Magnetic criteria of aromaticity in a benzene cation and anion: how does the Jahn–Teller effect influence the aromaticity?

The aromatic/antiaromatic behavior of the Jahn–Teller (JT) active benzene cation and anion has been investigated using Density Functional Theory (DFT) calculations of Nuclear Independent Chemical Shifts (NICS) and magnetic susceptibility. NICS parameters have been scanned along the Intrinsic Distortion Path (IDP) for the benzene cation showing antiaromaticity which decreases with increasing deviation from D_6h to D_2h symmetry. Changes in NICS values along the IDP from D_6h to C_2v in the benzene anion revealed non-aromatic character.     

On the application of a laser T-jump apparatus for perturbation of ionic micellar solutions

A laser T-jump apparatus which permits the detection of relaxation processes in ionic micellar solutions by conductivity measurements without addition of dyes or electrolytes, is briefly described. The apparatus is used to determine the time constants as well as the relative amplitudes of the slow relaxation process in the system H₂O-NaDS at 15 and 25°C. The time constants are in good agreement with those obtained by other methods. The concentration dependence of the relative amplitudes is well described by the existing theory. The comparison yields, in particular, that at room temperature the mean aggregation number of the NaDS micelles decreases with rising temperature.     

3D-QSAR,molecular docking and in silico ADMET studies of propiophenone derivatives with anti-HIV-1 protease activity

Structural Chemistry - HIV protease inhibitors are one of the most important agents for the treatment of HIV infection. In this work, molecular modeling studies combining 3D-QSAR, molecular...     

Synthesis,characterization, DFT calculations and antimicrobial activity of Cd(II) complexes with the condensation product of 2-quinolinecarboxaldehyde and Girard’s T reagent

The chloro (1) and isocyanato (2) Cd(II) complexes with the condensation product of 2-quinolinecarboxaldehyde and trimethylammonium acetohydrazide chloride (Girard’s T reagent) (HLCl) have been synthesized and characterized by elemental analysis, IR, and NMR spectroscopy. The crystal structure of chloro Cd(II) complex (1) was determined. In 1 and 2, coordination surrounding of Cd(II) consists of deprotonated hydrazone ligand coordinated through NNO-donor atoms and two monodentates at the rest of the coordination places. Quantum chemical calculations of the molecular structures and the relative stabilities of linkage isomers of the Cd(II) complex showed that the isomer with N–Cd–N coordination of OCN^? is the most stable. The investigated Cd(II) complexes showed lower activity than standard antimicrobial drugs.     

137Cs and 40K in some traditional herbal teas collected in the mountain regions of Serbia

Herbal teas are an important part of traditional medicine in Serbia. The objective of the present study was to determine the activity concentrations of ⁴⁰K and ¹³⁷Cs in herbal tea, using the gamma spectroscopy method. The samples were collected during the period 2011–2012 in three mountain regions in Western and Central Serbia. The activity concentrations of ⁴⁰K and ¹³⁷Cs were found to be in the range of 130–1160 and 0.7–124 Bq kg^?1, respectively. The average annual effective dose equivalents from ingestion of ⁴⁰K and ¹³⁷Cs for an adult person consuming one cup of herbal tea daily were found to be 588.4–5250.2 nSv for ⁴⁰K and 4.0–706.1 nSv for ¹³⁷Cs. Our investigation showed that the herbal teas originating from Maljen, Zlatibor and Tara mountains are radiologically safe for human consumption.     

Quantification of malondialdehyde by HPLC‐FL – application to various biological samples

Malondialdehyde (MDA) is stabile product of lipid peroxidation (LPO), and therefore MDA is frequently used as a biomarker of LPO. To determine MDA level in various biological samples (human plasma, fish liver tissue and cells in culture), we used an HPLC method with fluorescent detection based on 2‐thiobarbituric acid (TBA) assay. The method was validated by the use of spiked pooled plasma samples. In tested concentration range (0.15–3.0 µmol/L) the method was linear (R² = 0.9963), the between‐day variability (coefficient of variations, CVs) was between 4.7 and 7.6%, the within‐day variability CVs was between 2.6 and 6.4% and recovery was between 91.2 and 107.6%. The level of MDA in human plasma (healthy male, non‐smokers, 46.3 ± 4.7 years; N = 38) was 2.2 ± 1.4 µmol/L; that in liver tissue of common carp (Cyprinus carpio; N = 12) was 0.02 ± 0.004 µmol/g tissue, and in cultured cells (human laryngeal carcinoma cells; N = 10) it was 0.18 ± 0.02 nmol/mg proteins. The HPLC‐FL method is rapid, accurate and reliable to follow the extent of LPO in various biological samples, particularly in samples in which a low level of MDA is expected, such as cells in culture. Owing to the rapid analytical process and run time, it can be used for routine analysis of MDA in clinical laboratory. Copyright © 2014 John Wiley & Sons, Ltd.