Molecular structure, spectroscopic, solvatochromic, dyeing performance and biological evaluations of heterocyclic azo dye, 4-[(E)-(4-hydroxy-2-methylphenyl)diazenyl]-1,5-dimethyl-2-phenyl-1,2-dihydro-3H-pyrazol-3-one

The exploring AI-generated pyrazalone derivatives as antifungal agents: Bringing together molecular docking and quantum chemical approaches

Candida albicans, an opportunistic fungal pathogen, is the most prevalent species among the twenty types of Candida responsible for candidiasis in humans. The condition is characterized by symptoms such as itching, redness, skin rashes, fever, septic shock, and infections of mucous membranes. This study explores the potential of pyrazolones and their AI-generated derivatives as effective treatments for these fungal infections. We conducted molecular docking, quantum molecular simulations, drug-likeness study, spectroscopic analysis, electrostatic potential analysis, and topological analysis to evaluate the potential of these derivatives as effective pharmaceuticals alongside molecular dynamics (MD) simulations. Our results show that several of these derivatives bind strongly to the target protein N-myristoyl transferase (NMT), showing a range of binding energies from -9.2 to -9.8 kcal/mol. Further insights revealed that D1 interacts with the NMT protein through two hydrogen-bonding residues HIS-227 and LEU-355, while D2 forms hydrogen bonds with ASP-110 and VAL-108. The ADMET profiling performed using the pkCSM platform identified D1 as a lead candidate, exhibiting optimal intestinal absorption and a maximum total clearance rate, which aligns with the criteria for drug-likeness and therapeutic viability. Additionally, our results showed that these derivatives had stronger binding affinities as compared to the parent compound. Molecular dynamics simulations of selected complexes (D1, D2, D5, and D6) over 120 ns demonstrated their structural stability and dynamic flexibility, as indicated by metrics encompassing root mean square fluctuation (RMSF), root mean square deviation (RMSD), radius of gyration (Rg), and solvent accessible surface area (SASA). The values of RMSD, remaining well within the permissible 4 Å threshold, reflect minimal structural fluctuation, that support the concept of stable complexes during the simulation. Quantum chemical calculations revealed that D1 and D4 had enhanced reactivity, which may improve their ability to interact with biological targets. This study also compared experimental and theoretical approaches to analyzing the properties of the parent compound. Our computational findings demonstrate that derivatives D1 and D2 exhibit strong binding to NMT, a validated antifungal target, with interactions critical for disrupting fungal cell viability. ADMET profiling further identifies D1 as a promising lead with favorable pharmacokinetics, suggesting its potential to inhibit Candida albicans growth in vivo. These results position our derivatives as biologically relevant candidates for experimental validation, advancing the development of novel antifungal therapies.

Nonlinear optical properties of azo sulfonamide derivatives

CONTEXT

The present work deals with the linear and nonlinear optical properties such as the dipole moment, polarizability, total hyperpolarizability, electric field-induced second harmonic generation, and hyper-Rayleigh scattering first hyperpolarizability of four heterocyclic azo compounds containing the sulfonamide group considered promise in nonlinear optic. The obtained polarizability and hyperpolarizability were supported by the frontier molecular orbital analysis. The properties have been effectively estimated and thoroughly examined to shed light on the nonlinear optical activity based on the density functional theory. The observed results show a high total first hyperpolarizability β tot up to 2503 a.u. and a low energy gap E g less than 1.41 eV. An inverse relationship has been obtained between the β tot and E g . The calculated E g values confirm that charge occurs within the azo sulfonamides. The new study provides a promising avenue for the development of these azo sulfonamides as novel NLO materials.

METHODS

The molecular modeling and the theoretical studies were performed with Gaussian software packages. The B3LYP/6-311 + G** level was used for optimization. All the linear and nonlinear optical properties reported here are obtained using the DFT. The optimized structures and their frontier molecular orbitals were plotted using the GaussView 5.1 program.

Determination of water content in dimethyl sulfoxide/N,N-dimethyl formamide and methanol content in ethanol by solvatochromism of azo dye, 2-(tert-butyl)-4-methoxy-6-(naphthalen-1-yldiazenyl) phenol

A novel 2-(tert-butyl)-4-methoxy-6-(naphthalen-1-yldiazenyl)phenol (NAP) was synthesized by coupling reaction of 2-tert-butyl-4-methoxyphenol with diazotized naphthylamine as diazo component. The azo dye was characterized by NMR, FT-IR and UV-vis spectroscopic techniques. The visible spectrum of NAP was recorded in different solvents and at different pHs. NAP exhibited a large wavelength shift with increasing solvent polarity, showing significant color change over a wide range in different solvents. The determination of water content in organic solvents miscible with water such as dimethyl sulfoxide (DMSO)/N,N-dimethyl formamide (DMF) and methanol content in ethanol, which is also a common mixture were investigated with NAP which is azo dye. The present reported solvatochromic compound for the determination of water content in DMSO/DMF and methanol content in ethanol showed a fairly wide linear range compared to some previously reported solvatochromic compounds in the literature. In addition, the solvatochromism of NAP allows the determination of methanol content in ethanol, which has caused many deaths, with a fast, cheap and easy method.

Spectral deconvolution associated to the Gaussian fit as a tool for the optimization of photovoltaic electrocoagulation applied in the treatment of textile dyes

The objective of this study was to investigate the color removal in a binary mixture of azo dyes from the photovoltaic electrocoagulation (EC) technique, using spectral deconvolution and the Gaussian fit for qualitative and quantitative determination of the physical color parameter. Initially, a conventional energy source was used to feed the EC reactor and the experimental design was conducted according to the Rotational Central Compound Design (RCCD). The spectral deconvolution method associated to the Gaussian fit aided in the description of the composition of the sample matrix, In the first step, through the Analysis of Variance, the RCCD and the three-dimensional surface response graphs, the optimized operating conditions were identified, which corresponded to 1320 A m^-2 with an reaction time of 16.6 min, and an expected removal of 98.40% for Scarlet Red (SR) dye and 1160 A m^-2 with a run time of 15.7 min and 97.9% removal for Turquoise Blue (TB) dye. Using the photovoltaic module as the power source of the EC reactor, a maximum removal of 97 ± 0.43% for TB dye and 98% ± 0.81 for SR was obtained. The results encourage the applicability of photovoltaic module-fed EC technology as a promising alternative for the treatment of effluents containing textile dyes, as well as the use of the spectral deconvolution method associated with the Gaussian fit, for the reliability and precision of the results.