Synthesis and In Silico Investigation of Isatin-Based Schiff Bases as Potential Inhibitors for Promising Targets against SARS-CoV-2.

Despite the significant development in vaccines and therapeutics cocktails, there is no specific treatment available for coronavirus disease 2019 (COVID-19), caused by the new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Targeting the main protease (M) of SARS-CoV-2, which possesses a key role in producing the essential viral structural and functional proteins, can be considered an efficient way to control this potentially lethal infection. Recently, some of Michael acceptor-pharmacophore containing inhibitors have been suggested as successful suppressors of the main protease.

In silico investigation of the therapeutic and prophylactic potential of medicinal substances bearing guanidine moieties against COVID-19.

Unlabelled: The current viral pandemic, coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), creates health, mental, economic, and other serious challenges that are better to say global crisis. Despite the existence of successful vaccines, the possible mutations which can lead to the born of novel and possibly more dangerous variants of the virus as well as the absence of definitive treatment for this potentially fatal multiple-organ infection in critically ill patients make us keep searching. Theoretically targeting human and viral receptors and enzymes via molecular docking and dynamics simulations can be considered a wise, rational, and efficient way to develop therapeutic agents against COVID-19.

A Highly Sensitive and Selective Quinazoline-Based Colorimetric Probe for Naked-Eye Detection of Fe Ions.

A novel quinazoline-based colorimetric sensor (probe 1) that detected Fe via naked-eye in a buffered MeOH: HO (8:2) solvent system within a neutral pH range was synthesized and its structure was confirmed by H-NMR, C-NMR, FT-IR, and Mass spectroscopy. Its photophysical properties were also studied. The sensitivity and selectivity factor in the presence of 16 metal ions was examined by utilizing absorption titrations.

Stereoselective synthesis of spirocyclic pyrrolidines/pyrrolizidines/pyrrolothiazolidines using l-proline functionalized manganese ferrite nanorods as a novel heterogeneous catalyst.

An efficient, green, one-pot, and three-component protocol has been reported for the stereoselective synthesis of a new class of spiro thiazolidines. A series of spiro-heterocycle derivatives were produced stereoselectively in high yields by the reaction of 5-arylidene thiazolidine-2,4-diones, isatin, and secondary amino acids in the presence of MnCoCuFeO@l-proline (MCCFeO@l-proline) magnetic nanorods as a novel nanocatalyst. The synthesized catalyst was fully characterized for thermal stability, magnetic properties, and other physicochemical properties numerous techniques.

Molecular docking and dynamics studies of Nicotinamide Riboside as a potential multi-target nutraceutical against SARS-CoV-2 entry, replication, and transcription: A new insight.

The highly contagious Coronavirus Disease 2019 (COVID-19) caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), which is a newborn infectious member of the dangerous beta-coronaviruses (β-CoVs) following SARS and MERS-CoVs, can be regarded as the most significant issue afflicting the whole world shortly after December 2019. Considering CoVs as RNA viruses with a single-stranded RNA genome (+ssRNA), the critical viral enzyme RNA dependent RNA polymerase (RdRp) is a promising therapeutic target for the potentially fatal infection COVID-19. Nicotinamide riboside (NR), which is a naturally occurring analogue of Niacin (vitamin B3), is expected to have therapeutic effects on COVID-19 due to its super close structural similarity to the proven RdRp inhibitors.

Cavity-trapped electrons: lithium doped tetracyano-2,6-naphthoquinodimethane (TNAP) systems.

The interesting features in the lithium based electride motived us to explore new species with electride properties. To achieve this goal, the tetracyano-2,6-naphthoquinodimethane (TNAP) species has been used as backbone to investigate systematic addition of lithium atoms to the TNAP backbone (Li@TNAP (n = 1-4) species) through density functional theory (DFT) simulation. After finding the most stable geometries for each Li@TNAP (n = 1-4) species by full optimization process, we show their electronic-structural features in this work.

Green Synthesis, Biological Activity Evaluation, and Molecular Docking Studies of Aryl Alkylidene 2, 4-thiazolidinedione and Rhodanine Derivatives as Antimicrobial Agents.

Aims And Objective: The magic scaffolds rhodanine and thiazolidine are very important heterocyclic compounds in drug design and discovery. Those are important heterocyclic compounds that have attracted a great deal of attention due to the fact that they exhibit a variety of bioactivities including antibacterial, antifungal, antiviral, antimalarial, and anti-inflammatory activities. These agents often exhibit selective toxicity.

High-efficiency purification of sulforaphane from the broccoli extract by nanostructured SBA-15 silica using solid-phase extraction method.

Sulforaphane, a promising phytochemical, has received much attention in recent decades as a potential anticarcinogenic compound. In this research work, a novel, specific and affordable method has been developed for the separation and purification of natural sulforaphane from broccoli extract using SBA-15 mesoporous silica. SBA-15 was found to be the most efficient in the purification of sulforaphane compared to some of the conventionally used adsorbents and zeolites.

A novel aluminum-sensitive fluorescent chemosensor based on 4-aminoantipyrine: An experimental and theoretical study.

A practical and an efficient Schiff base fluorescent chemosensor, salicylidene-4-aminoantipyrinyl-4-aminophenol (A2) has been synthesized through the condensation procedure of 1-phenyl-2,3-dimethyl-4-(N-2-hydroxybenzylidene)-3-pyrazoline-5-one and 4-aminophenol. Compound A2 has displayed a considerable fluorescence enhancement with high selectivity and sensitivity toward Al ion and exhibited an emission band at 484 nm, which contained a low detection limit (LOD) of 1.06 × 10 M.

Design, synthesis, biological assessment and molecular docking studies of new 2-aminoimidazole-quinoxaline hybrids as potential anticancer agents.

In a search for novel antiproliferative agents, a series of quinoxaline derivatives containing 2-aminoimidazole (8a-8x) were designed and synthesized. The structures of synthesized compounds were confirmed by IR, H NMR, C NMR, Mass Spectroscopy and analyzed using HSQC, COSY, ROESY, HMBC techniques. The anticancer activity of all derivatives were evaluated for colon cancer and breast cancer cell lines by the MTT assay and acridine orange/ethidium bromide double staining method.

A new fluorene-based Schiff-base as fluorescent chemosensor for selective detection of Cr and Al.

2-((9H-fluoren-2-ylimino) methyl)phenol (F3) was synthesized by condensation reaction of 9H-fluoren-2-amine and 2-hydroxybenzaldehyde in EtOH and characterized by its melting point, H-,C NMR and molecular mass. F3 exhibits a high selectivity for detection of Cr and Al ions as a fluorescent chemosensor and showed a single emission band at 536nm upon excitation at 333nm according to fluorescence emission studies. The addition of Cr and Al make a significant increase in fluorescent intensity at 536nm in CHCN, while other metal ions have almost no influence on the fluorescence.

Na-ion batteries based on the inorganic BN nanocluster anodes: DFT studies.

It has been recently indicated that the Li-ion batteries may be replaced by Na-ion batteries because of their low safety, high cost, and low-temperature performance, and lack of the Li mineral reserves. Here, using density functional theory calculations, we studied the potential application of BN nanoclusters as anode in Na-ion batteries. Our calculations indicate that the adsorption energy of Na and Na are about -23.

A DFT study on the central-ring doped HBC nanographenes.

Nanographenes (NGs) are a segment of graphene whose dangling bonds are saturated with hydrogen atoms, introducing different properties and promising applications. Here we investigate the electronic, thermodynamic, optical, and structural properties of four CXYH NGs (X=B, and Al; and Y=N, and P) based on the density functional theory calculations. It was mainly found that 1) BN-NG is planar molecule and the others are buckybowl-shaped ones, 2) The bowl-to-bowl inversion Gibbs free energies (ΔG) of buckybowl shaped NGs are very huge and the rate constant is very small, hindering the inversion, 3) The relative energetic stability order based on the standard enthalpy of formation (ΔH) is as BN>AlN>BP>AlP, which the BN, and AlN doped NGs are stable at room temperature but the BP and AlP doped ones are instable, 4) The electrical conductivity order of magnitude is inverse of that of stability, 5) An exciton binding energy is predicted in the range of 0.

Hypothermic activity of acetaminophen; involvement of GABAA receptor, theoretical and experimental studies.

Objectives: The mechanism of hypothermia action of acetaminophen (APAP) remains unclear even 125 years after its synthesis. Acetaminophen produces hypothermia. The mechanism of this reduction in core body temperature is not clear but evidence shows that it is not dependent on opioid and cannabinoid receptors.

Novel coumarin-based fluorescent probe for selective detection of Cu(II).

We report an efficient and convenient method for preparing nitro-3-carboxamide coumarin derivatives, proposed as novel fluorescent chemosensor, through microwave irradiation. This compound can be used as fluorescent probe for Cu(2+) with selectivity over other metal ions in aqueous solution. The fluorescence of 6-nitro-N-[2-(dimethylamino)ethyl]-2-oxo-2H-chromene-3-carboxamide(3) is the highest in the presence of Cu(2+), with stronger excitation at λ=320nm than for the other cations tested.

Quantum dots and ionic liquid-sensitized effect as an efficient and green catalyst for the sensitive determination of glucose.

A novel fluorescence (FL) method using water-soluble CdSe quantum dots (QDs) is proposed for the fluorometric determination of hydrogen peroxide and glucose. Water-soluble CdSe QDs were synthesized by using thioglycolic acid as stabilizer in aqueous solutions. The nanoparticles were structurally and optically characterized by X-ray powder diffraction (XRD), dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FTIR), UV-Vis absorption spectroscopy, photoluminescence (PL) emission spectroscopy and transmission electron microscope (TEM).

New insights into the mechanism of iron-catalyzed cross-coupling reactions.

The mechanism of the iron-catalyzed cross-coupling of alkyl halides with aryl Grignard reagents is studied by a combination of GC monitoring and DFT calculation. Herein, we investigate two possible reaction pathways, the regular oxidative addition (OA) pathway and the atom transfer (AT) pathway that might occur in the rate-limiting step. The computational studies revealed that the AT pathway requires less energy than the regular OA pathway.

The use of imidazolium ionic liquid/copper complex as novel and green catalyst for chemiluminescent detection of folic acid by Mn-doped ZnS nanocrystals.

A novel chemiluminescence (CL) method using water-soluble Mn-doped ZnS quantum dots (QDs) as CL emitter is proposed for the chemiluminometric determination of folic acid in pharmaceutical formulation. Water-soluble Mn-doped ZnS QDs were synthesized by using L-cysteine as stabilizer in aqueous solutions. The nanoparticles were structurally and optically characterized by X-ray powder diffraction (XRD), dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FTIR), UV-Vis absorption spectroscopy and photoluminescence (PL) emission spectroscopy.

Determination of epinephrine in pharmaceutical formulation by an optimized novel luminescence method using CdS quantum dots as sensitizer.

In this article, a novel chemiluminescence method using water-soluble CdS quantum dots (QDs) as sensitizers is proposed for the chemiluminometric determination of epinephrine. The method is based on the quenching effect of epinephrine on the chemiluminescence emission generated by the mixing of CdS quantum dots (QDs) with hydrogen carbonate (HCO3(-)) in the presence of hydrogen peroxide (H2O2) in an alkaline medium. The optimization of variables influencing the chemiluminescence response of the method has been carried out by using experimental design.

Immunohistochemical expression of vascular endothelial growth factor and its correlation with tumor grade in breast ductal carcinoma.

Breast cancer is the most common cause of cancer-related death in female, after lung cancer. Angiogenesis is essential for tumor growth and metastasis; therefore, antiangiogenesis strategies for treatment of cancer are currently an issue of interest. The role of vascular endothelial growth factor that assumed to be most potent angiogenesis factor is ambiguous in breast cancer.

Antioxidant and free radical scavenging activity of H. officinalis L. var. angustifolius, V. odorata, B. hyrcana and C. speciosum.

Extracts of 4 medicinal and aromatic plants were investigated for their antioxidant potency employing six various established in vitro system: H. officinalis L. var.