Coumarin-Benzothiazole Based Azo Dyes: Synthesis, Characterization, Computational, Photophysical and Biological Studies

Formulating Reduced Density Gradient Approaches for Noncovalent Interactions

This work elucidates several forms of reduced electron density gradient (RDG) to describe noncovalent interactions (NCIs). By interpreting the RDG as a local moment function, we systematically leveraged Weizacker's and Fermi's local moments. This resulted in high-fidelity RDG representations consistent with the NCI analysis. In addition, the RDG version derived from the Lagrangian kinetic energy density is conveniently normalized. These results suggest the nonexistence of a particular RDG formulation when performing NCI analysis. Thus, an in-depth examination of the theoretical foundations connecting the RDG function with the nature of noncovalent interactions is necessary.

In silico drug design strategies for discovering novel tuberculosis therapeutics

INTRODUCTION

Tuberculosis remains a significant concern in global public health due to its intricate biology and propensity for developing antibiotic resistance. Discovering new drugs is a protracted and expensive endeavor, often spanning over a decade and incurring costs in the billions. However, computer-aided drug design (CADD) has surfaced as a nimbler and more cost-effective alternative. CADD tools enable us to decipher the interactions between therapeutic targets and novel drugs, making them invaluable in the quest for new tuberculosis treatments.

AREAS COVERED

In this review, the authors explore recent advancements in tuberculosis drug discovery enabled by in silico tools. The main objectives of this review article are to highlight emerging drug candidates identified through in silico methods and to provide an update on the therapeutic targets associated with Mycobacterium tuberculosis.

EXPERT OPINION

These in silico methods have not only streamlined the drug discovery process but also opened up new horizons for finding novel drug candidates and repositioning existing ones. The continued advancements in these fields hold great promise for more efficient, ethical, and successful drug development in the future.

Unraveling the crystal structure, stability and drug likeness of 1,3,4-oxadiazole derivatives against Myelofibrosis: a combined experimental and computational investigation

Herein, we report the synthesis and characterization of novel 1,3,4-oxadiazole derivatives, 2-methoxybenzyl 5-(4-chlorophenyl)-1,3,4-oxadiazole-2-carboxylate (C1) 2-methoxybenzyl 5-(2-chlorophenyl)-1,3,4-oxadiazole-2-carboxylate (C2), and methoxybenzyl 5-(3-chlorophenyl)-1,3,4-oxadiazole-2-carboxylate (C3) obtained through desulfurative cyclization reaction. The compound C2 was crystallized, and its crystal structure was elucidated using single-crystal X-ray diffraction technique. The Hirshfeld surface analysis was carried out to analyze, visualize and globally appreciate the weak interactions involved in crystal packing. These analyses were complemented by Quantum Theory of Atoms In Molecules (QTAIM) and Reduced Density Gradient (RDG), which allowed us to decipher the nature and types of attractive forces that contribute to maintain the crystal structure of the titled compound. Moreover, the ADME profile of the compound was predicted to assess its drug likeness. Finally, in silico studies were performed to explore the binding affinity of the compounds (C1-3) against Myelofibrosis through molecular docking and molecular dynamic simulations.Communicated by Ramaswamy H. Sarma.

Recent advances in the synthesis of new benzothiazole based anti-tubercular compounds

This review highlights the recent synthetic developments of benzothiazole based anti-tubercular compounds and their in vitro and in vivo activity. The inhibitory concentrations of the newly synthesized molecules were compared with the standard reference drugs. The better inhibition potency was found in new benzothiazole derivatives against M. tuberculosis. Synthesis of benzothiazole derivatives was achieved through various synthetic pathways including diazo-coupling, Knoevenagel condensation, Biginelli reaction, molecular hybridization techniques, microwave irradiation, one-pot multicomponent reactions etc. Other than recent synthetic developments, mechanism of resistance of anti-TB drugs is also incorporated in this review. Structure activity relationships of the new benzothiazole derivatives along with the molecular docking studies of selected compounds have been discussed against the target DprE1 in search of a potent inhibitor with enhanced anti-tubercular activity.

Combination of smartphone digital image colorimetry and UV-Vis spectrophotometry as detection systems with solidified floating organic drop microextraction as preconcentration method for the quantification of methyl red in wastewater samples

In this study, a portable smartphone-based digital image colorimetric system (SDIC) was designed and integrated with a solidified floating organic drop microextraction method (SFODME) for the quantification of methyl red in textile wastewater samples. The RGB (red, green, and blue) data were evaluated for each captured image, and the green channel was selected for quantification due to its linear response for the analyte. Under optimal conditions, an acceptable linear range was recorded for the analyte. The proposed method recorded a limit of detection (LOD) value of 0.046 mg/L. The developed microextraction method was also combined with UV-Vis spectrophotometry, which recorded an LOD value of 0.012 mg/L. Real sample analysis was carried out with textile wastewater samples to check the applicability/accuracy of the developed method, using a matrix matching calibration strategy to enhance quantification accuracy. Satisfactory percent recoveries in the range of 93.3%-114.3% and 92%-92.7% were recorded for the SFODME-SDIC and SFODME-UV methods, respectively.

Synthesis, computational study, solvatochromism and biological studies of thiazole-owing hydrazone derivatives

In the present work, we have synthesized thiazole-hydrazone conjugates 5(a–h) and characterized them using various analytical techniques such as UV, IR, NMR, and mass spectrometry. Solvatochromic properties were evaluated in ten solvents with different polarity and quantum chemical parameters using a DFT study. The antibacterial activity results revealed that compounds 5c, 5d and 5g exhibited good efficacy and that the remaining compounds displayed significant activity. The synthesized compounds were screened for their cytotoxic activity against HepG2 and MCF-7 cell lines, and all the synthesized compounds exhibited significant potency towards the screened cancer cell lines. The anti-inflammatory efficacy of the synthesized thiazole derivatives was determined against MMP-2 and MMP-9, and some of the compounds showed significant activity. Furthermore, the in silico molecular docking was performed with the COX-2 receptor.

Preparation of magnetic Co–Fe layered double hydroxides and its adsorption properties for the removal of methyl orange

In this study, Co–Fe layered double hydroxides are prepared by a hydrothermal method. The Co–Fe layered double hydroxides are used as an adsorbent for the investigation of the thermodynamic parameters and adsorption kinetics of methyl orange from aqueous solution. The results show that adsorption is affected by adsorbent dosage, adsorption time, and temperature. The characteristics of samples are investigated using X-ray powder diffraction, scanning electron microscopy, Fourier-transform infrared spectroscopy, and N2 adsorption–desorption isotherms. The adsorption saturation level of Co–Fe layered double hydroxides on methyl orange is studied, with the results showing that the maximum uptake capacity for methyl orange is 10.21 mg g−1 based on Co–Fe layered double hydroxides. The adsorption kinetics of methyl orange is consistent with the Temkin isotherm equation and quasi-secondary kinetic model. Furthermore, separation is easily accomplished under the action of an applied magnetic field. The prepared Co–Fe layered double hydroxides can be applied as an effective adsorbent for decontamination of anionic dyes in industrial effluents.

A Coumarin-azo Derived Colorimetric Chemosensor for Hg2+ Detection in Organic and Aqueous Media and its Extended Real-world Applications

Pollution caused by the release of toxic heavy metals into the environment by industrial and farming processes has been regarded as a major problem worldwide. This has attracted a great deal of attention into restoration and remediation. Mercury is classified as a toxic heavy metal which has posed significant challenges to public and environmental health. To date, conventional methods for mercury detection rely on expensive, destructive, complex, and highly specialized methods. Evidently, there is a need to develop systems capable of easily identifying and quantifying mercury within the environment. In this way, organic-based colorimetric chemosensors are gaining increasing popularity due to their high sensitivity, selectivity, cost-effectiveness, ease of design, naked-eye, and on-site detection ability. The formation of coumarin-azo derivative AD1 was carried out by a conventional diazotization reaction with coumarin-amine 1c and N,N-dimethylaniline. Sensor AD1 displayed remarkable visual colour change upon mercury addition with appreciable selectivity and sensitivity. The detection limit was calculated as 0.24 µM. Additionally, the reversible nature of AD1 allowed for the construction of an IMPLICATION type logic gate and Molecular Keypad Lock. Chemosensor AD1 displayed further sensing applications in real-world water samples and towards on-site assay methods. Herein, we describe a coumarin-derived chemosensor bearing an azo (N = N) functionality for the colorimetric and quantitative determination of Hg²⁺ in organic and aqueous media.

(E)-3-(2-(4-methylthiazol-2-yl)hydrazineylidene)chromane-2,4-dione

(E)-3-(2-(4-methylthiazol-2-yl)hydrazineylidene)chromane-2,4-dione was synthesized for the first time and the compound was characterized by 1H and 13C spectroscopy, IR spectroscopy, and UV-Vis. The chemical structure and isomeric configuration of the molecule were confirmed by single-crystal X-ray diffraction.

Coumarin-pyridone conjugate as a fluorescent tag for LFPs visualization and electrochemical sensor for nitrite detection

In this work, a D–π–A based coumarin–pyridone conjugate (CPC) was synthesised by a one-pot multicomponent reaction and the structure was proven from infrared and nuclear magnetic resonance spectroscopies and high-resolution mass spectrometry.

Synthesis and pharmacological activities of azo dye derivatives incorporating heterocyclic scaffolds: a review

Nowadays, there is significant interest in the synthesis of heterocycle-incorporated azo dye derivatives as potential scaffolds in the pharmaceutical sector. The pharmaceutical or drug industries need a simplistic synthesis approach that can afford a wide range of azo dye derivatives. The incorporation of the heterocyclic moiety into the azo dye scaffold has improved the bioactive properties of the target derivatives. The various biological and pharmacological applications of drugs such as anti-fungal, anti-tuberculosis, anti-viral, anti-inflammatory, anti-cancer, anti-bacterial, DNA binding, and analgesic properties can be easily tuned by introducing heterocyclic moieties. To date, continuous efforts are being made in the search for more potent, new, and safe synthetic methodologies for azo dye derivatives. This review presents a brief discussion of the facile synthetic approaches and the relevance of the title compound and its derivatives towards various biological activities. Thus, the synthesis of azo dye derivatives incorporating heterocyclic scaffolds such as imidazole, pyrazole, thiazole, oxazolone, thiophene, pyrrole, benzothiazole and quinoline moieties and their pharmacological applications are discussed briefly.

Nowadays, there is significant interest in the synthesis of heterocycle-incorporated azo dye derivatives as potential scaffolds in the pharmaceutical sector.