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  • Open access
  • 77 Reads
Microwave assisted synthesis of CoFe2O4 nanoparticles by utilizing organic promoters and evaluation of its properties

Nano-sized spinel ferrites are highly regarded owing to their special optical, electrical and magnetic properties. Cobalt ferrite, CoFe2O4, is a nominee of particular interest due to its high saturation magnetization, high coercivity, strong anisotropy and excellent chemical stability. The synthesis of these materials with a pure crystalline phase is sometimes limited due to the required high temperatures for their calcination. In this work, we report a one-pot simple synthesis procedure of cobalt ferrite by the auto-combustion under microwave irradiation into a domestic microwave oven with a power of 900W for 30 min. Glycine and ammonium nitrate were used as organic promoters and metal nitrates as precursors. The synthesized nanoparticles were characterized by fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), vibrating sample magnetometer (VSM), scanning electron microscopy (SEM) and energy dispersion of x-ray spectrometry (EDX) techniques. The electrochemical properties and capability of the prepared product as a pseudocapacitive material were evaluated using cyclic voltammetry (CV) tests in details.

  • Open access
  • 68 Reads
Molecular docking studies on synthetic therapeutic agents for COVID-19

Coronavirus disease (COVID-19) is an infectious disease caused by coronavirus 2 (SARS CoV-2) who have been detected for the first time in Wuhan China in December 2019. The rapid spread of this highly contagious and pathogenic virus led to the declaration of the pandemic by the World Health Organization (WHO) on March 11, 2020. In these conditions, the discovery of new antiviral agents is extremely important. For the development of the anti-SARS-CoV-2 drugs, the fastest way is to find potential molecules from the marketed drugs by molecular docking studies. Molecular docking studies have been performed to identify and visualize the most likely interaction of the ligand with the protein/enzyme receptor. The docking score and hydrogen bonds formed with the amino acids from of the group interaction atoms are used to predict the binding modes, the binding affinity, and the orientation of the docked ligands in the active site of the protein/enzyme receptor. The docking study have been carried out with synthetic anti-viral agents (13) and anti-inflammatory agents (2) as ligands against the SARS-CoV-2 main protease (PD ID: 6W63, PD ID: 6WNP), SARS-CoV-2 spike glycoprotein (closed state) (PD ID: 6VXX), SARS-CoV-2 chimeric receptor-binding domain complexed with its receptor human ACE2 (PD ID: 6VW1), SARS-CoV-2 RNA-dependent RNA polymerase (PD ID: 6M71), SARS-CoV-2 3CL protease (3CL pro) (PD ID: 6M2N).

  • Open access
  • 65 Reads
Molecular Docking Studies on Various Food Grades Dyes as a Potential Inhibitor of COVID-19

In December 2019, the Coronavirus disease-2019 (COVID-19 virus) had emerged in Wuhan, China. The first resolved COVID-19 crystal structure (main protease) has been developed and various repurposing activities are in process. In this study, a knowledge gap concerning COVID-19 with the previously known fatal Coronaviruses (CoVs) epidemics, SARS, and MERS CoVs, has been covered by investigation of sequence statistics, molecular modelling, virtual screening, docking, and sequence comparison statistics of the COVID-19 main protease. COVID-19 Mpro formed a sequence similarity group with SARS CoV that was distant from MERS CoV. The identity % was 96 and 51 for COVID-19/SARS and COVID-19/MERS CoV sequence comparisons, respectively. We have used molecular docking and molecular interaction approaches to identify small molecules that bind to the isolated Viral S-protein at its host receptor region. Screened food-grade dyes were chosen for finding the binding affinity against COVID-19 main protease (PDB ID: 6lu7). Further, ADME and toxicity profiling of the molecules were performed as substantiate studies. The results indicate that molecules have good solubility and pharmacodynamics properties, they also obey Lipinski’s rule, which makes them promising compounds to pursue further biochemical and cell-based assays to explore their potential for use against nCOVID-19. We hypothesize that the top score identified molecules may be used to limit the viral recognition of host cells and/or disrupt host-virus interactions.

  • Open access
  • 33 Reads
Preparation of Cu4SnS4 /CuCo2S4 nanoparticles using combustion reaction accelerated by organic driving agents under microwave irradiation

Copper based sulfide-rich nanomaterials have recently attracted attentions in various applications due to inexpensive, abundance and non-toxicity of their constituent elements. Cu4SnS4 and CuCo2S4 as the members of this family have exhibited good capability with a stable manner in solar cells, energy storage electrodes, batteries, etc. In this work, through a facile and rapid combustion reaction accelerated by microwave irradiation, Cu4SnS4/CuCo2S4 nanoparticles was prepared. Thiourea was used as a sulphur source and also organic driving agent. The features of the synthesized product were studied using fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersion of x-ray spectrometry (EDX) techniques. The FT-IR and XRD results showed the formation of a multi-components structure containing orthorhombic crystal phase of Cu4SnS4 alongside carrollite CuCo2S4 phase. Some electrochemical properties of the as-prepared nanomaterial was investigated by performing cyclic voltammetry (CV) tests in different electrolytes.

  • Open access
  • 59 Reads
Interactions between isoniazid and a-hydroxycarboxylic acids

The present study refers to the preparation of isonicotinic acid hydrazide (isoniazid, inh) co-crystals with two α-hydroxycarboxylic acids. The interaction of glycolic acid (H2ga) or mandelic acid (H2ma) resulted in the formation of co-crystals or salts of composition (inh)·(H2ga) (1) and [Hinh]+[Hma]·(H2ma) (2) when reacted with isoniazid. An N'-(propan-2-ylidene)isonicotinic hydrazide hemihydrate, (pinh)·1/2(H2O) (3), was also prepared by condensation of isoniazid with acetone in the presence of glycolic acid. The prepared compounds were well characterized by elemental analysis, and spectroscopic methods, and their three-dimensional molecular structure was determined by single crystal X-ray crystallography.

  • Open access
  • 313 Reads
Synthesis and leishmanicidal activity of molecular hybrids 1,2,3-triazole-chalcones.

Leishmaniasis is a largely neglected infection caused by Leishmania spp. parasites. The first-line treatment, antimoniate meglumine, has a large number of adverse effects, high cost, and is developing resistance, hence the necessity of developing new alternatives. We report here the synthesis of (2E)-1-[1-(4-methoxyphenyl)-5-methyl-1H-1,2,3-triazol-4-yl]-3-arylprop-2-en-1-one derivatives and the evaluation of their leishmanicidal activities. A series of 16 compounds were synthesized in three steps starting from p-anisidine with moderate to good yields and their biological activities were evaluated in vitro on Leishmania mexicana promastigotes and RAW 264.7 cells. The synthesis of the 1,2,3-triazol and chalcone moieties were made using a cycloaddition with acetylacetone followed by a Claisen-Schmidt condensation using different substituted benzaldehydes. Our results indicate that ten compounds were active against the parasite with IC50 between 0.8-11.6 µM. Most of the active compounds are fluorinated, being the most active compound one that presents an o-trifluoromethyl moiety.

  • Open access
  • 70 Reads
Sustainable synthesis of polymeric materials versus fine chemicals via CO2 addition to epoxides

Increasing concerns about global warming and a potential energy crisis have prompted the search for new technologies for converting CO2, a notorious greenhouse gas resulting from fossil fuel burning. Due to the high chemical inertness of CO2 molecule, chemical reactions involving CO2 activation usually face large energy barriers and require the development of highly effective catalysts.

In this context, the use of carbon dioxide as a source of C1 is a relevant topic in the scientific community and, over the last decade, there has been a remarkable scientific and technological advance in terms of the development of chemical processes for converting CO2 into products with added value. We highlight the reaction of CO2 addition to epoxides, from which it is possible to selectively obtain two types of products: cyclic carbonates and polycarbonates, both with relevant applications, such as green solvents and in plastic engineering, respectively.

In this work, we present our recent results on the application of metal complexes of tetrapyrrolic macrocycles (porphyrins and phthalocyanines) as catalysts in CO2 addition reactions to epoxides. The effects of substrate, catalyst structure, as well as the reaction conditions (temperature and CO2 pressure) on the modulation of the reaction selectivity will be discussed. So far, using cyclohexene oxide as substrate, Cr(III) porphyrin-based catalysts showed high activity and selectivity for polycarbonates while Al(III) cationic phthalocyanines led to the formation of polymers containing high ether linkage content. Furthermore, using styrene oxide as substrate, Zn(II) and Cu(II) phthalocyanine catalysts derived from natural-based terpene derivatives (menthol and myrtenol) led to the formation of cyclic carbonates with 100% selectivity.

  • Open access
  • 47 Reads
Cu.BTC MOF as a novel and efficient catalyst for the synthesis of 1, 8-dioxo-octa-hydro xanthene

A copper-based metal-organic framework with 1, 3, 5-tricarboxylic acid linkers was prepared through a facile hydrothermal method. This MOF has not been used in organic reactions widely. Cu.BTC was employed as an affordable, competent heterogeneous catalyst in 1, 8-dioxo-octa-hydro xanthene synthesis. Additionally, the structure, morphology, and porosity of this catalyst were considered. Various techniques such as FE-SEM, BET, EDS, FT-IR, and XRD applied to this aim. As a result, Cu.BTC had a mesoporous structure, an excellent specific surface area, and high purity. Some privileges of using this heterogeneous catalyst in 1, 8-dioxo-octa-hydro xanthene synthesis are mild condition, increased activity, ease in separation, and reusability. Also, 1, 8-dioxo-octa-hydro xanthene was obtained via simple recrystallization.

  • Open access
  • 56 Reads
Interactions of alkyl-gallates with SARS-CoV-2 main protease: a molecular docking approach

10 natural and semi-synthetic compounds (gallic acid and alkyl gallates) are investigated by in silico methods in order to evaluate their potential inhibitory activity against SAR-CoV-2 using X-ray structure of SARS-CoV-2 main protease bound to Boceprevir at 1.45 A (PDB ID: 6WNP). Evaluation of drug-likeness in terms of Lipinski’s rule of Five and docking results in terms of docking score and interactions with the amino acids residues form the active binding site of the target protein, are reported. Promising results are obtained for Octyl 3,4,5-trihydroxybenzoate, that exhibits the greatest docking score.

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