Solvent, substituents and pH effects towards the spectral shifts of some highly colored indicators

Masoud, Mamdouh S.; Elsamra, Rehab M. I.; Hemdan, Sokaina Saad

doi:10.2298/jsc170204032m

Cited by 29 publications

(24 citation statements)

References 24 publications

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“…Of 15 possible NFκB dimers, the predominant mediator of NFκB inflammatory gene expression is the ubiquitous RelA:p50 heterodimer (1). At rest, inhibitors of κB (IκB)s sequester RelA:p50 in the cytoplasm by masking its DNA binding region and nuclear localization signal (5–7). In response to stimuli, IκBs are phosphorylated by IκB kinase (IKK), which triggers their ubiquitination and proteolysis (8, 9).…”

Section: Introductionmentioning

confidence: 99%

Signaling Crosstalk Mechanisms That May Fine-Tune Pathogen-Responsive NFκB

Adelaja

Hoffmann

2019

Front. Immunol.

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Precise control of inflammatory gene expression is critical for effective host defense without excessive tissue damage. The principal regulator of inflammatory gene expression is nuclear factor kappa B (NFκB), a transcription factor. Nuclear NFκB activity is controlled by IκB proteins, whose stimulus-responsive degradation and re-synthesis provide for transient or dynamic regulation. The IκB-NFκB signaling module receives input signals from a variety of pathogen sensors, such as toll-like receptors (TLRs). The molecular components and mechanisms of NFκB signaling are well-understood and have been reviewed elsewhere in detail. Here we review the molecular mechanisms that mediate cross-regulation of TLR-IκB-NFκB signal transduction by signaling pathways that do not activate NFκB themselves, such as interferon signaling pathways. We distinguish between potential regulatory crosstalk mechanisms that (i) occur proximal to TLRs and thus may have stimulus-specific effects, (ii) affect the core IκB-NFκB signaling module to modulate NFκB activation in response to several stimuli. We review some well-documented examples of molecular crosstalk mechanisms and indicate other potential mechanisms whose physiological roles require further study.

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Section: Introductionmentioning

confidence: 99%

Signaling Crosstalk Mechanisms That May Fine-Tune Pathogen-Responsive NFκB

Adelaja

Hoffmann

2019

Front. Immunol.

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“…The shorter wavelength band in the UV region of 247–326 nm was ascribed mainly to the π–π* transition of the aromatic system present in the structure of the studied dyes. The second band observed in the region of 335–635 nm ( Figure 1 a) was assigned to n–π* transition with a considerable charge-transfer character (CT transition) [ 61 ]. The charge-transfer nature of this band was deduced from its broadness, as from the sensitivity of its λ max to the type of substituent attached to the azo coupler [ 62 ].…”

Section: Resultsmentioning

confidence: 99%

Substituent and Solvent Polarity on the Spectroscopic Properties in Azo Derivatives of 2-Hydroxynaphthalene and Their Difluoroboranes Complexes

Skotnicka

Czeleń

2021

Materials

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Novel fluorescent dyes such as difluoroborane complexes of 1-phenylazonaphthalen-2-ol derivatives were successfully synthesized and characterized with a focus on the influence of a substituent and a solvent on the basic photophysical properties. 1H, 11B, 13C, 15N, and 19F nuclear magnetic resonance (NMR) spectra of substituted 1-phenylazonaphthalen-2-ol difluoroboranes and their parent azo dyes were recorded and discussed. The absorption and emission properties of synthesized compounds were investigated in solvents of varying polarity. They were found to be fluorescent despite the presence of the azo group. The azo group rotation was blocked by complexing with -BF2 to get a red shift in absorption. Solvent-dependent spectral properties of compounds were investigated using Lipper-Mataga and Bakhshiev plot. The calculated DFT energies and Frontier Molecular Orbitals calculations of the studied compounds were proved to be consistent with the experimental observations.

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“…All compounds possess an azo group conjugated to two arenes. The trans azo isomer possesses a lower steric hindrance compared to the cis isomer with possible azo-hydrazone tautomerism (15) .…”

Section: Resultsmentioning

confidence: 99%

“…The Kamlet-Taft's Eq. (3) (15) was used in order to describe in this case the overall solvent effects. Eq.…”

Section: Solvatochromism Polarity Scales Collerations Kamlet-taft's Methodsmentioning

confidence: 99%

Solvatochromism Effect Studies on Electronic Absorption Spectral of Some Hydroxy Tolyl Azo Benzaldehyde dyes.

Jebaly¹

2017

Journal of Natural Sciences, Life and Applied Sciences

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The electronic absorption spectra of some prepared substituted aryl azo compounds were recorded in organic solvents of different polarities. The electronic transitions are assigned. The solvents and substituents effects on the spectral behaviour are studied and interpreted. The solvent induced spectral effects have been analyzed using multiple linear regression technique. The Kamlet-Taft and Catalan’s solvent scales were found to be the most suitable for describing the solvatochromic shifts of the absorption spectra. The solute–solvent interactions were determined based on multilinear solvation energy relationships concept. The phenomena of tautomersim were discussed with the possibility of forming intra and intermolecular hydrogen bonds.

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Solvent, substituents and pH effects towards the spectral shifts of some highly colored indicators

Cited by 29 publications

References 24 publications

Signaling Crosstalk Mechanisms That May Fine-Tune Pathogen-Responsive NFκB

Signaling Crosstalk Mechanisms That May Fine-Tune Pathogen-Responsive NFκB

Substituent and Solvent Polarity on the Spectroscopic Properties in Azo Derivatives of 2-Hydroxynaphthalene and Their Difluoroboranes Complexes

Solvatochromism Effect Studies on Electronic Absorption Spectral of Some Hydroxy Tolyl Azo Benzaldehyde dyes.

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