Synthesis, structure–activity relationship and molecular docking of cyclohexenone based analogous as potent non-nucleoside reverse-transcriptase inhibitors

Exploring flexibility, intermolecular interactions and ADMET profiles of anti-influenza agent isorhapontigenin: A quantum chemical and molecular docking study

Isorhapontigenin (IRPG) drug emerges as promising efficient inhibitor for H1N1 and H3N2 subtypes which belong to influenza A virus; reported with IC₅₀ value of 35.62 and 63.50 μM respectively. When experimental data are compared to the predicted geometrical parameters and vibrational assignments (FT-IR and FT-Raman), the findings indicated a strong correlation. The absorption bands of π→π∗ transitions are revealed through UV-Vis electronic properties; this confirms that the IRPG molecule shows strong bands. Through NBO and HOMO-LUMO analysis, the kinetic stability and chemical reactivity of the IRPG molecule were investigated. By using an MEP map, the IRPG's electrophilic and nucleophilic site selectivity was assessed. In a molecular docking investigation, the IRPG molecule shows a stronger inhibition constant and binding affinity for the H1N1 and H3N2 influenza virus. The IRPG molecule thus reveals good biological actions in nature and can be used as a potential therapeutic drug candidate for H1N1 and H3N2 virus A influenza.

Synthesis, characterization, DFT analysis and docking studies of a novel Schiff base using 5-bromo salicylaldehyde and β-alanine

Poly(ADP-ribose) polymerase-1(PARP-1) is a DNA-dependent enzyme, forming part of ADP-ribosyltransferase family. Although some PARP inhibitors find therapeutical applications in cancer therapy and exhibits crucial role in DNA damage response. Here a novel Schiff base, (E)-3-((5-bromo-2-hydroxybenzylidene) amino) propanoic acid was synthesized using 5-bromo salicylaldehyde and β-alanine. Characterization was carried out using IR, UV-Vis,1H and 13C NMR and mass spectrum. Present study involves the evaluation of a novel Schiff base as an inhibitor against human breast cancer cell lines (pdb:3GEY) using 2-(dimethylamino)-N-(6-oxo-5,6-dihydrophenanthridin-2-yl) acetamide (DDA) as a native ligand. In silico study of 3GEY inhibitor is a variant of PARP-15, docking with two different ligands (E)-3-((5-bromo-2-hydroxybenzylidene) amino) propanoic acid (SBL) and the native ligand. Synthesized ligandis docked in to the B chain of PARP enzyme binding site to visualize the best docked poseand favorable ligand-protein binding interactions. Swiss ADME tool determines the drug likeness and strongly suggests that SBL can be a promising candidate to fight against breast cancer. DFT studies were done to support the experimental results using B3LYP/6-311+G(d,p) and geometry optimization was performed. Various thermodynamic parameters and NLO properties were found out. ECD and VCD spectrum were explained using DFT studies. Vibrational and Raman frequencies were also reported. HOMO-LUMO band gaps, Mulliken charges were calculated and the electrostatic potential surface was mapped with various properties. Experimental findings obtained are in good agreement with that of theoretical DFT analysis.

Mechanistic evaluation of a novel cyclohexenone derivative's functionality against nociception and inflammation: An in-vitro, in-vivo and in-silico approach

The synthesis of a novel cyclohexanone derivative (CHD; Ethyl 6-(4-metohxyphenyl)-2-oxo-4-phenylcyclohexe-3-enecarboxylate) was described and the subsequent aim was to perform an in vitro, in vivo and in silico pharmacological evaluation as a putative anti-nociceptive and anti-inflammatory agent in mice. Initial in vitro studies revealed that CHD inhibited both cyclooxygenase-2 (COX-2) and 5-lipoxygenase (5-LOX) enzymes and it also reduced mRNA expression of COX-2 and the pro-inflammatory cytokines TNF-α and IL-1β. It was then shown that CHD dose dependently inhibited chemically induced tonic nociception in the abdominal constriction assay and also phasic thermal nociception (i.e. anti-nociception) in the hot plate and tail immersion tests in comparison with aspirin and tramadol respectively. The thermal test outcomes indicated a possible moderate centrally mediated anti-nociception which, in the case of the hot plate test, was pentylenetetrazole (PTZ) and naloxone reversible, implicating GABAergic and opioidergic mechanisms. CHD was also effective against both the neurogenic and inflammatory mediator phases induced in the formalin test and it also disclosed anti-inflammatory activity against the phlogistic agents, carrageenan, serotonin, histamine and xylene compared with standard drugs in edema volume tests. In silico studies indicated that CHD possessed preferential affinity for GABAA, opioid and COX-2 target sites and this was supported by molecular dynamic simulations where computation of free energy of binding also favored the formation of stable complexes with these sites. These findings suggest that CHD has prospective anti-nociceptive and anti-inflammatory properties, probably mediated through GABAergic and opioidergic interactions supplemented by COX-2 and 5-LOX enzyme inhibition in addition to reducing pro-inflammatory cytokine expression. CHD may therefore possess potentially beneficial therapeutic effectiveness in the management of inflammation and pain.

Computational drug design strategies applied to the modelling of human immunodeficiency virus-1 reverse transcriptase inhibitors

Reverse transcriptase (RT) is a multifunctional enzyme in the human immunodeficiency virus (HIV)-1 life cycle and represents a primary target for drug discovery efforts against HIV-1 infection. Two classes of RT inhibitors, the nucleoside RT inhibitors (NRTIs) and the nonnucleoside transcriptase inhibitors are prominently used in the highly active antiretroviral therapy in combination with other anti-HIV drugs. However, the rapid emergence of drug-resistant viral strains has limited the successful rate of the anti-HIV agents. Computational methods are a significant part of the drug design process and indispensable to study drug resistance. In this review, recent advances in computer-aided drug design for the rational design of new compounds against HIV-1 RT using methods such as molecular docking, molecular dynamics, free energy calculations, quantitative structure-activity relationships, pharmacophore modelling and absorption, distribution, metabolism, excretion and toxicity prediction are discussed. Successful applications of these methodologies are also highlighted.