Classical chemical sciences
The effect of melittin incorporated into the phospholipid bilayer of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) at mole fractions up to 3.75 mol% have been investigated. The study reveals a considerable influence of melittin on the phase transition profile and volumetric properties of the DPPC bilayer. The temperature dependence of the coefficient of expansion, , and the volume fluctuations of DPPC – melittin bilayer membranes in their different transition phases were determined by using pressure perturbation calorimetry (PPC), a relatively new and efficient technique, and differential scanning calorimetry (DSC). The experiments were carried out in the temperature range from 10 to 85 °C. Incorporating melittin up to 1.25 mol% into the lipid bilayer abolishes the pretransition. Remarkably, there is no shift in the transition temperature up to 2.5 mol% melittin, while more than one shoulder is observed at the low-temperature side of the DSC peak for 3.75 mol%, and a slight shift in melting temperature,Tm to 32oC. This could be linked to the lytic property of melittin at these high peptide concentrations.
Keywords: Pressure perturbation calorimetry, DSC, coefficient of thermal expansion, volume change, phospholipids, Melittin.
Molecularly imprinted polymer (MIP) particles tailored for bisphenol A (BPA) were prepared using a 1:8:7 molar ratio of BPA the template, methacrylic acid (MAA) the functional monomer, and ethylene glycol dimethacrylate (EGDMA) the cross-linker. These colloidal particles were tested for rapid competitive binding by capillary electrophoresis with ultraviolet detection (CE-UV). Good interface binding efficiencies were obtained for BPA even in the presence of 2-hydroxy-4-methoxy benzophenone (HMB) as a structurally related compound at high concentrations. The specifically bound BPA could be desorbed rapidly out of the interface cavities by 5% triethylamine in methanol. However reusability was demonstrated by repeated injections of BPA that bound to MIP particles without regeneration of the cavities.
Keywords: bisphenol A, capillary electrophoresis, competitive binding, molecularly imprinted polymers, reusability, specificity
Materials and environmental chemistry
The environmental friendly inhibitor system glycine-Zn2+, has been investigated by weight loss method. A synergistic effect exists between glycine and Zn2+ system. The formulation consisting of 250 ppm of glycine and 50 ppm of Zn2+ offers good inhibition efficiency of 82%. Polarization study reveals that this formulation functions as an anodic inhibitor. The FTIR spectra study leads to the conclusion that the Fe2+-Gly complex formed on anodic sites of the metal surface controlled the anodic reaction and Zn(OH)2 formed on the cathodic sites of the metal surface controlling the cathodic reaction. The surface morphology and the roughness of the metal surface have been analyzed with atomic force microscopy. A suitable mechanism of corrosion inhibition is proposed based on the results obtained from weight loss study and surface analysis technique. The eco-friendly inhibitor glycine-Zn2+ system may find application in cooling water system.
Keywords: Glycine, corrosion inhibitor, synergistic effect, carbon steel, well water, zinc ion, amino acids
Phytoremediation is an innovative technology that uses plants in order to remediate polluted water and soil. A 10 week study in flower pots was performed in order to determine the arsenic (As) removal potential of Shoenoplectus americanus, Eleocharis macrostachya and Baccharis salicifolia and also to evaluate their tolerance capacity to increasing doses of As. The experiment involved five different treatments with distinct As concentrations (1, 2, 3, 4 and 5 mg L-1 ) and a control (tap water) to determine the acclimatization capacity of the species to the different concentrations. The number of plants and their height were determined during the experiment. The values for the factors of translocation, accumulation and enrichment were obtained at the end of the experiment; the maximum values for these factors were, respectively, 1.86, 92.13 and 1.63 for E. macrostachya, 1.73, 59.74 and 0.56 for S. americanus and 8.96, 27.94 and 6.72 for B. salicifolia. The maximum growth value belonged to the S americanus. The maximum concentration of As in water tolerated by E. macrostachya and B. salicifolia were 2 and 3 mg L-1 respectively. B. Salicifolia, has no tolerance for environments with high concentrations of arsenic. S. americanus showed the highest As accumulation capacity and the greatest tolerance in the tested concentrations. E. macrostachya proved to be translocator plants and S. americanus was confirmed to be a stabilizer plant with a high potential for phytostabilization and rhizofiltration techniques.
Keywords: phytoremediation; arsenic removal; arsenic contaminated soil and water; Shoenoplectus americanus; Eleocharis macrostachya; Baccharis salicifolia
Saving energy loss through the conduction is the major objective of several advanced countries so superconductors are the essential material to achieve such these demands. The present investigations were concerned by synthesis of pure BPSCCO (Bi0.5Pb0.5)2Sr2Ca1Cu2O8 and its variant zirconium containing composites with general formula : Bi1+xZrxPbSr2Ca1Cu2Oz, where x=0.1, 0.2 and 0.3 mole % respectively, were prepared via solution route (Freeze Drying Technique ) to obtain nano-product. ZrO2 has a limited effect on the main crystalline superconductive 2212-phase as x amount added increase as indicated in XRD measurements. SE-microscopy along with EDX proved that, solution route was the best in the degree of homogneties and exact molar ratios. ZrO2 exhibits strong interactions on Raman spectral modes of 2212-phase . ZrO2 has a slight effect on Tc’s even with maximum addition x=0.3 mole. Finally the application of ZrO2- nano-additives to the 2212-BPSCCO superconductors enhance the super-conduction mechanism and consequently save too much the amount of electricity loss on the main nets of electricity.
Keywords: Nano-additives, superconductors, SEM, XRD, Raman Spectrum, ZrO2
The present work describes the removal of Cr(III) by adsorption on activated Acacia nilotica leaf powder using batch process. This plant is locally available in arid and semi arid zone of Rajasthan (local name-Babul). Parameters like adsorbent mass, pH, shaking speed, particle size, contact time were studied at different initial Cr(III) concentrations. The adsorption process of Cr(III) was tested with Langmuir and freundlich models. Desorption studies were also performed.
Keywords: Cr(III), adsorption isotherm, desorption
Biochemistry, molecular biology and biotechnology
The diet is the main source of minerals and trace elements, thus exposure to dietary essential elements has a direct impact on human health. Magnesium is a major component of the bones, but furthermore it influences the nervous system and muscle activity. Therefore its needs must be met via nutrition. There is a non-negligible discrepancy between intake and requirements. So magnesium is often uptaken in form of nutrition supplements. Thus there is an interest in the amount of magnesium in natural products, where it is supposed to vary. In this study, various commercially available tea bags of different kinds of tea (black tea, green tea, fruit tea and herbal tea) were analysed for their magnesium content. After a microwave assisted digestion with nitric acid and water at temperatures up to 220°C, the element concentration was measured with ICP-OES (inductively coupled plasma-optical emission spectroscopy) as it is a simultaneous, fast and reliable method with low detection limits. All samples were prepared in duplicate. In all samples high amounts of magnesium (approx. 1 g kg-1) could be found. No statistically significant differences were registered between the different classes of teas.
Keywords: magnesium, black tea, fruit tea, green tea, herbal tea, ICP-OES
Ficus carica L. is a well-known Mediterranean plant, its fructus - the fig- is consumed widely, mostly in the southern region of Europe. It’s a member of the Moraceae family, one of the earliest crops. It can be consumed raw, dried or even as jam as a part of the Mediterranean diet. One part of our research was to determine the volatile components of Ficus carica L. The composition of volatile components are important for the determination of fruit quality. We compared two extraction methods, examined by SPME-GC/MS. Two preparation methods were used: directly measured by SPME, and also samples made by steam distillation. Figs has an important role as phytonutrition. Mineral element content was determined by ICP. Fig is a good source of elements for Ca, Cr, Cu, Fe, K, Mg, Mn and Mo, since eating 5 dkg of dried fig covers more than 15% of the Recommended Dietry Allowances.
Keywords: Ficus carica L., SPME, phytonutrition, mineral elements
Industrial and engineering chemistry
Nowadays a lot of synthetic methods of isopropyl chloroacetate using different catalysts such as sulfonic acids (p-toluene-sulfonic acid and amino-sulfonic acid), inorganic metal salts of organic sulfonates (Ce(CH3SO3)3·H2O, Ca(CH3SO3)2·2H2O, Al(CH3SO3)3·4H2O, Zn(CH3SO3)2·4H2O, La(CH3SO3)3·4H2O, Cu(CH3SO3)2·4H2O, Zn(p-CH3C6H4SO3)2·5H2O, Zn(C6H5SO3)2·6H2O, CH3(CH2)11SO3Na and (CH3(CH2)11SO3)3Fe), ionic liquids ([(CH2)4SO3HPy]HSO4 and [C1imCH2COOH]HSO4), inorganic salts (Ce(SO4)3·4H2O, NaHSO4, KHSO4, [Fe2(OH)n(SO4)3-n/2]m, CPVC-FeCl3, NH4Fe(SO4) ·12H2O, PVC-FeCl3, FeCl3 ·6H2O and SnCl4), PCl3, heteropolyacids (H3PO40W12.xH2O and TiSiW12O40/TiO2), solid superacids (SO4 2-- Fe2O3, SO4 2-/TiO2-La3+, SO4 2-/TiO2, SO4 2-/TiO2-Sm3+, SO4 2—NiO, SO4 2-/TiO2-Nd3+, SO4 2-- Al2O3, SO4 2-/TiO2-Gd3+ and SO4 2-/TiO2-Ce3+) and inorganic salts of organic acids (Nd(CF3COO)3) have been reviewed in the present paper. The yields of isopropyl chloroacetate are improved by the addition of above catalysts. These methods are having the advantages of simple process and low investment costs.
Keywords: overview; synthetic study; isopropyl chloroacetate; catalysts
Effects of the different reaction conditions on the synthetic method of isoamyl benzoate have been reviewed in the present article. Different catalysts that consist of p-toluenesulfonic acid (PTSA), Zr(SO4)2·4H2O, NaHSO4·H2O and Ti(SO4)2/TiO2 have also been introduced. The reaction conditions include the reaction time, the molar ratio of benzoic acid to isoamyl alcohol, the amount of the catalyst, the microwave heating method and the Ti loading amount, etc. The optimum reaction time, the molar ratio of benzoic acid to isoamyl alcohol, the amount of the catalyst, the microwave heating method and the Ti loading amount are beneficial to improve the yield of the product, isoamyl benzoate.
Keywords: effect; reaction conditions; synthesizing; isoamyl benzoate