Multi-scale Assembly in Nano-scaled Sepia Melanin Natural Dye

Mbonyiryivuze, Agnes; Nuru, Z.Y.; Kotsedi, L.; Mwakikunga, Bonex W.; Dhlamini, Simon Mokhotjwa; Park, E.; Mâaza, M.

doi:10.1016/j.matpr.2015.08.028

Cited by 17 publications

(19 citation statements)

References 36 publications

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“…Several SEM images showing the morphology of sepia melanin, at different magnifications, are presented in Figure 4c–f [41].…”

Section: Physicochemical Propertiesmentioning

confidence: 99%

“…The final step is represented by post sectioning staining [17,34,52,58,59,60]. Figure 4a,b) presents the multi-scale assembly hierarchical morphology in the sepia melanin [41]. The most relevant results are presented in Table 4.…”

Section: Physicochemical Propertiesmentioning

confidence: 99%

“…SEM and TEM images showing the multi-scale assembly hierarchical morphology of Sepia melanin at different magnifications; melanin nanoparticle scaled at 2nm ( a ); melanin nanoparticle highlighting the internal organization in a form of a block-copolymer-like structure ( b ); secondary self-aggregation of melanin nanospheres in polydisperse large clusters ( c – e ); deflated clusters with a wide size distribution form of self-aggregates ( f ) (Reprinted with permission from Ref. [41]).…”

Section: Figurementioning

confidence: 99%

See 2 more Smart Citations

From Extraction to Advanced Analytical Methods: The Challenges of Melanin Analysis

Pralea

Moldovan

Petrache

et al. 2019

IJMS

182

193

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The generic term “melanin“ describes a black pigment of biological origin, although some melanins can be brown or even yellow. The pigment is characterized as a heterogenic polymer of phenolic or indolic nature, and the classification of eu-, pheo- and allo- melanin is broadly accepted. This classification is based on the chemical composition of the monomer subunit structure of the pigment. Due to the high heterogeneity of melanins, their analytical characterization can be a challenging task. In the present work, we synthesized the current information about the analytical methods which can be applied in melanin analysis workflow, from extraction and purification to high-throughput methods, such as matrix-assisted laser desorption/ionization mass-spectrometry or pyrolysis gas chromatography. Our thorough comparative evaluation of analytical data published so far on melanin analysis has proven to be a difficult task in terms of finding equivalent results, even when the same matrix was used. Moreover, we emphasize the importance of prior knowledge of melanin types and properties in order to select a valid experimental design using analytical methods that are able to deliver reliable results and draw consistent conclusions.

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“…Several SEM images showing the morphology of sepia melanin, at different magnifications, are presented in Figure 4c–f [41].…”

Section: Physicochemical Propertiesmentioning

confidence: 99%

Section: Physicochemical Propertiesmentioning

confidence: 99%

Section: Figurementioning

confidence: 99%

See 1 more Smart Citation

From Extraction to Advanced Analytical Methods: The Challenges of Melanin Analysis

Pralea

Moldovan

Petrache

et al. 2019

IJMS

182

193

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show abstract

“…Essential biopolymers such as proteins and carbohydrates have been successfully characterized and well-established by detailing their monomeric units, bond patterns and sequence determination, largely with specificity to their respective active site [5] , [6] . With respect to melanin, however, characterization of structure and its details have not yet been completely understood due to many limiting factors such as insolubility in broad range of organic solvents, purification strategies that may give rise to changes in its structural features and organization of melanin as a polymer [7] .…”

Section: Introductionmentioning

confidence: 99%

Genetic validation and spectroscopic detailing of DHN-melanin extracted from an environmental fungus

Raman

Ramasamy

2017

Biochemistry and Biophysics Reports

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Accurate characterization of melanin using analytical methodologies has proved to be difficult due to its heterogeneity, insolubility in wide pH and broad range of solvents. The present study was undertaken to characterize melanin extracted from an environmental Aspergillus fumigatus AFGRD105 by studying its genes, chemical properties and spectral data. A gene based approach to confirm the type of melanin carried out indicated the extracted melanin to be of the dihydroxynaphthalene type. On comparison with synthetic melanin, UV–Vis and IR spectra of the extracted melanin revealed characteristic peaks that can be further used for confirmation of DHN-melanin extracted from any source. Solid state 13C NMR spectroscopy established the presence of the hydroxyl-naphthalene moiety and validated the results obtained by genetic analysis. The correct assignment of the observed spectral frequency characteristic of functional groups can be further adapted in future works that deal with binding capacities and biomolecule systems involving melanin.

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“…This pattern is similar to the FT-IR spectra of other DOPA-based MN or the FT-IR spectrum of MN obtained from sepia ink. [47,48] differences can be observed between the FT-IR spectra of CMC and MN #2 (see Fig. 5), despite the fact that MN #2 is grey-black in color.…”

Section: Discussionmentioning

confidence: 98%

Interleukin-1β and -6 release from immune cells by DOPA-based melanin as free pigment or complexed to carboxymethylcellulose

Vercruysse

Farris

Whalen

2017

Preprint

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We have observed that many polysaccharides can promote the oxidation of 3,4-dihydroxyphenylalanine (DOPA) into melanin-like pigments leading to the formation of water-soluble polysaccharide/melanin complexes. These pigments were characterized by size exclusion chromatography and FT-IR spectroscopy. The effect on the secretion of interleukin (IL) -1 and IL-6 from immune cells by DOPA-based melanin synthesized in the presence or absence of carboxymethylcellulose (CMC) was evaluated. We observed that the melanin/CMC complex had a more potent effect on both IL secretions compared to the melanin prepared from DOPA in the absence of any polysaccharide. The study of the effect of melanins on the IL secretion by immune or other cells will help illuminate the potential contributions of this broad class of pigments to pathological conditions like Parkinson's disease or ochronosis.

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Multi-scale Assembly in Nano-scaled Sepia Melanin Natural Dye

Cited by 17 publications

References 36 publications

From Extraction to Advanced Analytical Methods: The Challenges of Melanin Analysis

From Extraction to Advanced Analytical Methods: The Challenges of Melanin Analysis

Genetic validation and spectroscopic detailing of DHN-melanin extracted from an environmental fungus

Interleukin-1β and -6 release from immune cells by DOPA-based melanin as free pigment or complexed to carboxymethylcellulose

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