Synthesis, structural investigations and in vitro biological evaluation of N, N-dimethyl aniline derivatives based azo dyes as potential pharmacological agents

A Comprehensive Examination of Heterocyclic Scaffold Chemistry for Antitubercular Activity

Tuberculosis is a communicable disease which affects humans particularly the lungs and is transmitted mainly through air. Despite two decades of intensive research aimed at understanding and combating tuberculosis, persistent biological uncertainties continue to hinder progress. Nowadays, heterocyclic compounds have proven themselves in effective treatment of tuberculosis because of their wide range of biological and pharmacological activities. Antituberculosis or antimycobacterial agents encompass a broad array of compounds utilized singly or in conjunction to combat Mycobacterium infections, spanning from tuberculosis to leprosy. Here, we summarize the synthesis of various heterocyclic compounds which includes the greener synthetic route as well as use of nano compounds as catalyst along with their anti TB activities.

Tailoring selective triclosan azo-adducts: Design, synthesis, and anti-mycobacterial evaluation

A series of triclosan azo-adducts were synthesized to investigate their structure-activity relationship against Mycobacterium tuberculosis and non-tuberculous mycobacteria. The series' most potent compound was four and sixteen times more active than triclosan and rifabutin against drug-resistant Mycobacterium abscessus, respectively, while being less cytotoxic to human macrophages than triclosan on day one. Additionally, one of the azo-adducts was twice as efficient against M. tuberculosis as triclosan and twice as effective against Mycobacterium marinum as isoniazid. Furthermore, the synthesized azo-adducts were equally effective against M. abscessus strains overexpressing InhA, suggesting that these compounds work through a distinct mechanism.

In Silico and In Vitro Studies of Novel Azomethines on DNA Repair Genes in Gastric Cell Lines

We herein report the determination of the cytotoxic activity and expression profiles of some DNA repair genes of newly synthesized azomethines in the gastric cancer cell line (AGS). The studied novel compounds were synthesized by a condensation reaction and received compounds were characterized by 1H and 13C NMR spectroscopy methods. Furthermore, they were applied to the AGS cell line at eight different concentrations (0.1-50 µg/mL). Anticancer activities were determined using the MTT method. Expression levels of ATR, ERCC1, TOP2A, and ABCB1 genes were determined by the RT-PCR method. Biochemical parameters were also examined. The interaction of proteins with other proteins was investigated with the String v11 program. The IC50 values of compounds 1, 2, and 3 obtained after 72 h were 23.10, 8.93, and 1.58 µg/mL, respectively. The results demonstrate that the cytotoxic activity of compound 3 on AGS cancer cells is higher in comparison with other molecules. It was determined that the expression levels of ATR, TOP2A, and ABCB1 genes in compounds 1, 2, and 3 were decreased compared to the control group. In addition, it was determined that ERCC1 gene expression increased in compound 3, decreased in compound 2, and remained unchanged in compound 1 (p < 0.001). In AGS gastric cancer cells, a 64% decrease was detected for GST levels in compound 1, while a 38% decrease in GSH levels in compound 2. In addition, compounds 1-3 were examined at the molecular level with computational techniques and the docking studies revealed 4LN0 as a target protein.

Investigation on intermolecular interaction of synthesized azo dyes with bovine serum albumin

This research was performed using spectroscopic techniques and molecular docking to elucidate the mechanisms of interaction between bovine serum albumin (BSA) and two novel synthesized azo dyes. The titration of dyes into BSA solution results in quenching of fluorescence emission by complex formation. The UV-Vis spectroscopy confirms that formation of complex in ground state between both dyes and BSA induces conformational and micro environmental changes of the protein. Based on the calculation of the thermodynamic parameters, it can be concluded that both dyes spontaneously bind onto BSA, and van der Waals force and hydrogen bonding interaction played a predominant roles in the process of spontaneous bonding. The average binding distance (r) between protein and both dyes was calculated by Förster energy transfer measurements and revealed both dyes bind to the BSA residues of tryptophan over short distances. The results of molecular docking studies indicated that the probable binding location of both dyes is subdomain IB of BSA via hydrophobic interaction and hydrogen bond. Furthermore, as shown by synchronous fluorescence and Fourier transform infrared spectroscopy, both dyes can lead to conformational changes of BSA, which alter its biological functions.Communicated by Ramaswamy H. Sarma.

Binding elucidation of azo dyes with human serum albumin via spectroscopic approaches and molecular docking techniques

The large number of synthesized azo dyes is widely applied in the food, pharmaceutical, cosmetic, textile, and leather industries. In this study, the binding mechanism of two synthesized dyes with human serum albumin (HSA); as the most abundant protein in plasma; was elucidated by fluorescence spectroscopy, Fourier-transform infrared spectroscopy and molecular modeling methods. The fluorescence quenching measurements showed that each dye can quench the intrinsic fluorescence of HSA via a dynamic quenching mechanism with an increase in concentration. From the thermodynamic data observations, revealed that the binding process is a spontaneous molecular force for each dye with HSA due to hydrophobic interactions and hydrogen bonding. FT-IR spectra showed that the secondary structure of the protein changes due to interaction of each dye with HSA. Furthermore, docking simulation demonstrated that the probable binding location of both dyes is subdomain IIA of HSA (Sudlow site I) and that complex formed is stabilized by hydrophobic interactions and hydrogen bonding.Communicated by Ramaswamy H. Sarma.

Multi technique investigation on interaction between 5-(2-thiazolylazo)-2,4,6-triaminopyrimidine and HSA and BSA

In research laboratories and in various industries, azo compounds are among the most effective and commonly used organic dyes. The association between human (HSA) and bovine (BSA) serum albumins with 5-(2-thiazolylazo)-2,4,6-triaminopyrimidine (TTP) was investigated in this research using spectroscopy methods and molecular modeling study. The fluorescence quenching results showed that the quenching mechanisms were static and dynamic processes for HSA and BSA, respectively. From the thermodynamic observations, it is clear that the binding process is a spontaneous molecular interaction, in which van der Waals and hydrogen bonding interactions for HSA and hydrophobic interaction for BSA play the major roles. According to Förster energy transfer, non-radiative energy transferred from HSA and BSA to TTP, is provided by close distance (r₀) between TTP and Trp residues of HSA and BSA. The synchronous fluorescence spectroscopy, FT-IR findings and UV-Vis absorption data confirm that TTP can induce conformational and micro environmental changes in both the proteins. Furthermore, docking results predicted the probable binding site of TTP in subdomain IIA of HSA and BSA molecules where Trp residues are located. Types of amino acid residues surrounding the TTP molecule supported that van der Waals forces, hydrophobic forces and electrostatic forces play important roles in stabilization of drug-protein complexes formed.Communicated by Ramaswamy H. Sarma.

Azobenzene as Antimicrobial Molecules

Azo molecules, characterized by the presence of a -N=N- double bond, are widely used in various fields due to their sensitivity to external stimuli, ch as light. The emergence of bacterial resistance has pushed research towards designing new antimicrobial molecules that are more efficient than those currently in use. Many authors have attempted to exploit the antimicrobial activity of azobenzene and to utilize their photoisomerization for selective control of the bioactivities of antimicrobial molecules, which is necessary for antibacterial therapy. This review will provide a systematic and consequential approach to coupling azobenzene moiety with active antimicrobial molecules and drugs, including small and large organic molecules, such as peptides. A selection of significant cutting-edge articles collected in recent years has been discussed, based on the structural pattern and antimicrobial performance, focusing especially on the photoactivity of azobenzene and the design of smart materials as the most targeted and desirable application.

Synthesis, characterization and biological investigations of potentially bioactive heterocyclic compounds containing 4-hydroxy coumarin

In this paper, we have reported the synthesis of a series of heterocyclic azo dyes containing 4-hydroxy coumarin by diazo-coupling reaction. The structural aspect of the newly synthesized compounds was accomplished by various physico-chemical techniques like UV-Visible, FT-IR, NMR, and mass spectrometry. The computational calculations and geometrical optimization of the newly synthesized azo dyes were investigated by using Gaussian software with the help of Density functional theory (DFT)/B3LYP method using 6-31G(d,p) basis set at gaseous phase. Also, the quantum chemical parameters were evaluated to understand the structural activity concept of the dyes. The pharmacological efficacy of the azo dyes was investigated by antimicrobial, antitubercular, DNA cleavage and in silico molecular docking studies. All the newly synthesized compounds were able to exhibit significant inhibitory activity against tested microbes. Further, the in silico molecular docking showed effective binding properties of the compounds against RpsA target receptor.