Synthesis, solvatochromic properties and biological evaluation of some novel azo-hydrazone tautomeric dyes

Inhibition of NF-кB Expression in LPS-Induced RAW264.7 Macrophage Cells by a Thiazolidinone Derivative (TZDOCH2CH3)

To date, various derivatives of thiazolidinone in a variety of cell lines have been investigated. The present study aimed to evaluate the toxicity and inhibitory effects of a thiazolidinone derivative called 5-(2,4-bis-4-ethoxy-phenyl azo)-3-hydroxy-benzylidine)-2,4-thiazolidinone (TZD-OCH2CH3) on the expression of NF-кB in LPS-induced RAW264.7 macrophage cell lines. Different concentrations of the MTT assay(0-120 μg/mL) were performed to estimate the biological rate of the cells. The half-maximal inhibitory concentration (IC50) of TZD-OCH2CH3-treated RAW264.7 cells was found to be 115 μg/mL. To determine the inhibitory effect of the synthesized compound on the expression changes of NF-кB, the RAW264.7cells were initially induced with LPS and then treated by 15, 30 and 60 μg/mL of TZD-OCH2CH3. Realtime PCR results confirmed a strong inhibitory effect of TZD-OCH2CH3 on the expression of NF-кB inLPS-induced RAW264.7 cells (IC50 = 48 μg/mL). Overall, these findings suggested that the derivative TZDOCH2CH3 had a significant anti-inflammatory effect.

Solvent polarity sensitive characteristics of various tautomers of azo compounds: Linear and nonlinear optical properties

Solvents as complex environments can induce considerable effects on the physical, chemical and biological properties of solute molecules. In this work, solvent polarity sensitive characteristics of two tautomers of different azo compounds were studied by using of spectroscopic and Z-scan techniques. In this case, nature and various molecular interactions contribution on the spectral behaviors of azo and hydrazone forms of selected samples were investigated by Kamlet-Abboud-Taft and Catalan models. Moreover, the obtained results of Z-scan indicate that self-defocusing, saturable and reverse saturable absorption features of azo dyes depend highly on substituents and molecular environment polarity characteristic. In this case, media polarity properties have the same effects on the third order nonlinear absorption coefficient and nonlinear refractive index values. Therefore, by measuring one of the third order nonlinear optical coefficients, it is possible to predict solvent polarity effects on the other nonlinear optical coefficient. The calculated dipole moments with high values in the molecular excited state also reveal the probability of molecular charge transfer characteristics. In this case, by excitation process, sample I indicate high dipole moment values in comparison to other samples. Therefore, the results can give useful information about the application of selected samples for designing various optical devices.

Classifications, properties, recent synthesis and applications of azo dyes

In this work, we have presented a very detailed review of the different classification of azo dyes as a function of the number of azo groups and the appropriate functional groups. Then we pointed out some chemical properties of these dyes such as reactivity, isomerization and tautomerism and listed. In the following, we have summarized some recent syntheses of azo dyes and the mechanism of azo dye/polymer conjugation. Finally, we indicate the principle of Gewald's reaction and its application to the synthesis of new azo dyes.

Study of interaction between ionic liquids and orange G in aqueous solution with UV-vis spectroscopy and conductivity meter

The interactions between Orange G (OG) with three kinds of ionic liquid surfactants (C₁₀mimBF₄, C₁₂mimBF₄, C₁₆mimBF₄) and CTAB were studied with UV-Vis spectra and conductivity measurements. The systematic changes in UV-Vis spectra with an increase of carbon-chain length may be observed in presence of OG. They correspond to CMC of every system, respectively, and the CMCs of four systems have exhibit the decrease of CMCs compared to pure surfactant. The binding constants are calculated from the results of conductivity measurements in the order of C₁₆mimBF₄>CTAB>C₁₂mimBF₄>C₁₀mimBF₄. Furthermore, system behaviors presented significant association of complex formation and micelles formation, i.e. the change in UV-Vis spectra before and after the formation of micelles in mixed systems. In addition, Fourier-transform infrared (FT-IR) spectroscopy and ¹H NMR analysis further confirmed that the complexes are formed by hydrogen bond and van der Waal force. These findings could provide scientific guidance for extraction and separation of dyes.

Novel push-pull heterocyclic azo disperse dyes containing piperazine moiety: Synthesis, spectral properties, antioxidant activity and dyeing performance on polyester fibers

Six novel push-pull azo disperse dyes were synthesized via classical azo coupling reaction using 2-amino-thiazolyl derivatives as the diazo components and 1-(4-bromobenzyl)-4-phenylpiperazine as a key coupling intermediate. The structures of the dyes and synthesized intermediate were confirmed by FT-IR, (1)H NMR, (13)C NMR and UV-vis analyses. The solvatochromic behavior of the dyes was studied in a set of 10 solvents of different polarity and considerable results were obtained. The prepared heterocyclic azo dyes were applied for dyeing polyester fibers and their dyeing properties were studied. The fastness properties of the dyed fabrics such as wash, light and rubbing fastness degrees were measured by standard methods. Investigation of antioxidant activity of compounds was carried out by ferric reducing antioxidant power (FRAP) method. The synthesized dyes exhibited significant antioxidant activities.