Classical chemical sciences
Crystal structure of 2,7-diethoxy-1-(4-nitrobenzoyl)naphthalene C21H19NO5, is reported and discussed on the characteristics of the spatial organization of single molecule and molecular aggregation as contrasted with a homologous compound. The molecular structures of these compounds differ only in the kind of alkoxy group of 2,7-positions of the naphthalene rings, i.e., ethoxy groups for title compound and methoxy groups for homologue. In single molecular crystal structures of these compounds, 4-nitrobenzoyl group is non-coplanarly attached to the naphthalene ring. The molecules exhibit axial chirality, with either R or S stereogenic axis. The two pairs of the enantiomeric molecules are related by two-fold helical axis in the asymmetric unit of P21/n space group for title compound and P21/c one for homologue, showing the number of molecules (Z) is four for both compounds. In their molecular packing structures, (R)- and (S)-enantiomers are connected to each other by … stacking interactions, forming centrosymmetric dimeric molecular aggregates. However, the aggregation structures of the dimers are apparently different between title compound and homologue. The dimeric units of title compound are stacked into columnar structure with (sp2)C–H…O=C non-classical hydrogen bonds between identical enantiomers along a-axis. The columns are connected by (sp2)C–H…OEt non-classical hydrogen bonds between identical enantiomers along c-axis to give sheet-like aggregation spreading on ac-plane. The sheets are piled up through (sp3)C–H… non-classical hydrogen bonds between opposite enantiomeric molecules of next dimeric aggregates along b-axis giving layers. On the other hand, the dimeric molecular aggregates of homologue are connected into flattish column by (sp3)C–H…O=C non-classical hydrogen bonds and (sp3)C–H… non-classical hydrogen bonds between identical enantiomers. The columns are linked into waving plate through weak (sp2)C–H… non-classical hydrogen bonds. In title compound, difference between … stacking interactions and non-classical hydrogen bonds is smaller than homologue in contribution to the whole of molecular packing structure.
Keywords: Centrosymmetric dimeric molecular aggregate, molecular motif, non-classical hydrogen bonds, … stacking interaction
Experimental bipolar disorder (BD) was induced by repeated daily injection of the increasing doses of d-amphetamine sulfate (AMPH) (2-4 mg kg-1, 18 injections) in male young adult Wistar rats characterized by temporal arousal mimicked mania, and reduced exploratory and locomotor activities associated with behavioural depression under the condition of withdrawal of AMPH. At the end of the injection course, a stimulation of the lipid peroxidation processes and alterations in the mitochondrial and cytoplasmic activities of both arginase and nitric oxide synthase (NOS) were observed in the regions of brain corticolimbic system (prefrontal cortex, striatum, hippocampus and hypothalamus) and blood leukocytes. We have shown for the first time that a reversal treatment with the mixture of the specific probiotics with psycho- and antifungal activities in free (PMF) and zeolite-immobilized (PMZ) forms, and/or with a mood stabilizer, sodium valproate (VPA) inhibited oxidative stress and modulated differentially the L-arginine metabolic pathways in the brain and blood following AMPH-induced BD. Both PMF and PMZ efficiently normalized the activities of arginase isoforms and upregulated the suppressed intracellular NOS along with the gut microbiota restoration and prevention of the histopathological changes in the brain regions accompanied by normalization of rat behaviour.
Keywords: Arginase, bipolar disorder, d-amphetaminelipid peroxidation, nitric oxide synthase, probiotics, sodium valproate
Materials and environmental chemistry
The study was carried out at Menia Governorate during 2014/2015 sugar beet season under field conditions. The temperature is an important environmental factor that has an effect on the rate of development, survival and in any other biological and ecological aspects for the cotton leafworm, Spodoptera littoralis (Boisd.). Seasonal abundance of the insect population and prediction of field generation throw a light on the temperature influence on insect development in the field. The data obtained in this work showed that the cotton leafworm, S. littoralis had four generations on sugar beet during the period from September 1st to March 1st. The predicted peaks of generations could be detected when the accumulated thermal units reach 524.27 degree days (dd's). The predicted peaks for the four generations detected earlier or later +3 to -2 days than the observed peaks. The expected peaks and the corresponding expected generations for cotton leafworm could be helpful to design the IPM control program.
Keywords: Sugar beet, Spodoptera littoralis, remote sensing, prediction of generation
Heavy metals are mostly occurring naturally in the environment and their concentrations may be altered by anthropogenic activities such as wastes disposal. The study investigated and determined the presence of heavy metals in Ts’osane solid-waste dumping site in Maseru. Soil samples were randomly collected from the dumping site and screened qualitatively through chloride and hydroxide precipitation. Quantitative analyses of the acid leachate for few suspected heavy metals – cobalt, chromium, copper, iron, lead, manganese and zinc were done using Atomic Absorption Spectrometry resulting in concentration in the range of 0.2 to 95 μg g-1 of soil which are way above the soil’s holding capacity that ranged between 0.05 and 0.225 μg g-1 of soil. Other parameters studied included the effect of pH, temperature and time of exposure to water. This revealed that prolonged exposure to water mimicking continued rainy conditions could lead to different leaching rates with copper ions demonstrating the lowest leaching rate over a period of five weeks as opposed to manganese which demonstrates about 170% on the fifth week relative to the first week, while as expected lower pH and higher temperatures favoured leaching of the metal ions. Lastly the soil-metal holding capacity was determined whereby it was shown that the soil bound lead the strongest (90%) while iron was the weakest bound (20%). The obtained values are worrisome since this dumpsite is upstream of the municipal water source for the Maseru Municipality.
Keywords: heavy metals, solid-waste dumpsite, leaching, temperature, pH, adsorption capacity
Chemical and biological aspects of life
Interaction of naturally occurring bioactive flavonoids 5,6,7-trihydroxyflavone (Baicalein) and 7,8-dihydroxyflavone (DHF) binding with calf thymus deoxyribose nucleic acid (dsDNA) was studied by employing UV absorption, fluorescence, circular dichroism, cyclic voltammetric and molecular modeling techniques. All studies were confirmed that the structural changes of DNA binding to the flavonoid. From the CV results positive shift in peak potential and increased peak current of the flavonoid in the presence of DNA and then the fluorescence quenching of DNA-flavonoids system indicated the intercalative mode of binding between flavonoid and DNA. CD studies suggest the conformational changes in DNA upon interaction with the flavonoids. Molecular docking simulation methods are used as tools to delineate the binding mode and probable location of the flavonoids and their effects on the stability and conformation of Ct-(ds) DNA. Furthermore, Baicalein can bind with more potential with Ct-(ds) DNA than DHF. This is helpful to understand the molecular aspects of binding mode and provides direction for the use and the design of new effective therapeutic agents. These results could provide useful information for insight into the pharmacological mechanism of flavonoids.
Keywords: Flavonoid interaction, Ct-(ds) DNA, spectroscopy, cyclic voltammetry, docking
Industrial and engineering chemistry, biotechnology
This research tested the hypothesis of whether fatty acid saturation and chain length of feedstock oil has any effect on the physico-chemical properties of synthesized kerosene-like fuel. Biodiesel was obtained from the feedstocks via transesterification and were subjected to distillation under vacuum between 50 to 100 oC to obtain kerosene-like fuel as the final product. The heat value, flash points, kinematic viscosity and specific gravity values were obtained and found to be within the stipulated range of fossil kerosene. The products were analysed using infrared spectrometer to confirm the presence of the functional groups in the kerosene-like fuel produced. Furthermore, Analysis by the elemental analyser showed that the kerosene-like fuel obtained from coconut oil has a significantly higher heat content value (9211.9 Kcal.Kg-1) than that from cashew-nut oil (5699.4 Kcal.Kg-1). This distinction in heat value can be ascribed to the nature of fatty acid in the oils as coconut oil is significantly more saturated and has shorter fatty acid hydrocarbon chain length than cashew-nut oil.
Keywords: Kerosene-like fuel, cashew-nut oil, coconut oil, transesterification
Theoretical and computational chemistry
The methodology is given for the evaluation of activation energy of diffusion and self-diffusion based on the application of spatial-energy parameter (Р-parameter). The corresponding calculations are made for 57 structures. The calculation results are in accordance with the experimental data.
Keywords: Spatial-energy parameter, structural interactions, diffusion, activation energy