413
  • scopus:84868582218
ISSN
1520-5207
DOI
10.1021/jp306436f
language
English
LU publication?
yes
id
a0500049-96ab-41b2-9497-f91a9c1fa8d6 (old id 3160649)
date added to LUP
2012-11-13 13:15:31
date last changed
2017-08-20 04:05:24
@article{a0500049-96ab-41b2-9497-f91a9c1fa8d6,
  abstract     = {The molecular mechanisms by which the black eumelanin biopolymers exert their photoprotective action on human skin and eyes are still poorly understood, owing to critical insolubility and structural heterogeneity issues hindering direct investigation of excitation and emission behavior. Recently, we set up strategies to obtain water-soluble 5,6-dihydroxyindole (DHI)-based polymers as useful models for disentangling intrinsic photophysical properties of eumelanin components from aggregation and scattering effects. Herein, we report the absorption properties and ultrafast emission dynamics of two separate sets of DHI-based monomer-dimer-polymer systems which were made water-soluble by means of poly(vinyl alcohol) or by galactosyl-thio substitution. Data showed that dimerization and polymerization of DHI result in long-lived excited states with profoundly altered properties relative to the monomer and that glycosylation of DHI imparts monomer-like behavior to oligomers and polymers, due to steric effects hindering planar conformations and efficient interunit electron communication. The potential of S-glycation as an effective tool to probe and control emission characteristics of eumelanin-like polymers is disclosed.},
  author       = {Corani, Alice and Huijser, Annemarie and Iadonisi, Alfonso and Pezzella, Alessandro and Sundström, Villy and d'Ischia, Marco},
  issn         = {1520-5207},
  language     = {eng},
  number       = {44},
  pages        = {13151--13158},
  publisher    = {The American Chemical Society},
  series       = {The Journal of Physical Chemistry Part B},
  title        = {Bottom-Up Approach to Eumelanin Photoprotection: Emission Dynamics in Parallel Sets of Water-Soluble 5,6-Dihydroxyindole-Based Model Systems.},
  url          = {http://dx.doi.org/10.1021/jp306436f},
  volume       = {116},
  year         = {2012},
}