Vol 6, No 1 (2015)

March 2015



Table of Contents

Editorial

Hakan Arslan
10.5155/eurjchem.6.1.i-i.1261
Editorial Board
i-i
Hakan Arslan
10.5155/eurjchem.6.1.ii-v.1262
Graphical Contents
ii-v

Research Article

Kuthair Mohammed Mahdi, Nabeel Abed Abdul-Reda, Najim Aboud Al-Masoudi
10.5155/eurjchem.6.1.1-7.1139

A new series of (5-pregnen-20-on-3α-yl)-substituted-benzoate analogues (10-13), (5-pregnene-20-on-3α-yl)-3-(substituted)acrylate derivatives (17-19) as well as the (17-(2-acetoxyacetyl)pregen-3α-yl)-3,4,5-trihydroxybenzoate (21) were synthesized from the β-pregenenolone scaffolds, by applying Mitsunobu reaction. All new compounds were characterized by 1H, 13C and 2D NMR spectroscopy. The inversion in configuration at C-3 during the formation of α-ester analogues was confirmed by NOESY NMR spectroscopy. The new compounds were evaluated for their in vitro antiviral activity against the replication of HIV-1 and HIV-2 in MT-4 cells. Compounds 18 showed an EC50 value of >1.95 mg/mL. In addition, preliminary structure-activity relationship and molecular modeling of compound 18 has been studied.

1-7
Reza Golbedaghi, Majid Rezaeivala, Leila Albeheshti
10.5155/eurjchem.6.1.8-11.1127

Five new complexes [CdH2L(NO3)]ClO4 (1), [ZnH2L](ClO4)2 (2), [NiH2L](ClO4)2 (3), [CuH2L](ClO4)2 (4) and [CoH2L](ClO4)2 (5) were prepared by reaction of a new Schiff base ligand and different metal ions in 1:1 ratios. The new Schiff base ligand H2L was synthesized by reaction of 2-(4-(2-formylphenoxy)butoxy) benzaldehyde and ethanol amine and characterized with IR, 1H and 13C NMR and elemental analysis. The synthesized complexes were also characterized by IR and elemental analysis in all cases and 1H, 13C NMR and COSY in the case of [CdH2L(NO3)]ClO4 and [ZnH2L](ClO4)2 complexes.

8-11
Hutaf Mustafa Baker, Raed Ahmad Ghanem
10.5155/eurjchem.6.1.12-20.1129

The removal of sulfate using Jordanian bentonite has been investigated in this study. The surface of the bentonite was modified by calcinations at different temperature. The batch experiments of the equilibrium studies were carried out under different operating conditions. Kinetic modeling for the removal of sulfate ion was investigated using a pseudo-second-order, intraparticle diffusion and Elovich kinetic models to predict the rate constants and equilibrium capacities for this process using column reactor. It was found that intraparticle diffusion of the sulfate ion is the rate limiting step and played an important role in the mechanism of sulfate ion adsorption depending on the obtained activation energy, which was 32.8 kJ/mol. Also, the sorption isotherm analyzed using both the Langmuir and Freundlich models as a function of temperature. The isothermal data found to be fitted Langmuir model rather than Freundlich model. The positive value of ΔH (15.2 kJ/mol) indicated that the adsorption of sulfate ions on the adsorbent was an endothermic process and the positive value of ΔS (22.1 J/mol.K) indicated that the adsorption is favorable with small positive value of the free energy (ΔG).

12-20
Enis Ben Bnina, Anis Romdhane, Majda Daami-Remadi, Hichem Ben Jannet
10.5155/eurjchem.6.1.21-30.1137

We report herein the convenient procedures for the efficient and easy synthesis, and the antimicrobial and the anti-acetylcholinesterase evaluation of two new series of (R)-limonene derivatives. A substantial modification aimed at targeting to discover novel structures with a better antimicrobial and anti-acetylcholinesterase (anti-AChE) activities. The condensation of (R)-limonene (1) with various arylnitrile oxides led, via the 1,3-dipolar cycloaddition reaction, conducted with complete region-specificity, to a series of new limonene-dihydroisoxazoles, 2a-h. On the other hand, N-alkylation of the previously prepared limonene-lactam derivative (3) yielded the corresponding dipolarophile (4), which affords by condensation with arylnitrile oxides the expected new dihydroisoxazoles, 5a-h. The target compounds were completely characterized by 1H NMR, 13C NMR and MS. All the synthesized heterocyclic compounds were tested for their antimicrobial and anti-acetylcholinesterase activities. The dihydroisoxazoles 2a (IZ = 13.25 mm, cc = 1 mg/mL) and 5b (IZ = 13.75 mm, cc = 1 mg/mL) exhibited the highest antifungal activity. The greatest anti-acetylcolinesterase activity was exhibited by 2f (IC50 = 82±3 µg/mL) and by 5a (IC50 = 99±1 µg/mL).

21-30
Baharak Sehatnia, Reza Emamali Sabzi, Farshad Kheiri, Abbas Nikoo
10.5155/eurjchem.6.1.31-36.1138

In the present work, a new Graphene-TiO2 (GR-TiO2) modified glassy carbon electrode (GCE) is suggested for sensitive electrochemical determination of metronidazole (MTZ). Electrochemical studies revealed that GR-TiO2 nanoparticles increased the efficiency of electron transfer kinetics by increasing the available surface area of the electrode and charge mobility between MTZ and GR-TiO2 modified electrode. Compared to bare GCE, the modified electrode greatly enhanced the reduction signal of MTZ. The electrochemical behaviour of the modified electrode and the electrochemical reduction of MTZ were investigated with electrochemical impedance spectroscopy, cyclic voltammetry and differential pulse voltammetry techniques. The charge transfer coefficient (α) was calculated to be 0.694. Under optimized conditions, the linear concentration range and detection limit of MTZ were 5.0×10-7 to 2.5×10-5 M-1 and 5.4×10-8 (S/N = 3), respectively. Finally, this sensing method was successfully applied for the determination of MTZ in human blood serum and urine samples.

 

 

31-36
Summyia Masood, Rehana Saeed, Maria Ashfaq
10.5155/eurjchem.6.1.37-43.1146

The electrical conductance of nickel sulfate (NiSO4.6H2O) solutions in aqueous, aqueous polyvinyl alcohol (PVOH; 0.1, 0.5 and 0.9 g/dL), aqueous methanol (CH3OH) system (30%, v:v) and aqueous PVOH+CH3OH systems were measured in the concentration ranges 0.4×10-2 to 10×10-2 mol/L, at different temperatures (298, 303, 308, 313 and 318 K). Ionic interactions of nickel sulfate in aqueous and mixed solvent systems were measured by conductometric analysis. Different relations were used to evaluate conductometric data, for the calculation of molar conductance, molar conductance at infinite dilution (Ʌ°m), degree of dissociation (a), dissociation constant (Kd) and Walden product. The increased in Ʌ°mvalues with the increase in percent composition of aqueous PVOH, show that PVOH interaction with solvents (water and methanol) was higher as compare to PVOH interaction with NiSO4. Solvent effect was also studied by spectrophotometric analysis of NiSO4 in aqueous, aqueous PVOH and aqueous PVOH + CH3OH system. Thermodynamic parameters for dissociation process such as energy of activation (Ea#), free energy change of activation (ΔGd#), enthalpy change of activation (ΔHd#), and entropy change of activation (ΔSd#) were also calculated as a function of temperature and solvent composition.

37-43
Mahmoud Najim Al-Jibouri, Saad Mohammad Hasun
10.5155/eurjchem.6.1.44-47.1140

New transition metal complexes of quinoxaline-2,3-dione-thiosemicarbazone ligand were prepared and characterized by elemental analysis, 1H and 13C NMR spectroscopy. The ligand (LH) was obtained by the reaction of 6,7-dimethyl-quinoxaline-2,3(1H,4H)-dione with thiosemicarbazide. All the complexes are found to be monomer in nature and have tetrahedral geometry. The IR spectra data revealed that the new Schiff base behaved as monobasic tridentate ligand through deprotonation of thiol-SH group, oxygen atom of C=O of pyrazine moiety and nitrogen atom of azomethine -C=N- group. However, the molar conductivity measurements proved the neutral nature of all metal complexes in DMSO solution, as well as the magnetic moment measurements investigated the high spin properties of all complexes.

44-47
Mohamed Farid Cheira
10.5155/eurjchem.6.1.48-56.1143

The chelating aminomethylphosphonic resin Amberlite IRC747 is used for uranium recovery from a synthetic phosphoric acid solution. The operating conditions of uranium extraction have been experimentally optimized by the batch technique viz., the phosphoric acid concentration, the contact time, the initial uranium concentration and the temperature. The effect of some interfering ions upon the effective capacity of the resin has also been examined. It has thus been found that the maximum uranium adsorption capacity of the studied chelating resin was found to attain 86.5 mg/g at 5 M phosphoric acid using 0.1 g resin for 120 min contact time with 50 mL acid assaying 200 mg U/L and room temperature. The obtained equilibrium data agreed well with the Langmuir isotherm model and the relevant thermodynamic parameters (ΔG, ΔH and ΔS) were evaluated and the uranium adsorption was found to be an endothermic reaction and of spontaneous nature. From the kinetic experiments it was shown that U(VI) adsorption followed the pseudo-second order kinetics model and the intraparticle diffusion model. Also, it has been possible to reveal from the kinetic and isotherm data the chemisorption nature of uranium on the Amberlite IRC747 resin. The adsorbed uranium ions can almost be completely eluted with 0.8 M (NH4)2CO3 solution from the loaded resin at room temperature. The studied optimized conditions have successfully been applied for uranium recovery from Abu Zaabal wet process phosphoric acid (WPPA).

48-56
Ali AbdelHamid Deeb, Mamdoh Bahgat El‐Hossami, Ahmed Awad Mohammed Abdelgawad
10.5155/eurjchem.6.1.57-62.1145

Active methylene compound such as ethyl acetoacetate was coupled with diazotized arylamines to give ethyl arylazoacetoacetates. When the obtained compounds refluxed with 3-hydrazinyl-4,5-diphenyl-1H-pyrazolo[3,4-c]pyridazine in the presence of ethanol yielded 1-(4, 5-Diphenyl-1H-pyrazolo[3, 4-c]pyridazin-3-yl)-3-methyl-4-(2-phenylhydrazono)-1H-pyrazol-5(4H)-one derivatives. The dyes were applied to polyester fabric, and their absorption spectral characteristics, fastness properties and color assessment measured.

57-62
Abdulrahman Salim Al-Harbi, Reda Mohammady Abdel-Rahman, Abdullah Mohamed Asiri
10.5155/eurjchem.6.1.63-70.1147

New potential enzyme inhibitors, fluorine-substituted thiobarbituric acid derivatives (2, 3, 9, 8 and 12) and their fused/isolated heterocyclic nitrogen systems (5, 6, 10 and 14) have been obtained from heterocyclization of fluorinated N, Nʹ-disubstituted thiourea (1, 7 and 11) with malonic acid followed by ring closure reactions with primary nitrogen reagents. Structures of the synthesized products have been deduced from their elemental analysis and spectral data. Anti-HIV-1 and inhibition of cyclin-dependent kinase2 (CDK2) for cell tumor division for the synthesized compounds were also evaluated.

63-70
Raed Ahmad Ghanem
10.5155/eurjchem.6.1.71-77.1158

Segregation of antimony trioxide (ATO) from back-coated textiles was studied for two types of textile samples: A (ATO-Hexabromocyclododecane) and B (ATO-Decabromodiphenyl ether). Samples A was found to lose 5.3, 12, 28 and 39 %wt:wt of the amount of ATO originally present due to thermal ageing and UV exposure, respectively. Thermal ageing was performed at 25, 60 and 90 °C compared to 11.0, 17.3, 26.0 and 20.4 % wt:wt of ATO for sample B. The release follows first order kinetics with rate constants of 7.59×10-3, 1.89×10-2, 4.80×10-2 and 2.60×10-2 day-1, respectively, for type A and 9.20×10-3, 2.06×10-2, 4.10×10-2 and 3.83×10-2 day-1 for type B aged at 25, 60, 90 °C and UV exposure, respectively. Migration of ATO from the backcoated textile into simulated biological fluids was also studied for different type of samples under different ageing conditions using Head-over-Heels and contact blotting tests. The presence of biological fluids enhances the migration of ATO.

71-77
Mohammad Mahmoud Ibrahim
10.5155/eurjchem.6.1.78-83.1148

A new series of substituted pyrazolines (6-10) were synthesized in moderate to excellent yield by treatment of chalcones (1-5) with hydrazine monohydrate. The carbothioamide compounds (11-14) were obtained in 65% to quantitative yield by treatment of chalcones (2, 4, and 5) either with thiosemicarbazide or with phenylisothiocyanate. All new compounds were characterized by various spectroscopic methods such as 1H NMR, 13C NMR, DEPT, COSY, HSQC spectroscopy, elemental analysis, and high resolution mass spectroscopy. The obtained compounds are currently under biological investigations, and the results will be reported elsewhere.

78-83
Moustafa Ahmed Gouda, Mohamed Hamdy Helal
10.5155/eurjchem.6.1.84-87.1149

One-pot condensation of malononitrile (1), 4-methylpentan-2-one (2), aryl carboxaldehyde (3a-f) and ammonium acetate in ethanol afforded 2-amino-5-isopropyl-4-(4-aryl)-6-methylnicotinonitriles (4a-f). The antioxidant activity of the new synthesized compounds was evaluated and the result showed all compound exhibited weak anti-oxidant activities.

84-87
Ali AbdelHamid Deeb, Wafaa Ibrahim El-Eraky, Sebaey Mahgoub Mohamed
10.5155/eurjchem.6.1.88-92.1166

The present study describes the chemical synthesis and antimicrobial evaluation of some new pyridazine and triazolopyridazine derivatives. The structure assignments of the new compounds are based on chemical and spectroscopic evidences. The Study results showed that derivatives 6a, 6b, 6g and 6i have promising inhibitory activity against (Micrococcus luteus). Compound 6i has also noticeable inhibition activity against (Escherichia coli) and compound 3g show remarkable activity against (Candida albicans). Rest of compounds showed moderate to low activity against the examined microorganisms.

88-92
Ramesh Perla, Nitin Wasantrao Fadnavis
10.5155/eurjchem.6.1.93-97.1150

The total synthesis of pectinolide H and 4'-epi-pectinolide H was accomplished with 27% yield in nine steps from inexpensive and commercially available compound, (+)-diethyl tartrate ((+)DET)) by employing swern oxidation, Wittig olefination, Grignard and lactonization reactions.

93-97