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  • Open access
  • 72 Reads
Identification of natural products for the treatment of Alzheimer’s disease: 3D-similarity search

Glycogen synthase kinase 3 (GSK-3), one of the main tau kinases involved in a variety of cellular processes, has been evidenced as a promising target for Alzheimer’s disease (AD) treatment. In recent years, great efforts have been made to discover new molecules with an enhanced profile that inhibit GSK-3 and display efficacy in AD treatment. SAR502250, a new discover selective GSK3 inhibitor with AD therapeutic potential, represents a good alternative to future design specific inhibitors against this condition. SAR502250 was used as a query in a 3D similarity search on the SPECS database to select new natural compounds as possible GSK-3 inhibitors. According to ShapeTanimoto, TanimotoCombo, and ComboScore matrics, the first 10 SPECS natural compounds were selected and structurally analyzed. The ADMETox, physicochemical parameters, and toxicity related risks profiles of the selected natural compounds were also investigated. The 3D-similarity results in conjunction with pharmaceutical profiles revealed the potential use of natural compounds as GSK-3 inhibitors for Alzheimer's disease therapy.

  • Open access
  • 65 Reads
Identification of less harmful pesticides against honey bees: shape-based similarity analysis

The high concentration of the pesticide residues existing in vegetation, crops, and various edible products and the prolonged exposure to them, can harm human life and contribute to the disappearance of honey bees, several avian and animal species. The honey bees (Apis mellifera), efficient pollinators in addition to honey producers, are also considered important non-target test species for terrestrial toxicity assessment of chemicals. In this context, using thiacloprid and acetamiprid as queries, we performed a 3D similarity search to select new potential products with less harmful effects against bees. For similarity search, a small dataset of 302 compounds with pesticide activity, compiled from literature, was used. The first 10 compounds were selected and structurally analyzed according to the TanimotoCombo metrics, and compared with each of these two queries known to be effective, easily metabolized, and less toxic for bees. This approach came as a forward step in the research of pesticide ecotoxicological risk assessment, for the evaluation of their potential impact on the pollinator insects and the environment.

  • Open access
  • 63 Reads
In silico study of some natural flavonoids as potential agents against COVID-19: preliminary results

Flavonoids, widely distributed in fruits, vegetables, and medicinal herbs, are compounds with multiple biological benefits to human health from anti-inflammatory, antioxidant, anticancer, antibacterial to antiviral activity. Coronavirus disease 2019 (Covid-19), a serious concern in the world today, is a disease of the respiratory tract involving moderate to severe symptoms of pneumonia, with a major incidence in older people and patients having chronic diseases. This emergency health situation led us to evaluate the possible use of natural products to prevent respiratory diseases. The present study aims to report the potential of four natural flavonoids, known to have anti-inflammatory and antiviral activity, as anti-SARS-CoV-2 through their binding on 6YNQ protein receptor. Molecular docking study with the FRED program was chosen as an appropriate tool to analyze the interaction of natural flavonoids, quercetin, luteolin, galangin, and narigenin, with the SARS-CoV-2 main protease and to rank the conformations through a scoring function to predict their binding affinity. Overall, our preliminary results indicate the potential of the titled natural flavonoids to fight the new coronavirus, Covid-19.

  • Open access
  • 80 Reads
Protective effect of Cyclolepis genistoides aqueous extract against cellular oxidative stress

The development of neuroprotective agents constitutes one of the most promising strategies to treat neurodegenerative disorders, such as Parkinson’s disease (PD). Oxidative stress (OS) is a major contributor to the death of dopaminergic neurons in PD. In the present work, we investigated the in vitro effect of aqueous extracts of three Argentinian medicinal plants, Agalinis genistifolia (Cham. & Schltdl.) D'Arcy, Cyclolepis genistoides Gillies ex D. Don and Margyricarpus pinnatus (Lam.) Kuntze, on metal-induced OS. These species have been traditionally used to treat PD-related symptoms, such as paralysis for A. genistifolia, and inflammation for C. genistoides and M. pinnatus. To evaluate the potential neuroprotective activity of the aqueous extracts, we used the human neuroblastoma cell line IMR-32 exposed to ferric ammonium citrate (FAC) as OS inducer. Whereas cells exposed to FAC exhibited increased levels of reactive oxygen species (ROS) after the treatment with A. genistifolia and M. pinnatus (50 µg/ml extract), the exposure to C. genistoides extract at 20 µg/ml showed a reduction of ROS levels. In line with this finding, we found that C. genistoides treatment decreased lipid peroxidation under the same conditions (20 µg/ml). Furthermore, the induction of ROS production by manganese in IMR-32 cells and by FAC in N27 rat dopaminergic cells was attenuated by the exposure to C. genistoides extract. Our results suggest that the aqueous extract of C. genistoides has potential as source of neuroprotective agents than can target OS, a hallmark of neuronal death in PD.

  • Open access
  • 61 Reads
In silico study of the interaction between casein with tocopherols: preliminary evaluation of lipophilic substrate inclusion on proteic matrix

Bovine casein is a family of milk proteins with hydrophilic and hydrophobic regions that show block distribution within the protein chain. These amphiphilic properties offer great potential as a material for being used as a matrix for transport active materials as tocopherol. In this work, we aim to evaluate the interaction of α1-casein, the main fraction of the casein, with vitamin E by docking calculations. Docking studies were conducted by using SwissDock and DockThor servers. Using specific scoring functions based on energy terms were obtained the best protein-ligand binding models. The observed interactions between vitamin E and amino acid residues consisting of several hydrophobic interactions (e.g. with Tyr119, Ala144, Trp179, Met211, Pro212). A few hydrogen bonds were observed between phenyl group of vitamin E and carboxylate group of glutamic acid residue (e.g. with Glu85, Glu148). In conclusion, the results suggest that exists a major interaction of vitamin E with random coil structure that the interaction with segments formed by α-helix and β-sheet. This implies that in random coil segments predominance hydrophobic domains.

  • Open access
  • 74 Reads
One-pot selective functionalization of polysaccharides with urea

Natural Polysaccharides are polymers composed of monosaccharide units bound together by glycosidic linkages. In their native form, these polymers may not be able to provide all the desired properties for a particular application. Thus, the functionalization of its reactive hydroxyl groups would change their surface properties. In this work, we evaluated the derivatization of OH groups of maltodextrin polysaccharide with urea. By a one-pot selective procedure carried out at room temperature for 3 h, urea united at maltodextrin through covalent bonding was obtained. The results showed that after functionalization with urea, the pH and solubility in polar solvents of the new material increased. Derivatization of maltodextrin with urea confers stability, and terminal primary amine groups on the surface of this material represent a versatile reactive functional group for conjugation with other molecules for potential applications in the development of new materials.

  • Open access
  • 93 Reads
Facile microwave-assisted synthesis of heterostructured CuCo2S4/CuCo2O4 nanoparticles using organic agent of thiourea

Ultra-fast one-put microwave assisted strategy is introduced for the synthesis of heterostructured CuCo2S4/CuCo2O4 nanoparticles into a domestic microwave oven with the power of 900 W for 20 minutes. Thiourea as an organic agent was used as a sulfur source and driving agent to lead the solvent free combustion reaction to obtain this earth-abundant and low-cost mixed chalcogenide/oxide product. The structural and morphological specifications were studied in details using powder x-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and energy dispersion of x-ray spectrometry (EDX). The employed strategy relatively clarifies a new facile, rapid and eco-friendly route to produce heterostructured nanocomposites for different functional purposes. The electrochemical properties of the prepared product as an electrode material in energy storage applications was studied in details.

  • Open access
  • 54 Reads
Quantitative crystal structure analysis of Complex: tris((1-((E)-o-tolyldiazenyl)naphthalen-2-yl)oxy)cobalt.

Recently, azo derivatives have attracted attention because the phenylazo-naphtholate group can provide N,O-bidentate chelation to stabilize transition or main group metal complexes. azo derivatives and their metal complexes are very important pigments for synthetic leather and vinyl polymers. On the other hand, Azo-metal chelates are known to be involved in a number of biological reactions, such as inhibi- tion of DNA, RNA, and protein synthesis, nitrogen fixation, and carcinogenesis. Furthermore, high-density optical data storage has been a subject of extensive research in the past decade.

The present work aimed chiefly to throw more light on the Structural characterization of the title mononuclear Co(II). The coordination behaviour of this azo compound towards Co(II) ion is reported using different analytical tools of single crystal X-ray diffraction analysis. Furthermore, the role of weak intermolecular interactions in the crystal packing has been analysed and quantified using Hirshfeld surface analysis.

  • Open access
  • 123 Reads
Theoretical study of the Aza˗Wittig reaction, Me3P=NR (R = Methyl or Phenyl) with aldehyde by the DFT and DFT-D methods (dispersion correction)

The Aza-Wittig reaction played an important role in organic transformations and has known considerable development in the construction of cyclic and acyclic compounds in neutral solvents in the absence of catalysts with a high yield of product.

Today, the use of iminophosphoranes (Phosphazenes) has become a powerful tool in organic synthesis strategies directed towards the construction of nitrogenous heterocycles. These can react with carbonyl compounds, an excellent method for the construction of C=N double bonds via intermolecular and intramolecular aza-Wittig reactions.

In this study, we were interested in the theoretical study of the reaction path of the aza˗Wittig reaction between trimethyl-iminophosphoranes (CH3) 3P=NR, R=CH3 or Ph) for the two substituents methyl and phenyl with ethanal, including continuum solvation. Our calculations were carried out by means of ab-initio calculations using the theory of DFT and DFT-D, dispersion correction term using the Grimme method [8] in the program Gaussian09, using the functional B3LYP and B3LYP-GD3BJ with a 6-31G ** base.

The results obtained allowed us to highlight the mechanisms of the Aza-Wittig reaction in particular after the addition of the term of dispersion correction or Van der Walls correction which provided a new description of this reaction and its chemical path.

  • Open access
  • 128 Reads
3-(Biphenyl)acrylates by one pot Suzuki cross coupling - Wittig olefination reactions

3-(Biphenyl)acrylates are prepared in good yield by one pot Suzuki cross coupling - Wittig olefination reactions. Central building blocks are 4-formyl- and 3-formylphenylboronic acids and the stabilized (carbomethoxymethylidene)triphenylphosphorane. Examples of one pot Suzuki - double Wittig combinations are shown, also.

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