On the Different Lipolytic Capability of Diverse Organs from Young Adult Guinea Pigs. A Chromatographic Study

JPC – Journal of Planar Chromatography – Modern TLC - In this study we conducted in-vitro incubation of whole-tissue homogenate of young adult guinea pig heart, kidney, testis, and...     

Studies on pyrrolidinones. Synthesis of 1,2,3,5,11,11a-hexahydroindolizino[7,6-b]indole-3,11-dione

Condensation of N-trimethylsilylindole with methyl N-trimethylsilyloxymethylpyroglutamate is the best method to obtain methyl N-indolylmethylpyroglutamate. Friedel-Crafts cyclization of the corresponding acid yields a new ketone (1,2,3,5,11,11a-hexahydroindolizino[7,6-b] indole-3,11-dione).     

Mixed-ligand complexes of copper(I) with diimines and phosphines: Effective catalysts for the coupling of phenylacetylene with halobenzene

New copper(I) mixed-ligand complexes 1–4 of the formula Cu(N–N)PR₃X, where N–N = 1,10-phenanthroline (phen), 2,2′-bipyridine (bpy), 5,5′-dimethyl-2,2′-bipyridine (5,5′dimbpy) and PR₃ = tricyclohexylphosphine, tris(2-cyanoethyl)phosphine and isopropyldiphenylphosphine, have been synthesized. The complexes were characterized by EA, IR, NMR and single crystal X-ray diffraction. The solution fluorescence emission spectra were measured. The single crystal X-ray analysis showed that the copper(I) ion is four-coordinate with a distorted tetrahedral geometry. The complexes catalyze the formation of diphenylacetylene from the coupling of halobenzene with phenylacetylene. The complex Cu(5,5′-dimethylbpy)P{(cyhexyl)₃}I showed the highest catalytic activity. At room temperature all four complexes exhibit, in dichloromethane, emission maxima in the 329–344 nm range, corresponding to intra-ligand excited states.     

Synthesis of a graphene‐based nanocomposite for the dispersive solid‐phase extraction of vancomycin from biological samples

The approach of this work was to study the capability of graphene‐based materials in the field of biological sample preparation. A polypyrrole/graphene composite was synthesized and characterized. The potential of the nanocomposite was investigated as a sorbent in dispersive solid‐phase extraction followed by high‐performance liquid chromatography with UV detection for vancomycin as a model drug. The effect of different parameters influencing extraction efficiency such as sample pH and sample volume, ionic strength, extraction time, type, and volume of desorption solvent and desorption time were investigated. A comparison study was also conducted between polypyrrole/graphene and some different novel and classic sorbents. Under optimized conditions, the calibration curve for vancomycin showed linearity in the range of 0.05–10 μg/mL. In addition, limits of detection, and quantification were 0.003 and 0.01 μg/mL, respectively. The intraday and interday relative standard deviations at a concentration of 0.05 μg/mL (n = 3) were 1.6 and 2.1%, respectively. Furthermore, the proposed method was successfully applied for the determination of vancomycin in plasma and urine samples. The relative recoveries indicated the feasibility of graphene‐based sorbents in biological sample analysis.     

An Eco‐friendly Three Component Manifold for the Synthesis of α‐Aminophosphonates under Catalyst and Solvent‐free Conditions,X‐ray Characterization and Their Evaluation as Anticancer Agents

A series of α‐aminophosphonates were synthesized through one‐pot condensation of aryl aldehydes, aryl amines and diethyl phosphite in the absence of any catalyst and organic solvents. All the synthesized α‐aminophosphonates were characterized by spectral and elemental analysis and in the case of compound 4j by X‐ray crystallography. Some of these new α‐aminophosphonate derivatives were found to have cytotoxic activity on the cancer cell line DU145 in vitro by the MTT method.     

Solid-phase extraction of Pb2+ ion from environmental samples onto L-AC-Ag-NP by flame atomic absorption spectrometry (FAAS)

The development of a solid-phase extraction (SPE) procedure for the pre-concentration of trace amounts of Pb²⁺ ion on 2-furan-2-yl-1-furan-2-ylmethyl-1H-benzoimidazole loaded on activated carbon modified with silver nanoparticles (L-AC-Ag-NP) was presented. The metal ion retained on the sorbent was quantitatively determined via complexation with the ligand. The complexed metal ion was efficiently eluted using 10 mL of 4 mol L^?1 sulphuric acid in 10 w/v% acetone. The influences of the analytical parameters, including pH, amounts of the ligand and the solid phase, eluent conditions and sample volume, on the recoveries of the metal ion were optimised. Using the optimised parameters, the linear response of the SPE method for Pb²⁺ ion were in the ranges of 0.2–160 µg L^?1, and the detection limit for Pb²⁺ ion was 0.034 µg L^?1. The proposed method exhibits a pre-concentration factor (PF) of 80 and an enhancement factor of 30 for Pb²⁺ ion. The presented results demonstrate the successful application of the proposed method for the determination of Pb²⁺ ion in some real samples with high recoveries (>93%) and reasonable relative standard deviation (RSD < 2%).     

Micellization of Pentanediyl-1,5-bis(hydroxyethylmethyl hexadecylammonium Bromide) as a Cationic Gemini Surfactant in Aqueous Solutions: Investigation Using Conductometry and Fluorescence Techniques

Pentanediyl-1,5-bis (hydroxyethylmethylhexadecylammonium bromide) was synthesized and characterized as a type of novel gemini cationic surfactant. Its solution properties were determined at various temperatures by conductivity measurements and the fluorescence quenching technique. The CMC increased in the range of 1.85 to 2.77 μmol⋅L⁻¹ as the temperature increased. The aggregation number was determined at various concentrations of NaBr solutions by the fluorescence quenching of pyrene. The thermodynamic parameters of micellization were determined using the mass law equation and the values of ΔG °, ΔH °and ΔS ° were determined for the micellization process.     

Comparison of two methods for determination of tomato paste solids: vacuum oven versus microwave oven

Two analytical procedures used to determine total, soluble, and insoluble solids in tomato paste were evaluated. The microwave oven (MO) method was compared to the vacuum oven (VO) method. The VO method is tedious and measured the three solids fractions in the paste directly, while the MO method measured the total solids directly but used an equation to calculate the water-soluble and -insoluble solids. The MO method was faster and less labor-intensive, and yielded small but statistically significant higher values for total and insoluble solids and lower statistically significant values for soluble solids.