Dra. Gerli-Candia, Lorena

Metabolite profile always hold important place for flavonoids as they are the major promoters of secondary metabolism in human body. For decades numerous flavonoids are explored for their structural activities which in turn helped them to meet various health promoting applications such as radical scavenging activity. Apart from conventional flavonoids their derivatives are also tend to exhibit similar kind of structural activity. Therefore, in the present work afzelin and juglanin – the glycosyl derivatives of kaemepferol an established flavonoid are subjected to structural activity relationship analysis using density functional theory. The structures of the two kaempferol glycosides are optimized and the optimized geometry is simulated to obtain frontier orbitals, electrostatic potential energy and molecular descriptors. The obtained results suggest that maximum amount of charge is accumulated over B-ring of two flavonoids, thus prefers to act as better electron donating region. Target predicted for two flavonoids over homosapien class reveal that the flavonoid highly prefers lyase and enzymatic targets for inhibition purpose.

The identification of drugs against the new coronavirus (SARS-CoV-2) is an important requirement. Natural products are substances that serve as sources of beneficial chemical molecules for the development of effective therapies. In this study, 187 natural compounds from Algerian herbal medicines were docked in the active site of SARS-CoV-2 main protease. The result indicates that Piperitol, Warfarin, cis-calamenen-10-ol and α-Cadinene are the structures with best affinity in the binding site of the studied enzyme and all of them respect the conditions mentioned in Lipinski’s rule and have acceptable ADMET proprieties; so, these compounds could have more potent antiviral treatment of COVID-19 than the studied compounds, and they have important pharmacokinetic properties and bioavailability.

A theoretical quantum study of the organophosphorus compound with formula C10H19OPCl2 (MEPCL2) was carried out. The results of the calculations show excellent agreement between experimental and computed frequencies evaluated at the B3LYP/6-311++G(d,p) level of theory. A study of the electronic properties, such as excitation energies and wavelengths were performed employing the time-dependent DFT (TD-DFT) method. Global a chemical reactivity of MEPCL2 was analyzed through global reactivity descriptors, while its local reactivity was analyzed by mean maps of the electrostatic potential. Also, the orbital energies values suggest that a charge transfer is occurring within the molecule.

The antioxidant power of eugenol and vitamin C was examined by analyzing the ability of these ligands to bind to the NADPH oxidase protein target and evaluating their bond interactions with critical residues. The results confirm that docked ligands are more stable in the specified active region of 2CDU during a MD simulation of 100 ns and 2CDU protein-ligand interactions with docked ligands showed significant hydrogen bond, hydrophobic, and water bridge formation. Eugenol exhibits hydrogen bond interactions with critical residues in the selective pocket in comparison to vitamin C. Also, eugenol had a similar binding orientation and very considerable stability in the selective pocket of 2CDU with a high binding energy with lipophilic energy. The electrostatic potential maps indicate that for eugenol, the –OH and –OCH3 sites, while that the –OH and –CO functional groups in vitamin C are responsible of the antioxidant activities of these compounds. HAT and SET mechanisms suggest that eugenol may become a better antioxidant than vitamin C.

In this work, a computational chemical study of Etoricoxib was carried out at the X/6311G(d,p) (where X=B3LYP, M06 and B97XD) level of theory, at the gas, aqueous and ethanol phases. Through the chemical reactivity descriptors derived from the DFT, it was possible to find that Etoricoxib structure exhibits a major chemical activity in water and ethanol phases in comparison to the gas phase, which suggests this drug would be more active in biological solvents like in blood, tissues and places where the ciclooxigenasa 2 (COX)-2 is found. In addition, a molecular docking analysis was conducted to study the interaction of Etoricoxib with the COX-2 active site. The results suggest that Etoricoxib interacts with 19 amino acid residues inside the COX-2 active site.

Nanoparticles (NPs) of new fluoride (SrF2 and MgF2) nanocompounds were synthesized by the simple chemical method of precipitation in ethanol. Synthesis of the strontium fluoride (SrF2)-magnesium oxide (MgO) nanocomposite was achieved through the ultrasonic method. These prepared nanopowders were characterized through Fourier transform infrared (FT-IR) spectroscopy, ultraviolet–visible (UV–Vis) spectroscopy, Powder X-ray Diffraction (PXRD) and Scanning Electron Microscopy (SEM). FT-IR confirmed the purity of the synthesized fluoride NPs by evaluation of the vibrations, and UV–Visible showed the intense absorption peaks of NPs. PXRD analysis indicated the average of particle size, and SEM demonstrated a nearly spherical morphology of the NPs. The antibacterical properties of the nanopowders on Staphylococcus Aureus, Bacillus Subtilis and E. Aklay bacteria were studied, with the strongest effect by the magnesium fluoride (MgF2) NPs and the SrF2-MgO nanocomposite.

SARS-CoV-2 is the pandemic disease-causing agent COVID-19 with high infection rates. Despite the progress made in vaccine development, there is an urgent need for the identification of antiviral compounds that can tackle better the different phases of SARS-CoV-2. The main protease (Mpro or 3CLpro) of SARS-CoV-2 has a crucial role in viral replication and transcription. In this study, an in silico method was executed to elucidate the inhibitory potential of the synthesized 6-tert-octyl and 6-8-ditert-butyl coumarin compounds against the major protease of SARS-CoV-2 by comprehensive molecular docking and density functional theory (DFT), ADMET properties and molecular dynamics simulation approaches. Both compounds shown favorable interactions with the 3CLpro of the virus. From DFT calculations, HOMO-LUMO values and global descriptors indicated promising results for these compounds. Furthermore, molecular dynamics studies revealed that these ligand-receptor complexes remain stable during simulations and both compounds showed considerably high binding affinity to the main SARS-CoV-2 protease. The results of the study suggest that the coumarin compounds 6-tert-octyl and 6-8-ditert-butyl could be considered as promising scaffolds for the development of potential COVID-19 inhibitors after further studies.

A new amlodipine-chitosan nanocomposite was built using amlodipine nanoparticles as primary scaffolds by spontaneous emulsification, and its complete elucidation was performed by using several spectrometric techniques. Our results indicate that the amlodipine-chitosan nanocomposite has better solubility than amlodipine at pH 7.4 with a nearly all the drug substance dissolved (97%) by the final time-point measured. The docking study support the existence of intermolecular interactions are established between amlodipine and chitosan

The largest threat to civilization since the Second World War is the spread of the new coronavirus disease (COVID-19). Therefore, there is an urgent need for innovative therapeutic medicines to treat COVID-19. Reusing bio-actives is a workable and efficient strategy in the battle against new epidemics because the process of developing new drugs is time-consuming. This research aimed to identify which herbal remedies had the highest affinity for the receptor and assess a variety of them for potential targets to suppress the SARS-CoV-2 Mpro. The use of AutoDock Vina for structure-based virtual screening was done first due to the importance of protein interactions in the development of drugs. Molecular docking was used in the comparative study to assess 89 different chemicals from medicinal herbs. To anticipate their effectiveness against the primary protease of SARS-CoV-2, more analysis was done on the ADMET profile, drug-likeness, and Lipinski’s rule of five. The next step involved three replicas of 100 ns-long molecular dynamics simulations on the potential candidates, which were preceded by calculations of the binding free energy of MM-GBSA. The outcomes showed that Achyrodimer A, Cinchonain Ib, Symphonone F, and Lupeol acetate all performed well and had the highest 6LU7 binding affinities. Using RMSD, RMSF, and protein-ligand interactions, the stability of the protein-ligand complex was assessed. The studies indicate that bioactive substances obtained from herbal medicines may function as a COVID-19 therapeutic agent, necessitating additional wet lab research to confirm their therapeutic potential, efficacy, and pharmacological capacity against the condition.

Two new phosphorus complexes, potassium trichlorothiocyanophosphate (III) (PTCTCP; K[PCl3(SCN)]) and potassium trichlorocyanophosphate (III) (PTCCP; K[PCl3(CN)]) were synthesized from the reaction of KSCN and KCN, respectively, with PCl3. The chemical formulas and compositions of these compounds were determined by elemental analysis and spectroscopic methods, such as phosphorus-31 nuclear magnetic resonance (NMR) spectroscopy (31P-NMR), Fourier transform infrared (FTIR) spectroscopy, ultraviolet-visible (UV-Vis) spectroscopy and mass spectrophotometry. All of the theoretical calculations and determinations of the properties of these compounds were performed as part of the Amsterdam Density Functional (ADF) program. Excitation energies were assessed using time-dependent perturbation density functional theory (TD-DFT). In addition, the molecular geometry was optimized and the frequencies and excitation energies were calculated using standard Slater-type orbital (STO) basis sets with triple-zeta quality double plus polarization functions (TZ2P) for all of the atoms. The assignment of the principal transitions and total densities of state (TDOS) for orbital analysis were performed using the GaussSum 2.2 program.