Properties and Function of Pyomelanin

Turick, Charles E.; Knox, Anna Sophia; Becnel, J.M.; Ekechukwu, A.A.; Milliken, Charles E.

doi:10.5772/10273

Cited by 47 publications

(64 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The presence of quinones in the pyomelanin structure was then confirmed by cyclic voltammetry indicating a two-step oxidation followed by a twostep reduction (Turick et al 2010). The electron-transfer properties of melanin polymers, including pyomelanin, also constitute a mechanism of electron transfer to solid electron acceptors like metal oxides and electrodes (Ellis and Griffiths 1974;Turick et al 2003Turick et al , 2010. This explains how staining shows the presence of reducing substances in tissues through the coupling of hydroxybenzene depigmenting-compound oxidation caused by reduction of ferricyanide (Mentner and Willis 1997).…”

Section: Analysis Of Pigment Derived From Hgamentioning

confidence: 80%

“…The FTIR analyses of pyomelanin produced from the auto-oxidation of HGA (HGA melanin) (David et al 1996) showed absorbance peaks consistent with the OH stretch of polymeric structures, aliphatic CH bonds, aromatic C¼C bonds conjugated with C¼O and/or COO-groups as well as phenolic OH groups. The presence of quinones in the pyomelanin structure was then confirmed by cyclic voltammetry indicating a two-step oxidation followed by a twostep reduction (Turick et al 2010). The electron-transfer properties of melanin polymers, including pyomelanin, also constitute a mechanism of electron transfer to solid electron acceptors like metal oxides and electrodes (Ellis and Griffiths 1974;Turick et al 2003Turick et al , 2010.…”

Section: Analysis Of Pigment Derived From Hgamentioning

confidence: 81%

“…The production of the precursor benzoquinone (BQA) (Zannoni et al 1969) shown in Fig. 3 is the pivotal first step in pigment formation similar to the formation of dopaquinone in melanin synthesis (Turick et al 2010). The oxidation product of HGA in aqueous solution was shown to be stable in acidic, neutral and weak alkaline media using cyclic voltammetry and that the subsequent chemical dimerisation is more probable for the oxidised form of HGA (Eslami et al 2014).…”

Section: Pigmentation In Aku: the Nature Of The Pigmentmentioning

confidence: 99%

See 2 more Smart Citations

The Pigment in Alkaptonuria Relationship to Melanin and Other Coloured Substances: A Review of Metabolism, Composition and Chemical Analysis

et al. 2015

View full text Add to dashboard Cite

The pigments found in plants, animals and humic substances are well described and classified. In humans considerable progress has been made with the main pigment melanin in defining its biochemistry, the different types and function. However, analytical techniques to show these differences in vivo are still not readily available. NMR and IR spectroscopy are relatively insensitive and reveal only major structural differences. Techniques utilising MS are useful in determining elemental content but require further studies to optimise conditions for accurate mass analysis. How the components may be structurally organised seems to be the most problematic with scanning TEM and the improved FTIR of use in this respect. As regards understanding the nature of the pigment related to HGA seen in patients with Alkaptonuria (AKU), it is still thought of as a melaninlike pigment simply because of its colour and likewise thought to be a polymer of undetermined size. It is important that detailed analysis be carried out to define more accurately this pigment. However, observations suggest it to be the same as the HGA-derived pigment, pyomelanin, produced by bacteria and containing both quinone and phenolic groups. The interesting developments in alkaptonuria will be to understand how such a polymer can cause such profound collagen and connective tissue damage and how best to reverse this process.

show abstract

Section: Analysis Of Pigment Derived From Hgamentioning

confidence: 80%

Section: Analysis Of Pigment Derived From Hgamentioning

confidence: 81%

Section: Pigmentation In Aku: the Nature Of The Pigmentmentioning

confidence: 99%

See 1 more Smart Citation

The Pigment in Alkaptonuria Relationship to Melanin and Other Coloured Substances: A Review of Metabolism, Composition and Chemical Analysis

et al. 2015

View full text Add to dashboard Cite

show abstract

“…1 Some MNs produced by fungi or bacteria are referred to as pyomelanin. 1,7 Pyomelanin is derived from homogentisic acid ((8) in Fig. 1) and this compound is also the precursor for the pigmentation observed in alkaptonuria (AKU) in humans.…”

Section: Introductionmentioning

confidence: 99%

Dark- or Light-Colored Melanins: Generating Pigments Using Fe2+ and H2O2

Vercruysse

Russell²,

Knight³

et al. 2017

Preprint

View full text Add to dashboard Cite

We have studied the formation of melanin-like pigments from catechol or pyrogallol and a wide range of other phenolic compounds using Fe 2+ and H 2 O 2 . Combining UV_Vis spectroscopic measurements and size-exclusion chromatography analyses we evaluated the impact of the intensity of the oxidation reaction by varying the concentration of H 2 O 2 present in the reaction mixtures. All compounds tested, except tyrosine, reacted readily leading to mixtures that were black, brown or yellow-orange in color. For many compounds tested, the use of increasing concentrations of H 2 O 2 resulted in either precipitation of the pigment or the formation of a soluble, lighter-colored pigment. With catechol or pyrogallol as model compounds, and using different concentrations of H 2 O 2 , several materials were synthesized, purified and dried. The physic-chemical properties of these materials were compared to the properties of melanin-like pigments synthesized from the same precursors using air-oxidation in an alkaline environment. For both precursors, a distinct chemical change, as judged from FT-IR spectroscopy, was introduced in the melanin structures when using H 2 O 2 as the oxidizing agent and the relative intensity of this distinct signal strengthened with increasing concentration of H 2 O 2 used in the reaction. In general, our results suggest that depending on the precursor molecule and the intensity of the oxidizing reaction conditions involved, light-or dark-colored melanin-like pigments can be generated. This may be an important factor when evaluating the visible outlook of histological or archeological specimens: the presence of a lighter color or the absence of a dark color may not necessarily mean the absence of melanin-like biomolecules.

show abstract

“…Pyomelanin is a negatively charged extracellular pigment of high molecular weight, derived from the tyrosine catabolism pathway [6, 18, 19]. 4-Hydroxyphenylpyruvate is converted to homogentisate (HGA) by 4-hydroxyphenylpyruvate dioxygenase (Hpd) (Fig.…”

Section: Introductionmentioning

confidence: 99%

NTBC Treatment of the Pyomelanogenic Pseudomonas aeruginosa Clinical Isolate PA1111 Inhibits Pigment Production and Increases Sensitivity to Oxidative Stress

2014

View full text Add to dashboard Cite

Pyomelanin is a brown/black extracellular pigment with antioxidant and iron acquisition properties that is produced by a number of different bacteria. Production of pyomelanin in Pseudomonas aeruginosa contributes to increased resistance to oxidative stress and persistence in chronic infections. We demonstrate that pyomelanin production can be inhibited by 2-[2-nitro-4-(trifluoromethyl) benzoyl]-1,3-cyclohexanedione (NTBC). This treatment increases sensitivity of pyomelanogenic P. aeruginosa strains to oxidative stress, without altering the growth rate or resistance to aminoglycosides. As such, NTBC has potential to function as an anti-virulence factor in treating pyomelanogenic bacterial infections.Electronic supplementary materialThe online version of this article (doi:10.1007/s00284-014-0593-9) contains supplementary material, which is available to authorized users.

show abstract

Properties and Function of Pyomelanin

Cited by 47 publications

References 37 publications

The Pigment in Alkaptonuria Relationship to Melanin and Other Coloured Substances: A Review of Metabolism, Composition and Chemical Analysis

The Pigment in Alkaptonuria Relationship to Melanin and Other Coloured Substances: A Review of Metabolism, Composition and Chemical Analysis

Dark- or Light-Colored Melanins: Generating Pigments Using Fe2+ and H2O2

NTBC Treatment of the Pyomelanogenic Pseudomonas aeruginosa Clinical Isolate PA1111 Inhibits Pigment Production and Increases Sensitivity to Oxidative Stress

Contact Info

Product

Resources

About