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International Journal of Biological... Sep 2017In this work, a novel and sustainable biosorbent, regenerated silk fibroin film (rSFF) was successfully prepared and its adsorbability to azo dyes (acid yellow 11,...
In this work, a novel and sustainable biosorbent, regenerated silk fibroin film (rSFF) was successfully prepared and its adsorbability to azo dyes (acid yellow 11, naphthol orange and direct orange S) was measured. At optimal conditions, the adsorption capacity of rSFF for acid yellow 11 reached up to 59.71mg/g, which was 1.23-fold higher than that of raw silk fibroin fibers. More importantly, rSFF exhibited a high level of flexibility and functionality as well as a good shaping ability, which were crucial for its practical application. The SEM results showed that rSFF was a porous material, indicating that it had more available adsorption sites compared with raw silk fibroin fibers, which might contribute to the higher adsorption capacity of rSFF. Isotherm equilibrium studies revealed that the azo dye adsorption process followed the Langmuir model, indicating that rSFF was a structurally homogenous adsorbent. The recycle test showed that rSFF had potential to be reused in a number of treatment cycles. After five cycles, its adsorbability to acid yellow 11 remained as high as 47.20mg/g. Finally, a scale-up experiment was performed for rSFF, and the results indicated that it was feasible for rSFF to extend the practical application.
Topics: Adsorption; Azo Compounds; Fibroins; Water Pollutants, Chemical
PubMed: 28478052
DOI: 10.1016/j.ijbiomac.2017.05.009 -
Journal of the American Chemical Society Sep 2017Biological tissue exhibits an absorbance minimum in the near-infrared between 700 and 900 nm that permits deep penetration of light. Molecules that undergo...
Biological tissue exhibits an absorbance minimum in the near-infrared between 700 and 900 nm that permits deep penetration of light. Molecules that undergo photoisomerization in this bio-optical window are highly desirable as core structures for the development of photopharmaceuticals and as components of chemical-biological tools. We report the systematic design, synthesis, and testing of an azobenzene derivative tailored to undergo single-photon photoswitching with near-infrared light under physiological conditions. A fused dioxane ring and a methoxy substituent were used to place oxygen atoms in all four ortho positions, as well as two meta positions, relative to the azobenzene N═N double bond. This substitution pattern, together with a para pyrrolidine group, raises the pK of the molecule so that it is protonated at physiological pH and absorbs at wavelengths >700 nm. This azobenzene derivative, termed DOM-azo, is stable for months in neutral aqueous solutions, undergoes trans-to-cis photoswitching with 720 nm light, and thermally reverts to the stable trans isomer with a half-life near 1 s.
Topics: Azo Compounds; Hydrogen-Ion Concentration; Infrared Rays; Isomerism; Photochemical Processes; Protons; Pyrrolidines
PubMed: 28885845
DOI: 10.1021/jacs.7b06471 -
Journal of the American Chemical Society Sep 2021The first α-boryl diazo compound that is capable of engaging in classic synthetic organic diazo reaction chemistry is described. The diazomethyl-1,2-azaborine , which...
The first α-boryl diazo compound that is capable of engaging in classic synthetic organic diazo reaction chemistry is described. The diazomethyl-1,2-azaborine , which is a BN isostere of phenyldiazomethane, is significantly more stable than phenyldiazomethane; its reaction chemistry ranges from C-H activation, O-H activation, [3+2] cycloaddition, and halogenation, to Ru-catalyzed carbonyl olefination. The demonstrated broad range of reactivity of diazomethyl-1,2-azaborine makes it an exceptionally versatile synthetic building block for the 1,2-azaborine heterocyclic motif.
Topics: Azo Compounds; Boron Compounds; Coordination Complexes; Cycloaddition Reaction; Esterification; Halogenation; Ruthenium
PubMed: 34431676
DOI: 10.1021/jacs.1c06112 -
Chemical Communications (Cambridge,... Mar 2006A photoswitchable azobenzene-phthalocyanine-azobenzene triad has been synthesized and its electrochemical properties determined. Energy transfer among the subunits...
A photoswitchable azobenzene-phthalocyanine-azobenzene triad has been synthesized and its electrochemical properties determined. Energy transfer among the subunits allows for modification of the E-Z ratio by selective excitation of the phthalocyanine moiety.
Topics: Azo Compounds; Electrochemistry; Indoles; Isoindoles; Molecular Structure; Photochemistry; Spectrophotometry, Ultraviolet; Stereoisomerism
PubMed: 16538242
DOI: 10.1039/b517518f -
The Journal of Organic Chemistry Sep 2017A convenient method for the synthesis of symmetrical azobenzenes is reported. This one-step procedure involves treatment of anilines with N-chlorosuccinimide (NCS) and...
A convenient method for the synthesis of symmetrical azobenzenes is reported. This one-step procedure involves treatment of anilines with N-chlorosuccinimide (NCS) and organic base 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU). A wide range of commercially available substituted anilines readily participate in this reaction to produce the corresponding azobenzenes in moderate-to-excellent yields in minutes.
Topics: Azo Compounds; Bridged Bicyclo Compounds, Heterocyclic; Molecular Structure; Succinimides
PubMed: 28846399
DOI: 10.1021/acs.joc.7b01530 -
Spectrochimica Acta. Part A, Molecular... Dec 2005The absorption spectra of mono- and bis-azo-derivatives obtained by coupling the diazonium salts of aromatic amines and 2,7-dihydroxynaphthalene have been studied in six...
The absorption spectra of mono- and bis-azo-derivatives obtained by coupling the diazonium salts of aromatic amines and 2,7-dihydroxynaphthalene have been studied in six organic solvents. The different absorption bands have been assigned and the effect of solvents on the charge transfer band is also discussed. The diagnostic IR spectral bands and 1H NMR signals are assigned and discussed in relation to molecular structure. Also, semi-empirical molecular orbital calculations using the atom superposition and electron delocalization molecular orbital (ASED-MO) theory have been performed to investigate the molecular and electronic structures of these compounds. According to these calculations, an intramolecular hydrogen bonding is essential for stabilization of such molecules.
Topics: Aniline Compounds; Azo Compounds; Electron Spin Resonance Spectroscopy; Hydrogen Bonding; Magnetic Resonance Spectroscopy; Models, Chemical; Molecular Structure; Naphthols; Spectrophotometry, Infrared; Spectrophotometry, Ultraviolet
PubMed: 15951233
DOI: 10.1016/j.saa.2005.04.018 -
European Journal of Medicinal Chemistry May 2014Vesicular Glutamate Transporters (VGLUTs) allow the loading of presynapic glutamate vesicles and thus play a critical role in glutamatergic synaptic transmission. VGLUTs...
Vesicular Glutamate Transporters (VGLUTs) allow the loading of presynapic glutamate vesicles and thus play a critical role in glutamatergic synaptic transmission. VGLUTs have proved to be involved in several major neuropathologies and directly correlated to clinical dementia in Alzheimer and Parkinson's disease. Accordingly VGLUT represent a key biological target or biomarker for neuropathology treatment or diagnostic. Yet, despite the pivotal role of VGLUTs, their pharmacology appears quite limited. Known competitive inhibitors are restricted to some dyes as Trypan Blue (TB) and glutamate mimics. This lack of pharmacological tools has heavily hampered VGLUT investigations. Here we report a rapid access to small molecules that combine benefits of TB and dicarboxylic quinolines (DCQs). Their ability to block vesicular glutamate uptake was evaluated. Several compounds displayed low micromolar inhibitory potency when size related compounds are thirty to forty times less potent (i.e. DCQ). We then confirmed the VGLUT selectivity by measuring the effect of the series on vesicular monoamine transport and on metabotropic glutamate receptor activity. These inhibitors are synthesized in only two steps and count among the best pharmacological tools for VGLUTs studies.
Topics: Animals; Azo Compounds; Coloring Agents; Dose-Response Relationship, Drug; Drug Design; Molecular Structure; Rats; Structure-Activity Relationship; Vesicular Glutamate Transport Proteins
PubMed: 24686010
DOI: 10.1016/j.ejmech.2014.03.056 -
Journal of the American Chemical Society Apr 2008An efficient synthesis of a family of heteroaromatic triazinium compounds, [2a]X-[2g]X (X = Cl, ClO4, NO3, and HSO4), from 2-(arylazo)pyridines via proton-catalyzed...
An efficient synthesis of a family of heteroaromatic triazinium compounds, [2a]X-[2g]X (X = Cl, ClO4, NO3, and HSO4), from 2-(arylazo)pyridines via proton-catalyzed heterocyclization is described. Characterization of the compounds is made by different spectroscopic, electrochemical techniques, as well as single-crystal structure determination of the triflate salt of a representative compound, [2a]CF3SO3. The bond parameters indicate that the tricyclo compound, 2a(+), is planar and aromatic with a N-N bond length of 1.275(6) A. These exhibited fluorescence with an emission maximum in the range of 540-535 nm with moderate quantum yields. The triazinium salts can be reduced in two successive one-electron steps as probed by cyclic voltammetry and coulometry. The paramagnetic radical intermediate 2a(*) is distinguished by a sharp and intense EPR spectrum. Fluorescence spectroscopy, circular dichroism, cyclic voltammetry, viscosity measurements, together with DNA melting studies have been used to characterize the binding of 2a(+) with calf thymus DNA. The emission quenching of the compound by [Fe(CN)6](4-) decreased when bound to DNA. As determined by a MTT assay, 2a(+) exhibited significant cytotoxicity at a higher concentration range of 1 mg/mL to 1 microg/mL; however, the % survival ratio increased with dilution. Cellular uptake studies of the referenced compound were followed by FACS analysis.
Topics: Animals; Azo Compounds; Cations; Cattle; Cell Line; Cell Survival; Chlorocebus aethiops; Circular Dichroism; Crystallography, X-Ray; Cyclization; DNA; Electron Spin Resonance Spectroscopy; Humans; Models, Molecular; Molecular Structure; Oxidation-Reduction; Pyridines; Spectrophotometry; Viscosity
PubMed: 18335991
DOI: 10.1021/ja710211u -
IARC Monographs on the Evaluation of... 1993
Review
Topics: Animals; Azo Compounds; Carcinogens; Coloring Agents; Female; Humans; Male; Mice; Mice, Inbred Strains; Rats; Rats, Inbred F344
PubMed: 8207860
DOI: No ID Found -
IARC Monographs on the Evaluation of... 1993
Review
Topics: Animals; Azo Compounds; Carcinogens; Coloring Agents; Female; Humans; Male; Rats; Rats, Inbred F344
PubMed: 8207858
DOI: No ID Found