Microwave induced synthesis of some fused thiazoloquinazoline derivatives under solvent free conditions using LiBr as a catalyst

Two rapid and efficient methods for the preparation off used thiazoloquinazoline derivatives by the reaction of chalcones with hydroxylamine, urea and hydrazine hydrate under solvent free condition and microwave exposure are reported. The aim of present work is to substitute toxic, dangerous, highly reactive chemicals with less reactive, less harmful but more selective building blocks which activate selective chemical reactions by proper catalysis and to replace substituted old technologies to new one characterized by the reduction of by-products and easy separation of products

Simultaneous quantification of Darunavir and Ritonavir in human plasma and pharmacokinetic study by LC MS/MS

285-296The combination of Darunavir (DRV) and Ritonavir (RTV) at a dose of 800/100mg has exhibit durable efficacy in both untreated and treated HIV positive patients with no observed DRV resistance-associated mutations (RAMs) and the RTV improves the pharmacokinetic profile of DRV by enhancing its bioavailability. Hence a sensitive high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method has been developed and validated for the simultaneous quantification of Darunavir (DRV) and Ritonavir (RTV) in human plasma. The chromatographic separation has been accomplished on Thermo Hypersil Gold (50×4.6mm, 3μ) analytical column using isocratic elution using 0.1% Formic Acid buffer solution/Acetonitrile (50:50, v/v) at a flow rate of 0.6 mL/min. The linearity of the method ranged 150.000 ng/mL to 15000.000 ng/mL & 10.000 ng/mL to 3000.00 ng/mL for DRV & RTV respectively, using 100 μL of plasma. The method was completely validated for its sensitivity, selectivity, linearity, accuracy and precision, recovery, matrix effect, stability, and dilution integrity. The absolute recovery for DRV ranged from 79.12 to 72.71 % while for RTV it ranged from 63.39% to 66.99 %. For DRV-D9 and RTV-D6 the recovery rates are 94.19 and 80.05% respectively. The method exhibit good intra-day and inter-day precision with low % CV of less than 5.0% at each quality control level for both the analytes. The developed method has been applied successfully for pharmacokinetic study in healthy humans by oral administration of Darunavir/Ritonavir tablets 400/50 mg (dose; 02x400/50 mg) in 77 healthy male volunteers under fed condition

USE OF NANOSIZED CHROMIUMDOPED Ti02 SUPPORTED ON ZEOLITE FOR METHYLENEBLUE DEGRADATION

ABSTRACT The photocatalytic degradation of methylene blue dye under visible light has been investigated using chromium modified titanium dioxide supported on zeolite (Cr- TiO:lzeolite). The photocatalyst was prepared by sol-gel method and characterized .by X-ray diffraction and SEM. The\u27 rate of photodegradation of dye was monitored spectrophotometrical/y.The effect of pH, dye concentration,amount of photocatalyst and intensity of light on the rate of photocatalytic reaction was observed. The results showed that the use of Cr-doped Ti02 increased the rate of photocatalytic degradation of methylene blue as compared to untreated Ti02. The photocatalytic mechanism of Cr-Ti02 catalyst has been tentatively discussed. Keywords: Methylene ,blue, zeolite, chromium, photocatalytic degradatio

Simultaneous quantification of Daclatasvir and Sofosbuvir in human plasma and pharmacokinetic study by LCMS/MS

47-58In the treatment of hepatitis C, direct-acting antivirals (DAA) are highly efficient and well tolerated with a series of DAA combinations available for treatment. A sensitive high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method has been developed and validated for the simultaneous quantification of Sofosbuvir (SOF) and Daclatasvir (DAC) in human plasma. Sofosbuvir D6 (SOF D6) and Daclatasvir 13C22H6 (DAC 13C22H6) are used as internal standard (IS). Quantification for both the analytes has been attained with MS-MS detection in positive ion mode using an Acquity UPLC system (Waters) equipped with Waters Xevo TQ MS system with a Gemini NX 5µ C18 (50 × 2.0mm) (Phenomenex) column, and a gradient mobile phase consisting 5 mM Ammonium Formate buffer: Acetonitrile at a flow rate of 0.300 mL/min is used as mobile phase to separate the analytes and detection is performed by electrospray ionization technique using the mass spectrometer. Full validation is performed for bio-analytical methods with respect to linearity, precision, accuracy, selectivity, carry-over, stability and dilution integrity. Linearity is obtained over a concentration range of 10.002 -3000.488 and 10.004 -3001.218 ng mL-1 for SOF and DAC respectively by applying weighted least-squares linear regression method (1/x2). The developed method was applied successfully in bioequivalence and/or clinical studies in 48 male subjects for the simultaneous quantification of SOF and DAC

Microwave Assisted Synthesis, characterization and biological studies of isonicotinoylhydrazones and their Manganese (II) complexes

Among the most promising cleaner and energy efficient technologies, microwave-assisted technique has been popularly used for organic and inorganic synthesis. The use of microwave ovens in chemical synthesis has increasingly grown, due to its ability to dramatically reduce reaction times, improve yields, and simplified procedures. It is, therefore planned to synthesize some new Mn (II) Schiff base complexes using microwave irradiation technique. The Schiff base ligands 1-(2-furanyl) ethanone isonicotinoylhydrazone (L5H), 1-(2-thienyl) ethanone isonicotinoylhydrazone (L6H), 1-(2- pyridyl) ethanone isonicotinoylhydrazone (L7H), 1-(2-naphthyl) ethanone isonicotinoylhydrazone (L8H), were prepared by the condensation reaction of isonicotinic acid hydrazide with corresponding ethanons in 1:1 molar ratio, respectively, in ethanol under microwave exposure. The Mn (II) complexes have been prepared by mixing MnCl2.4H2O in 1:1 and 1:2 molar ratios with monofunctional bidentate ligands. The structure of the ligands and their transition metal complexes were confirmed by the elemental analysis, molecular weight determinations, IR, electronic and EPR spectral studies. On the basis of these studies it is clear that the ligands coordinated to the metal atom in a monobasic bidentate mode, by O∩N donor system. Thus a tetrahedral environment around the Mn (II) ionhas been proposed. The antimicrobial activity of Schiff base ligands and their respective Mn (II) complexes were tested against some of pathogenic bacterial and fungal strains. The results indicated that the complexes showed higher activity than the parent ligands

Microwave-assisted synthesis of nitrogen-doped ZnO nanoparticles: Characterization and its comparative study on sonocatalytic, photocatalytic and sonophotocatalytic degradation of amido black

Nano rods like N-doped ZnO structures have been prepared using microwave-assisted method. Synthesized nanoparticles have been characterized by Field Emission Scanning Electron Microscopy (FESEM), Transmission Electron Microscopy (TEM), X-ray diffraction (XRD), energy dispersive X-ray (EDX), Fourier-transform Infrared Spectroscopy (FTIR) and ultraviolet-visible (UV-vis) spectroscopy. The N-doped ZnO catalyst has been further used for the degradation of amido black-10B (a non-biodegradable azo dye) using photocatalysis and sonocatalysis systems, separately and simultaneously. The experimental kinetic data followed the pseudo-first order model in photocatalytic, sonocatalytic and sonophotocatalytic processes but the rate constant of sonophotocatalysis has been found higher than the rate constants of photocatalysis and sonocatalysis processes due to the formation of more reactive radicals as well as active surface area of the catalyst.

Enhanced photocatalytic degradation of nigrosine dye from its aqueous solution using La2Ce2O7 nanoparticles

172-179In the present work, removal of nigrosine dye from its aqueous solution via combined photocatalysis and adsorption has been reported using ternary catalyst lanthanum cerate under visible light. The catalyst has been synthesized by citric acid assisted sol-gel method. XRD graph reveals that the average crystallite size of sample is found to be approximate 4.0 nm having cubic fluorite structure. There is 64.45% oxygen. 17.76% lanthanum and 17.79% cerium atoms present in the material, as observed by EDS result. FESEM results shows that obtained particles are in the form of rice grain shape arranged densely in homogeneous manner. TGA curve shows that there is a evaporation of moisture, nitrate and carbon. Two exothermic peaks are observed at about 170°C and 200°C in the DTA curve. The UV-Visible spectrum gives the band gap of lanthanum cerate and it is 3.0 eV. A spectrophotometer has been used to follow the photocatalytic degradation of nigrosine dye at specific intervals of time. The effect of various parameters such as pH, concentration of dye, photocatalyst dosage and light intensity has been studied on the rate of degradation. A tentative mechanism for degradation of nigrosine has been proposed involving superoxide and hydroperoxyl radicals as main oxidizing species

MW assisted synthesis of some heterocyclic compounds and their Mannich bases under solvent free conditions and their biological assay

A highly efficient MW assisted synthesis of different nitrogen containing heterocyclic compounds under solvent free conditions was reported. Their aminomethylation was carried out on acidic alumina under microwave irradiation to give the corresponding Mannich bases. The method is clean, fast, facile, efficient, low cost and environmentally benign. The structure of synthesized compounds has been characterized on the basis of their elemental analysis and spectral data. These compounds were evaluated for their antimicrobial activity against bacteria and fungi