Pyrolytic GC-MS analysis of melanin from black, gray and yellow strains of Drosophila melanogaster

Latocha, Małgorzata; Chodurek, Ewa; Kurkiewicz, Sławomir; Świa̧tkowska, Longina; Wilczok, Tadeusz

doi:10.1016/s0165-2370(00)00082-6

Cited by 42 publications

(43 citation statements)

References 23 publications

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“…Sulfur may also be indicative of the presence of pheomelanin, as the sulfur-containing amino acid cysteine is one of the key triggers for its formation (Robins 1991;Prota 1992); however, we find no evidence of this in our samples. There is also no evidence of eu-or pheomelanin breakdown products in the Py-GCMS chromatograms (Dworzanski and Debowski 1985;Latocha et al 2000), which show the presence of generic organic matter, including series of benzene and naphthalene compounds. Though the distribution pattern of n-alkane/n-alkene doublets is slightly different in the tadpole and its enclosing matrix, it is not different enough to rule out the possibility of some organic matter transfer.…”

Section: Organic Geochemistrymentioning

confidence: 97%

“…Melanin can act like a metal ion sink during diagenesis, leading to the build-up of these metals where melanin was present and allowing them to be used as a melanin biomarker . Zinc is known to naturally accumulate in red human hair, and levels of zinc commonly exceed those of copper in eu-and pheomelanin extracted from human hair (Latocha et al 2000). Another reason for higher zinc levels in the tadpole may be the presence of matrix metalloproteinases.…”

Section: Trace Metalsmentioning

confidence: 99%

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Bacteria or melanosomes? A geochemical analysis of micro-bodies on a tadpole from the Oligocene Enspel Formation of Germany

Barden

Bergmann

Edwards

et al. 2014

Palaeobio Palaeoenv

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Many exceptionally preserved fossils have long been thought the product of preservation by bacterial autolithification, based largely upon the presence of, micronsized, spherical or elongate bodies on their surface. This has recently been challenged by studies of similar fossils which cite morphological and geochemical evidence that these structures could be fossilized melanosomes, melanin-containing organelles. We geochemically analysed a tadpole from the Oligocene Enspel Formation, Germany, which displays such spherical bodies on its surface. Pyrolysis gas chromatography mass spectroscopy (Py-GCMS) and Fourier transform infrared spectrometry (FTIR) indicate that the organic remains of the tadpole are original and are not the result of external contamination, shown by the different chemical compositions of the fossil and its enclosing matrix. Py-GCMS also demonstrates the presence of bacterial and plant biomarkers in the matrix but not the tadpole, suggesting that the spherical bodies are unlikely to be bacterial, and also that such fossils do not develop their dark colour from incorporating plant material, as has been suggested. X-ray absorption spectroscopy (XAS) shows high levels of organically bound Zn(II) in the fossilized soft tissue, a metal known to chelate both eu-and pheomelanin.The zinc in the tadpole shows greater similarity to that bound in pheomelanized extant samples than to that in eumelanized ones. Though further geochemical analysis of both pure pheomelanin and bacterial samples is required to completely exclude a bacterial origin, these results are in line with a pheomelanic origin for the spherical bodies on the tadpole.

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Section: Organic Geochemistrymentioning

confidence: 97%

Section: Trace Metalsmentioning

confidence: 99%

Bacteria or melanosomes? A geochemical analysis of micro-bodies on a tadpole from the Oligocene Enspel Formation of Germany

Barden

Bergmann

Edwards

et al. 2014

Palaeobio Palaeoenv

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show abstract

“…Melanin is also used for diverse purposes in the pharmaceutical 3,5 , cosmetic 6,7 , food 8 , electronics 9 , and other industries 10,11 , as it has strong antioxidant activities, anti-radiation functions, anti-virus functions, hepatoprotective effects, and photoconductivity. It can be obtained by chemical synthesis from tyrosine or its derivatives 12,13 , or extracted from either animals 14,15 or plants 16,17 . Some microorganisms also produce melanins 18 , with physical and chemical properties that include high molecular weight, insolubility in water 19 , aqueous acids and common organic solvents, decolourization by oxidizing agents (KMnO 4 , NaOCl, and H 2 O 2 ), metal ion chelating ability, and strong UV-Vis absorption.…”

Section: Introductionmentioning

confidence: 99%

Characterization of melanin extracted from apricot (Armeniaca sibirica) and its effect on hydrazine-induced rat hepatic injury

Li¹,

Li²,

Zhao³

2016

ScienceAsia

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ABSTRACT:Melanin is a complex, highly coloured natural antioxidant with potent biological activities and diverse applications. A potential source of melanin is the Siberian apricot (Armeniaca sibirica) whose kernel skin is currently a waste by-product. To explore its potential, melanin from apricot kernel skin was extracted. The molecular mass was determined by gel chromatography and its structure was examined by elemental analysis, UV-Vis, infrared, and solid-state nuclear magnetic resonance ( 13 C-NMR) spectroscopy. In addition, its protective effect against hydrazineinduced hepatic injury in rats was evaluated. The results showed that melanin has < 5% sulphur (S) content, indicating that it consists mostly of eumelanin. Its UV-Vis, infrared and 13 C-NMR spectra were very similar to those of synthetic melanin, although it had relatively high carboxylate, aliphatic, and phenol-skeleton content. Two distinct fractions (2.4 ± 0.12 and 0. ± 560.1 kDa) were detected. Injections of hydrazine at 65 mg/kg body-weight (b.wt.) doses resulted in significant (p < 0.01) increases in lipid peroxidation (malondialdehyde contents) in liver homogenates and serum alanine aminotransferase and aspartate aminotransferase activities (64%, 69%, and 98% increase relative to the controls, respectively). It also induced significant (p < 0.05 or 0.01) decreases in liver homogenate catalase, glutathione peroxidase, and superoxide dismutase activities and reduced glutathione content (48%, 28%, 7%, and 98% reduction, respectively). Administering melanin prior to hydrazine, at 10 mg/kg b.wt., strongly inhibited these changes and ameliorated histopathological hepatic injury. The results indicated that melanin alleviated hydrazine-induced liver injury by relieving oxidative stress, which may provide a novel protective strategy for protection against liver diseases.

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“…1). In yellow mutant flies, production of black melanin is blocked and sulfur-containing pheomelanins accumulate (Latocha et al, 2000). How Yellow guides these reactions is unknown, although two other family members, Yellow-f1 and Yellow-f2, have dopachrome conversion activity (Han et al, 2002).…”

Section: Introductionmentioning

confidence: 99%

Megalin-dependent Yellow endocytosis restricts melanization in theDrosophilacuticle

2011

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SUMMARYThe cuticular exoskeleton of arthropods is a composite material comprising well-separated layers that differ in function and molecular constituents. Epidermal cells secrete these layers sequentially, synthesizing components of distal cuticle layers before proximal ones. Could the order of synthesis and secretion be sufficient to account for the precision with which cuticle components localize to specific layers? We addressed this question by studying the spatial restriction of melanization in the Drosophila wing. Melanin formation is confined to a narrow layer within the distal procuticle. Surprisingly, this tight localization depends on the multi-ligand endocytic receptor Megalin (Mgl). Mgl acts, in part, by promoting endocytic clearance of Yellow. Yellow is required for black melanin formation, and its synthesis begins as cuticle is secreted. Near the end of cuticle secretion, its levels drop precipitously by a mechanism that depends on Mgl and Rab5-dependent endocytosis. In the absence of Mgl, Yellow protein persists at higher levels and melanin granules form ectopically in more proximal layers of the procuticle. We propose that the tight localization of the melanin synthesis machinery to the distal procuticle depends not only on the timing of its synthesis and secretion, but also on the rapid clearance of these components before synthesis of subsequent cuticle layers.

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Pyrolytic GC-MS analysis of melanin from black, gray and yellow strains of Drosophila melanogaster

Cited by 42 publications

References 23 publications

Bacteria or melanosomes? A geochemical analysis of micro-bodies on a tadpole from the Oligocene Enspel Formation of Germany

Bacteria or melanosomes? A geochemical analysis of micro-bodies on a tadpole from the Oligocene Enspel Formation of Germany

Characterization of melanin extracted from apricot (Armeniaca sibirica) and its effect on hydrazine-induced rat hepatic injury

Megalin-dependent Yellow endocytosis restricts melanization in theDrosophilacuticle

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