Synthesis of some thiopyrimidine and thiazolopyrimidines starting from 2,6-dibenzylidene-3-methylcyclohexanone and its antimicrobial activities

A series of novel N-substituted arylidene, pyrazole, thioxopyrimidine and thiazolopyrimidine derivatives 2–7 were synthesized by initial reactions of 2-methyl-cyclohexanone with aromatic aldehydes to give 2,6-dibenzylidene-3-methylcyclohexanone 2. Some of the synthesized compounds were tested as antimicrobial agents. The detailed synthesis, spectroscopic data, and antimicrobial activities of the synthesized compounds were reported.     

Determination of Ofloxacin using a Highly Selective Photo Probe Based on the Enhancement of the Luminescence Intensity of Eu3+—Ofloxacin Complex in Pharmaceutical and Serum Samples

A rapid, simple and sensitive spectrofluorimetric method for determination of trace amount of ofloxacin was developed. At pH 5.1 the ofloxacin enhances the luminescence intensity of the Eu³⁺ ion in Eu³⁺- ofloxacin complex at λ_ex = 365 nm. The produced luminescence intensity of Eu³⁺-ofloxacin complex was in proportional to the concentration of ofloxacin. The working range for the determination of ofloxacin was 5.0 × 10^-9–5.0 × 10^-6 mol L^-1 with lower detection limit (LOD) and quantitative detection limit (QDL) of 3 × 10^-9 and 9 × 10^-9 mol L^-1, respectively. The enhancement mechanism of the luminescence intensity in the Eu³⁺-ofloxacin system has been also explained. The method revealed good selectivity for ofloxacin in the presence of coexisting substances and used successfully for the assay of ofloxacin in pharmaceutical preparations and serum. A comparison with other standard methods was also discussed.     

Preparation and characterization of uniform particles of flufenamic acid and its calcium and barium salts

Uniform fully dispersed particles of flufenamic acid, a widely used anti-inflammatory drug, were prepared by two different methods. In the first one, the drug solution in organic solvents was added to a non-solvent (water or aqueous solutions of stabilizers); while in the second procedure the drug was precipitated by acidifying its basic aqueous solutions. In addition calcium and barium salts of uniform spherical particles were obtained by precipitation in aqueous basic solutions of the drug. These salts are supposed to improve the drug reactivity. The prepared dispersions of the drug and its salts were examined by scanning electron microscopy, X-ray diffractometry and electrophoresis.     

Large neighborhood search for LNG inventory routing

Liquefied Natural Gas (LNG) is steadily becoming a common mode for commercializing natural gas. Due to the capital intensive nature of LNG projects, the optimal design of LNG supply chains is extremely important from a profitability perspective. Motivated by the need for a model that can assist in the design analysis of LNG supply chains, we address an LNG inventory routing problem where optimized ship schedules have to be developed for an LNG project. In this paper, we present an arc-flow formulation based on the MIP model of Song and Furman (Comput. Oper. Res., 2010). We also present a set of construction and improvement heuristics to solve this model efficiently. The heuristics are evaluated based on a set of realistic test instances that are very large relative to the problem instances seen in recent literature related to this problem. Extensive computational results indicate that the proposed methods are computationally efficient in finding optimal or near optimal solutions and are substantially faster than state-of-the-art commercial optimization software.     

Generation of polarization entangled photons using concurrent type-I and type-0 processes in AlGaAs ridge waveguides

A technique to generate polarization entangled photons using concurrent type-I and type-0 second-order nonlinear processes in monolithic Bragg reflection waveguides is presented and analyzed. Concurrent phase matching is achieved by lithographic tuning of the waveguide ridge width. Nearly perfect entanglement is achievable on-chip through appropriate epistructure design without the need of spectral filtering and group velocity compensation. Theoretical calculations predict that a high quantum interference visibility could be experimentally achieved with the pair generation rate of each process being approximately 3.0×10(6) pairs/s/mW/GHz.     

Comparing the capability of collision/reaction cell quadrupole and sector field inductively coupled plasma mass spectrometers for interference removal from 90Sr, 137Cs,and 226Ra

Here we report a quantitative comparison of sector field inductively coupled plasma mass spectrometry (ICP-SFMS) and collision/reaction cell inductively coupled plasma quadrupole mass spectrometry (ICP-QMS) for the detection of ⁹⁰Sr, ¹³⁷Cs, and ²²⁶Ra at ultra-trace levels. We observed that the identification and quantification of radioisotopes by ICP-MS were hampered by spectral (both isobaric and polyatomic ions) and non-spectral (matrix effect) interferences. ICP-QMS has been used to eliminate the isobaric ⁹⁰Sr/⁹⁰Zr interference through the addition of O₂ into the collision cell as a reactant gas. Zr⁺ ions were subsequently converted into ZrO⁺, whereas Sr⁺ ions were not reactive. In addition, the isobaric interference of ¹³⁷Ba on ¹³⁷Cs was eliminated by the addition of N₂O gas in the cell, which led to the formation of BaO⁺ and BaOH⁺ products, whereas Cs⁺ remained unreactive. Furthermore, He and H₂ were used in the collision/reaction cell to eliminate polyatomic ions formed at m/z 226. A comparison of the results obtained by ICP-SFMS after a chemical separation of Sr from Zr and Cs from Ba was performed. Finally, to validate the developed analytical procedures, measurements of the same samples were performed by γ-ray spectroscopy.     

Preparation,characterization and biological activity of novel metal-NNNN donor Schiff base complexes

Novel Schiff base (H₂L) ligand is prepared via condensation of benzil and triethylenetetraamine. The ligand is characterized based on elemental analysis, mass, IR and ¹H NMR spectra. Metal complexes are reported and characterized based on elemental analyses, IR, ¹H NMR, solid reflectance, magnetic moment, molar conductance, and thermal analyses (TG, DTG and DTA). 1:1 [M]:[H₂L] complexes are found from the elemental analyses data having the formulae [M(H₂L)Cl₂]·yH₂O (M = Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II)), [Fe(H₂L)Cl₂]Cl·H₂O, [Th(H₂L)Cl₂]Cl₂·3H₂O and [UO₂(H₂L)](CH₃COO)₂·2H₂O. The metal chelates are found to be non-electrolytes except Fe(III), Th(IV) and UO₂(II) complexes are electrolytes. IR spectra show that H₂L is coordinated to the metal ions in a neutral tetradentate manner with 4Ns donor sites of the two azomethine N and two NH groups. The geometrical structures of these complexes are found to be octahedral. The thermal behaviour of these chelates is studied where the hydrated complexes lose water molecules of hydration in the first step followed immediately by decomposition of the anions and ligand molecules in the subsequent steps. The activation thermodynamic parameters are calculated using Coats–Redfern method. The ligand (H₂L), in comparison to its metal complexes, is screened for its antibacterial activity. The activity data show that the metal complexes have antibacterial activity more than the parent Schiff base ligand and cefepime standard against one or more bacterial species.     

Synthesis of 8‐hydroxyquinolium chloroacetate and synthesis of complexes derived from 8‐hydroxyquinoline,and characterization,density functional theory and biological studies

8‐Hydroxyquinolium chloroacetate ( L¹ ) was synthesized and characterized. The results suggest that L¹ loses ethyl chloroacetate ion on coordination at low pH (2–5) and consequently it behaves as 8‐hydoxyquinoline ( L² ). Cu²⁺, Co²⁺, Pt⁴⁺, Pd²⁺, Au³⁺, Ag⁺ and Nd³⁺ complexes derived from L² have been synthesized and characterized using spectral, magnetic and thermal measurements. L² acts as a neutral bidentate ligand in the case of Cu²⁺, Co²⁺, Pt⁴⁺, Pd²⁺ and Nd³⁺ complexes and as a mononegative bidentate ligand in the case of Au³⁺ and Ag⁺ complexes. Octahedral geometry is proposed for Cu²⁺, Co²⁺ (grey) and Pt⁴⁺ complexes and square‐planar for Co²⁺ (green), Pd²⁺ and Au³⁺ complexes. The bond lengths, bond angles, chemical reactivities, binding energies and dipole moments for all compounds were evaluated using density functional theory and molecular electrostatic potential for L¹ . Superoxide dismutase radical scavenger‐like activity and cytotoxic activity of the complexes towards HepG2 liver cancer cells has been screened. Cytotoxicity measurements show that Ag⁺ and Pd²⁺ complexes have the highest cytotoxic activity while L¹ , Cu²⁺, Co²⁺ (grey), Co²⁺ (green), Pt⁴⁺ and Nd³⁺ complexes have no cytotoxic activity. Copyright © 2015 John Wiley & Sons, Ltd.     

Androgen receptor antagonists and anti-prostate cancer activities of some synthesized steroidal candidates

In continuation of our previous work, a novel series of steroid derivatives were synthesized and their androgen receptor (AR) antagonist activities and in vivo antiandrogenic properties were evaluated. Twenty-one heterocyclic derivatives containing a cyanopyrane ring fused to a steroidal moiety were conveniently synthesized and screened for their antagonistic, antiandrogen and prostate anticancer activities comparable to that of bicalutamide as the reference control. Some of the compounds exhibited better antagonistic, antiandrogen and prostate anticancer activities than the reference controls. Initially the acute toxicity of the compounds was assayed via the determination of their LD(50). Synthetic steroidal structures fused to a substituted cyanopyrane ring seem to be a promising approach in the search for novel leads for potent antagonistic, antiandrogen and prostate anticancer agents.     

Physicochemical properties of {1-methyl piperazine (1) + water (2)} system at T = (298.15 to 343.15) K and atmospheric pressure

Densities (ρ) and viscosities (η) of aqueous 1-methylpiperazine (1-MPZ) solutions are reported at T = (298.15 to 343.15) K. Refractive indices (n_D) are reported at T = (293.15 to 333.15) K, and surface tensions (γ) are reported at T = (298.15 to 333.15) K. Derived excess properties, except excess viscosities (Δη), are found to be negative over the entire composition range. The addition of 1-MPZ reduces drastically the surface tension of water. The temperature dependence of surface tensions is explained in terms of surface entropy (S^S) and enthalpy (H^S). The measured and derived properties are used to probe the microscopic liquid structure of the bulk and surface of the aqueous amine solutions.