PMID- 9895237
OWN - NLM
STAT- MEDLINE
DCOM- 19990331
LR  - 20190826
IS  - 0891-5849 (Print)
IS  - 0891-5849 (Linking)
VI  - 26
IP  - 3-4
DP  - 1999 Feb
TI  - Lipoxygenase/H2O2-catalyzed oxidation of dihdroxyindoles: synthesis of melanin 
      pigments and study of their antioxidant properties.
PG  - 446-53
AB  - 5,6-Dihydroxyindole (DHI) and 5,6-dihydroxyindole-2-carboxylic acid (DHICA), 
      which are important intermediates in melanogenesis, can be converted into the 
      corresponding melanin pigments by the action of the lipoxygenase/H2O2 system. 
      Kinetic and HPLC analyses indicate that both DHI and DHICA are good substrates 
      for this enzymatic system. Enzyme activity on both substrates was measured in 
      comparison with peroxidase and tyrosinase; the oxidizing behaviour of 
      lipoxygenase is more similar to that of peroxidase rather than that of 
      tyrosinase. The antioxidant properties of DHI- and DHICA-melanins have been 
      investigated in comparison with other kinds of melanins. DHICA-melanin shows a 
      more pronounced antioxidant effect than that of DHI-melanin and this behaviour 
      can be ascribed to the different structure and solubility of the two pigments. 
      The mixed polymer synthesized from DHI and DHICA is the most effective one. Some 
      implications about the possible explanation of the above mentioned behaviour are 
      discussed.
FAU - Blarzino, C
AU  - Blarzino C
AD  - Department of Biochemical Sciences, University of Rome La Sapieza, Italy.
FAU - Mosca, L
AU  - Mosca L
FAU - Foppoli, C
AU  - Foppoli C
FAU - Coccia, R
AU  - Coccia R
FAU - De Marco, C
AU  - De Marco C
FAU - Rosei, M A
AU  - Rosei MA
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - Free Radic Biol Med
JT  - Free radical biology & medicine
JID - 8709159
RN  - 0 (Antioxidants)
RN  - 0 (Free Radicals)
RN  - 0 (Indoles)
RN  - 0 (Melanins)
RN  - 4790-08-3 (5,6-dihydroxy-2-indolylcarboxylic acid)
RN  - BBX060AN9V (Hydrogen Peroxide)
RN  - EC 1.13.11.12 (Lipoxygenase)
RN  - Z3OC8499KG (5,6-dihydroxyindole)
SB  - IM
MH  - Antioxidants/*metabolism
MH  - Catalysis
MH  - Chromatography, High Pressure Liquid
MH  - Free Radicals
MH  - Hydrogen Peroxide/*metabolism
MH  - Indoles/*metabolism
MH  - Kinetics
MH  - Lipoxygenase/*metabolism
MH  - Melanins/*biosynthesis
MH  - Oxidation-Reduction
EDAT- 1999/01/23 00:00
MHDA- 1999/01/23 00:01
CRDT- 1999/01/23 00:00
PHST- 1999/01/23 00:00 [pubmed]
PHST- 1999/01/23 00:01 [medline]
PHST- 1999/01/23 00:00 [entrez]
AID - S0891-5849(98)00225-1 [pii]
AID - 10.1016/s0891-5849(98)00225-1 [doi]
PST - ppublish
SO  - Free Radic Biol Med. 1999 Feb;26(3-4):446-53. doi: 10.1016/s0891-5849(98)00225-1.