Pyrolysis-gas chromatography-mass spectrometry of synthetic neuromelanins

Dzierżęga‐Lęcznar, Anna; Chodurek, Ewa; Stępień, Karolina; Wilczok, Tadeusz

doi:10.1016/s0165-2370(01)00122-x

Cited by 19 publications

(24 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Main pyrolysis products of the eumelanin standard were identified as benzene, pyrrole, phenol, indole, and their alkyl derivatives, which is fully consistent with the data reported earlier [15][16][17][18]. The pyrolysate of CysDOPAmelanin was dominated by sulfur-containing compounds, such as: thiophene, thiazole, and thiazolidine derivatives, hydroxybenzothiazole and 1,4-benzothiazine.…”

Section: Resultssupporting

confidence: 89%

“…Sulfur-containing heterocycles are typical products of thermally degraded pheomelanins. In our previous reports we have postulated to regard them as the pyrolytic markers of pheomelanin-type subunits in naturally occurring pigments [15,16,18]. Like the eumelanin markers, the pheomelanin markers also retain structural information about the parent monomer units, from which they arise.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Melanin from epidermal human melanocytes: Study by pyrolytic GC/MS

Stępień

Dzierżęga‐Lęcznar

Kurkiewicz

et al. 2009

J. Am. Soc. Mass Spectrom.

View full text Add to dashboard Cite

Pigmentation of human skin is determined by the presence of melanin, the polymeric pigment that is produced in melanocytes and transferred to adjacent keratinocytes. Epidermal melanocytes produce two distinct types of melanin pigments: eumelanin, composed mainly of indole-type monomers, and pheomelanin that contains benzothiazine-type backbone. Eumelanin protects skin against UV-induced damages, whereas pheomelanin is believed to act as a potent UV photosensitizer and promote carcinogenesis. In this study, pyrolysis in combination with gas chromatography and mass spectrometry (Py-GC/MS) was applied for structural studies of the epidermal pigment isolated from the cultured human melanocytes. The analysis was preceded by investigations of DOPA-originated synthetic eumelanin and pheomelanin standards. This allowed determination of pyrolytic markers for both types of melanin pigments. To obtain additional information on the natural pigment structure, the samples were thermally degraded in the presence of tetramethylammonium hydroxide as the derivatizing agent. It was shown that the analyzed pigment from normal human epidermal melanocytes derived from moderately pigmented skin is of eumelanin type with little incorporation of a pheomelanin component. The results indicate that Py-GC/MS is a rapid and efficient technique for the differentiation of epidermal melanin types and may be an alternative to commonly used methods based on chemical degradation.

show abstract

Section: Resultssupporting

confidence: 89%

Section: Resultsmentioning

confidence: 99%

Melanin from epidermal human melanocytes: Study by pyrolytic GC/MS

Stępień

Dzierżęga‐Lęcznar

Kurkiewicz

et al. 2009

J. Am. Soc. Mass Spectrom.

View full text Add to dashboard Cite

show abstract

“…Although pyrolysis-GC-MS has been used to some success for melanin identification and structural analysis [17], most melanin preparations are contaminated with proteins [29]. We have found that purified proteins, due to their content of aromatic amino acids, give thermal degradation product signatures similar to that of plant melanin but degradation product yield is less than 10% of that seen with melanin (data not shown).…”

Section: Discussionmentioning

confidence: 84%

“…Pyrolysis-GC-MS has been successfully used in melanin identification and structural analysis [17] and together with other approaches has determined that melanin polymers are based on the indole structural unit [18]. Fig.…”

Section: Melanin Isolated From Echinacea Activates Monocytesmentioning

confidence: 99%

Melanin: dietary mucosal immune modulator from Echinacea and other botanical supplements

Pugh

Balachandran

Lata

et al. 2005

International Immunopharmacology

View full text Add to dashboard Cite

“…Pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) is commonly regarded as especially powerful technique providing valuable structural information about many natural products which, like melanins, are of relatively high molecular mass and heteropolymeric structure [15]. Our previous work demonstrated that Py-GC/MS analysis is suitable for identification of 5-S-cysteinylDA-derived heterocyclic units in synthetic melanin copolymers [16] and may be regarded as an approach alternative to chemical treatment in this respect. To improve the chromatographic properties of some of the pyrolysis products expected to originate from non-melanin components of NM specimens, additional experiments were performed using the thermally assisted hydrolysis methylation method.…”

mentioning

confidence: 99%

GC/MS analysis of thermally degraded neuromelanin from the human substantia nigra

Dzierżęga‐Lęcznar

Kurkiewicz

Stępień

et al. 2004

J. Am. Soc. Mass Spectrom.

View full text Add to dashboard Cite

Neuromelanin (NM) is a complex polymer pigment found in catecholaminergic neurons of the human brain. The structure, formation pathway, and physiological function of NM have not yet been clarified, but interest in this polymer has been sparked by the suggestion that NM is involved in cell death in Parkinson's disease. In the current study, pyrolysis-gas chromatography/mass spectrometry analysis was applied for structural investigation of NM isolated from the human substantia nigra, using synthetic eumelanin and pheomelanin-type pigments as reference materials. None of the heterocyclic, sulfur-containing compounds being characteristic thermal degradation products of cysteinyldopamine-derived units of synthetic pheomelanin standard was detected in the pyrolysates of natural NM. The results suggest that nigral pigment isolated from normal brain tissue does not contain benzothiazine-type monomer units. Pyrolytic experiments in the presence of a derivatizing agent allowed identification of high levels of saturated and monounsaturated straight-chain C14-C18 fatty acids and led to the conclusion that a part of a lipid component is chemically bound to the NM macromolecule. The nigral pigment was also shown to be tightly associated with an isoprenoid-type compound.

show abstract

Pyrolysis-gas chromatography-mass spectrometry of synthetic neuromelanins

Cited by 19 publications

References 25 publications

Melanin from epidermal human melanocytes: Study by pyrolytic GC/MS

Melanin from epidermal human melanocytes: Study by pyrolytic GC/MS

Melanin: dietary mucosal immune modulator from Echinacea and other botanical supplements

GC/MS analysis of thermally degraded neuromelanin from the human substantia nigra

Contact Info

Product

Resources

About