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Bioresource Technology May 2022This study presents an eco-friendly and efficient technology, using immobilized enzymes, vault-encapsulated laccases (vlaccase), for decolorization and detoxification of...
This study presents an eco-friendly and efficient technology, using immobilized enzymes, vault-encapsulated laccases (vlaccase), for decolorization and detoxification of dyes. Vault encapsulation remarkably improved the performance of laccase at industrially relevant conditions, including neutral to alkaline pH and relatively high temperatures. Two representative anthraquinone and azo dyes, Reactive Blue 19 and Acid Orange 7, respectively, were rapidly decolorized (72% and 80%) by vlaccase treatment while natural laccase (nlaccase) achieved 40% and 32% decolorization. The toxicity of treated and untreated dyes was tested on model bacterial, algal, and insect cells. The inhibitory effects of dyes towards selected bacteria were reduced in vlaccase-treated samples. The chlorophyll synthesis in algae was less inhibited by dyes after vlaccase treatment. Furthermore, the toxicity of dye degradation products to insect cells was significantly mitigated in the vlaccase group. Collectively, these results indicate that vlaccase is a stable and strong enzymatic system for removing dyes from waters.
Topics: Azo Compounds; Biodegradation, Environmental; Coloring Agents; Enzymes, Immobilized; Laccase; Nanoparticles
PubMed: 35318145
DOI: 10.1016/j.biortech.2022.127040 -
Organic & Biomolecular Chemistry Mar 2015We have devised a room temperature process for the cyclopropanation of electron-poor olefins using unstabilised diazo compounds, generated under continuous flow...
We have devised a room temperature process for the cyclopropanation of electron-poor olefins using unstabilised diazo compounds, generated under continuous flow conditions. This protocol was applied to a wide range of different diazo species to generate functionalised cyclopropanes which are valuable 3D building blocks.
Topics: Azo Compounds; Cyclopropanes; Molecular Structure
PubMed: 25600950
DOI: 10.1039/c5ob00019j -
International Journal of Molecular... Jun 2020Two series of new hexasubstituted cyclotriphosphazene derivatives were successfully synthesized and characterized. These derivatives are differentiated by two types of...
Two series of new hexasubstituted cyclotriphosphazene derivatives were successfully synthesized and characterized. These derivatives are differentiated by two types of linking units in the molecules such as amide-azo () and azo-azo (). The homologues of the same series contain different terminal substituents such as heptyl, nonyl, decyl, dodecyl, tetradecyl, hydroxyl, carboxyl, chloro, nitro, and amino groups. All the intermediates and final compounds were characterized using Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance spectroscopy (NMR), and Carbon, Hydrogen, and Nitrogen (CHN) elemental analysis. Liquid crystal properties for all compounds were determined using polarized optical microscope (POM). It was found that only intermediates with nitro and alkoxyl terminal chains showed a smectic A phase. All the final compounds with alkoxyl substituents are mesogenic with either smectic A or C phases. However, other intermediates and compounds were found to be non-mesogenic. The study on the fire retardancy of final compounds was determined using limiting oxygen index (LOI) method. The LOI value of pure polyester resin (22.53%) was increased up to 24.71% after treating with 1 wt% of hexachlorocyclotriphosphazene (HCCP). Moreover, all the compounds gave positive results on the LOI values and compound with the nitro terminal substituent showed the highest LOI value of 27.54%.
Topics: Amides; Azo Compounds; Flame Retardants; Liquid Crystals; Microscopy, Polarization; Molecular Structure; Nitriles; Oxygen; Phosphorus Compounds; Spectroscopy, Fourier Transform Infrared
PubMed: 32560033
DOI: 10.3390/ijms21124267 -
Journal of the American Chemical Society Oct 2017Photodynamic therapy (PDT) utilizes photoirradiation in the presence of photosensitizers to ablate cancer cells via generation of singlet oxygen (O), but it is important...
Photodynamic therapy (PDT) utilizes photoirradiation in the presence of photosensitizers to ablate cancer cells via generation of singlet oxygen (O), but it is important to minimize concomitant injury to normal tissues. One approach for achieving this is to use activatable photosensitizers that can generate O only under specific conditions. Here, we report a novel photosensitizer that is selectively activated under hypoxia, a common condition in solid tumors. We found that introducing an azo moiety into the conjugated system of a seleno-rosamine dye effectively hinders the intersystem crossing process that leads to O generation. We show that the azo group is reductively cleaved in cells under hypoxia, enabling production of O to occur. In PDT in vitro, cells under mild hypoxia, within the range typically found in solid tumors (up to about 5% O), were selectively ablated, leaving adjacent normoxic cells intact. This simple and practical azo-based strategy should be widely applicable to design a range of activatable photosensitizers.
Topics: Azo Compounds; Cell Hypoxia; Cell Line, Tumor; Humans; Photochemotherapy; Photosensitizing Agents
PubMed: 28872304
DOI: 10.1021/jacs.7b05019 -
Regulatory Toxicology and Pharmacology... Aug 2017Azo dyes represent the by far most important class of textile dyes. Their biotransformation by various skin bacteria may release aromatic amines (AAs) which might be...
Azo dyes represent the by far most important class of textile dyes. Their biotransformation by various skin bacteria may release aromatic amines (AAs) which might be dermally absorbed to a major extent. Certain AAs are well known to have genotoxic and/or carcinogenic properties. Correspondingly, azo dyes releasing one of the 22 known carcinogenic AAs are banned from clothing textiles in the European Union. In the present study, we investigated the mutagenicity of 397 non-regulated AAs potentially released from the 470 known textile azo dyes. We identified 36 mutagenic AAs via publicly available databases. After predicting their mutagenicity potential using the method by Bentzien, we accordingly allocated them into different priority groups. Ames tests on 18 AAs of high priority showed that 4 substances (22%) (CASRN 84-67-3, 615-47-4, 3282-99-3, 15791-87-4) are mutagenic in the strain TA98 and/or TA100 with and/or without rat S9 mix. Overall, combining the information from the Ames tests and the publicly available data, we identified 40 mutagenic AAs being potential cleavage products of approximately 180 different parent azo dyes comprising 38% of the azo dyes in our database. The outcome of this study indicates that mutagenic AAs in textile azo dyes are of much higher concern than previously expected, which entails implications on the product design and possibly on the regulation of azo dyes in the future.
Topics: Animals; Azo Compounds; Clothing; Coloring Agents; Mutagenicity Tests; Mutagens; Rats; Textiles
PubMed: 28655654
DOI: 10.1016/j.yrtph.2017.06.012 -
Chemical Communications (Cambridge,... Oct 2021RNA is an emerging drug target that opens new perspectives in the treatment of viral and bacterial infections, cancer and a range of so far incurable genetic diseases.... (Review)
Review
RNA is an emerging drug target that opens new perspectives in the treatment of viral and bacterial infections, cancer and a range of so far incurable genetic diseases. Among the various strategies towards the design and development of selective and efficient ligands for targeting and detection of therapeutically relevant RNA, photoswitchable RNA binders represent a very promising approach due to the possibility to control the ligand-RNA and protein-RNA interactions by light with high spatiotemporal resolution. However, the field of photoswitchable RNA binders still remains underexplored due to challenging design of lead structures that should combine high RNA binding selectivity with efficient photochemical performance. The aim of this highlight article is to describe the development of photoswitchable noncovalent RNA binders and to outline the current situation and perspectives of this emerging interdisciplinary field.
Topics: Azo Compounds; Benzylidene Compounds; HIV; Humans; Ligands; Light; RNA; Stereoisomerism
PubMed: 34585681
DOI: 10.1039/d1cc04241f -
Nature Nanotechnology Apr 2020Optical technologies allowing modulation of neuronal activity at high spatio-temporal resolution are becoming paramount in neuroscience. In this respect,...
Optical technologies allowing modulation of neuronal activity at high spatio-temporal resolution are becoming paramount in neuroscience. In this respect, azobenzene-based photoswitches are promising nanoscale tools for neuronal photostimulation. Here we engineered a light-sensitive azobenzene compound (Ziapin2) that stably partitions into the plasma membrane and causes its thinning through trans-dimerization in the dark, resulting in an increased membrane capacitance at steady state. We demonstrated that in neurons loaded with the compound, millisecond pulses of visible light induce a transient hyperpolarization followed by a delayed depolarization that triggers action potential firing. These effects are persistent and can be evoked in vivo up to 7 days, proving the potential of Ziapin2 for the modulation of membrane capacitance in the millisecond timescale, without directly affecting ion channels or local temperature.
Topics: Action Potentials; Animals; Azo Compounds; Cell Membrane; Hippocampus; Mice; Neurons
PubMed: 32015505
DOI: 10.1038/s41565-019-0632-6 -
Biochimica Et Biophysica Acta Jan 1963
Topics: Azo Compounds; DNA; Deoxyribonucleosides; Diazomethane; Methylation
PubMed: 13959813
DOI: 10.1016/0006-3002(63)90126-4 -
The Journal of Organic Chemistry Apr 2014The first example for the preparation of enantioenriched azo compounds from hydrazones and Morita-Baylis-Hillman adducts has been developed, affording azo compounds...
(DHQ)2AQN-catalyzed asymmetric substitution of isatin-derived hydrazones with O-Boc-protected Morita-Baylis-Hillman adducts: A strategy for synthesizing enantioenriched azo compounds incorporating an oxindole scaffold.
The first example for the preparation of enantioenriched azo compounds from hydrazones and Morita-Baylis-Hillman adducts has been developed, affording azo compounds incorporating an oxindole scaffold in up to 91% yield along with a 93% ee value under the catalysis of (DHQ)2AQN.
Topics: Anthraquinones; Azo Compounds; Catalysis; Ethers; Hydrazones; Indoles; Isatin; Molecular Structure; Oxindoles; Stereoisomerism
PubMed: 24670223
DOI: 10.1021/jo5003246 -
Molecules (Basel, Switzerland) Jun 2020Three series of azo dyes derived from 2-amino-5-aryl-1,3,4-thiadiazoles and aniline, -dimethylaniline and phenol were synthesized in high yields by a conventional...
Three series of azo dyes derived from 2-amino-5-aryl-1,3,4-thiadiazoles and aniline, -dimethylaniline and phenol were synthesized in high yields by a conventional diazotization-coupling sequence. The chemical structures of the prepared compounds were confirmed by H-NMR, C-NMR, IR, UV-Vis spectroscopy, mass spectrometry and elemental analysis. In addition, the X-ray single crystal structure of a representative azo dye was presented. For explicit determination of the influence of a substituent on radiation absorption in UV-Vis range, time-dependent density functional theory calculations were performed.
Topics: Azo Compounds; Models, Molecular; Molecular Structure; Spectrophotometry, Ultraviolet; Thiadiazoles
PubMed: 32570910
DOI: 10.3390/molecules25122822