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Studies on structure characterization of tryptophan melanin: Comparison between filament and curie‐point pyrolysis gas chromatography/mass spectrometry
Author(s) -
Vèkey Karoly,
Tamás József,
Somogyi Arpád,
Bertazzo Antonella,
Costa Carlo,
Allegri Graziella,
Seraglia Roberta,
Traldi Piero
Publication year - 1992
Publication title -
organic mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 121
eISSN - 1096-9888
pISSN - 0030-493X
DOI - 10.1002/oms.1210271111
Subject(s) - pyrolysis , ethylbenzene , chemistry , indole test , tryptophan , mass spectrometry , toluene , organic chemistry , pyrolysis–gas chromatography–mass spectrometry , gas chromatography , chromatography , amino acid , biochemistry
Structural studies of a synthetic melanin, obtained by means of performic acid oxidation of tryptophan, were carried out by pyrolysis gas chromatography/mass Spectrometry (Py‐GC/MS). To identify the best pyrolysis conditions, both Curie‐point pyrolysis and filament pyrolysis were employed and the effects of pyrolysis temperatures and times were studied. Using the first approach, various compounds were identified: toluene, ethylbenzene, styrene, indole, methylindole, ethylindole, phenol, cresol and ethylphenol. Using filament pyrolysis some interesting differences could be observed. Whereas toluene, ethylbenzene, phenol, cresol and methylindole were found, neither indole nor ethylindole was detected. Instead, new pyrolysis products were evident, such as methylpyrrole and indolin‐2‐one. Hence filament pyrolysis seems to activate different thermal decomposition pathways of the melanin under study. It is suggested that tryptophan melanin is a polymer containing indole and hydroxyindole derivatives as subunits.