Structural and biological study of synthesized anthraquinone series of compounds with sulfonamide feature

Toxicity of anthraquinone derivatives in relation to non-linear optical properties and electron correlation

1,4-Dialkylamino -5,8-dihydroxy anthraquinones are investigated using density functional theory (DFT) and time-dependent DFT (TD-DFT) for their growth inhibitory potential. The frontier molecular orbital shows that the electron density is located at the anthraquinone core and at the substituents NH and OH in both HOMO as well as in LUMO. The chemical potential and electrophilicity index showed a direct relation, while hardness and hyperhardness had an inverse association with an energy gap. The results of the molecular docking analysis revealed that the anthraquinone molecules have a high affinity for the primary targets of the DNA topoisomerase IIα enzyme. The docking results showed good binding ability with extremely energetically stable scores ranging from -8.9 to -7.6 kcal/mol. Electron correlation descriptors showed a direct link with NLO properties and toxicity.

Drug Repositioning as a Therapeutic Strategy against Streptococcus pneumoniae: Cell Membrane as Potential Target

A collection of repurposing drugs (Prestwick Chemical Library) containing 1200 compounds was screened to investigate the drugs' antimicrobial effects against planktonic cultures of the respiratory pathogen Streptococcus pneumoniae. After four discrimination rounds, a set of seven compounds was finally selected, namely (i) clofilium tosylate; (ii) vanoxerine; (iii) mitoxantrone dihydrochloride; (iv) amiodarone hydrochloride; (v) tamoxifen citrate; (vi) terfenadine; and (vii) clomiphene citrate (Z, E). These molecules arrested pneumococcal growth in a liquid medium and induced a decrease in bacterial viability between 90.0% and 99.9% at 25 µM concentration, with minimal inhibitory concentrations (MICs) also in the micromolar range. Moreover, all compounds but mitoxantrone caused a remarkable increase in the permeability of the bacterial membrane and share a common, minimal chemical structure consisting of an aliphatic amine linked to a phenyl moiety via a short carbon/oxygen linker. These results open new possibilities to tackle pneumococcal disease through drug repositioning and provide clues for the design of novel membrane-targeted antimicrobials with a related chemical structure.

In vitro and in silico evaluation of N-(alkyl/aryl)-2-chloro-4-nitro-5- [(4-nitrophenyl)sulfamoyl]benzamide derivatives for antidiabetic potential using docking and molecular dynamic simulations

A series of N-(alkyl/aryl)-2-chloro-4-nitro-5-[(4-nitrophenyl)sulfamoyl]benzamide derivatives were synthesized and evaluated for its in vitro antidiabetic potential against α-glucosidase and α-amylase enzymes and also for its antimicrobial potential. Compounds N-(2-methyl-4-nitrophenyl)-2-chloro-4-nitro-5-[(4-nitrophenyl)sulfamoyl]benzamide and N-(2-methyl-5-nitrophenyl)-2-chloro-4-nitro-5-[(4-nitrophenyl)sulfamoyl]benzamide were found to be the most potent α-glucosidase and α-amylase inhibitors with IC₅₀ values of 10.13 and 1.52 µM, respectively. The docking results depicted reasonable dock score -10.2 to -8.0 kcal/mol (α-glucosidase), -11.1 to -8.3 kcal/mol (α-amylase) and binding interactions of synthesized molecules with respective targets with enzymes. During molecular dynamic simulations, analysis of RMSD of ligand protein complex suggested stability of the most active compound at binding site of target proteins. Compound N-(2-chloro-4-nitrophenyl)-2-chloro-4-nitro-5-[(4-nitrophenyl)sulfamoyl] benzamide showed antibacterial potential against Gram positive and Gram negative bacteria and compound N-(2-methyl-5-nitrophenyl)-2-chloro-4-nitro-5-[(4-nitrophenyl)sulfamoyl] benzamide showed excellent antifungal potential against Candida albicans and Aspergillus niger. The computational studies were also executed to predict the drug-likeness and ADMET properties of the title compounds. The N-(alkyl/aryl)-2-chloro-4-nitro-5-[(4-nitrophenyl)sulfamoyl]benzamide derivatives showed significant antidiabetic and antimicrobial potential which is equally supported by the molecular dynamic and docking studies. This study will prove useful in revealing the molecular structure and receptor target site details which can be further utilized for the development of newer active antidiabetic and antimicrobial agents.

Journey of anthraquinones as anticancer agents - a systematic review of recent literature

Anthraquinones are privileged chemical scaffolds that have been used for centuries in various therapeutic applications. The anthraquinone moiety forms the core of various anticancer agents. However, the emergence of drug-resistant cancers warrants the development of new anticancer agents. The research endeavours towards new anthraquinone-based compounds are increasing rapidly in recent years. They are used as a core chemical template to achieve structural modifications, resulting in the development of new anthraquinone-based compounds as promising anticancer agents. Mechanistically, most of the anthraquinone-based compounds inhibit cancer progression by targeting essential cellular proteins. Herein, we review new anthraquinone analogues that have been developed in recent years as anticancer agents. This includes a systematic review of the recent literature (2005-2021) on anthraquinone-based compounds in cell-based models and key target proteins such as kinases, topoisomerases, telomerases, matrix metalloproteinases and G-quadruplexes involved in the viability of cancer cells. In addition to this, the developments in PEG-based delivery of anthraquinones and the toxicity aspects of anthraquinone derivatives are also discussed. The review dispenses a compact background knowledge to understanding anthraquinones for future research on the expansion of anticancer therapeutics.

Thiophene-2-carboxamide derivatives of anthraquinone: A new potent antitumor chemotype

The anthraquinone scaffold has long been known as a source of efficacious antitumor drugs. In particular, the various chemical modifications of the side chains in this scaffold have yielded the compounds potent for the wild type tumor cells, their counterparts with molecular determinants of altered drug response, as well as in vivo settings. Further exploring the chemotype of anticancer heteroarene-fused anthraquinones, we herein demonstrate that derivative of anthra[2,3-b]thiophene-2-carboxamide, (compound 8) is highly potent against a panel of human tumor cell lines and their drug resistant variants. Treatment with submicromolar or low micromolar concentrations of 8 for only 30 min was sufficient to trigger lethal damage of K562 chronic myelogenous leukemia cells. Compound 8 (2.5 μM, 3-6 h) induced an apoptotic cell death as determined by concomitant activation of caspases 3 and 9, cleavage of poly(ADP-ribose) polymerase, increase of Annexin V/propidium iodide double stained cells, DNA fragmentation (subG1 fraction) and a decrease of mitochondrial membrane potential. Neither a significant interaction with double stranded DNA nor strong inhibition of the DNA dependent enzyme topoisomerase 1 by 8 were detectable in cell free systems. Laser scanning confocal microscopy revealed that some amount of 8 was detectable in mitochondria as early as 5 min after the addition to the cells; exposure for 1 h caused significant morphological changes and clustering of mitochondria. The bioisosteric analog 2 in which the thiophene ring was replaced with furan was less active although the patterns of cytotoxicity of both derivatives were similar. These results point at the specific role of the sulfur atom in the antitumor properties of carboxamide derivatives of heteroarene-fused anthraquinone.

Sulfonamide phenylalanine (SPA) series of analogues as an antibacterial, antifungal, anticancer agents along with p53 tumor suppressor-DNA complex inhibitor - part 1

A series of N-[1-benzyl-2-oxo-2-substituted(ethyl)] benzene/p-toluene sulfonamide (K1-K12) are synthesized. Structure of the synthesized analogues has been confirmed by FT-IR, ¹H & ¹³C NMR and ESI-MS spectroscopic techniques. All the synthesized analogues (K1-K12) have also been examined for their in-vitro antibacterial and antifungal activities. Compounds showed good antibacterial and antifungal activity against standard drug. Anticancer study has been carried out on three cancer cell lines PC-3, MCF-7 and A549 on two different concentrations (mg/mL and μg/mL). The K4 sulfonamide analogue showed better anticancer activity amongst all analogues against PC-3 and A549 cell lines. K4 inhibit G0/G1 phase in cell-cycle analysis experiment. All synthesized molecules (K1-K12) dock at junction p53-DNA and make hydrogen bonded with residues of p53 protein as per docking study. ADMET predictions of synthesized phenylalanine sulfonamide analogues (K1-K12) has been done using 'Lipinski rule' and it has been observed that all synthesized analogues did not violate the rule. Electronic, chemical properties and mulliken atomic charges of analogues were calculated using density functional theory (DFT). Communicated by Ramaswamy H. Sarma.

Synthesis, FT-IR and NMR characterization, antimicrobial activity, cytotoxicity and DNA docking analysis of a new anthraquinone derivate compound

A new anthraquinone [1-(2-Aminoethyl)piperazinyl-9,10-dioxo-anthraquinone] derivative was synthesized and characterized by density functional theory (DFT) calculations, experimental and theoretical vibrational spectroscopy and NMR techniques. The most stable molecular structure of the title molecule was determined by DFT B3LYP method with 6-31++G(d,p) and 6-311++G(d,p) basis sets. The fundamental vibrational wavenumbers, IR and Raman intensities for the optimized structure of the investigated molecule were calculated and compared with the experimental vibrational spectra. The vibrational assignment of the molecule was done using the potential energy distribution analysis. The molecular electrostatic potential (MEP), highest occupied molecular orbital (HOMO) and lowest occupied molecular orbital (LUMO) were also calculated. The antibacterial activities of the new anthraquinone derivative against Gram-positive and Gram-negative bacteria were determined, and it was shown that the highest effectiveness was against Staphylococcus aureus and S. epidermidis while no activity was against Gram-negative bacteria. Moreover, the antimycotic activity of the title compound was examined and the cytotoxicity of anthraquinone derivate was determined. In order to find the possible inhibitory activity of the title compound, molecular docking of the molecule was carried out against DNA. The results indicated that the mentioned compound has a good binding affinity to interact with the DC3, DG4, DA5, DC21 and DC23 residues of DNA via the intermolecular hydrogen bonds. [Formula: see text] Communicated by Ramaswamy H. Sarma.