Enhancement of Haloperidol Binding Affinity to Dopamine Receptor via Forming a Charge-Transfer Complex with Picric Acid and 7,7,8,8-Tetracyanoquinodimethane for Improvement of the Antipsychotic Efficacy

Haloperidol (HPL) is a typical antipsychotic drug used to treat acute psychotic conditions, delirium, and schizophrenia. Solid charge transfer (CT) products of HPL with 7,7,8,8-tetracyanoquinodimethane (TCNQ) and picric acid (PA) have not been reported till date. Therefore, we conducted this study to investigate the donor–acceptor CT interactions between HPL (donor) and TCNQ and PA (π-acceptors) in liquid and solid states. The complete spectroscopic and analytical analyses deduced that the stoichiometry of these synthesized complexes was 1:1 molar ratio. Molecular docking calculations were performed for HPL as a donor and the resulting CT complexes with TCNQ and PA as acceptors with two protein receptors, serotonin and dopamine, to study the comparative interactions among them, as they are important neurotransmitters that play a large role in mental health. A molecular dynamics simulation was ran for 100 ns with the output from AutoDock Vina to refine docking results and better examine the molecular processes of receptor–ligand interactions. When compared to the reactant donor, the CT complex [(HPL)(TCNQ)] interacted with serotonin and dopamine more efficiently than HPL only. CT complex [(HPL)(TCNQ)] with dopamine (CTtD) showed the greatest binding energy value among all. Additionally, CTtD complex established more a stable interaction with dopamine than HPL–dopamine.     

Improving the Thermal Behavior and Flame-Retardant Properties of Poly(o-anisidine)/MMT Nanocomposites Incorporated with Poly(o-anisidine) and Clay Nanofiller

The synthesis of MMT and poly(o-anisidine) (MMT/POA) clay nanocomposites was carried out by using the chemical oxidative polymerization of POA and MMT clay with POA, respectively. By maintaining the constant concentration of POA, different percentage loads of MMT clay were used to determine the effect of MMT clay on the properties of POA. The interaction between POA and MMT clay was investigated by FTIR spectroscopy, and, to reveal the complete compactness and homogeneous distribution of MMT clay in POA, were assessed by using scanning-electron-microscope (SEM) analysis. The UV–visible spectrum was studied for the optical and absorbance properties of MMT/POA ceramic nanocomposites. Furthermore, the horizontal burning test (HBT) demonstrated that clay nanofillers inhibit POA combustion.     

Microbial Degradation,Spectral analysis and Toxicological Assessment of Malachite Green Dye by Streptomyces exfoliatus

Malachite green (MG) dye is a common environmental pollutant that threatens human health and the integrity of the Earth’s ecosystem. The aim of this study was to investigate the potential biodegradation of MG dye by actinomycetes species isolated from planted soil near an industrial water effluent in Cairo, Egypt. The Streptomyces isolate St 45 was selected according to its high efficiency for laccase production. It was identified as S. exfoliatus based on phenotype and 16S rRNA molecular analysis and was deposited in the NCBI GenBank with the gene accession number {"type":"entrez-nucleotide","attrs":{"text":"OL720220","term_id":"2159919206","term_text":"OL720220"}}OL720220. Its growth kinetics were studied during an incubation time of 144 h, during which the growth rate was 0.4232 (µ/h), the duplication time (td) was 1.64 d, and multiplication rate (MR) was 0.61 h, with an MG decolorization value of 96% after 120 h of incubation at 25 °C. Eleven physical and nutritional factors (mannitol, frying oil waste, MgSO₄, NH₄NO₃, NH₄Cl, dye concentration, pH, agitation, temperature, inoculum size, and incubation time) were screened for significance in the biodegradation of MG by S. exfoliatus using PBD. Out of the eleven factors screened in PBD, five (dye concentration, frying oil waste, MgSO₄, inoculum size, and pH) were shown to be significant in the decolorization process. Central composite design (CCD) was applied to optimize the biodegradation of MG. Maximum decolorization was attained using the following optimal conditions: food oil waste, 7.5 mL/L; MgSO₄, 0.35 g/L; dye concentration, 0.04 g/L; pH, 4.0; and inoculum size, 12.5%. The products from the degradation of MG by S. exfoliatus were characterized using high-performance liquid chromatography (HPLC) and gas chromatography-mass spectrometry (GC-MS). The results revealed the presence of several compounds, including leuco-malachite green, di(tert-butyl)(2-phenylethoxy) silane, 1,3-benzenedicarboxylic acid, bis(2-ethylhexyl) ester, 1,4-benzenedicarboxylic acid, bis(2-ethylhexyl) ester, 1,2-benzenedicarboxylic acid, di-n-octyl phthalate, and 1,2-benzenedicarboxylic acid, dioctyl ester. Moreover, the phytotoxicity, microbial toxicity, and cytotoxicity tests confirmed that the byproducts of MG degradation were not toxic to plants, microbes, or human cells. The results of this work implicate S. exfoliatus as a novel strain for MG biodegradation in different environments.     

Magnetic,Electronic, and Optical Studies of Gd-Doped WO3: A First Principle Study

Tungsten trioxide (WO₃) is mainly studied as an electrochromic material and received attention due to N-type oxide-based semiconductors. The magnetic, structural, and optical behavior of pristine WO₃ and gadolinium (Gd)-doped WO₃ are being investigated using density functional theory. For exchange-correlation potential energy, generalized gradient approximation (GGA+U) is used in our calculations, where U is the Hubbard potential. The estimated bandgap of pure WO₃ is 2.5 eV. After the doping of Gd, some states cross the Fermi level, and WO₃ acts as a degenerate semiconductor with a 2 eV bandgap. Spin-polarized calculations show that the system is antiferromagnetic in its ground state. The WO₃ material is a semiconductor, as there is a bandgap of 2.5 eV between the valence and conduction bands. The Gd-doped WO₃’s band structure shows few states across the Fermi level, which means that the material is metal or semimetal. After the doping of Gd, WO₃ becomes the degenerate semiconductor with a bandgap of 2 eV. The energy difference between ferromagnetic (FM) and antiferromagnetic (AFM) configurations is negative, so the Gd-doped WO₃ system is AFM. The pure WO₃ is nonmagnetic, where the magnetic moment in the system after doping Gd is 9.5599575 μB.     

A Computational Analysis of the Intrinsic Plasticity of Five-Coordinate Cu(II) Complexes and the Factors Leading to the Breakdown of the Orbital Directing Effect in Paddlewheel Secondary Building Units

Quantum chemical calculations on model copper paddlewheel (CPW) complexes of general formula [Cu₂(μ₂-O₂CR)₄L₂] establish two local coordination geometries at the metal centers depending on the balance between equatorial and axial ligand fields. When the equatorial field is stronger than the axial field (large ligand field asymmetry), dominates the stereochemical activity of the d⁹ shell resulting in a relatively rigid, “orbitally directed” planar or square pyramidal structure. However, if the axial field is significantly increased, or the equatorial field moderately weakened, a small ligand field asymmetry results and both and are involved in the stereochemical activity. This results in a “plastic,” distorted trigonal bipyramidal geometry where the former axial ligand moves into one of the original four equatorial positions. Linkers already used to synthesize zinc-dabco MOFs (dabco = 1,4-diazabicyclo[2.2.2]octane) are shown to generate plastic CPW secondary building unit analogs with potential implications for conferring breathing behavior for MOFs which would currently be assumed to be rigid. © 2019 Wiley Periodicals, Inc.     

Antibacterial and antioxidant potency of floral honeys from different botanical and geographical origins

In order to assess their physicochemical and antioxidant properties as well as their antimicrobial potency, four varieties of honey from different botanical and geographical origins were used. The agar incorporation method was used to determine the antimicrobial potency of honeys. The total phenol content was determined by a modified Folin-Ciocalteu method and the free radical scavenging activity by the Fe³⁺ reducing power (FRAP) assay. Manuka honey was the most effective against Staphylococcus aureus Oxa R and S. aureus Oxa S with a Minimum Inhibitory Concentration (MIC) of 6% and 7%, respectively, whereas wild carrot honey was the most effective against Pseudomonas aeruginosa, with a MIC of 12%. Lavender honey was the least effective against all tested strains, even though was found to have the lowest pH and water content. Manuka honey had the highest content of polyphenols, with 899.09 ± 11.75 mg gallic acid/kg, whereas lavender honey had the lowest, with 111.42 ± 3.54 mg gallic acid/kg. A very significant correlation (r value was 0.9079 at P < 0.05) was observed between the total polyphenolic content and the Fe²⁺ content formed in the presence of the honey antioxidants. The differences between honey samples in terms of antibacterial and antioxidant activity could be attributed to the natural variations in floral sources of nectar and the different locations.     

Ab initio calculations of surface structure and electronic properties caused by adsorption of Ca atoms on a Si(1 1 0) surface

The adsorption of Ca metals onto a Si(1 1 0) surface has been theoretically investigated by first-principle total-energy calculations. We employed a local density approximation of the density functional theory as well as a pseudopotential theory to study the atomic and electronic properties of the Ca/Si(1 1 0) structure. The (1×1) and (2×1) surface structures were considered for Ca coverages of 0.5 and 0.25 ML, respectively. It is found that the (1×1) phase is not expected to occur even for rich Ca regime. It was found that Ca adatoms are adsorbed on top of the surface and form a bridge with the uppermost Si atoms. The most stable structure of Ca/Si(1 1 0)-(2×1) surface produces a semiconducting surface band structure with a direct band gap that is slightly smaller than that of the clean surface. We have observed one filled and two empty surface states in the gap region. These empty surface states originated from the uppermost Si dangling bond states and the Ca 4s states. Furthermore, the Ca-Si bonds have an ionic nature with almost complete charge transfer from Ca to the surface Si atoms. The structural parameters of the ground state atomic configuration are detailed and compared with the available results of metal-adsorbed Si(1 1 0) surface, Ca/Si(0 0 1), and Ca/Si(1 1 1) structures.     

Optical solitons and bifurcation analysis in fiber Bragg gratings with Lie symmetry and Kudryashov’s approach

A combination of Lie symmetry analysis and Kudryashov’s approach secures optical soliton solutions with fiber Bragg gratings. The bifurcation analysis is carried out, and the phase portrait is presented.

     

Synthesis of New Naphthyl Aceto Hydrazone-Based Metal Complexes: Micellar Interactions,DNA Binding,Antimicrobial, and Cancer Inhibition Studies

In the present study, naphthyl acetohydrazide (HL) ligand was prepared and used for the synthesis of new six amorphous transition metal (Co(II), Ni(II), Cu(II), Zn(II), Pb(II), Cd(II)) complexes. All the compounds were characterized by elemental analysis, UV-vis, FT-IR, ¹H- and ¹³C-NMR, and Matrix-Assisted Laser Desorption Ionization (MALDI). The solubilization study was carried out by estimating the interaction between the metal complexes with surfactants viz. sodium stearate (SS) and Cetyltrimethylammonium bromide (CTAB). UV-Visible spectroscopy was employed to determine partitioning and binding parameters, whereas electrical conductivity measurements were employed to estimate critical micellar concentration (CMC), the extent of dissociation, and free energy of micellization. The CT-DNA interaction of synthesized compounds with DNA represents the major groove binding. The synthesized ligand and metal complexes were also tested against bacterial and fungal strains and it has been observed that Cu(II) complex is active against all the strains except Candida albicans, while Cd(II) complex is active against all bacterial and fungal strains except Pseudomonas. Among all compounds, only the Pd(II) complex shows reasonable activity against cervical cancer HeLa cell lines, representing 97% inhibition.     

Hierarchical Tubular Architecture Constructed by Vertically Aligned CoS2-MoS2 Nanosheets for Hydrogen Evolution Electrocatalysis

Developing efficient electrocatalysts for the hydrogen evolution reaction (HER) is crucial for establishing a sustainable and environmentally friendly energy system, but it is still a challenging issue. Herein, hierarchical tubular-structured CoS₂-MoS₂/C as efficient electrocatalysts are fabricated through a unique metal–organic framework (MOF) mediated self-sacrificial templating. Core–shell structured MoO₃@ZIF-67 nanorods are used both as a precursor and a sacrificial template to form the one-dimensional tubular heterostructure where vertically aligned two-dimensional CoS₂-MoS₂ nanosheets are formed on the MOF-derived carbon tube. Trace amounts of noble metals (Pd, Rh, and Ru) are successfully introduced to enhance the electrocatalytic property of the CoS₂-MoS₂/C nanocomposites. The as-synthesized hierarchical tubular heterostructures exhibit excellent HER catalytic performance owing to the merits of the hierarchical hollow architecture with abundantly exposed edges and the uniformly dispersed active sites. Impressively, the optimal Pd-CoS₂-MoS₂/C-600 catalyst delivers a current density of 10 mA cm⁻² at a low overpotential of 144 mV and a small Tafel slope of 59.9 mV/dec in 0.5 m H₂SO₄. Overall, this MOF-mediated strategy can be extended to the rational design and synthesis of other hollow heterogeneous catalysts for scalable hydrogen generation.