Computational evaluation of quinones of Nigella sativa L. as potential inhibitor of dengue virus NS5 methyltransferase

Aedes aegypti is the primary vector for the transmission of the dengue virus, which causes dengue fever, dengue hemorrhagic illness and dengue shock syndrome. There is now no antiviral medication available to treat DENV, which kills thousands of people each year and infects millions of individuals. A possible target for the creation of fresh and efficient dengue treatments is the DENV-3 NS5 MTase. So, Nigella sativa quinones were examined using in silico methods to find natural anti-DENV compounds. The in silico docking was conducted utilising the Discovery Studio software on the quinones of N. sativa and the active site of the target protein DENV-3 NS5 MTase. In addition, the druggability and pharmacokinetics of the lead compound were assessed. Dithymoquinone was comparable to the reference compound in terms of its ability to bind to the active site of target protein. Dithymoquinone met the requirements for drug likeness and Lipinski's principles, as demonstrated by the ADMET analysis and drug likeness results. The current study indicated that the dithymoquinone from N. sativa had anti-DENV activity, suggesting further drug development and dengue treatment optimisation.Communicated by Ramaswamy H. Sarma.

Investigation of cathinone analogs targeting human dopamine transporter using molecular modeling

In a step towards understanding the structure-property relationship among Synthetic Cathinones (SCs), a combined methodology based on Density Functional Theory (DFT), Administration, Distribution, Metabolism, Excretion, and Toxicity (ADMET) predictions, docking and molecular dynamics simulations have been applied to correlate physicochemical descriptors of various SCs to their biological activity. The results from DFT and molecular docking studies correlate well with each other explaining the biological activity trends of the studied SCs. Quantum mechanical descriptors viz. polarizability, electron affinity, ionization potential, chemical hardness, electronegativity, molecular electrostatic potential, and ion interaction studies unravel the distinguishingly reactive nature of Group D (pyrrolidine substituted) and Group E (methylenedioxy and pyrrolidine substituted) compounds. According to ADMET analysis, Group D and Group E molecules have a higher probability of permeating through the blood-brain barrier. Molecular docking results indicate that Phe76, Ala77, Asp79, Val152, Tyr156, Phe320, and Phe326 constitute the binding pocket residues of hDAT in which the most active ligands MDPV, MDPBP, and MDPPP are bound. Finally, to validate the derived quantum chemical descriptors and docking results, Molecular Dynamics (MD) simulations are performed with homology-modelled hDAT (human dopamine transporter). The MD simulation results revealed that the majority of SCs remain stable within the hDAT protein's active sites via non-bonded interactions after 100 ns long simulations. The findings from DFT, ADMET analysis, molecular docking, and molecular dynamics simulation studies complement each other suggesting that pyrrolidine-substituted SCs (Group D and E), specifically, MPBP and PVN are proven potent SCs along with MDPV, validating various experimental observations.Communicated by Ramaswamy H. Sarma.

Molecular Docking Assessment of Cathinones as 5-HT2AR Ligands: Developing of Predictive Structure-Based Bioactive Conformations and Three-Dimensional Structure-Activity Relationships Models for Future Recognition of Abuse Drugs

Commercially available cathinones are drugs of long-term abuse drugs whose pharmacology is fairly well understood. While their psychedelic effects are associated with 5-HT2AR, the enclosed study summarizes efforts to shed light on the pharmacodynamic profiles, not yet known at the receptor level, using molecular docking and three-dimensional quantitative structure-activity relationship (3-D QSAR) studies. The bioactive conformations of cathinones were modeled by AutoDock Vina and were used to build structure-based (SB) 3-D QSAR models using the Open3DQSAR engine. Graphical inspection of the results led to the depiction of a 3-D structure analysis-activity relationship (SAR) scheme that could be used as a guideline for molecular determinants by which any untested cathinone molecule can be predicted as a potential 5-HT2AR binder prior to experimental evaluation. The obtained models, which showed a good agreement with the chemical properties of co-crystallized 5-HT2AR ligands, proved to be valuable for future virtual screening campaigns to recognize unused cathinones and similar compounds, such as 5-HT2AR ligands, minimizing both time and financial resources for the characterization of their psychedelic effects.

Conception of Cellulose/Alginate/Mesalazine microspheres by solvent evaporation technique for drug release: Experimental and theoretical investigations

Preparation of microspheres containing Mesalazine referred to as 5-aminosalicylic acid (5-ASA) for colon targeting drug was carried out using the emulsion solvent evaporation technique. The formulation was based on 5-ASA as the active agent, sodium Alginate (SA) andEthylcellulose (EC) as encapsulating agents, with polyvinyl alcohol (PVA) as emulsifier. The effects ofthe following processing parameters, 5-ASA %, EC:SA ratio and stirring rate on the properties of the resulting products in the form microspheres were considered. The samples were characterized using Optical microscopy, SEM, PXRD, FTIR, TGA, and DTG. In vitro release of 5-ASA from the different batches of microspheres was tested in biologically simulated fluids, (gastric; SGF, pH 1.2 for 2 h), then (intestinal fluid SIF, pH 7.4for 12 h) at 37 °C. The release kinetic results have been treated mathematically relaying on Higuchi's and Korsmeyer-Peppas' models for drug liberation. DOE study was performed to evaluate the interactive effects of variables on the drug entrapment and microparticle sizes. Molecular chemical interactions in structures were optimized using DFT analysis.

Synthesis, DFT Analysis, and Evaluation of Antibacterial and Antioxidant Activities of Sulfathiazole Derivatives Combined with In Silico Molecular Docking and ADMET Predictions

Synthetic modifications of sulfathiazole derivatives become an interesting approach to enhance their biological properties in line with their applications. As a result, sulfathiazole derivatives become a good candidate and potential class of organic compounds to play an important role towards medicinal chemistry. In present study, one thiazole derivative and two new sulfathiazole derivatives are synthesized with 94% and 72–81% yields, respectively. Furthermore, the synthesized compounds were evaluated for their in vitro antibacterial activity against two Gram-negative (E. coli and P. aeruginosa) and two Gram-positive bacterial strains (S. pyogenes and S. aureus) by disk diffusion method. Among synthesized compounds, compound 11a showed potent inhibitory activity against Gram-negative, E. coli with 11.6 ± 0.283 mm zone of inhibition compared to standard drug sulfamethoxazole (15.7 ± 0.707 mm) at 50 mg/mL. The radical scavenging activities of these compounds were evaluated using DPPH radical assay, and compound 11a showed the strongest activity with IC₅₀ values of 1.655 μg/mL. The synthesized compounds were evaluated for their in silico molecular docking analysis using S. aureus gyrase (PDB ID: 2XCT) and human myeloperoxidase (PDB ID: 1DNU) and were found to have minimum binding energy ranging from −7.8 to −10.0 kcal/mol with 2XCT and −7.5 to −9.7 with 1DNU. Compound 11a showed very good binding score −9.7 kcal/mol with both of the proteins and had promising alignment with in vitro results. Compound 11b also showed high binding scores with both proteins. Drug likeness and ADMET of synthesized compounds were predicted. The DFT analysis of synthesized compounds was performed using Gaussian 09 and visualized through Gauss view 6.0. The structural coordinates of the lead compounds were optimized using B3LYP/6–31 G (d,p) level basis set without any symmetrical constraints. Studies revealed that all the synthesized compounds might be candidates for further antibacterial and antioxidant studies.

Overview of the major classes of new psychoactive substances, psychoactive effects, analytical determination and conformational analysis of selected illegal drugs

The misuse of psychoactive substances is attracting a great deal of attention from the general public. An increase use of psychoactive substances is observed among young people who do not have enough awareness of the harmful effects of these substances. Easy access to illicit drugs at low cost and lack of effective means of routine screening for new psychoactive substances (NPS) have contributed to the rapid increase in their use. New research and evidence suggest that drug use can cause a variety of adverse psychological and physiological effects on human health (anxiety, panic, paranoia, psychosis, and seizures). We describe different classes of these NPS drugs with emphasis on the methods used to identify them and the identification of their metabolites in biological specimens. This is the first review that thoroughly gives the literature on both natural and synthetic illegal drugs with old known data and very hot new topics and investigations, which enables the researcher to use it as a starting point in the literature exploration and planning of the own research. For the first time, the conformational analysis was done for selected illegal drugs, giving rise to the search of the biologically active conformations both theoretically and using lab experiments.