The spectrophotometric determination of sulphate after its extraction with methyltricaprylammonium chloride into cyclohexane

Improvements are described to Flynn's procedure for the extraction of sulphate with Aliquat-336 and its subsequent determination as sulphuric acid. A single-point photometric measurement with sodium 2,4-dinitrophenate is applied to the determination of sulphate (ca. 10 mg kg^?1) in soils, and also in sulphur in organic compounds after oxygen flask combustion.     

Kinetic modeling of liquid-phase adsorption of reactive dyes on activated carbon

In this paper, adsorption equilibrium and kinetics of three reactive dyes from their single-component aqueous solutions onto activated carbon were studied in a batch reactor. Effects of the initial concentration and adsorbent particle size on adsorption rate were investigated Adsorption equilibrium data were then correlated with several well-known equilibrium isotherm models. The kinetic data were fitted using the pseudo-first-order equation, the pseudo-second-order equation, and the intraparticle diffusion model. The respective characteristic rate constants were presented. A new adsorption rate model based on the pseudo-first-order equation has been proposed to describe the experimental data over the whole adsorption process. The results show that the modified pseudo-first-order kinetic model generates the best agreement with the experimental data for the three single-component adsorption systems.     

The Potent Oxidant Anticancer Activity of Organoiridium Catalysts

Platinum complexes are the most widely used anticancer drugs; however, new generations of agents are needed. The organoiridium(III) complex [(η⁵‐Cp^xbiph)Ir(phpy)(Cl)] ( 1‐Cl ), which contains π‐bonded biphenyltetramethylcyclopentadienyl (Cp^xbiph) and C^N‐chelated phenylpyridine (phpy) ligands, undergoes rapid hydrolysis of the chlorido ligand. In contrast, the pyridine complex [(η⁵‐Cp^xbiph)Ir(phpy)(py)]⁺ ( 1‐py ) aquates slowly, and is more potent (in nanomolar amounts) than both 1‐Cl and cisplatin towards a wide range of cancer cells. The pyridine ligand protects 1‐py from rapid reaction with intracellular glutathione. The high potency of 1‐py correlates with its ability to increase substantially the level of reactive oxygen species (ROS) in cancer cells. The unprecedented ability of these iridium complexes to generate H₂O₂ by catalytic hydride transfer from the coenzyme NADH to oxygen is demonstrated. Such organoiridium complexes are promising as a new generation of anticancer drugs for effective oxidant therapy.     

Synthesis,anticancer, and computational studies of 1, 3, 4-oxadiazole-purine derivatives

Theophylline-7-acetic acid (acefylline) ( 3 ) and its derivatives are pharmacologically active compounds and generally recognized as bronchodilators for the treatment of respiratory diseases like acute asthma for over 70 years. In this article, synthesis of 2-((5-((1,3-dimethyl-2,6-dioxo-2,3-dihydro-1H-purin-7(6H)-yl)methyl)-1,3,4-oxadiazol-2-yl)thio)-N-arylacetamides ( 10a-j ) has been reported. All the synthesized derivatives ( 10a-j) were structurally verified by FT-IR, ¹H NMR, ¹³C NMR and evaluated for their anti-cancer (using MTT assay), hemolytic and thrombolytic potential. N-(4-Chlorophenyl)-2-(5-((1,3-dimethyl-2,6-dioxo-2,3-dihydro-1H-purin-7(6H)-yl)methyl)-1,3,4-oxadiazol-2-ylthio)acetamide ( 10g ) was found to be the most active against human liver cancer cell lines (Huh7) having cell viability 53.58 ± 1.28 using 100 μg/mL concentration of compound which was further in-silico modelled to describe the possible mechanistic insights for its anti-proliferative activity. The results of hemolytic and thrombolytic activities indicated that these derivatives were less toxic and hold considerable potential as a drug candidate. 2-(5-((1,3-Dimethyl-2,6-dioxo-2,3-dihydro-1H-purin-7(6H)-yl)methyl)-1,3,4-oxadiazol-2-ylthio)-N-(2-fluorophenyl)acetamide ( 10c ) of the series was found to be least toxic with 0.1% hemolysis relative to ABTS (95.5%) as positive control. 2-(5-((1,3-Dimethyl-2,6-dioxo-2,3-dihydro-1H-purin-7(6H)-yl)methyl)-1,3,4-oxadiazol-2-ylthio)-N-(tetrahydro-2H-pyran-4-yl)acetamide ( 10j ) exhibited potent clot lysis activity (90%) as compared to negative control DMSO (0.57%).     

Phytochemical studies on the seed extract of Piper nigrum Linn

The petroleum ether extract of dried ground seeds of Piper nigrum Linn. and some column fractions of this extract were subjected to GC and GC-MS analysis, resulting in the identification of fourteen compounds (1-14) by using NIST Mass spectral search program 1998 and the Kovat's retention indices. Ten of the compounds (1, 2, 4-12) are reported for the first time from this plant. All the fractions showed insecticidal activity against the fourth instar larvae of Aedes aegypti and against the fourth instar larvae of Anopheles stephensi Liston, determined by the WHO method.     

New insecticidal amides from petroleum ether extract of dried Piper nigrum L. whole fruits

The petroleum ether extract of dried ground whole fruits of Piper nigrum L. afforded 20 compounds (1-20) including two new insecticidal amides named as pipnoohine (1), and pipyahyine (2), seven reported for the first time from this plant (12, 13, 15-17, 19, 20), and eleven known compounds (3-11, 14, 18). The structure of 1 has been elucidated as (2E,4E,12Z)-N-(4-methylpentyl)octadeca-2,4,12-trienamide and that of 2 as (2E,4E,11E)-12-(benzo[1,3]dioxol-5-yl)-N-(3-methylbutyl)dodeca-2,4,11-trien-amide through extensive ID-, 2D-NMR spectral studies and chemical reactions. The known compounds have been identified through comparison of their spectral data with those reported in literature. 1 and 2 exhibited toxicity at 35.0 and 30.0 ppm respectively against fourth instar larvae of Aedes aegypti L. by WHO method.     

Synthesis,characterization, electrochemistry and evaluation of biological activities of some ferrocenyl Schiff bases

Synthesis of ferrocenyl Schiff bases ( 1–6 ) was carried out by the condensation reaction of 4‐ferrocenyl aniline with different substituted aromatic aldehydes and acetyl acetone. Compounds were characterized by physical measurements, elemental analysis, FT‐IR, ¹H‐NMR and ¹³C‐NMR spectroscopy. Single crystal X‐ray analysis of compound 2 showed the co‐planarity of both aromatic rings connected by a C–N double bond. Compounds demonstrated reversible one‐electron redox behavior and their peak currents were found to increase linearly with the square root of the sweep rate ν^1/2. The overall electrode processes were found to be diffusion controlled. Compounds 1 and 4 showed low cytotoxicity and appreciable antifungal, antioxidant and DNA protection activities. Copyright © 2010 John Wiley & Sons, Ltd.     

NiO@CuO@Cu bilayered electrode: two-step electrochemical synthesis supercapacitor properties

Present work deals with a two-step synthesis and electrochemical properties of nickel oxide @copper oxide@copper (NiO@CuO@Cu) bilayered electrode. In the first step, anodization (40 V for 25 min) of Cu foil has been carried out for forming Cu-hydroxide@Cu which when annealed at 300 °C for 1 h produces CuO@Cu. In the second step, Ni-hydroxide is deposited onto CuO@Cu by applying current density of 0.03 A/cm² for 3 min which when re-annealed at 300 °C for 1 h gives out NiO@CuO@Cu bilayered electrode. Obtained NiO@CuO@Cu bilayered electrode demonstrates separate CuO and NiO phases. The electrochemical properties have obtained using cyclic voltammetry, galvonostatic charge-discharge, and Nyquist plot measurements that reveal an importance of NiO@CuO@Cu as a potential electrode material in the electrochemical supercapacitor application with 58.14, 51.25, and 4.73 F g^?1 values in 0.5 M, NaOH, KOH, and Na₂SO₄ electrolytes, respectively, measured at 2 mVs^?1 scan rate.     

Efficient batch and continuous flow Suzuki cross-coupling reactions under mild conditions, catalysed by polyurea-encapsulated palladium (II) acetate and tetra-n-butylammonium salts

Suzuki cross-coupling reactions are effected in both conventional organic solvents, under continuous flow conditions at 70 degree C, and in batch mode in supercritical carbon dioxide (scCO2), at temperatures as low as 40 degrees C in the presence of palladium(II) acetate microencapsulated in polyurea [PdEnCat] and tetra-n-butylammonium salts.     

Polyphenolic profiling of Ipomoea carnea Jacq. by HPLC-DAD and its implications in oxidative stress and cancer

Ipomoea carnea Jacq. is an important folklore medicinal plant, assessed for its underexplored biological potential. Antioxidant, cytotoxic, antiproliferative and polyphenolic profile of whole plant was evaluated using various techniques. Maximum extract recovery (29% w/w), phenolic [13.54 ± 0.27 μg GAE/mg dry weight (DW)] and flavonoid (2.11 ± 0.10 μg QE /mg DW) content were recorded in methanol-distilled water (1:1) flower extract. HPLC-DAD analysis quantified substantial amount of six different polyphenols ranging from 0.081 to 37.95 μg/mg extract. Maximum total antioxidant and reducing potential were documented in methanol-distilled water and acetone-distilled water flower extracts (42.62 ± 0.47 and 24.38 ± 0.39 μg AAE/mg DW) respectively. Ethanol-chloroform root extract manifested highest free radical scavenging (IC₅₀ of 61.22 μg/mL) while 94.64% of the extracts showed cytotoxicity against brine shrimps. Ethanol leaf extract exhibited remarkable activity against THP-1 cell line (IC₅₀ = 8 ± 0.05 μg/mL) and protein kinases (31 mm phenotype bald zone).