Analysis of the structure of synthetic and natural melanins by solid-phase NMR

Duff, G A; Roberts, James E.; Foster, Natalie

doi:10.1021/bi00418a067

Cited by 66 publications

(47 citation statements)

References 27 publications

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“…In fact, model melanins (obtained from dopa, dopamine, or DHI) give the most intense 13 C NMR signals in the aromatic region (90-160 ppm range), with a weaker signal due to carboxyl/quinone groups in the 160-180 ppm range (typically at about 170 ppm), and a weaker signal in the aliphatic region (about 10-90 ppm) due to the uncyclized side chains of precursor catecholamines. [24] This is well exemplified by the spectrum of a synthetic L-dopa melanin shown in Fig. 3.…”

Section: C-cpmas Nmr Studies Of Mgsmentioning

confidence: 76%

Characterization of human hair melanin and its degradation products by means of magnetic resonance techniques

Ghiani¹,

Baroni²,

Burgio³

et al. 2008

Magnetic Reson in Chemistry

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Melanin granules (MGs) have been extracted from human Chinese black hairs by either acid hydrolysis (CH-typeand a soluble but still pigmented fraction called melanin free acid (MFA). MFA can be isolated by precipitation at acidic pH. The 13 C-CPMAS NMR and EPR spectra of these derivatives indicated that ROM has a structure very similar to that of parent MGs, whereas MFA shows a decrease of the protein content with respect to the melanin and a decreased amount of bound iron. Thus, the oxidative degradation of CP-type MGs is a process not involving the bulk of MGs, but rather it proceeds from the solvent-exposed outer parts to the interior.

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Section: C-cpmas Nmr Studies Of Mgsmentioning

confidence: 76%

Characterization of human hair melanin and its degradation products by means of magnetic resonance techniques

Ghiani¹,

Baroni²,

Burgio³

et al. 2008

Magnetic Reson in Chemistry

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“…Various techniques, including electron paramagnetic resonance [75], X-ray diffraction [76], infrared, ultraviolet and visible spectroscopy [77], and nuclear magnetic resonance [78], have been used to elucidate the melanin structure from different organisms. These studies have shown that fungi can produce different types of melanins by oxidative polymerization of phenolic or indolic compounds [11,27].…”

Section: Pathways Of Melanin Biosynthesismentioning

confidence: 99%

Production of Melanin Pigment by Fungi and Its Biotechnological Applications

Sponchiado¹,

Sousa²,

Andrade³

et al. 2017

Melanin

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Production of the microbial pigments is one of the emerging fields of research due to a growing interest of the industry for safer products, easily degradable and eco-friendly. Fungi constitute a valuable source of pigments because they are capable of producing high yields of the substance in the cheap culture medium, making the bioprocess economically viable on the industrial scale. Some fungal species produce a dark-brown pigment, known as melanin, by oxidative polymerization of phenolic compounds, such as glutaminyl-3,4-dihydroxybenzene (GDHB) or catechol or 1,8-dihydroxynaphthalene (DHN) or 3,4-dihydroxyphenylalanine (DOPA). This pigment has been reported to act as "fungal armor" due to its ability to protect fungi from adverse conditions, neutralizing oxidants generated in response to stress. Apart from the scavenging activity, melanin exhibits other biological activities, including thermoregulatory, radio-and photoprotective, antimicrobial, antiviral, cytotoxic, anti-inflammatory, and immunomodulatory. Studies have shown that the media composition and cultivation conditions affect the pigment production in fungi and the manipulation of these parameters can result in an increase in pigment yield for large-scale pigment production. This chapter presents a comprehensive discussion of the research on fungal melanin, including the recently discovered biological activities and the potential use of this pigment for various biotechnological applications in the fields of biomedicine, dermocosmetics, materials science, and nanotechnology.

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“…However, the indole, pyrrole, and dihydroindole units in the spectrum published in Ref. [8] are not unambiguously identifiable owing to the comparatively low resolution. In the CP/MAS "N NMR spectrum, on the other hand, signals for aliphatic amino groups are present.…”

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confidence: 96%