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1.
Food Chem ; 338: 128012, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-32927202

RESUMO

The inactivation of S. Typhimurium and A. flavus along with quality degradation kinetics was studied during combined microwave-infrared (MW-IR) heating of paprika. The spatial changes in the distribution of temperature and variation in water activity (aw) of the paprika samples resulted in a 7.389 log reduction in S. Typhimurium, and 6.182 log reduction in A. flavus. During heating, the deterioration of red pigments was more pronounced compared to that of the yellow pigments. The alteration of color was observed to be due to the increase in a large number of brown pigments. The inhibition of DPPH radicals accelerated with an increase in the power level of MW-IR radiation; the inhibition rate increased from 0.0859 to 0.1485 s-1. Also, the pungency of dried paprika was found to increase due to moisture reduction, inactivation of peroxidase, and the short-duration of heating.


Assuntos
Capsicum/microbiologia , Micro-Ondas , Pasteurização/métodos , Adulto , Ácido Ascórbico/análise , Aspergillus flavus , Capsicum/química , Feminino , Microbiologia de Alimentos , Calefação , Humanos , Raios Infravermelhos , Cinética , Masculino , Pigmentação , Pigmentos Biológicos/química , Salmonella typhimurium , Paladar , Temperatura
2.
Nat Commun ; 11(1): 5081, 2020 10 08.
Artigo em Inglês | MEDLINE | ID: mdl-33033236

RESUMO

Diatom is an important group of marine algae and contributes to around 20% of the global photosynthetic carbon fixation. Photosystem I (PSI) of diatoms is associated with a large number of fucoxanthin-chlorophyll a/c proteins (FCPIs). We report the structure of PSI-FCPI from a diatom Chaetoceros gracilis at 2.38 Å resolution by single-particle cryo-electron microscopy. PSI-FCPI is a monomeric supercomplex consisting of 12 core and 24 antenna subunits (FCPIs), and 326 chlorophylls a, 34 chlorophylls c, 102 fucoxanthins, 35 diadinoxanthins, 18 ß-carotenes and some electron transfer cofactors. Two subunits designated PsaR and PsaS were found in the core, whereas several subunits were lost. The large number of pigments constitute a unique and huge network ensuring efficient energy harvesting, transfer and dissipation. These results provide a firm structural basis for unraveling the mechanisms of light-energy harvesting, transfer and quenching in the diatom PSI-FCPI, and also important clues to evolutionary changes of PSI-LHCI.


Assuntos
Proteínas de Ligação à Clorofila/química , Diatomáceas/metabolismo , Transferência de Energia , Complexo de Proteína do Fotossistema I/química , Complexos de Proteínas Captadores de Luz/química , Complexos de Proteínas Captadores de Luz/metabolismo , Pigmentos Biológicos/química , Pigmentos Biológicos/metabolismo , Subunidades Proteicas/química
3.
Phys Rev Lett ; 125(3): 033604, 2020 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-32745420

RESUMO

We demonstrate Bragg diffraction of the antibiotic ciprofloxacin and the dye molecule phthalocyanine at a thick optical grating. The observed patterns show a single dominant diffraction order with the expected dependence on the incidence angle as well as oscillating population transfer between the undiffracted and diffracted beams. We achieve an equal-amplitude splitting of 14ℏk (photon momenta) and maximum momentum transfer of 18ℏk. This paves the way for efficient, large-momentum beam splitters and mirrors for hot and complex molecules.


Assuntos
Ciprofloxacino/química , Indóis/química , Modelos Químicos , Antibacterianos/química , Interferometria/métodos , Modelos Moleculares , Pigmentos Biológicos/química , Espalhamento de Radiação
4.
Proc Natl Acad Sci U S A ; 117(30): 17599-17606, 2020 07 28.
Artigo em Inglês | MEDLINE | ID: mdl-32647063

RESUMO

Fossilized carotenoid hydrocarbons provide a window into the physiology and biochemistry of ancient microbial phototrophic communities for which only a sparse and incomplete fossil record exists. However, accurate interpretation of carotenoid-derived biomarkers requires detailed knowledge of the carotenoid inventories of contemporary phototrophs and their physiologies. Here we report two distinct patterns of fossilized C40 diaromatic carotenoids. Phanerozoic marine settings show distributions of diaromatic hydrocarbons dominated by isorenieratane, a biomarker derived from low-light-adapted phototrophic green sulfur bacteria. In contrast, isorenieratane is only a minor constituent within Neoproterozoic marine sediments and Phanerozoic lacustrine paleoenvironments, for which the major compounds detected are renierapurpurane and renieratane, together with some novel C39 and C38 carotenoid degradation products. This latter pattern can be traced to cyanobacteria as shown by analyses of cultured taxa and laboratory simulations of sedimentary diagenesis. The cyanobacterial carotenoid synechoxanthin, and its immediate biosynthetic precursors, contain thermally labile, aromatic carboxylic-acid functional groups, which upon hydrogenation and mild heating yield mixtures of products that closely resemble those found in the Proterozoic fossil record. The Neoproterozoic-Phanerozoic transition in fossil carotenoid patterns likely reflects a step change in the surface sulfur inventory that afforded opportunities for the expansion of phototropic sulfur bacteria in marine ecosystems. Furthermore, this expansion might have also coincided with a major change in physiology. One possibility is that the green sulfur bacteria developed the capacity to oxidize sulfide fully to sulfate, an innovation which would have significantly increased their capacity for photosynthetic carbon fixation.


Assuntos
Cianobactérias/fisiologia , Fotossíntese , Enxofre/metabolismo , Carotenoides/química , Carotenoides/metabolismo , Cromatografia Líquida , Cromatografia Gasosa-Espectrometria de Massas , Espectrometria de Massas , Fotossíntese/genética , Pigmentos Biológicos/química , Pigmentos Biológicos/metabolismo
5.
J Oleo Sci ; 69(8): 809-814, 2020 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-32641604

RESUMO

In this work, the evolution of virgin olive oil from 4 olive varieties when stored at 5°C, 10°C and 20°C for a period of up to 3 years was studied. Free acidity increased progressively for the 4 varieties, staying below the limit for extra virgin olive oil, even at the highest temperature. The peroxide value also increased, reaching its maximum after about 28 months of storage, when some samples stored at 20°C exceeded the limit for extra virgin olive oil. The maximum values for K270 and K232 were reached at the end of the storage period, also exceeding the limit for extra virgin olive oil in the case of some varieties stored at 20°C. Oxidative stability decreased by 38%-50% depending on the storage temperature and the variety. Most of the color indexes increased in value because of the degradation of the oil pigments.


Assuntos
Armazenamento de Alimentos/métodos , Azeite de Oliva/química , Temperatura , Cor , Azeite de Oliva/análise , Oxirredução , Peróxidos/análise , Pigmentos Biológicos/química , Fatores de Tempo
6.
Arch Insect Biochem Physiol ; 105(2): e21728, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32710467

RESUMO

Re-nd, which was induced from the wild-type C108 by the chemical mutagen N-methane-N-methylnitrourea, is a nondiapause red-egg mutant of silkworm Bombyx mori. The special significance of the Re-nd mutant is that it is an independent dominant mutant. The aim of this study was to establish the type of pigment responsible for the red coloration in the Re-nd mutant eggs in silkworm. We compared the eggs of Re-nd mutants with those of the other B. mori egg color strains and confirmed that the Re-nd mutant is the only strain with red color and red pigment granules in nondiapause, showing this mutant belongs to the pigmentation in the serosa. We speculated that the red substance, which contributed to the bright red pigmentation for nondiapause eggs of the Re-nd mutant, could potentially be a novel pigment according to its solubility, optimum absorption peak, and oxidation-reduction reaction. Moreover, we have successfully constituted the system for enrichment, extraction, and purification of the red substance responsible for the Re-nd mutant, providing a new method for the separation and purification of other known and unknown pigments or substances.


Assuntos
Bombyx/química , Óvulo/química , Pigmentos Biológicos/química , Animais , Bombyx/genética , Cromatografia Líquida de Alta Pressão/métodos , Extração Líquido-Líquido/métodos , Mutação , Pigmentação/genética
7.
Food Chem ; 326: 126962, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32413753

RESUMO

A concise method of natural blue pigment from Vaccinium bracteatum thunb. leaves (VBTL) was proposed firstly in this research. The potential properties of new pigment source needed to be assessed for further application. During the shelf life and thermal-accelerated storage, the blue pigment was prone to stable in the mildly acidic system, which was observed retention of 35.85% for storage of 12 weeks in pH 4.0. The 65% of blue pigment retained after the in vitro simulated digestion. The blue pigment exhibited inhibition effect on the pancreatic α-amylase (IC50 = 2.915 mg/mL). The analysis of inhibition kinetics indicated the blue pigment was an uncompetitive inhibitor. Through fluorescence quenching and circular dichroism study, the blue pigment inhibited α-amylase activity via the structural unfolding of α-amylase molecule and changing the secondary structure. These findings provided the new evidence of the digestion resistibility of VBTL pigment and the functional food - "Wu mi".


Assuntos
Inibidores Enzimáticos/química , Pigmentos Biológicos/química , Extratos Vegetais/química , Vaccinium myrtillus/química , alfa-Amilases/antagonistas & inibidores , Folhas de Planta/química , alfa-Amilases/química
8.
Sci Rep ; 10(1): 7704, 2020 05 07.
Artigo em Inglês | MEDLINE | ID: mdl-32382042

RESUMO

Pink biofilms are multispecies microbial communities that are commonly found in moist household environments. The development of this pink stain is problematic from an aesthetic point of view, but more importantly, it raises hygienic concerns because they may serve as a potential reservoir of opportunistic pathogens. Although there have been several studies of pink biofilms using molecular analysis and confocal laser scanning microscopy, little is known about the spatial distributions of constituent microorganisms within pink biofilms, a crucial factor associated with the characteristics of pink biofilms. Here we show that Raman spectroscopic signatures of intracellular carotenoids and polyenes enable us to visualize pigmented microorganisms within pink biofilms in a label-free manner. We measured space-resolved Raman spectra of a pink biofilm collected from a bathroom, which clearly show resonance Raman bands of carotenoids. Multivariate analysis of the Raman hyperspectral imaging data revealed the presence of typical carotenoids and structurally similar but different polyenes, whose spatial distributions within the pink biofilm were found to be mutually exclusive. Raman measurements on individual microbial cells isolated from the pink biofilm confirmed that these distributions probed by carotenoid/polyene Raman signatures are attributable to different pigmented microorganisms. The present results suggest that Raman microspectroscopy with a focus on microbial pigments such as carotenoids is a powerful nondestructive method for studying multispecies biofilms in various environments.


Assuntos
Biofilmes , Carotenoides/isolamento & purificação , Polienos/isolamento & purificação , Rhodococcus/isolamento & purificação , Carotenoides/química , Humanos , Microbiota , Microscopia Confocal , Pigmentos Biológicos/química , Pigmentos Biológicos/isolamento & purificação , Polienos/química , Rhodococcus/crescimento & desenvolvimento , Análise Espectral Raman
9.
Mar Drugs ; 18(4)2020 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-32290208

RESUMO

The marine-derived fungus Aspergillus falconensis, isolated from sediment collected from the Canyon at Dahab, Red Sea, yielded two new chlorinated azaphilones, falconensins O and P (1 and 2) in addition to four known azaphilone derivatives (3-6) following fermentation of the fungus on solid rice medium containing 3.5% NaCl. Replacing NaCl with 3.5% NaBr induced accumulation of three additional new azaphilones, falconensins Q-S (7-9) including two brominated derivatives (7 and 8) together with three known analogues (10-12). The structures of the new compounds were elucidated by 1D and 2D NMR spectroscopy and HRESIMS data as well as by comparison with the literature. The absolute configuration of the azaphilone derivatives was established based on single-crystal X-ray diffraction analysis of 5, comparison of NMR data and optical rotations as well as on biogenetic considerations. Compounds 1, 3-9, and 11 showed NF-κB inhibitory activity against the triple negative breast cancer cell line MDA-MB-231 with IC50 values ranging from 11.9 to 72.0 µM.


Assuntos
Antineoplásicos/química , Organismos Aquáticos/química , Aspergillus/química , Benzopiranos/química , Sedimentos Geológicos/microbiologia , Pigmentos Biológicos/química , Animais , Antineoplásicos/farmacologia , Organismos Aquáticos/isolamento & purificação , Aspergillus/isolamento & purificação , Benzopiranos/farmacologia , Linhagem Celular Tumoral/efeitos dos fármacos , Oceano Índico , Concentração Inibidora 50 , Pigmentos Biológicos/farmacologia
10.
J Colloid Interface Sci ; 569: 195-203, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-32113016

RESUMO

Green microalgae are promising and sustainable bioenergy and biomass feedstocks, that specifically utilize blue and red light for photosynthesis. Using carbon dots (CDs) to optimize photoluminescence is an attractive strategy for enhancing microalgal bioresource production; however, CD synthesis traditionally requires harsh conditions and laborious procedures. Little research has focused on developing CDs with tunable emission that precisely satisfy photosynthetic requirements. In this work, we directionally prepared non-toxic CDs using a simple method, which could adsorb light at spectra 500-600 nm and emit red light at 580-700 nm. CDs significantly promoted microalgae (Chlorella) growth by ~15%. Meanwhile, potential intracellular bioresources, pigments, carbohydrates, proteins, and lipids were generally enhanced. CDs, combined with an extracellular polymeric substance of microalgal cells, served as numerous micro-bulbs for Chlorella irradiation to sustainably provide optimized light. In this context, photosystems I and II were both stimulated. As such, we prepared CDs with tunable emission, which could significantly enhance microalgae and bioresource production.


Assuntos
Biotecnologia/métodos , Carbono/química , Chlorella/química , Corantes Fluorescentes/química , Pontos Quânticos/química , Carboidratos/química , Matriz Extracelular de Substâncias Poliméricas/metabolismo , Luz , Lipídeos/química , Microalgas/metabolismo , Fotossíntese , Pigmentos Biológicos/química , Proteínas/química
11.
Biomed Res Int ; 2020: 7579430, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32185218

RESUMO

Background: Barbary fig (Opuntia spp), called prickly pear, is a cultivated species belonging to family Cactaceae. It produces fruits one time per year during a short season. It is largely spreading in the Mediterranean countries. The aim of the study was to investigate the physicochemical and biochemical analysis of powder of prickly pear fruit peels of three Moroccan varieties (Aakria, Derbana, and Mles). Material and Methods. Both physicochemical analysis (humidity, water activity, Brix, ash content, pH, and total titratable acidity) and biochemical analysis (total carotenoid content, betalain content, total polyphenolic content, and ascorbic acid content) were effectuated according to protocols reported within the present research work. Results: Regarding the physiochemical analysis, the humidity of powder of prickly pear fruit peels ranged from 10.173 ± 0.002 to 15.27 ± 0.02%. The water activity (aw) ranged from 0.17 ± 0.002 to 0.336 ± 0.002. The values of Brix ranged from 68.67 ± 0.33 to 74.22 ± 0.51° Bx. pH values ranged from 5.41 ± 0.01 to 5.62 ± 0.01. The total titratable acidity values ranged from 0.644 ± 0.014 to 0.76 ± 0.007 g citric acid/100 g DM (dry matter). The ash content ranged from 1.02 ± 0.02 to 11.41 ± 0.03 g/100 g DM. Regarding the biochemical analysis, the total carotenoid content ranged from 5.14 ± 0.10 to 9.79 ± 0.06 mg/g of FM (Fresh matter). The total betalain content ranged from 2 ± 0.69 to 37.66 ± 2.65 mg/100 g of DM. The total polyphenolic content ranged from 1739.92 ± 13.69 to 2409.66 ± 43.65 mg gallic acid equivalent (GAE)/100 g of DM. The ascorbic content values ranged from 186.78 ± 13.23 to 294.04 ± 5.81 mg/100 g of DM. Conclusion: The results showed an interesting richness of the investigated powder in pigments (betacyanins, indicaxanthins, and carotenoids) and nutritional compounds including sugar, proteins, and vitamins that make this powder interesting for being used as a dye in food.


Assuntos
Corantes/química , Frutas/química , Opuntia/química , Pigmentos Biológicos/química , Antioxidantes/química , Ácido Ascórbico/química , Betacianinas/química , Carotenoides/química , Clima , Fenóis/química , Extratos Vegetais/química , Pós/química , Pyrus , Estresse Fisiológico/fisiologia
12.
J Antibiot (Tokyo) ; 73(5): 320-323, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32024969

RESUMO

Chaetomium globosum is a filamentous fungus from which we have previously isolated a series of interesting natural products. Here, we isolated a previously unknown natural product from the culture of C. globosum. Through spectroscopic and crystallographic characterization, we determined the compound to be a new dimerized azaphilone-type product which we termed cochliodone J (1). Furthermore, our investigation into the biological activity of the natural product determined that 1 was cytotoxic to human cervix carcinoma HeLa cells with an IC50 of 17.3 µM. Lastly, a plausible biosynthetic mechanism for 1 is suggested based on our previous study on the biosynthesis of a closely related compound, cochliodone A (2).


Assuntos
Antineoplásicos/farmacologia , Benzopiranos/farmacologia , Chaetomium/química , Pigmentos Biológicos/farmacologia , Neoplasias do Colo do Útero/tratamento farmacológico , Antineoplásicos/química , Antineoplásicos/isolamento & purificação , Benzopiranos/química , Benzopiranos/isolamento & purificação , Feminino , Células HeLa , Humanos , Concentração Inibidora 50 , Pigmentos Biológicos/química , Pigmentos Biológicos/isolamento & purificação
13.
Sci Adv ; 6(6): eaay6415, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32076649

RESUMO

Phototrophic organisms are superbly adapted to different light environments but often must acclimate to challenging competition for visible light wavelengths in their niches. Some cyanobacteria overcome this challenge by expressing paralogous photosynthetic proteins and by synthesizing and incorporating ~8% chlorophyll f into their Photosystem I (PSI) complexes, enabling them to grow under far-red light (FRL). We solved the structure of FRL-acclimated PSI from the cyanobacterium Fischerella thermalis PCC 7521 by single-particle, cryo-electron microscopy to understand its structural and functional differences. Four binding sites occupied by chlorophyll f are proposed. Subtle structural changes enable FRL-adapted PSI to extend light utilization for oxygenic photosynthesis to nearly 800 nm. This structure provides a platform for understanding FRL-driven photosynthesis and illustrates the robustness of adaptive and acclimation mechanisms in nature.


Assuntos
Luz , Modelos Moleculares , Fotossíntese , Complexo de Proteína do Fotossistema I/química , Complexo de Proteína do Fotossistema I/metabolismo , Sequência de Aminoácidos , Sítios de Ligação , Microscopia Crioeletrônica , Pigmentos Biológicos/química , Ligação Proteica , Conformação Proteica , Relação Estrutura-Atividade
14.
Molecules ; 25(3)2020 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-32046151

RESUMO

Manufacturing beer with a high biological value requires identifying new methods for increasing the health-enhancing compounds level. The aim of this study was to increase the biological value of beer by adding antioxidant-rich eggplant (Solanum melongena L.) peel extract (EPE). The total phenolic content (TPC), total flavonoid content (TFC), and total monomeric anthocyanin content (TMA) were determined. Moreover, the antioxidant activity was evaluated by different radical scavenging assays. The addition of different levels of EPE resulted in a significant increase of TPC and TFC of beer samples from 0.426 to 0.631 mg GAE/mL, and from 0.065 to 0.171 mg CE/mL, respectively. The EPE-supplemented beer samples developed a reddish color because of the presence of anthocyanin pigments. The TMA content of beer varied from 0.011 to 0.083 mg D3G/mL with the level of added EPE. The HPLC analysis indicated that the anthocyanins prevailing in the eggplant peels were delphinidin-3-rutinoside, delphininidin-3-glucoside and delphinidin-3-rutinoside-5-glucoside. The radical scavenging assays indicated a linear increase of the antioxidant activity following EPE addition, without altering the physicochemical parameters of the beer. These results are promising for using the EPE as a functional ingredient for beer production.


Assuntos
Cerveja , Extratos Vegetais/química , Solanum melongena/química , Antocianinas/química , Antioxidantes/química , Cromatografia Líquida de Alta Pressão/métodos , Cor , Flavonoides/química , Hipersensibilidade Alimentar , Frutas/química , Glucosídeos/química , Fenóis/química , Pigmentos Biológicos/química
15.
Anal Chim Acta ; 1098: 140-147, 2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-31948577

RESUMO

Ultramarine blue particles as a novel visible label has been used to develop immunochromatographic assay (ICA). The ultramarine blue particles, as a sodalite mineral with formula: (Na,Ca)8[(S,Cl,SO4,OH)2(Al6Si6O24)], can generate a blue visible signal were used as a label for ICA. Ultramarine blue particles were applied to a sandwich immunoassay to detect hepatitis B virus surface antigen (HBsAg). Ultramarine blue particles were separated from ultramarine blue industrial product by centrifugation. The polyacrylic acid (PAA) was used to modify the carboxyl group on the surface of ultramarine blue particles. The goat anti-HBsAg monoclonal antibody was modified on ultramarine blue particles by EDC/NHS activation of the carboxyl groups. In the presence of HBsAg, the immune ultramarine blue particles were bound on test line zone and forming a blue line on ICA strip which was directly readout by naked eye and quantitatively measured by Image J software. Under optimal conditions, the color depth of test line was linearly correlated with the concentration of HBsAg in concentration range from 1 to 50 ng mL-1. The calibration equation was y = 385.796 + 97.2298x (R2 = 0.9872), with limit of detection (LOD) of 0.37 ng mL -1(S/N = 3). The sensitivity of this novel ICA was better than that of ICA based on traditional gold nanoparticles as reporter probe. The ultramarine blue particles offer an alternative type of visible label nanomaterial for the development of ICA.


Assuntos
Antígenos de Superfície da Hepatite B/análise , Imunoensaio/métodos , Pigmentos Biológicos/química , Tamanho da Partícula , Propriedades de Superfície
16.
Spectrochim Acta A Mol Biomol Spectrosc ; 230: 118037, 2020 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-31958603

RESUMO

Fluorescent dyes are of immense interest due to their nontrivial applications in cell imaging to observe different micro organelles and their functions. We have discovered organic Beet-root extracted water soluble fluorescent (BREWSF) dye as an efficient pigment for effective cell imaging. The extraction of this pigment from beet root and its preservation is very easy and cost effective. The BREWSF dye is characterized by IR, UV-Vis, NMR, mass, fluorescence spectroscopy and flowcytometry. By applying this dye on different types of human cells we obtained very good results in fluorescence microscopy, flowcytometry and confocal cell imaging. We also have noticed that this dye takes very less internalization time to produce very good fluorescence image and flowcytometry results of cells and also remains stable at different pH levels.


Assuntos
Beta vulgaris/química , Corantes Fluorescentes/química , Imagem Óptica , Pigmentos Biológicos/química , Linhagem Celular Tumoral , Citometria de Fluxo , Corantes Fluorescentes/isolamento & purificação , Humanos , Microscopia Confocal , Microscopia de Fluorescência , Pigmentos Biológicos/isolamento & purificação , Raízes de Plantas/química , Coloração e Rotulagem
17.
PLoS One ; 15(1): e0227866, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31945132

RESUMO

A purple cactus pear (Opuntia ficus-indica) extract (CP) was encapsulated in double emulsions (DE) gelled with gelatin (DE-CP-G) and with gelatin and transglutaminase (DE-CP-GT), as well as in a DE with a liquid external aqueous phase (DE-CP), in order to study the retention of betanin as colorant agent. Both gelled DEs showed a predominantly elastic behavior, in contrast with DE-CP. The degradation rate constant of betanin was significantly higher in DE-CP-GT (90.2 x 10-3 days-1) than in DE-CP-G (11.0 x 10-3 days-1) and DE-CP (14.6 x 10-3 days-1) during cold-storage (4 °C). A shift towards yellow color was found in all the systems during cold-storage (4 °C) and after thermal treatment (70°C/30 min), especially in DE-CP-GT, denoting a higher degradation of betanin. Betalamic acid, cyclo-Dopa 5-O-ß-glucoside, 17-decarboxy-betanin and neobetanin were identified by UHPLC-MS/MS as degradation products of betanin.


Assuntos
Betacianinas/química , Géis/química , Opuntia/química , Extratos Vegetais/química , Betalaínas/química , Betalaínas/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Emulsões/química , Frutas/química , Pigmentos Biológicos/química , Piridinas/química , Piridinas/isolamento & purificação , Espectrometria de Massas em Tandem , Transglutaminases/química
18.
Molecules ; 25(1)2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31906260

RESUMO

Yam yellow pigments (YP) are natural pigments formed during the storage of freshly cut yam (Dioscorea opposita) under certain conditions. The interaction of YP with calf thymus DNA (ctDNA) and its protective effect against DNA oxidative damage were investigated using multiple spectroscopic techniques, competitive binding experiments, viscosity measurements, and gel electrophoresis. Results showed that YP participated in intercalative binding with ctDNA. YP exhibited a protective effect against hydroxyl-induced DNA damage, which was attributed to the high hydroxyl radical scavenging activity of YP. Our findings improve our understanding of the mechanism of interaction between YP and ctDNA, and provide a theoretical basis for the application of YP in the food and drug industry.


Assuntos
Dioscorea/química , Depuradores de Radicais Livres/química , Radical Hidroxila/química , Pigmentos Biológicos/química , Ligação Competitiva , DNA/química , DNA/metabolismo , Dano ao DNA , Dioscorea/metabolismo , Radical Hidroxila/metabolismo , Cinética , Pigmentos Biológicos/isolamento & purificação , Pigmentos Biológicos/metabolismo , Espectrometria de Fluorescência
19.
Nanoscale ; 12(5): 3068-3075, 2020 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-31976994

RESUMO

The emerging properties of mimicking enzymes open up new horizons for nanomaterials. Regulating their enzyme-like activity and exploiting their applications are currently the hot topics for nanozymes. Among their activities, the pro-oxidant and antioxidant capabilities of nanozymes are important to determine their unique physiological functions. In this paper, we demonstrate that PtRu NPs exhibit multiple enzyme-like activities (e.g. peroxidase, oxidase, ferroxidase, catalase and SOD) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity. The PtRu bimetallic nanozymes therefore show pro-oxidant and anti-oxidant functions. It was found that the enzyme-like activities of PtRu NPs are highly dependent on the Pt/Ru molar ratio and show a similar trend in the order of activity: Pt90Ru10 > Pt75Ru25 > Pt > Pt40Ru60, indicating that proper alloying of Pt with Ru can enhance both pro- and anti-oxidant capabilities. By employing the ferroxidase-like activity and catalase-like activity, we verified the applications of PtRu nanozymes in the detection of Fe2+ ions, and tried for the first time to protect Monascus pigments (MPs) from hydrogen peroxide oxidation. These results not only provide an effective way to optimize the pro- and anti-oxidant capabilities of nanozymes, but also provide prospects for the applications of nanozymes in protecting biologically active natural products.


Assuntos
Antioxidantes/química , Ferro/análise , Nanopartículas Metálicas/química , Monascus/química , Oxirredutases/química , Pigmentos Biológicos/química , Platina/química , Rutênio/química
20.
Sci Rep ; 10(1): 1336, 2020 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-31992722

RESUMO

Amaranth has two morphological types described as red and green morphs. Previous studies have extensively characterised red morph amaranth regarding both morphological and chemical properties including antioxidant activity, antioxidant phytochemical profile, mineral content and proximate composition. However, there is scarce information concerning green morph amaranth. Hence, the present study evaluated 12 green morph genotypes for proximate composition, antioxidant activity, antioxidant pigments, minerals, and phytochemicals. Green morph amaranth was found to contain abundant carbohydrates, dietary fiber and protein. We found notable levels of inorganic minerals including potassium, calcium, magnesium, iron, manganese, copper and zinc. Antioxidant capacity quantified as free radical quenching capacity varied between 27 and 48 µg g-1 Trolox equivalents. We additionally quantified antioxidants, including total phenolics, total flavonoid equivalents and vitamin C, as well as the antioxidant pigments carotenoids, chlorophylls and betalains. These data indicated that four green morph genotypes could be considered as enriched in their antioxidant profiles. Green morph amaranth could be a potential source of nutritional components and antioxidant phytochemicals in the human diet providing opportunities to address mineral nutrient deficiencies and provide an antioxidant rich food.


Assuntos
Amaranthus/química , Antioxidantes/farmacologia , Nutrientes/farmacologia , Extratos Vegetais/farmacologia , Alelos , Amaranthus/genética , Antioxidantes/química , Genótipo , Minerais/química , Nutrientes/química , Compostos Fitoquímicos/química , Compostos Fitoquímicos/farmacologia , Pigmentos Biológicos/química , Extratos Vegetais/química , Característica Quantitativa Herdável , Verduras
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