Synthesis and Structural Characterization of (2,4-Diamino-5-(3′,4′,5′-Trimethoxybenzyl)Pyrimidine Copper (II)) Complex

Abstract  The reaction of Cu(OOCCH₃)₂·H₂O with (2,4-diamino-5-(3′,4′,5′-trimethoxybenzyl) pyrimidine (trimethoprim) in ethanolic solution at 80 °C affords the title complex which has been characterized by elemental, IR, and NMR (¹H and ¹³C).The crystal structure has been determined by single crystal X-ray diffraction. Compound 1 (C₃₆H₄₈Cu₂N₈O₁₄) is triclinic, space group P-1 with a = 7.2676(4) ?, b = 11.6721(7) ?, c = 12.8279(8) ?, α = 95.839(1)°, β = 93.456(1)°, γ = 105.541(1)°, Z = 1. Two copper atoms are coordinated directly to each other as well as are held together by four bridging aceto groups. Each copper atom is also bonded opposite the Cu–Cu vector to a trimethoprim molecule through the N(1) atom of the pyrimidine ring. Trimethoprim acts as a monodentate ligand through the pyrimidine nitrogen N(1) atom. The complex was screened for the activity against several bacteria, showing more activity against bacteria as compared to trimethoprim. Graphical Abstract  To enhance the activity of trimethoprim, its derivative was prepared and there bacterial activity against several bacteria was analyzed.      

Synthesis of (2,4-Diamino-5-(3′,4′,5′-trimethoxybenzyl) Pyrimidine) Copper (II) Complex at 20–25 °C and its Structural Characterization

Abstract  The title copper (II) complex with Trimethoprim was prepared at 20–25 °C and its crystal structure was determined by single crystal X-ray diffraction. Compound (C₃₆H₅₀Cu₃N₈O₁₆) is triclinic, space group P-1 with a = 6.4642(5) ?, b = 12.5495(9) ?, c = 13.4911(10) ?, α = 77.518(1)°, β = 85.326(1)°, γ = 84.413(2)°, Z = 1. In this compound, three copper atoms are bonded to each other, two terminal coppers are bonded to three oxygen atoms and N₁ of pyrimidine ring of Trimethoprim and central copper is bonded to four oxygen atoms. The amino nitrogen atoms are not involved in the coordination to the metal. Graphical Abstract  To enhance the activity of trimethoprim, its derivative was prepared and there bacterial activity against several bacteria was analyzed.      

Instantaneous work hardening behaviour of two-phase tungsten heavy alloys: a phenomenological approach

ABSTRACT

The present work describes a phenomenological approach to explain the instantaneous behaviour of tungsten heavy alloys (WHAs) in heat-treated and swaged conditions. The strengths and elongation values of heat-treated materials are lower and higher than those of the swaged samples respectively. The heat-treated materials exhibit two slopes in true stress–true plastic strain curves and follow the Ludwigson constitutive equation. On the other hand, swaged materials display a single slope and adhere to typical Swift constitutive equation. The latter reflect the presence of pre-strain in the materials due to swaging deformation. The fracture surfaces in heat-treated materials consist of W-W decohesion along with matrix rupture and W-cleavage, while swaged samples consist of mainly W-cleavage. Both the materials display three typical stages (I, II and III) of work hardening. The second derivatives of true stress–true plastic strain curves of these alloys exhibit a perfect parabola although the nature of true stress–true strain as well as true stress–true plastic strain curves is quite different in heat-treated and swaged materials. This has been observed for the first time in WHAs consisting of matrix and W-grains. The shape of the parabola is simple and easy to fit. The fitting parameters of parabolas have been successfully employed to explain the flow behaviour of a large number of tungsten heavy alloys having two-phase microstructure in different processing conditions.     

Spectroscopic properties of Dy(3+) ions in NaF-B(2)O(3)-Al(2)O(3) glasses

This paper reports the optical properties of Dy(3+) in sodium fluoroborate glasses of the type XNaF.(89-X)B(2)O(3).10 Al(2)O(3).1Dy(2)O(3) (where X=8, 12, 16, 20 and 24). Judd-Ofelt intensity parameters (Omega(2), Omega(4), Omega(6)) are derived from the absorption spectra. The Judd-Ofelt theory has been applied to interpret the local environment of Dy(3+) ions and bond covalency of RE-O bond. These parameters have been used to calculate radiative transition probabilities (A(rad)), lifetimes (tau(R)) and branching ratios (beta(R)) for the excited level (4)F(9/2). The predicted values of tau(R) are compared with the measured values for (4)F(9/2) level for five glass compositions (Glass (A-E)). The stimulated emission cross-section sigma(lambda(P)) are also evaluated for the (4)F(9/2)-->(6)H(J) (J=11/2, 13/2, and 15/2) transitions.     

Electrospun PDA‐CA Nanofibers toward Hydrophobic Coatings

Nowadays, encapsulated dyes in a polymeric matrix have opened up new perspectives in many applications such as filtration of subatomic particles, composite reinforcement, multifunctional membranes, tissue engineering scaffolds, wound dressing, coatings, medical purposes as well as sensors. In the presented work, we report on electrospinning neat peryelene dianhydride based thermoplastic elastomers. Perylene‐3, 4,9, 10‐tetracarboxylic dianhydride (PDA) is encapsulated into cellulose acetate (CA) electrospun fibers, which was prepared from 12 % cellulose acetate solution, at 20 kV with a distance of 10 cm. The flow rate was 0.2 ml · h^–1. These water repellent nanofibrous coatings are anticipated to serve as hydrophobic coatings. Scanning electron microscope is used to study the properties of the electrospun PDA‐CA nanofibers.     

Dark Energy Models and Cosmic Acceleration with Anisotropic Universe in f（T） Gravity

This paper is devoted to studing the accelerated expansion of the universe in context of f（T） theory of gravity. For this purpose, we construct different f（T） models and investigate their cosmological behavior through equation of state parameter by using holographic, new agegraphic and their power-law entropy corrected dark energy models. We discuss the graphical behavior of this parameter versus redshif~ for particular values of constant parameters in Bianchi type I universe model. It is shown that the universe lies in different forms of dark energy, namely quintessence, phantom, and quintom corresponding to the chosen scale factors, which depend upon the constant parameters of the models.     

Fixed-Dose Combination Antibiotics Interacting with a Quaternary Ammonium Disinfectant: Insights from Spectral and Chromatographic Measurements

Core–shell architecture of surfactant micelles can act to shield active drug molecules from the adverse environmental conditions and enhance their bioavailability. In the present study the molecular interactions of a fixed dose combination (FDC) containing ofloxacin (OFX) and ornidazole (ORN), with cetyltrimethylammonium bromide (CTAB, a quaternary ammonium surfactant) were investigated under normal physiological pH (pH 7.4?±?0.1). The impact of the cationic micelle on the spectral and physiochemical properties of the FDC components OFX and ORN was systematically examined by electronic spectroscopy. Micellar liquid chromatography and differential spectral methods were used to optimize analysis of the magnitude of binding constants and related Gibbs energies. The results suggest the potential solubilization of drugs in the external part of the micelles, which may prove to be more helpful for their controlled release. These outcomes have been verified by the binding capacities of drug–CTAB combinational system that may be helpful to customize the uptake of drug molecules in cells.     

Phytochemical screening and chemical variability in volatile oils of aerial parts of Morinda morindoides

Morinda morindoides is an important Liberian traditional medicine for the treatment of malaria, fever, worms etc. The plant was subjected to integrated approaches including phytochemical screening and gas chromatography mass spectrometry (GC–MS) analyses. Phytochemical investigation of the powdered plant revealed the presence of phenolics, tannins, flavonoids, saponins, terpenes, steroidal compounds and volatile oil. Steam distillation followed by GC–MS resulted in the identification of 47 volatiles in its aerial parts: 28 were in common including various bioactive volatiles. Major constituents of leaves were phytol (43.63%), palmitic acid (8.55%) and geranyl linalool (6.95%) and stem were palmitic acid (14.95%), eicosane (9.67%) and phytol (9.31%), and hence, a significant difference in the percentage composition of aerial parts was observed. To study seasonal changes, similarity analysis was carried out by calculating correlation coefficient (r) and vector angle cosine (z) that were more than 0.91 for stem-to-stem and leaf-to-leaf batches indicating considerable consistency.     

Elemental characterisation of strawberry grown in Islamabad by <Emphasis Type="Italic">k</Emphasis><Subscript>0</Subscript>-instrumental neutron activation analysis and atomic absorption spectrophotometry and its dietary assessment

Mineral contents of strawberry, collected from different farms of Islamabad were analysed by semi-absolute k ₀-instrumental neutron activation analysis and atomic absorption spectrophotometry. The samples were irradiated at two research reactors located in Pakistan Institute of Nuclear Science & Technology (PINSTECH), Islamabad. The analytical methodologies were validated by analysing reference materials, IAEA-336 (lichen) and IAEA-V-10 (hay powder). In all the samples, a total of 26 elements were quantified, among them 16 elements (Ca, Cd, Cl, Co, Cr, Cs, Fe, K, Mg, Mn, Na, Pb, Ru, Sc, Sr and Zn) were found in all the samples. The determined elemental concentrations in strawberry were compared with the reported values from other countries. In comparison with the mineral contents of other fruits, strawberry stands best source of Mn and the second most important source of K after banana. Intake of trace metals through this source was calculated and it was found that strawberry provides Mn (1.95–3.68 mg/kg), Cr (19.2–46.3 × 10⁻³ mg/kg), Fe (3.45–8.72 mg/kg), K (1,520–1,670 mg/kg) and Mg (100–220 mg/kg), which forms 26, 19, 14, 7 and 7% of the recommended dietary allowances for the respective metals. The daily intake of Cd and Pb were compared with the provisional tolerable weekly intake defined by FAO/WHO.