Study of natural anthraquinone colorants by EPR and UV/vis spectroscopy

Machatová, Zuzana; Barbieriková, Zuzana; Poliak, Peter; Jančovičová, Viera; Lukeš, Vladimı́r; Brezová, Vlasta

doi:10.1016/j.dyepig.2016.04.046

Cited by 43 publications

(32 citation statements)

References 73 publications

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“…purpurin L −1 ). Purpurin was chosen as a polyketide pigment in orange-red hue, which absorbs in the UV area (250–270 nm) as many polyketides [ 43 ], and also in the visible range 458–520 nm [ 44 ]. Thus, the absorbance of an authentic colored standard purpurin (Sigma-Aldrich) was estimated at different concentrations using an UV-visible spectrophotometer (Shimadzu UV-1800 Spectrophotometer).…”

Section: Methodsmentioning

confidence: 99%

Biodiversity of Pigmented Fungi Isolated from Marine Environment in La Réunion Island, Indian Ocean: New Resources for Colored Metabolites

Fouillaud

Venkatachalam

Llorente

et al. 2017

JoF

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Marine ecosystems cover about 70% of the planet surface and are still an underexploited source of useful metabolites. Among microbes, filamentous fungi are captivating organisms used for the production of many chemical classes of secondary metabolites bound to be used in various fields of industrial application. The present study was focused on the collection, isolation, screening and genotyping of pigmented filamentous fungi isolated from tropical marine environments around La Réunion Island, Indian Ocean. About 150 micromycetes were revived and isolated from 14 marine samples (sediments, living corals, coral rubble, sea water and hard substrates) collected in four different locations. Forty-two colored fungal isolates belonging to 16 families, 25 genera and 31 species were further studied depending on their ability to produce pigments and thus subjected to molecular identification. From gene sequence analysis, the most frequently identified colored fungi belong to the widespread Penicillium, Talaromyces and Aspergillus genera in the family Trichocomaceae (11 species), then followed by the family Hypocreaceae (three species). This study demonstrates that marine biotopes in La Réunion Island, Indian Ocean, from coral reefs to underwater slopes of this volcanic island, shelter numerous species of micromycetes, from common or uncommon genera. This unstudied biodiversity comes along with the ability for some fungal marine inhabitants, to produce a range of pigments and hues.

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Section: Methodsmentioning

confidence: 99%

Biodiversity of Pigmented Fungi Isolated from Marine Environment in La Réunion Island, Indian Ocean: New Resources for Colored Metabolites

Fouillaud

Venkatachalam

Llorente

et al. 2017

JoF

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“…Different functional groups on AQs profoundly affect the appearance of their UV-vis spectra (see Table 1), as do hydrogen bonds and other intramolecular interactions. [24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41] These characteristics influence photophysical properties and reactivity in PET processes, which can be analyzed by Rehm-Weller's equation and is a useful rule of thumb for selecting a catalyst. Other factors such as ɛ, absorptivity, and E* red (V vs SHE, the standard hydrogen electrode) must be taken into account during photocatalysis.…”

Section: Photophysical and Photochemical Properties Of Aqsmentioning

confidence: 99%

“…AQ derivatives display absorption and emission that correlate with the electronic properties of their substituents. The λ max gives some information about how much energy an excited state can help to a photoinduced electron transfer (PET), [24,27] for example, the lower the wavelength of absorption, the greater energy the singlet and triplet excited states will possess.…”

Section: Photophysical and Photochemical Properties Of Aqsmentioning

confidence: 99%

“…[32] Intermolecular hydrogen bonds with solvent molecules stabilize both the ground and excited states. [24] Several AAQs are strongly dependent on solvent polarity, with triplet quantum yields (Φ T ), decreasing in more polar solvents. N-Substituted 1-AAQs exhibit lower ϕ f and lifetimes compared to unsubstituted compounds; ϕ f was affected by the polarity of solvent and hydrogen bonding to solvent.…”

Section: Photophysical and Photochemical Properties Of Aqsmentioning

confidence: 99%

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Anthraquinones: Versatile Organic Photocatalysts

et al. 2020

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Anthraquinones (AQs) constitute the largest group of natural pigments, are commonly found in dyes, and are widely used in the textile industry due their photostability. They combine high absorptivity in the visible region with high excited‐state reduction potentials, making them effective acceptors of electrons and hydrogen atoms. AQs can be employed as organic catalysts in photooxidation reactions as well to produce reactive oxygen species (ROS). All these methods feature green chemistry aspects such as avoiding heavy metals, reducing waste, using inexpensive reagents, employing environmentally low‐impact solvents, and oxidizing with O2. This review covers the application of AQs in photoredox catalysis.

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“…In addition, it has excellent heat and light stability [3,4]. Moreover, besides these properties, several studies have reported CA to act as antioxidant against free radicals and reactive oxygen species (ROS), such as singlet oxygen [5][6][7][8].…”

Section: Introductionmentioning

confidence: 99%

Carminic Acid Linked to Silica Nanoparticles as Pigment/Antioxidant Bifunctional Excipient for Pharmaceutical Emulsions

et al. 2020

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The incorporation of pigments and natural polyphenols into inorganic matrices, resulting in a hybrid material that improves the resistance and chemical stability of the pigments and the antioxidant capacity of the materials, has been of great interest to the pharmaceutical, chemical and food industries. The aim of this work was to prepare and characterize a bifunctional pigment–antioxidant nanomaterial-based carminic acid-decorated solid core-mesoporous shell silica nanoparticles, evaluating its properties as a pigment, its antioxidant capacity and its properties as a chemical stabilizer of emulsions. The chemical stability of oil-in-water (O/W) Pickering emulsions was evaluated determining the stability of vitamin E solubilized in the oil phase. Carminic acid was attached through the action of coupling ethylcarbodiimide hydrochloride (EDC)/N-hydroxysuccinimide (NHS) agents, and the resulting spherical and homogeneous nanoparticles showed a diameter close to 175 nm. A notorious change of emulsion color was observed by the addition of the nanomaterial. Emulsions showed an attractive pink color, and when the pH was adjusted to pH 3 and pH 9, a change in color was observed, analogous to carminic acid in solution. The nanomaterial incorporation also improved chemical stability, decreasing vitamin E consumption to 9.26% of the initial value, demonstrating an important antioxidant effect of the developed nanomaterial.

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Study of natural anthraquinone colorants by EPR and UV/vis spectroscopy

Cited by 43 publications

References 73 publications

Biodiversity of Pigmented Fungi Isolated from Marine Environment in La Réunion Island, Indian Ocean: New Resources for Colored Metabolites

Biodiversity of Pigmented Fungi Isolated from Marine Environment in La Réunion Island, Indian Ocean: New Resources for Colored Metabolites

Anthraquinones: Versatile Organic Photocatalysts

Carminic Acid Linked to Silica Nanoparticles as Pigment/Antioxidant Bifunctional Excipient for Pharmaceutical Emulsions

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