Computational studies of the properties and activities of selected trisubstituted benzimidazoles as potential antitubercular drugs inhibiting MTB-FtsZ polymerization

Antidiabetes and antioxidant potential of Schiff bases derived from 2-naphthaldehye and substituted aromatic amines: Synthesis, crystal structure, Hirshfeld surface analysis, computational, and invitro studies

Three Schiff bases were synthesised by the condensation reaction between 2-napthaldehyde and aromatic amines to afford (E)-N-mesityl-1-(naphthalen-2-yl)methanimine (L1), (E)-N-(2,6-dimethylphenyl)-1-(naphthalen-2-yl)methanimine (L2) and (E)-N-(2,6-diisopropylphenyl)-1-(naphthalen-2-yl)methanimine (L3). The synthesised compounds were characterised using UV-visible, NMR (13C & 1H), and Fourier transform infrared spectroscopic methods while their purity was ascertained by elemental analysis. Structural analysis revealed that the naphthalene ring is almost coplanar with the imine functional group as evident by C1-C10-C11-N1 torsion angles of 176.4(2)° and 179.4(1)° in L2 and L3, respectively. Of all the various intermolecular contacts, H⋯H interactions contributed mostly towards the Hirshfeld surfaces of both L2 (58.7 %) and L3 (69.7 %). Quantum chemical descriptors of L1 - L3 were determined using Density Functional Theory (DFT) and the results obtained showed that the energy band gap (ΔE) for L1, L2 and L3 are 3.872, 4.023 and 4.004 eV respectively. The antidiabetic potential of the three compounds were studied using α-amylase and α-glucosidase assay. Compound L1 showed very promising antidiabetic activities with IC50 values of 58.85 μg/mL and 57.60 μg/mL while the reference drug (Acarbose) had 405.84 μg/mL and 35.69 μg/mL for α-amylase and α-glucosidase respectively. In-silico studies showed that L1 docking score as well as binding energies are higher than that of acarbose, which are recognized inhibitors of α-amylase together with α-glucosidase. Further insight from the RMSF, RMSD and RoG analysis predicted that, throughout the simulation L1 showcased evident influence on the structural stability of α-amylase. The antioxidant potential of the compounds was carried out using nitric oxide (NO), ferric reducing ability power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays. The compounds exhibited good to fairly antioxidant properties with L1 as well as L3 having IC50 values of 70.91 and 91.21 μg/mL respectively for NO scavenging activities assay, which comparatively outshined acarbose (reference drug) with IC50 value of 109.95 μg/mL. Pharmacology and pharmacokinetics approximations of L1 - L3 showed minimal violation of Lipinski's Ro5 and this projects them to be less toxic and orally bioavailable as potential templates for the design of therapeutics with antioxidant and antidiabetic activities.

Mycobacterial FtsZ and inhibitors: a promising target for the anti-tubercular drug development

The emergence of multidrug-resistant tuberculosis (MDR-TB) strains has rendered many anti-TB drugs ineffective. Consequently, there is an urgent need to identify new drug targets against Mycobacterium tuberculosis (Mtb). Filament Forming Temperature Sensitive Gene Z (FtsZ), a member of the cytoskeletal protein family, plays a vital role in cell division by forming a cytokinetic ring at the cell's center and coordinating the division machinery. When FtsZ is depleted, cells are unable to divide and instead elongate into filamentous structures that eventually undergo lysis. Since the inactivation of FtsZ or alterations in its assembly impede the formation of the Z-ring and septum, FtsZ shows promise as a target for the development of anti-mycobacterial drugs. This review not only discusses the potential role of FtsZ as a promising pharmacological target for anti-tuberculosis therapies but also explores the structural and functional aspects of the mycobacterial protein FtsZ in cell division. Additionally, it reviews various inhibitors of Mtb FtsZ. By understanding the importance of FtsZ in cell division, researchers can explore strategies to disrupt its function, impeding the growth and proliferation of Mtb. Furthermore, the investigation of different inhibitors that target Mtb FtsZ expands the potential for developing effective treatments against tuberculosis.

Ligand-Guided Investigation of a Series of Formamidine-Based Thiuram Disulfides as Potential Dual-Inhibitors of COX-1and COX-2

A series of thiuram disulfides 1-6 which had been previously synthesized and characterized,^[1] were studied for their potential therapeutic properties. Target-fishing analyses through HitPick and SwissTarget prediction identified COX1 and COX2, which are essential biomolecules in cancer-related inflammations, as the possible targets for compounds 1 and 4 among all the compounds tested. These two proteins have enjoyed interest as targets for treating some neoplastic cancer types such as breast, colorectal, skin, pancreatic, haematological and head cancers. The inhibitory potency of 1 and 4 as lead anticancer drug candidates with dual-target ability against COX1 and COX2 was examined through molecular docking, molecular dynamics simulation and post-MD analyses such as binding energy calculation, RMSD, RMSF, and RoG. The two compounds had better docking scores and binding energies than the known inhibitors of COX1 and COX2. Insights from the RMSD, RMSF, and RoG suggested that both 1 and 4 showed observable influence on the structural stability of these targets throughout the simulation. The reported observations of the effects of 1 and 4 on the structures of COX1 and COX2 indicate their probable inhibitory properties against these target proteins and their potential as lead anticancer drug candidates.

Anti-Inflammatory and Anti-Rheumatic Potential of Selective Plant Compounds by Targeting TLR-4/AP-1 Signaling: A Comprehensive Molecular Docking and Simulation Approaches

Plants are an important source of drug development and numerous plant derived molecules have been used in clinical practice for the ailment of various diseases. The Toll-like receptor-4 (TLR-4) signaling pathway plays a crucial role in inflammation including rheumatoid arthritis. The TLR-4 binds with pro-inflammatory ligands such as lipopolysaccharide (LPS) to induce the downstream signaling mechanism such as nuclear factor κappa B (NF-κB) and mitogen activated protein kinases (MAPKs). This signaling activation leads to the onset of various diseases including inflammation. In the present study, 22 natural compounds were studied against TLR-4/AP-1 signaling, which is implicated in the inflammatory process using a computational approach. These compounds belong to various classes such as methylxanthine, sesquiterpene lactone, alkaloid, flavone glycosides, lignan, phenolic acid, etc. The compounds exhibited different binding affinities with the TLR-4, JNK, NF-κB, and AP-1 protein due to the formation of multiple hydrophilic and hydrophobic interactions. With TLR-4, rutin had the highest binding energy (−10.4 kcal/mol), poncirin had the highest binding energy (−9.4 kcal/mol) with NF-κB and JNK (−9.5 kcal/mol), respectively, and icariin had the highest binding affinity (−9.1 kcal/mol) with the AP-1 protein. The root means square deviation (RMSD), root mean square fraction (RMSF), and radius of gyration (RoG) for 150 ns were calculated using molecular dynamic simulation (MD simulation) based on rutin’s greatest binding energy with TLR-4. The RMSD, RMSF, and RoG were all within acceptable limits in the MD simulation, and the complex remained stable for 150 ns. Furthermore, these compounds were assessed for the potential toxic effect on various organs such as the liver, heart, genotoxicity, and oral maximum toxic dose. Moreover, the blood–brain barrier permeability and intestinal absorption were also predicted using SwissADME software (Lausanne, Switzerland). These compounds exhibited promising physico-chemical as well as drug-likeness properties. Consequently, these selected compounds portray promising anti-inflammatory and drug-likeness properties.

Design, synthesis, and computational studies of benzimidazole derivatives as new antitubercular agents

The increase in the drug-resistant strains of Mycobacterium tuberculosis has led researchers to new drug targets. The development of new compounds that have effective inhibitory properties with the selective vital structure of Mycobacterium tuberculosis is required in new scientific approaches. The most important of these approaches is the development of inhibitor molecules for Mycobacterium cell wall targets. In this study, first of all, the antitubercular activity of 23 benzimidazole derivatives was experimentally determined. And then molecular docking studies were carried out with 4 different targets: Arabinosyltransferase C (EmbC), Filamentous Temperature Sensitive Mutant Z (FtsZ), Protein Tyrosine Phosphatase B (PtpB), and Decaprenylphosphoryl-β-D-ribose-2'-oxidase (DprE1). It has been determined that benzimidazole derivatives show activity through the DprE1 enzyme. It is known that DprE1, which has an important role in the synthesis of the cell envelope from Arabinogalactan, is also effective in the formation of drug resistance. Due to this feature, the DprE1 enzyme has become an important target for drug development studies. Also, it was chosen as a target for this study. This study aims to identify molecules that inhibit DprE1 for the development of more potent and selective antitubercular drugs. For this purpose, molecular docking studies by AutoDock Vina, and CDOCKER and molecular dynamics (MD) simulations and in silico ADME/Tox analysis were implemented for 23 molecules. The molecules exhibited binding affinity values of less than -8.0 kcal/mol. After determining the compound's anti-TB activities by a screening test, the best-docked results were detected using compounds 20, 21, and 30. It was found that 21, was the best molecule with its binding affinity value, which was supported by MD simulations and in silico ADME modeling results.Communicated by Ramaswamy H. Sarma.

Identifying the analogues of berberine as promising antitubercular drugs targeting Mtb-FtsZ polymerisation through ligand-based virtual screening and molecular dynamics simulations

Berberine, an active compound in the extract of golden seal (an age-long remedy for many infections) has been confirmed to be responsible for the extract's activity against multi-drug resistant strain of Mycobacterium tuberculosis. There is no available study that shows the exact target of berberine in M tuberculosis, although it is confirmed that berberine inhibits the polymerisation of filamentous temperature-sensitive mutant Z (FtsZ), an important bacteria cytokinesis protein, in Escherichia coli, suggesting that FtsZ could as well be the target of berberine in M tuberculosis. In this study, we carried out ligand-based virtual screening to identify analogues of berberine followed by molecular dynamics (MD) simulations of the complexes of Mtb-FtsZ with berberine (berb1) and the five selected analogues (berb9 [ZINC1709414], berb37 [ZINC238749993], berb38 [ZINC13509022], berb43 [ZINC14765594], and berb48 [ZINC238758595]). Post-MD analyses such as binding free energy, RMSD, RMSF, RoG and hydrogen bond lifetime analysis were used to understand the interactions between these ligands and the receptor. The results suggested that Mtb-FtsZ could likely be the target of berberine in M tuberculosis as it forms a stable complex coupled with a significantly high binding energy. The study also identified other potential inhibitors of MTB-FtsZ polymerisation. Berb38 specifically showed greater interaction with the residues at the binding site of the protein, forming a far more stable complex with the receptor than any of the other compounds under investigation, including berberine itself. ADME properties calculations also predicted all the ligands to be bioactive as orally administered drugs.

Design of New Schiff-Base Copper(II) Complexes: Synthesis, Crystal Structures, DFT Study, and Binding Potency toward Cytochrome P450 3A4

We report the synthesis and crystal structures of three new copper(II) Schiff-base complexes. The complexes have been characterized by elemental analysis and Fourier transform infrared (FT-IR) and UV-visible spectroscopies. The X-ray diffraction (XRD) analysis reveals that complexes 1 and 3 crystallize in a monoclinic space group C2/c and 2 in a triclinic space group P1̅, each adopting a square planar geometry around the metal center. We use a density functional theory method to explore the quantum chemical properties of these complexes. The calculation proceeds with the three-dimensional (3D) crystal structure characterization of the complexes in which the calculated IR and UV-vis values are comparable to the experimental results. Charge distribution and molecular orbital analyses enabled quantum chemical property prediction of these complexes. We study the drug-likeness properties and binding potentials of the synthesized complexes. The in silico outcome showed that they could serve as permeability-glycoprotein (P-gp) and different cytochrome P450 substrates. Our calculations showed that the complexes significantly bind to cytochrome P450 3A4.