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Organic Letters Mar 2021Presented is an economical means of removing fluorine from various highly fluorinated arenes using NaBH. The procedure was adapted for different classes of...
Presented is an economical means of removing fluorine from various highly fluorinated arenes using NaBH. The procedure was adapted for different classes of perfluoroarenes. A novel isomer of an emerging class of organic dyes based on the carbazole phthalonitrile motif was succinctly synthesized in two steps from tetrafluorophthalonitrile, demonstrating the utility of the hydrodefluorination procedure. Initial exploration of the dye shows it to be photoactive and capable of facilitating contrathermodynamic styrenoid / isomerization.
Topics: Carbazoles; Catalysis; Coloring Agents; Halogenation; Isomerism; Molecular Structure
PubMed: 33587637
DOI: 10.1021/acs.orglett.0c04305 -
Journal of Hazardous Materials Sep 2023Polyethylene (PE) and industrial dyes are recalcitrant pollutants calling for the development of sustainable solutions for their degradation. Laccases have been explored...
Polyethylene (PE) and industrial dyes are recalcitrant pollutants calling for the development of sustainable solutions for their degradation. Laccases have been explored for removal of contaminants and pollutants, including dye decolorization and plastic degradation. Here, a novel thermophilic laccase from PE-degrading Lysinibaccillus fusiformis (LfLAC3) was identified through a computer-aided and activity-based screening. Biochemical studies of LfLAC3 indicated its high robustness and catalytic promiscuity. Dye decolorization experiments showed that LfLAC3 was able to degrade all the tested dyes with decolorization percentage from 39% to 70% without the use of a mediator. LfLAC3 was also demonstrated to degrade low-density polyethylene (LDPE) films after eight weeks of incubation with either crude cell lysate or purified enzyme. The formation of a variety of functional groups was detected using Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). Damage on the surfaces of PE films was observed via scanning electron microscopy (SEM). The potential catalytic mechanism of LfLAC3 was disclosed by structure and substrate-binding modes analysis. These findings demonstrated that LfLAC3 is a promiscuous enzyme that has promising potential for dye decolorization and PE degradation.
Topics: Polyethylene; Laccase; Coloring Agents; Hydrolases; Environmental Pollutants
PubMed: 37413797
DOI: 10.1016/j.jhazmat.2023.131986 -
Frontiers in Bioscience (Landmark... Jan 2013This chapter provides an overview of the chemical structures and properties of aromatic amines and their role in the development and utility of azo dyes. Approaches to... (Review)
Review
This chapter provides an overview of the chemical structures and properties of aromatic amines and their role in the development and utility of azo dyes. Approaches to the design of environmentally benign alternatives to genotoxic primary aromatic amines, as azo dye precursors, are included.
Topics: Amines; Azo Compounds; Cellulose; Coloring Agents; Cotton Fiber; Mutagens
PubMed: 23276915
DOI: 10.2741/4093 -
International Journal of Molecular... Oct 2022Three hair dyes of Arianor madder red 306003 (R), Arian or Straw Yellow 306005 (Y), and Arianor ebony 306020 (E) were removed from an aqueous solution in a batch mode...
Three hair dyes of Arianor madder red 306003 (R), Arian or Straw Yellow 306005 (Y), and Arianor ebony 306020 (E) were removed from an aqueous solution in a batch mode using a powder of oak cupules coated with ZnO (COZ). The COZ-adsorbent material was characterized in terms of XRD, FT-IR, and SEM analysis. The best conditions for the uptake of hair dyes by COZ were investigated. For Y dye, the best uptake was estimated on 0.06 g of COZ at 7.0 pH for 150 min. The E dye uptake requires 120 min on 0.05 g of COZ at 9.0 pH. For E hair dye, kinetic data revealed a pseudo-first-order model for E hair dye and a pseudo-second-order model for R and Y. Equilibrium data exhibited consistency with the Langmuir isotherm model for the adsorption of E dye onto COZ, and the Freundlich isotherm model for the adsorption of R and Y hair dyes onto COZ. Isotherms models of D-R and Temkin were also examined. The thermodynamic parameters (-ve ∆G and +ve ∆H and ∆S) demonstrated that the removal of hair dyes by COZ is spontaneous, endothermic, and feasible. The adsorption capacity of COZ for R, Y, and E uptake was found to be 55.5, 52.6, and 135.1 mg·g, respectively. Furthermore, COZ reusability was demonstrated after five cycles of regeneration, with a negligible decline in adsorption extent (13.08%, 13.85, and 10.20% for R, Y, and E, respectively) in comparison to its initial capacity.
Topics: Adsorption; Coloring Agents; Hair Dyes; Hydrogen-Ion Concentration; Kinetics; Powders; Quercus; Spectroscopy, Fourier Transform Infrared; Thermodynamics; Water; Water Pollutants, Chemical; Zinc Oxide
PubMed: 36233265
DOI: 10.3390/ijms231911959 -
Ultrasonics Sonochemistry Jul 2016Textile dyeing assisted by ultrasonic energy has attained a greater interest in recent years. We report ultrasonic dyeing of nanofibers for the very first time. We chose...
Textile dyeing assisted by ultrasonic energy has attained a greater interest in recent years. We report ultrasonic dyeing of nanofibers for the very first time. We chose cellulose nanofibers and dyed with two reactive dyes, CI reactive black 5 and CI reactive red 195. The cellulose nanofibers were prepared by electrospinning of cellulose acetate (CA) followed by deacetylation. The FTIR results confirmed complete conversion of CA into cellulose nanofibers. Dyeing parameters optimized were dyeing temperature, dyeing time and dye concentrations for each class of the dye used. Results revealed that the ultrasonic dyeing produced higher color yield (K/S values) than the conventional dyeing. The color fastness test results depicted good dye fixation. SEM analysis evidenced that ultrasonic energy during dyeing do not affect surface morphology of nanofibers. The results conclude successful dyeing of cellulose nanofibers using ultrasonic energy with better color yield and color fastness results than conventional dyeing.
Topics: Cellulose; Color; Coloring Agents; Microscopy, Electron, Scanning; Nanofibers; Ultrasonics
PubMed: 26964959
DOI: 10.1016/j.ultsonch.2016.01.020 -
Brazilian Journal of Biology = Revista... 2023Amazonian strains of Cyathus spp. and Geastrum spp. were studied for the ability to discolor the trypan blue azo dye and reduce its toxicity. Discoloration of trypan...
Amazonian strains of Cyathus spp. and Geastrum spp. were studied for the ability to discolor the trypan blue azo dye and reduce its toxicity. Discoloration of trypan blue dye (0.05%) was evaluated in solid and aqueous medium over different periods. The reduction of dye toxicity after treatment was assessed by seed germination and the development of lettuce seedlings (Lactuca sativa L.) and toxicity test in Artemia salina (L.) larvae. All evaluated strains showed the potential to reduce the color intensity of trypan blue dye. Cyathus strains reached 96% discoloration, and C. albinus and C. limbatus also reduced dye toxicity. Geastrum strains showed a high efficiency degree in color reduction, reaching 98% discoloration, however, the by-products generated during the process presented toxicity and require further investigation. For the first time, Amazonian strains of gasteroid fungi degrading trypan blue are reported, some even reducing its toxicity. Thus, making them promising sources of enzymes of interest to bioremediation scenarios involving synthetic dyes.
Topics: Trypan Blue; Azo Compounds; Biodegradation, Environmental; Basidiomycota; Fungi; Coloring Agents
PubMed: 38055583
DOI: 10.1590/1519-6984.277577 -
Cellular Signalling Sep 2023Genetically encoded Ca indicators have become widely used in cell signalling studies as they offer advantages over cell-loaded dye indicators in enabling specific...
Genetically encoded Ca indicators have become widely used in cell signalling studies as they offer advantages over cell-loaded dye indicators in enabling specific cellular or subcellular targeting. Comparing responses from dye and protein-based indicators may provide information about indicator properties and cell physiology, but side-by-side recordings in cells are scarce. In this study, we compared cytoplasmic Ca concentration ([Ca]) changes in insulin-secreting β-cells recorded with commonly used dyes and indicators based on circularly permuted fluorescent proteins. Total internal reflection fluorescence (TIRF) imaging of K depolarization-triggered submembrane [Ca] increases showed that the dyes Fluo-4 and Fluo-5F mainly reported stable [Ca] elevations, whereas the proteins R-GECO1 and GCaMP5G more often reported distinct [Ca] spikes from an elevated level. [Ca] spiking occurred also in glucose-stimulated cells. The spikes reflected Ca release from the endoplasmic reticulum, triggered by autocrine activation of purinergic receptors after exocytotic release of ATP and/or ADP, and the spikes were consequently prevented by SERCA inhibition or P2Y-receptor antagonism. Widefield imaging, which monitors the entire cytoplasm, increased the spike detection by the Ca dyes. The indicator-dependent response patterns were unrelated to Ca binding affinity, buffering and mobility, and probably reflects the much slower dissociation kinetics of protein compared to dye indicators. Ca dyes thus report signalling within the submembrane space excited by TIRF illumination, whereas the protein indicators also catch Ca events originating outside this volume. The study highlights that voltage-dependent Ca entry in β-cells is tightly linked to local intracellular Ca release mediated via an autocrine route that may be more important than previously reported direct Ca effects on phospholipase C or on intracellular channels mediating calcium-induced calcium release.
Topics: Calcium; Insulin-Secreting Cells; Signal Transduction; Endoplasmic Reticulum; Coloring Agents; Calcium Signaling; Adenosine Triphosphate
PubMed: 37437828
DOI: 10.1016/j.cellsig.2023.110805 -
Scientific Reports May 2022Polypropylene fibres are difficult to dye using commonly used techniques due to the high crystallinity and non-polar aliphatic structure, that lack reactive places for...
Polypropylene fibres are difficult to dye using commonly used techniques due to the high crystallinity and non-polar aliphatic structure, that lack reactive places for dyes in the molecule. Dyeing PP fabric in scCO with antibacterial dyes merged the dyeing and finishing methods, resulting in a more productive technique in terms of water and energy consumption. Unmodified polypropylene fabric was dyed with 4-[2-[4-(ethenylsulphonyl)phenyl]diazenyl]-N,N-diethylbenzenamine antibacterial dye under scCO medium. The influences of scCO working parameters, such as dye concentration, pressure, dyeing time, and temperature, on fabric dye absorption expressed as color strength were studied. The color strength (K/S) was measured as well as CIELAB color parameters. The results were compared with its water dyeing analogue and it was observed that color strength as well as color depth (L) of the samples dyed in scCO were noticeably better than its water counterpart. In both scCO and water, the fastness properties (washing, rubbing, and light) of the dyed samples were excellent. Antibacterial activity of the dyed polypropylene sample in scCO was estimated and the results indicated good antibacterial efficiency.
Topics: Anti-Bacterial Agents; Carbon Dioxide; Coloring Agents; Polypropylenes; Sulfones; Water
PubMed: 35610356
DOI: 10.1038/s41598-022-12680-w -
Applied Microbiology Jan 1966The inactivation of foot-and-mouth disease virus was studied by means of the interaction of neutral red, Toluidine Blue, and methylene blue with visible light. The...
The inactivation of foot-and-mouth disease virus was studied by means of the interaction of neutral red, Toluidine Blue, and methylene blue with visible light. The virus, Type A, strain 1, CANEFA of Argentine origin, was grown in tissue culture and tested in the crude and clarified state. Virus and dye were mixed and incubated together at 4 C for 45 min in the dark, or were mixed and immediately exposed to the visible light source without prior incubation together. Mixtures of crude virus and dye, under any of the experimental conditions used, did not inactivate more than 1 to 2 logs of viral infectivity when held in the dark or when exposed to light during a period of 45 min. Complete inactivation of virus was achieved when clarified virus and dye were mixed and immediately exposed to the visible light source for 15 min. Prior incubation of clarified virus and dye permitted inactivation by methylene blue only, whereas no incubation prior to exposure resulted in three of the dyes contributing to inactivation. A concentration of 6 mug of neutral red, Toluidine Blue, methylene blue, and crystal violet was used per milliliter of virus suspension. Crystal violet was not a good viral inactivator under the conditions of the experimentation. Inactive virus induced the formation of neutralizing antibodies in adult chickens and mice. The antibody titer stimulated by the antigen treated with methylene blue and visible light was probably significant.
Topics: Animals; Antiviral Agents; Aphthovirus; Coloring Agents; Culture Techniques; Foot-and-Mouth Disease; Light; Mice; Poultry
PubMed: 4288063
DOI: 10.1128/am.14.1.86-91.1966 -
Molecules (Basel, Switzerland) Feb 2012The mechanisms of suppression and enhancement of photocurrent/conversion efficiency (performance) in dye-sensitized solar cells, using carotenoid and chlorophyll... (Review)
Review
The mechanisms of suppression and enhancement of photocurrent/conversion efficiency (performance) in dye-sensitized solar cells, using carotenoid and chlorophyll derivatives as sensitizers, were compared systematically. The key factor to enhance the performance was found to be how to minimize interaction among the excited-state dye-sensitizer(s). In a set of retinoic-acid (RA) and carotenoic-acid (CA) sensitizers, having n conjugated double bonds, CA7 gave rise to the highest performance, which was reduced toward RA5 and CA13. The former was ascribed to the generation of triplet and the resultant singlet-triplet annihilation reaction, while the latter, to the intrinsic electron injection efficiency. In a set of shorter polyene sensitizers having different polarizabilities, the one with the highest polarizability (the highest trend of aggregate formation) exhibited the higher performance toward the lower dye concentration and the lower light intensity, contrary to our expectation. This is ascribed to a decrease in the singlet-triplet annihilation reaction. The performance of cosensitization, by a pair of pheophorbide sensitizers without and with the central metal, Mg or Zn, was enhanced by the light absorption (complementary rather than competitive), the transition-dipole moments (orthogonal rather than parallel) and by the pathways of electron injection (energetically independent rather than interactive).
Topics: Carotenoids; Chlorophyll; Coloring Agents; Solar Energy; Tretinoin
PubMed: 22357317
DOI: 10.3390/molecules17022188