PMID- 29350885
OWN - NLM
STAT- MEDLINE
DCOM- 20190207
LR  - 20190215
IS  - 1755-148X (Electronic)
IS  - 1755-1471 (Linking)
VI  - 31
IP  - 4
DP  - 2018 Jul
TI  - Unexpected impact of esterification on the antioxidant activity and 
      (photo)stability of a eumelanin from 5,6-dihydroxyindole-2-carboxylic acid.
PG  - 475-483
LID - 10.1111/pcmr.12689 [doi]
AB  - To inquire into the role of the carboxyl group as determinant of the properties 
      of 5,6-dihydroxyindole melanins, melanins from aerial oxidation of 
      5,6-dihydroxyindole-2-carboxylic acid (DHICA) and its DHICA methyl ester 
      (MeDHICA) were comparatively tested for their antioxidant activity. MALDI MS 
      spectrometry analysis of MeDHICA melanin provided evidence for a collection of 
      intact oligomers. EPR analysis showed g-values almost identical and signal 
      amplitudes (DeltaB) comparable to those of DHICA melanin, but spin density was one 
      order of magnitude higher, with a different response to pH changes. Antioxidant 
      assays were performed, and a model of lipid peroxidation was used to compare the 
      protective effects of the melanins. In all cases, MeDHICA melanin performed 
      better than DHICA melanin. This capacity was substantially maintained following 
      exposure to air in aqueous buffer over 1 week or to solar simulator over 3 hr. 
      Different from DHICA melanin, MeDHICA melanin was proved to be fairly soluble in 
      different water-miscible organic solvents, suggesting its use in dermocosmetic 
      applications.
CI  - (c) 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
FAU - Micillo, Raffaella
AU  - Micillo R
AD  - Department of Chemical Sciences, University of Naples "Federico II", Naples, 
      Italy.
FAU - Iacomino, Mariagrazia
AU  - Iacomino M
AD  - Department of Chemical Sciences, University of Naples "Federico II", Naples, 
      Italy.
FAU - Perfetti, Marco
AU  - Perfetti M
AD  - Department of Chemical Sciences, University of Naples "Federico II", Naples, 
      Italy.
FAU - Panzella, Lucia
AU  - Panzella L
AD  - Department of Chemical Sciences, University of Naples "Federico II", Naples, 
      Italy.
FAU - Koike, Kenzo
AU  - Koike K
AD  - Hair Care Products Research Laboratories, Kao Corporation, Sumida, Tokyo, Japan.
FAU - D'Errico, Gerardino
AU  - D'Errico G
AD  - Department of Chemical Sciences, University of Naples "Federico II", Naples, 
      Italy.
FAU - d'Ischia, Marco
AU  - d'Ischia M
AD  - Department of Chemical Sciences, University of Naples "Federico II", Naples, 
      Italy.
FAU - Napolitano, Alessandra
AU  - Napolitano A
AUID- ORCID: 0000-0003-0507-5370
AD  - Department of Chemical Sciences, University of Naples "Federico II", Naples, 
      Italy.
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20180214
PL  - England
TA  - Pigment Cell Melanoma Res
JT  - Pigment cell & melanoma research
JID - 101318927
RN  - 0 (Antioxidants)
RN  - 0 (Indoles)
RN  - 0 (Melanins)
RN  - 12627-86-0 (eumelanin)
RN  - 4790-08-3 (5,6-dihydroxy-2-indolylcarboxylic acid)
SB  - IM
MH  - Antioxidants/*chemistry
MH  - Esterification
MH  - Hydrogen-Ion Concentration
MH  - Indoles/*chemistry
MH  - Melanins/*chemistry
OTO - NOTNLM
OT  - (photo)stability
OT  - 5,6-dihydroxyindole-2-carboxylic acid methyl ester
OT  - EPR spectroscopy
OT  - MALDI MS analysis
OT  - antioxidant
OT  - melanin
OT  - solubility
EDAT- 2018/01/20 06:00
MHDA- 2019/02/08 06:00
CRDT- 2018/01/20 06:00
PHST- 2017/10/11 00:00 [received]
PHST- 2018/01/03 00:00 [accepted]
PHST- 2018/01/20 06:00 [pubmed]
PHST- 2019/02/08 06:00 [medline]
PHST- 2018/01/20 06:00 [entrez]
AID - 10.1111/pcmr.12689 [doi]
PST - ppublish
SO  - Pigment Cell Melanoma Res. 2018 Jul;31(4):475-483. doi: 10.1111/pcmr.12689. Epub 
      2018 Feb 14.