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Publisher: European Journal of Chemistry   (Total: 1 journals)   [Sort by number of followers]

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European J. of Chemistry     Open Access   (Followers: 30)
Journal Cover
European Journal of Chemistry
Number of Followers: 30  

  This is an Open Access Journal Open Access journal
ISSN (Print) 2153-2249 - ISSN (Online) 2153-2257
Published by European Journal of Chemistry Homepage  [1 journal]
  • Graphical Contents

    • Authors: Hakan Arslan
      PubDate: 2018-12-31
      DOI: 10.5155/eurjchem.9.4.iii-vii.1822
      Issue No: Vol. 9, No. 4 (2018)
       
  • Synthesis and spectroscopic study of transition metal complexes of
           tridentate ligand formed by direct condensation of o-vanillin and
           2-aminophenol: X-ray structural characterization of the zinc(II) complex

    • Authors: Amadou Gueye, Farba Bouyagui Tamboura, Jean-Marc Planeix, Nathalie Gruber, Mohamed Gaye
      Pages: 281 - 286
      Abstract: The reactions of the Schiff base 2-((2-hydroxyphenylimino)methyl)-6-methoxyphenol (H2L), obtained by direct condensation of 2-aminophenol and 2-hydroxy-3-methoxybenzaldehyde, with some transition  metal ions (Mn(II), Co(II), Ni(II), Cu(II) and Zn(II)) afforded complexes of general formulae [M2(L)2(solvent)x] (M: Mn, Co, Ni, Cu or Zn; Solvent: DMSO or H2O). These compounds were characterized by elemental analysis, UV-Vis, IR, 1H- and 13C-NMR spectroscopies, molar conductivity and room temperature magnetic measurements. The structure of zinc(II) complex has been determined by X-ray crystallography. Crystal data for C32H34N2O8S2Zn2 (M =769.47 g/mol): Orthorhombic, space group Pbca (no. 61), a = 16.3176(7) Å, b = 9.1247(3) Å, c = 21.8274(10) Å, V = 3250.0(2) Å3, Z = 4, T = 173(2) K, μ(MoKα) = 1.658 mm-1, Dcalc = 1.573 g/cm3, 28116 reflections measured (4.5° ≤ 2Θ ≤ 60.3°), 4457 unique (Rint = 0.0409, Rsigma = 0.0371) which were used in all calculations. The final R1 was 0.0307(0.0466) and wR2 was 0.0649 (0.0701) (all data). The coordination sphere of the Zn center is best described as a trigonal bipyramid.
      PubDate: 2018-12-31
      DOI: 10.5155/eurjchem.9.4.281-286.1761
      Issue No: Vol. 9, No. 4 (2018)
       
  • TD-DFT calculations, electronic structure, natural bond orbital analysis,
           nonlinear optical properties electronic absorption spectra and
           antimicrobial activity application of new bis-spiropipridinon/pyrazole
           derivatives

    • Authors: Shimaa Abdel Halim
      Pages: 287 - 302
      Abstract: A new bis-spiropipridinon/pyrazole compound and some of its derivatives are characterized in terms of several theoretical parameters such as density of states (DOS), molecular electrostatic potentials (MEPs), non-linear optical (NLO) properties and electrophilicity. The electronic structure and nonlinear optical properties of the studied compounds 1-5 are investigated theoretically at the DFT-B3LYP/6-311G(d,p) level of theory. The effect of substituents of different strengths on the geometry and energetic are analyzed and discussed. The static dipole moment (µ), polarizability (α), anisotropy polarizability (Δα), and first order hyperpolarizability (βtot), are parameters for NLO of the studied compounds have been calculated at the same level of theory and compared with the prototype para-nitro-aniline (PNA). The electronic absorption spectra of the studied compounds are recorded in the UV-VIS region, in both ethanol and dioxane solvents. The theoretical spectra computed at a new hybrid exchange-correlation functional using the Coulomb-attenuating method (CAM-B3LYP) at the 6-311G(d,p) bases set in gas phase and with the polarizable continuum model (PCM) in dioxane and ethanol indicate a good agreement with the observed spectra. The antimicrobial activity for studied compounds was investigated. The antimicrobial activity results revealed that compound 4 has a good potency against Gram positive bacteria (E. coli) and Gram negative bacteria (P. vulgaris) in comparison with doxymycin standard. The structure activity relationship SAR has been studied for the studied compounds by DFT calculations, moreover, confirmed practical antimicrobial  activity results.
      PubDate: 2018-12-31
      DOI: 10.5155/eurjchem.9.4.287-302.1706
      Issue No: Vol. 9, No. 4 (2018)
       
  • Crystal growth and some physicochemical studies on an organic
           intermolecular compound of anthranilic acid and N,N-dimethylamino
           benzaldehyde

    • Authors: Uma Shanker Rai, Manjeet Singh, Rama Nand Rai
      Pages: 303 - 310
      Abstract: The phase diagram of anthranilic acid and N,N-dimethylaminobenzaldehyde system gives two eutectics (E1 and E2) and a 1:1 intermolecular compound with congruent melting point. The mole fractions of anthranilic acid at E1 and E2 are 0.10 and 0.95, respectively. The negative values of heat of mixing of eutectics suggest that there is clustering of molecules in their eutectic liquid melt. The positive values of excess free energy for eutectics indicate that the interactions between the like molecules are stronger than those of unlike molecules. It can be inferred from single crystal X-ray analysis of the intermolecular compound that it crystallized in monoclinic unit cell with C2/c space group and a reasonably large sized intermolecular compound crystal was grown by slow evaporation technique at room temperature. The optical studies on the intermolecular compound give two strong emission bands with two lmax values one at 380 nm and second at 450 nm with total quantum efficiency 0.49.
      PubDate: 2018-12-31
      DOI: 10.5155/eurjchem.9.4.303-310.1720
      Issue No: Vol. 9, No. 4 (2018)
       
  • Removal of Methylene Blue in aqueous solutions by Electrocoagulation
           process: Adsorption, Kinetics, studies

    • Authors: Alain Stéphane Assémian, Konan Edmond Kouassi, Kopoin Adouby, Patrick Drogui, David Boa
      Pages: 311 - 316
      Abstract: The purpose of this study is to understand the mechanism driving the removal of methylene blue through electrocoagulation process. Experiments were carried out using iron as anode and cathode in a batch electrochemical cell operated in a monopolar configuration. The effects of operating parameters (initial pH, current density, initial dye concentration and energy consumption) on the removal of methylene blue from solution were investigated. The results showed that the optimum removal efficiency of 93.2% was achieved for a current density of 9.66 mA/cm2, optimal pH of 8±0.01 with a specific energy consumption of 7.451 kWh/m3. Afterwards, first and second-order rate equations were successively applied to study adsorption kinetics models. On top of usual correlation coefficients (r2), statistical test Chi-square (χ2) were applied to evaluate goodness of fit and consequently find out the best kinetic model. Results showed that MB adsorption process onto iron hydroxides formed in aqueous solution during electrocoagulation treatment followed a second-order kinetic.
      PubDate: 2018-12-31
      DOI: 10.5155/eurjchem.9.4.311-316.1736
      Issue No: Vol. 9, No. 4 (2018)
       
  • A mild and efficient method for the deprotection of trimethyl silyl
           alkynes using sodium ascorbate and copper sulphate

    • Authors: Ranjith Siddaraj, Raghu Ningegowda, Nanjunda Swamy Shivananju, Babu Shubha Priya
      Pages: 317 - 321
      Abstract: A competent and fast method for the deprotection of trimethyl silyl group was attained by using cheap, easily accessible, and nontoxic sodium ascorbate in combination with copper sulphate. The method labored was simple and effective for the cleavage of trimethyl silyl group from the protected trimethyl silyl alkynes to their corresponding alkyne derivatives. Wide functional group tolerance, shorter time period, simple procedure and high yields are the striking features of this protocol.
      PubDate: 2018-12-31
      DOI: 10.5155/eurjchem.9.4.317-321.1729
      Issue No: Vol. 9, No. 4 (2018)
       
  • Quinazolin derivatives as emerging alpha-glucosidase inhibitors

    • Authors: Ashok Reddy Ankireddy, Rambabu Gundla, Tuniki Balaraju, Venkanna Banothu, Krishna Prasad Gundla, Uma Addepally, Jithendra Chimakurthy
      Pages: 322 - 330
      Abstract: A series of C-7 substituted-2-morpholino-N-(pyridin-2-ylmethyl)quinazolin-4-amine have been synthesized and biochemical assay was examined against α-glucosidase function inhibition activity. A structure activity and structure property relationship study was experimented to surface the new hit compound. This study led to the identification of C-7substituted quinazolines with minimum inhibitory concentrations (MICs) in the preffered micromolar range in addition with interesting physicochemical properties. Biological evaluation yielded eight analogs which rose with significant α-glucosidase inhibition potency (IC50 values < 2 μM, where reference compound (Acarbose) potency value is IC50 = 0.586 uM) and could be promising candidates for further lead optimization.
      PubDate: 2018-12-31
      DOI: 10.5155/eurjchem.9.4.322-330.1748
      Issue No: Vol. 9, No. 4 (2018)
       
  • Spectrofluorimetric determination of Bisoprolol fumarate and Rosuvastatin
           calcium in a novel combined formulation and in human spiked plasma

    • Authors: Nada Sayed Abdelwahab, Nouruddin Wageh Ali, Marco Mounir Zaki, Adel Ahmed Ali, Mohamed Mohamed Abdelkawy
      Pages: 331 - 337
      Abstract: Sensitive, simple and rapid spectrofluorimetric method was developed for simultaneous determination of bisoprolol fumarate (BIS) and rosuvastatin calcium (ROS) in novel formulated tablets and in human spiked plasma depending on measuring their native fluorescence. The fluorescence intensity of BIS and ROS were measured in methanol at emission wavelength of 297 and 485 nm upon excitation at 227 and 242 nm, respectively. The emission spectrum of each drug reveals zero value at the emission wavelength of the other drug, thus allowing their simultaneous determination without any interference and without using any tedious derivatization steps. Excellent linearity was obtained over the range of 10-500 and 20-1000 ng/mL for BIS and ROS, respectively. The developed method was evaluated by applying to laboratory prepared mixtures and pharmaceutical formulation. The high sensitivity of the method was the motivation to its application for analysis of the cited drugs in spiked human plasma. Likewise, analytical and bioanalytical method validation was carried out following International Conference on Harmonisation guidelines and also statistical analysis with the reported methods was carried out and no significant difference was found. The developed method is the first developed spectrofluorimetric method for simultaneous determination of the newly formulated drugs.
      PubDate: 2018-12-31
      DOI: 10.5155/eurjchem.9.4.331-337.1753
      Issue No: Vol. 9, No. 4 (2018)
       
  • Selective colorimetric molecular probe for cyanide ion detection in
           aqueous solution

    • Authors: Yousef Mohammad Hijji, Hani Darwish Tabba, Rajeesha Rajan, Hamzeh Mohammad Abdel-Halim, Musa Ibrahim El-Barghouthi, Hutaf Mustafa Baker
      Pages: 338 - 346
      Abstract: 5-Nitro-2-hydroxybenzaldehyde (1) demonstrated to be a sensitive, and a selective molecular probe for cyanide ion (CN-) in aqueous media. In acetonitrile, compound 1 shows sensitivity and selectivity for cyanide, acetate and fluoride, in comparison to other investigated anions using both visual and spectroscopic means. In aqueous solution, the color becomes intense yellow upon addition of cyanide, while acetate showed this effect to a much lower extent. Significant spectral changes were also detected with the appearance of two new absorption bands at 358 and 387 nm. This was accompanied by concomitant intensity decrease for the band at 314 nm. Fluoride, dihydrogen phosphate, chloride, bromide, perchlorate, and azide showed negligible color and spectral changes for the probe in aqueous solutions. On the other hand, hydrogen sulfate caused fainting of the yellow color and gave a spectrum similar to that of the sensor in polar aprotic solvents. The cyanide ion was detected at micro molar levels in aqueous solutions with a stoichiometry of 1:1 for CN: probe in acetonitrile as the solvent. Cyanide, hydroxide, acetate, fluoride and dihydrogen phosphate showed identical changes to color and spectra, indicating a hydrogen bonding and a deprotonation mechanism.
      PubDate: 2018-12-31
      DOI: 10.5155/eurjchem.9.4.338-346.1777
      Issue No: Vol. 9, No. 4 (2018)
       
  • Crystal structure and Hirshfeld surface analysis of methyl
           1-(2,4-dichlorobenzyl)-5-methyl-1H-pyrazole-3-carboxylate

    • Authors: Abdullah Aydin, Mehmet Akkurt, Zehra Tugce Gur, Erden Banoglu
      Pages: 347 - 352
      Abstract: The title compound, C13H12Cl2N2O2, crystallizes with six molecules in the asymmetric unit, such that, the 1H-pyrazole rings are essentially planar. The six molecules are stabilized by intramolecular C-H···N and C-H···Cl interactions and the crystal structure is stabilized by intermolecular C-H···O hydrogen bonds, forming molecular sheets into paralel to the (-1 1 0) plane. These sheets are connected to each other by C-H···O hydrogen bonds and C-H···π interactions. In the Hirshfeld surface analysis, the H···H, Cl···H/H···Cl, C···H/H···C, O···H/H···O, N···H/H···N, Cl···Cl, Cl···O/O···Cl interactions add to 95.8% of the intermolecular contacts of the Hirshfeld surface area. The remaining contributions (2.9%) correspond to Cl···C/C···Cl, C···O/O···C, O···O and N···N interactions. Crystal Data for C13H12Cl2N2O2 (M = 299.15 g/mol): Triclinic, space group P-1 (no. 2), a = 12.0505(10) Å, b = 12.3189(11) Å, c = 29.184(3) Å, α = 88.565(4)°, β = 89.296(4)°, γ = 76.833(4)°, V = 4217.0(7) Å3, Z = 12, T = 296(2) K, μ(MoKα) = 0.460 mm-1, Dcalc = 1.414 g/cm3, 83073 reflections measured (2.8° ≤ 2Θ ≤ 47°), 12426 unique (Rint = 0.0411, Rsigma = 0.0235) which were used in all calculations. The final R1 was 0.0662 (I > 2σ(I)) and wR2 was 0.2481 (all data).
      PubDate: 2018-12-31
      DOI: 10.5155/eurjchem.9.4.347-352.1782
      Issue No: Vol. 9, No. 4 (2018)
       
  • A novel and expeditious synthesis of oxazolidinone drugs linezolid and
           eperezolid

    • Authors: Ranjith Siddaraj, Shivaraja Govindaiah, Raghu Ningegowda, Nanjunda Swamy Shivananju, Babu Shubha Priya
      Pages: 353 - 359
      Abstract: A concise and efficient synthesis of linezolid and eperezolid were accomplished through a convergent scheme utilizing diverse reaction conditions. The synthesis demonstrates utility of a new approach to facilitate the expeditious construction of 3-aryl-5-(substituted methyl)-2-oxazolidinones and easier insertion of N-acetyl group. This new approach offers the possibility of accessing related 2-oxazolidinone members easily as well as making additional analogues of Linezolid. The adopted method afforded high purity and excellent yield compared to other existing synthetic methods. The compounds were successfully characterized by known spectroscopic techniques.
      PubDate: 2018-12-31
      DOI: 10.5155/eurjchem.9.4.353-359.1783
      Issue No: Vol. 9, No. 4 (2018)
       
  • Synthesis, characterization and crystal structure of platinum(II)
           complexes with thiourea derivative ligands

    • Authors: Ebru Keskin, Ummuhan Solmaz, Gun Binzet, Ilkay Gumus, Hakan Arslan
      Pages: 360 - 368
      Abstract: Thiourea derivatives [N-(di-n-propylcarbamothioyl)-4-fluorobenzamide (HL1) and N-(di-n-propylcarbamothioyl)-4-bromobenzamide (HL2)] and their platinum complexes have been successfully synthesized and structurally characterized by spectroscopic 1H NMR, 13C NMR, COSY, HMQC, and FT-IR techniques. The structure of both complexes was also confirmed by single crystal X-ray diffraction studies. The study of X-ray single crystal diffraction shows that the supramolecular aggregation of the complexes is stabilized via weak interactions as well as stacking interactions such as C-H⋅⋅⋅π and π⋅⋅⋅π. The cis-[Pt(L1-S,O)2 showed C–H⋯π and π⋯π stacking interactions, whereas only C–H⋯π stacking interaction was observed in cis-[Pt(L2-S,O)2]. In addition, the strong classical and non-classical intermolecular hydrogen bonds are not found in the prepared complexes. Therefore, it can be said that the C–H⋯π and π⋯π stacking interactions play an important role in the formation of supramolecular structures of the complexes.
      PubDate: 2018-12-31
      DOI: 10.5155/eurjchem.9.4.360-368.1774
      Issue No: Vol. 9, No. 4 (2018)
       
  • Synthesis and biological evaluation of triphenyl-imidazoles as a new class
           of antimicrobial agents

    • Authors: Anupam Anupam, Mohammed Al-Bratty, Hassan Ahmad Alhazmi, Shamim Ahmad, Supriya Maity, Md Shamsher Alam, Waquar Ahsan
      Pages: 369 - 374
      Abstract: Newer triphenyl-imidazole derivatives (4a-h) were synthesized in good yields by the reaction of benzil and substituted benzaldehydes in equimolar quantities and refluxing the product with acetyl chloride thereafter. Structures were confirmed by using FT-IR, 1H NMR and 13C NMR spectroscopic methods. All the synthesized compounds were tested for their antimicrobial activity using agar diffusion technique against Gram positive (Staphhylococcus aureus and Bacillus subtilis), Gram negative (Escherichia coli and Pseudomonas aureginosa) as well as Fungal strain (Candida albicans). Interestingly compounds 4a, 4b, 4f and 4h showed significant antibacterial activity, whereas compound 4b was found to have remarkable activity against the fungal strain. The Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) of most active compounds were determined by broth dilution method and compound 4b emerged to have potent activities against most of the strains having MIC in the range of 25-200 µg/mL. To check the possible toxicities of the most active compounds, they were orally administered in rats and the concentration of liver enzymes serum glutamic-oxaloacetic transaminase (SGOT), serum glutamic pyruvic transaminase (SGPT) and alkaline phosphatase (ALKP) were determined. Compound 4h showed significant increase in the enzymes level depicting the hepatotoxicity. The structure-activity relationship studies showed the importance of electron withdrawing groups at the distant phenyl ring at ortho and para positions as the compounds having chloro or nitro at these positions tend to be more active than the compounds with electron releasing groups such as methoxy. These compounds may act as lead compounds for further studies and appropriate modification in their structure may lead to agents having high efficacy with lesser toxicity.
      PubDate: 2018-12-31
      DOI: 10.5155/eurjchem.9.4.369-374.1785
      Issue No: Vol. 9, No. 4 (2018)
       
  • Synthesis and characterization of new
           4-aryl-2-(2-oxopropoxy)-6-(2,5-dichlorothiophene)nicotinonitrile and their
           furo[2,3-b]pyridine derivatives: Assessment of antioxidant and biological
           activity

    • Authors: Mahmoud Al‐Refai, Mohammad Ibrahim, Abdullah Al‐Fawwaz, Armin Geyer
      Pages: 375 - 381
      Abstract: A new series of furo[2,3-b]pyridine derivatives bearing aryl substituents were synthesized in two steps, where, the cyano-(2H)-pyridones (1a-l) were converted to the corresponding nicotinonitriles (2a-l), followed by the Thorpe-Ziegler ring cyclization to the furo[2,3-b]pyridine derivatives (3a-l). All new compounds were characterized by 1D-NMR experiments (1H and 13C) and 2D-NMR experiments (COSY, HMBC and HSQC), as well as ESI-MS and HR-ESI-MS data. The new compounds were screened for their antioxidant activities by 2,2-diphenyl-1-picryl-hydrazylhydrate (DPPH) free radical assay. The highest radical scavenging effect was observed for nicotinonitriles 2d, 2h and 2l and furo[2,3-b]pyridines 3b, 3f and 3j by methanolic solvent at 4.0 mg/mL concentration. Remarkably, all nicotinonitriles and furo[2,3-b]pyridine exhibited a significant radical scavenging activity after 24 and 48 hours compared with 0.5 hour.
      PubDate: 2018-12-31
      DOI: 10.5155/eurjchem.9.4.375-381.1792
      Issue No: Vol. 9, No. 4 (2018)
       
  • Theoretical calculation of the exchange coupling constant in some
           polymeric nickel(II) complexes using range-separated functionals

    • Authors: Mohamed Abdalla Makhyoun, Raghdaa Adel Massoud
      Pages: 382 - 385
      Abstract: The magnetic parameters (J, g) of two nickel(II) 1D polymers (Ni(en)(ox) and Ni(ox) (ampy)2; where en = ethylene diamine, ox = oxalate, ampy = 4-amino-pyridine) were calculated using 6-311+G* basis set and six range-separated DFT functionals (CAM-B3LYP, LC-BLYP, wB97, wB97X, wB97X-D3 and B2T-PLYP) together with the hybrid B3LYP method for sake of comparison. We found that the wB97, CAM-B3LYP and wB97X-D3 methods gave approximate value of J for compound 1 and the B2T-PLYP method was found to be the best method for compound 2. The g values were calculated by the coupled perturbed approach. However, we assume that a higher approximation is needed in order to give satisfactory results for g. A new equation has been proposed to relate the experimental susceptibility to the J and g parameters. The Curie-Weiss law was included in this equation resulting in a good explanation of the steep part of the experimental curve below 20 K.
      PubDate: 2018-12-31
      DOI: 10.5155/eurjchem.9.4.382-385.1781
      Issue No: Vol. 9, No. 4 (2018)
       
  • Spectroscopic characterization of thiol adducts formed in the reaction of
           4-methylcatechol with DPPH in the presence of N-acetylcysteine

    • Authors: Masaki Ichitani, Hisako Okumura, Yugo Nakashima, Hitoshi Kinugasa, Mitsunori Honda, Ko-Ki Kunimoto
      Pages: 386 - 393
      Abstract: Nucleophiles such as thiol compounds have enhancing effects on the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activities of polyphenols. Several authors have suggested that regeneration of the catechol structure from o-quinone plays a key role in enhanced radical scavenging activity. We therefore explored the reaction of 4-methyl catechol (MC) with DPPH in the presence of N-acetylcysteine (NACys) to clarify the mechanism underlying activity enhancement. Four types of NACys adducts were isolated and purified by preparative HPLC after the reactions reached equilibrium and their structures were characterized spectroscopically using UV-Vis absorption, NMR, and LC-MS. Oxidation of MC using a periodate resin and subsequent reaction with NACys were also studied. LC-MS analyses revealed that a mono-NACys adduct is produced as the major product in the reaction of MC quinone with NACys, and direct reduction by NACys occurs in reactions with NACys MC quinones.
      PubDate: 2018-12-31
      DOI: 10.5155/eurjchem.9.4.386-393.1794
      Issue No: Vol. 9, No. 4 (2018)
       
  • Assessment of toxic and essential heavy metals in imported dried fruits
           sold in the local markets of Jordan

    • Authors: “Ayat Allah” Al-Massaedh, Ahmad Gharaibeh, Samah Radaydeh, Idrees Al-Momani
      Pages: 394 - 399
      Abstract: In the present study, the concentrations of nine heavy metals (Fe, Zn, Mn, Cu, Mg, Cr, Ni, Cd, and Pb) in six different imported dried fruit samples of different brands (Mangoes, black raisins, figs, apricots, plums, and cranberries) were determined by Flame Atomic Absorption Spectroscopy (FAAS) after wet digestion. Samples were collected from different stores in Amman, Jordan. The average concentration of the selected metals in the analyzed samples were found to be in the range of 1.70-8.70 (Fe), 0.15-0.72 (Zn), 0.09-0.59 (Mn), 0.07-0.46 (Cu), 2.5-53.4 (Mg), 0.06-0.15 (Cr), 0.17-0.29 (Ni), 0.01-0.05 (Cd), and 0.11-0.57 (Pb) µg/g. The highest concentrations of Fe, Zn, Mn, Mg, and Ni were found in dried figs, highest concentrations of Cr, Cd, and Pb were found in dried apricots, and highest concentrations of Cu was found in dried black raisins. The results obtained in this study showed that Mg and Fe have the highest concentrations in all analyzed samples, whereas, the lowest concentrations obtained were for Cd and Cr. The concentrations of the highly toxic metals (Pb and Cd) in the all analyzed samples were found to be below or in good agreement with the permissible limits set by different health organizations. The figures of merit obtained for the FAAS calibration curves are brilliant with good linearity (r2 > 0.99). The FAAS method was validated by determining limit of detection (LOD), limit of quantitation (LOQ), and percent recovery (%R) for all investigated metals. The results obtained in this work were compared with the literature reported values.
      PubDate: 2018-12-31
      DOI: 10.5155/eurjchem.9.4.394-399.1800
      Issue No: Vol. 9, No. 4 (2018)
       
  • Different spectrophotometric and TLC-densitometric methods for
           determination of olmesartan medoxomil and hydrochlorothiazide and their
           degradation products

    • Authors: Selvia Maged Adly, Maha Mohamed Abdelrahman, Nada Sayed Abdelwahab, Nourudin Wageh Ali
      Pages: 400 - 407
      Abstract: In this work, multivariate calibration models and TLC-densitometric methods have been developed and validated for quantitative determination of olmesartan medoxomil (OLM) and hydrochlorothiazide (HCZ) in presence of their degradation products, olmesartan (OL) and salamide (SAL), respectively. In the first method, multivariate calibration models including principal component regression (PCR) and partial least square (PLS) were applied. The wavelength range 210-343 nm was used and data was auto-scaled and mean centered as pre-processing steps for PCR and PLS models, respectively. These models were tested by application to external validation set with mean percentage recoveries 99.78, 100.01, 100.41 and 100.46% for OLM, HCZ, OL and SAL, respectively, for PLS model and also, 100.22, 100.40, 102.25 and 100.13% for them, respectively, for PCR model. The second method is TLC-densitometry at which the chromatographic separation was carried out using silica gel 60F254 TLC plates and the developing system consisted of a mixture of ethyl acetate:chloroform:methanol: formic acid:tri-ethylamine (60:40:4:4:1, by volume) with UV-scanning at 254 nm. The developed methods were successfully applied for determination of OLM and HCZ in their pharmaceutical dosage form. Also, statistical comparison was made between the developed methods and the reported method using student’s-t test and F-test and results showed that there was no significant difference between them concerning both accuracy and precision.
      PubDate: 2018-12-31
      DOI: 10.5155/eurjchem.9.4.400-407.1784
      Issue No: Vol. 9, No. 4 (2018)
       
  • Evaluation of antibacterial and antioxidant activities of three types of
           benzoin resin

    • Authors: Zineb Hacini, Fatima Khedja, Ibrahim Habib, Zaouia Kendour, Zineb Debba
      Pages: 408 - 411
      Abstract: The benzoin resin is used extensively in traditional medicine for its many reported therapeutic properties. The essential oils of three different types of benzoin resin were extracted using the traditional method in this study. The yield of essential oils of the white, red and gray types of resin was 1.01, 0.92 and 0.54%, respectively. The obtained extracts were tested against two types of pathogenic bacteria, Staphylococcus aureus and Escherichia coli. The tests showed that essential oil of gray type resin is effective against both Escherichia coli (14 mm) and Staphylococcus aureus (11 mm). The antioxidant activity has been also evaluated to compare the efficiency of different type of resin with DPPH· assay. In the DPPH· system, the antioxidant activity of the red resin extract (0.01 μg/mL) was superior to that of the white (27.32 μg/mL) and gray (42.90 μg/mL) extracts, with IC50 values, respectively.
      PubDate: 2018-12-31
      DOI: 10.5155/eurjchem.9.4.408-411.1755
      Issue No: Vol. 9, No. 4 (2018)
       
 
 
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