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Materials (Basel, Switzerland) Feb 2023Water-soluble azo derivatives of lignin were synthesized by the azo coupling reaction using organosolv ethanol lignin and diazonium salts based on sulfanilic acid and...
Water-soluble azo derivatives of lignin were synthesized by the azo coupling reaction using organosolv ethanol lignin and diazonium salts based on sulfanilic acid and p-nitroaniline. The structure of azo derivatives of lignin were studied by nuclear magnetic resonance, Fourier-transform infrared spectroscopy, and gel permeation chromatography. It was found that the azobenzene bonds formed in the azo coupling reaction of macromolecules impart the photosensitive properties to the synthesized polymers via cis-trans photoisomerization of the diazobenzene group. It was shown experimentally that the synthesized polymers exhibited good solubility both in the aqueous media in a wide (2-12) pH range and in DMSO and THF organic solvents, which opens up new prospects for their application.
PubMed: 36837154
DOI: 10.3390/ma16041525 -
Molecules (Basel, Switzerland) Dec 2016Nitrogen-containing molecules are key scaffolds that are widely applied in organic synthesis as precursors of highly functionalized materials, and are also investigated...
Nitrogen-containing molecules are key scaffolds that are widely applied in organic synthesis as precursors of highly functionalized materials, and are also investigated for their biological activities. This Special Issue collects seven innovative contributions which expand our knowledge of the chemistry of nitro compounds, amines, diazonium salts, and peptides, and that provide a good overview about their main reactivities.
Topics: Amines; Nitro Compounds; Nitroso Compounds; Peptides; Quaternary Ammonium Compounds
PubMed: 28025551
DOI: 10.3390/molecules22010009 -
RSC Advances Feb 2022A series of quinolizinium-based fluorescent reagents were prepared by visible light-mediated gold-catalyzed -difunctionalization between quinolinium diazonium salts and...
A series of quinolizinium-based fluorescent reagents were prepared by visible light-mediated gold-catalyzed -difunctionalization between quinolinium diazonium salts and electron-deficient alkyne-linked phenylethynyl trimethylsilanes. The electron-deficient alkynyl group of the quinolizinium-based fluorescent reagents underwent nucleophilic addition reaction with the sulfhydryl group on cysteine-containing peptides and proteins. The quinolizinium-based fluorescent reagents were found to function as highly selective reagents for the modification of cysteine-containing peptides and proteins with good to excellent conversions (up to 99%). Moreover, the modified BCArg mutants bearing cationic quinolizinium compounds 1b, 1d, 1e and 1h exhibit comparable activity in enzymatic and cytotoxicity assays to the unmodified one.
PubMed: 35424586
DOI: 10.1039/d1ra08329e -
Chemistry Central Journal Nov 2017A series of recently reported phenolic azo dyes 7a-e were prepared by coupling the thienyl diazonium sulfate of 3-Amino-4H-benzo[f]thieno[3,4-c](2H)chromen-4-one with...
BACKGROUND
A series of recently reported phenolic azo dyes 7a-e were prepared by coupling the thienyl diazonium sulfate of 3-Amino-4H-benzo[f]thieno[3,4-c](2H)chromen-4-one with selected diversely substituted phenolic and naphtholic derivatives. These compounds were evaluated for their antibacterial and antifungal activities. Furthermore their voltammetric behavior was compared at a glassy carbon electrode.
RESULTS
The voltammetric behavior of the five recently reported azo dyes has been compared at a glassy carbon electrode. It is shown that the azo dyes 7a-e with a hydroxyl group in the ortho position with respect to the azo bridge give rise to well defined, irreversible peaks for the oxidation and reduction process within a pH range of 2-7. The mechanisms of electrochemical oxidation of compound 7a-c and 7e are proposed. For the hydroxyl-substituted dyes, re-oxidation peaks were obtained in the subsequent scan. The antimicrobial activities of the reported compounds 7a-e along with the entire precursors 1-4 and 6a-e were performed against selected bacterial and fungal species and their activities compared to those of nystatin, griseofulvin and ciprofloxacin used as reference drugs.
CONCLUSIONS
The present study showed significant antimicrobial activity of compounds 6d, 7a and 7c,e against the tested microorganisms; this result confirms the antimicrobial potency of azo compounds and some of their precursors.
PubMed: 29159480
DOI: 10.1186/s13065-017-0345-6 -
The subacute toxicity and underlying mechanisms of biomimetic mesoporous polydopamine nanoparticles.Particle and Fibre Toxicology Oct 2023Recently, mesoporous nanomaterials with widespread applications have attracted great interest in the field of drug delivery due to their unique structure and good...
Recently, mesoporous nanomaterials with widespread applications have attracted great interest in the field of drug delivery due to their unique structure and good physiochemical properties. As a biomimetic nanomaterial, mesoporous polydopamine (MPDA) possesses both a superior nature and good compatibility, endowing it with good clinical transformation prospects compared with other inorganic mesoporous nanocarriers. However, the subacute toxicity and underlying mechanisms of biomimetic mesoporous polydopamine nanoparticles remain uncertain. Herein, we prepared MPDAs by a soft template method and evaluated their primary physiochemical properties and metabolite toxicity, as well as potential mechanisms. The results demonstrated that MPDA injection at low (3.61 mg/kg) and medium doses (10.87 mg/kg) did not significantly change the body weight, organ index or routine blood parameters. In contrast, high-dose MPDA injection (78.57 mg/kg) is associated with disturbances in the gut microbiota, activation of inflammatory pathways through the abnormal metabolism of bile acids and unsaturated fatty acids, and potential oxidative stress injury. In sum, the MPDA dose applied should be controlled during the treatment. This study first provides a systematic evaluation of metabolite toxicity and related mechanisms for MPDA-based nanoparticles, filling the gap between their research and clinical transformation as a drug delivery nanoplatform.
Topics: Biomimetics; Nanoparticles; Diazonium Compounds
PubMed: 37807046
DOI: 10.1186/s12989-023-00548-4 -
Angewandte Chemie (International Ed. in... Jan 2020Diazomethane is one of the most versatile reagents in organic synthesis, but its utility is limited by its hazardous nature. Although alternative methods exist to...
Diazomethane is one of the most versatile reagents in organic synthesis, but its utility is limited by its hazardous nature. Although alternative methods exist to perform the unique chemistry of diazomethane, these suffer from diminished reactivity and/or correspondingly harsher conditions. Herein, we describe the repurposing of imidazotetrazines (such as temozolomide, TMZ, the standard of care for glioblastoma) for use as synthetic precursors of alkyl diazonium reagents. TMZ was employed to conduct esterifications and metal-catalyzed cyclopropanations, and results show that methyl ester formation from a wide variety of substrates is especially efficient and operationally simple. TMZ is a commercially available solid that is non-explosive and non-toxic, and should find broad utility as a replacement for diazomethane.
Topics: Antineoplastic Agents; Cyclopropanes; Diazomethane; Esterification; Humans; Models, Molecular; Nitrogen Mustard Compounds
PubMed: 31793158
DOI: 10.1002/anie.201911896 -
Angewandte Chemie (International Ed. in... May 2020Expanding the toolbox of C-H functionalization reactions applicable to the late-stage modification of complex molecules is of interest in medicinal chemistry, wherein...
Expanding the toolbox of C-H functionalization reactions applicable to the late-stage modification of complex molecules is of interest in medicinal chemistry, wherein the preparation of structural variants of known pharmacophores is a key strategy for drug development. One manifold for the functionalization of aromatic molecules utilizes diazo compounds and a transition-metal catalyst to generate a metallocarbene species, which is capable of direct insertion into an aromatic C-H bond. However, these high-energy intermediates can often require directing groups or a large excess of substrate to achieve efficient and selective reactivity. Herein, we report that arene cation radicals generated by organic photoredox catalysis engage in formal C-H functionalization reactions with diazoacetate derivatives, furnishing sp -sp coupled products with moderate-to-good regioselectivity. In contrast to previous methods utilizing metallocarbene intermediates, this transformation does not proceed via a carbene intermediate, nor does it require the presence of a transition-metal catalyst.
Topics: Alkylation; Catalysis; Cations; Diazonium Compounds; Drug Development; Free Radicals; Hydrocarbons, Aromatic; Metals; Methane; Photochemistry
PubMed: 32068943
DOI: 10.1002/anie.202000684 -
RSC Advances Dec 2022Cinnamic acids are an important class of phenolic compounds, which have many beneficial effects on human health but are also interesting synthetic intermediates thanks...
Cinnamic acids are an important class of phenolic compounds, which have many beneficial effects on human health but are also interesting synthetic intermediates thanks to the presence of several reactive sites. While studying the reactivity of cinnamic acids with diazonium salts from aromatic amines, an unexpected reactivity has been discovered, leading to the formation of 1,2-diaza-1,3-dienes instead of traditional diazo-coupling products. The new compounds have been fully characterized by mono and bidimensional NMR spectroscopy and mass spectrometry. Preliminary studies on the biological activity of the compounds have been carried out testing both their antibacterial and antitumor activity, leading to promising results.
PubMed: 36605622
DOI: 10.1039/d2ra07515f -
Journal of the American Chemical Society Aug 2017Chemoselective modification of complex biomolecules has become a cornerstone of chemical biology. Despite the exciting developments of the past two decades, the demand...
Chemoselective modification of complex biomolecules has become a cornerstone of chemical biology. Despite the exciting developments of the past two decades, the demand for new chemoselective reactions with unique abilities, and those compatible with existing chemistries for concurrent multisite-directed labeling, remains high. Here we show that 5-hydroxyindoles exhibit remarkably high reactivity toward aromatic diazonium ions and this reaction can be used to chemoselectively label proteins. We have previously genetically encoded the noncanonical amino acid 5-hydroxytryptophan in both E. coli and eukaryotes, enabling efficient site-specific incorporation of 5-hydroxyindole into virtually any protein. The 5-hydroxytryptophan residue was shown to allow rapid, chemoselective protein modification using the azo-coupling reaction, and the utility of this bioconjugation strategy was further illustrated by generating a functional antibody-fluorophore conjugate. Although the resulting azo-linkage is otherwise stable, we show that it can be efficiently cleaved upon treatment with dithionite. Our work establishes a unique chemoselective "unclickable" bioconjugation strategy to site-specifically modify proteins expressed in both bacteria and eukaryotes.
Topics: 5-Hydroxytryptophan; Animals; Azo Compounds; Bacterial Proteins; Cell Line; Click Chemistry; Escherichia coli; Fluorescent Dyes; Humans; Immunoconjugates; Indoles; Models, Molecular; Proteins; Staining and Labeling
PubMed: 28787141
DOI: 10.1021/jacs.7b05125 -
Journal of Experimental Botany Oct 2019Light-dependent seed germination is induced by gibberellins (GA) and inhibited by abscisic acid (ABA). The widely accepted view of the GA/ABA ratio controlling...
Light-dependent seed germination is induced by gibberellins (GA) and inhibited by abscisic acid (ABA). The widely accepted view of the GA/ABA ratio controlling germination does not, however, explain the fact that seeds deficient in ABA still germinate poorly under shade conditions that repress germination. In Arabidopsis, MOTHER-OF-FT-AND-TFL1 (MFT) acts as a key negative regulator of germination, modulating GA and ABA responses under shade conditions. Under full light the oxylipin cis-12-oxo-phytodienoic acid (OPDA), a precursor of the stress-related phytohormone jasmonic acid, interacts with ABA and MFT to repress germination. Here, we show that under shade conditions both OPDA and ABA repress germination to varying extents. We demonstrate that the level of shade-induced MFT expression influences the ability of OPDA and/or ABA to fully repress germination. We also found that MFT expression decreases with seed age and this again correlates with the response of seeds to OPDA and ABA. We conclude that OPDA plays an essential role alongside ABA in repressing germination in response to shade and the combined effect of these phytohormones is integrated to a significant extent through MFT.
Topics: Abscisic Acid; Arabidopsis; Arabidopsis Proteins; Cyclopentanes; Diazonium Compounds; Gene Expression Regulation, Plant; Germination; Gibberellins; Light; Oxylipins; Plant Growth Regulators; Pyridines; Seeds
PubMed: 31326997
DOI: 10.1093/jxb/erz337