Vol 7, No 4 (2016)

December 2016

Table of Contents


Hakan Arslan
DOI 10.5155/eurjchem.7.4.i-i.1516
Editorial Board
Hakan Arslan
DOI 10.5155/eurjchem.7.4.ii-v.1517
Graphical Contents

Research Article

Ali Alshabrawy, Ahmed Mostafa, Nageh Abotaleb
DOI 10.5155/eurjchem.7.4.387-390.1451

A simple visible spectrophotometric method has been developed for determination of amlodipine in commercial tablets. Amlodipine (AMO) is 1,4-dihydropyridine derivative, this group when reacted with Folin-Ciocaluts phenol reagent in presence of 10% sodium carbonate, intense blue color was formed that exhibits maximum absorbance at wave length 745 nm. The intensity of color was found to be affected by many parameters. Optimization of the method parameters was done. The method was validated over a concentration range of 10 to 110 µg/mL. The values of each validation items were within the acceptable range for precision and accuracy. The lower limit for quantitation and lower of detection were founded to be 3.21 and 9.72 µg/mL, respectively. The proposed method was successfully applied to the quantitative determination of amlodipine in tablets without interference from tablet additives. The simplicity and accuracy of this method will allow many laboratories to determine the concentration of amlodipine in dosage form in easy way.

Shubhavathi Thimmaiah, Mallesha Ningegowda, Nanjunda Swamy Shivananju, Raghu Ningegowda, Ranjith Siddaraj, Babu Shubha Priya
DOI 10.5155/eurjchem.7.4.391-396.1477

An expeditious method for the synthesis of 3-benzazepinones has been developed by using a mixture of phosphorus pentoxide-methane sulfonic acid (Eaton’s reagent) at room temperature under solvent and metal catalyst free condition. Wide functional group tolerance, mild reaction conditions, simple procedure, ease of work-up and high yields is the citable features of this protocol.

Mohamed Abdel-Hamid Taher, Dawood Hosni Dawood, Mostafa Ibrahim Sanad, Ramadan Ahmed Hassan
DOI 10.5155/eurjchem.7.4.397-404.1478

Tecoma stans plant is well postulated to decrease blood glucose level, but its mode of action and the molecules responsible are still controversial. Thus, the aim of this study was to evaluate the effect of leaves methanol extract of Tecoma stans and some of its fractions on starch tolerance in healthy rats, in vitro inhibition of α-amylase, and their effects of sub-chronic administration of glucose, lipid pattern, kidney and liver functions and antioxidant status in streptozotocin (STZ) induced diabetic rats. In starch tolerance experiment, both ethyl acetate and crude flavonoids fractions decreased glycemic peak values in healthy rats to extent similar to that of acarbose. In STZ sub-chronic experiment all preparations of Tecoma stans significantly decreased fasting glucose with variable degrees. The results indicated that the crude methanol extract had the most antidiabetic potential followed by the methylene chloride rich alkaloid fraction while the crude flavonoids fraction achieved the lowest effect. All Tecoma stans different preparations have positive effects on serum lipid pattern, kidney and liver function parameters, in addition to the antioxidant parameters (MDA and GSH) in liver tissues. In conclusion, the present study suggested that the alkaloids synergistically act as antidiabetic agent with other bioactive compounds of Tecoma stans especially flavonoids as hypoglycemic agents and the ethyl acetate fraction had the most powerful effects.

Baqer Al-Mayyahi, Hadi Al-Lami, Athir Haddad
DOI 10.5155/eurjchem.7.4.405-409.1480

The nano four arms poly(lactide-b-N,N-dimethylaminoethylmethacrylate) were prepared by pentaerythritol-lactide atom transfer radical polymerization initiators having different repeating units (10, 25, 50 and 100) of L-lactide with the same amount of N,N-dimethylaminoethyl methacrylate by atom transfer radical polymerization reaction. The copolymers were characterized FT-IR, 1H NMR, 13C NMR and Gel permeation chromatography. These characterization methods confirmed the structures of prepared copolymers. Scanning electron microscopy, on the other hand, revealed that the presence of a nanostructure in the prepared copolymers attributed to the lactide fibers. Then, the thermal study was carried out on the copolymers the results have proven to increase the thermal stability of the copolymers with the increasing chain length of the lactide.

Tahani Achouak Chinar, Mohammed Benbouzid
DOI 10.5155/eurjchem.7.4.410-415.1486

The zeolitic porous material was prepared from kaolinitic clay (DD1 from Gebel Debbagh, Algeria) using a cheap and easy process to insert a sodium ion into the kaolinitic clay structure. The obtained zeolitic Linde Type-A (LTA) material was characterized by elemental analysis, infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy and X-ray diffraction techniques. The adsorption capacity of the zeolitic porous material was tested with methylene blue. The best correlation of experimental results was obtained with the Langmuir model giving a Qmax of 11.5 mg/g indicating a favorable process for the adsorption of the dye.

Ilkay Gumus, Cemal Koray Ozer, Don Vanderveer, Hakan Arslan
DOI 10.5155/eurjchem.7.4.416-420.1503

Copper(II) complex, cis-[Cu(L-κ2S,O)2] of N-(di-n-propylcarbamothioyl)cyclohexane carboxamide ligands (HL) has been synthesized and structurally characterized by various spectroscopic techniques and single crystal X-ray diffraction crystallography. The cis-[Cu(L-κ2S,O)2], C28H50CuN4O2S2: Monoclinic, space group P21/n (no. 14), a = 10.025(2) Å, b = 21.724(4) Å, c = 14.848(3) Å, β = 100.60(3)°, Z = 4, Dcalc = 1.259 g/cm3, 22069 reflections measured (5.88° ≤ 2Θ ≤ 50.2°), 5639 unique (Rint = 0.0630, Rsigma = 0.0678) which were used in all calculations. The final R1 was 0.0488 (≥2σ(I)) and wR2 was 0.1277 (all data). Single crystal analysis revealed that a square-planar coordination geometry is formed around the copper atom by two sulphur and two oxygen atoms of the related ligand, which are in a cis configuration.

Sami Abdullah Al-Harbi, Mahmoud Sayed Bashandy, Hammed Mohammed Al-Saidi, Adel Abbas Ahmed Emara, Shimaa Mohamed Abd El-Gilil
DOI 10.5155/eurjchem.7.4.421-430.1490

Thiazole Schiff base (H2L) ligand was synthesized from condensation of 2-amino-4-phenylthiazole with 4,6-diacetylresorcinol in the molar ratio 2:1. A series of Ag(I), Mn(II), Co(II) and Ni(II) complexes of H2L ligand was prepared and investigated by elemental analysis, IR, UV, 1H NMR, TGA and mass spectral data. Thiazol Schiff base ligand has two bidentate sets of N-O units which can coordinate with two metal ions to afford novel binuclear metal complexes. The directions of the coordinate bonds are from nitrogen atoms of the azomethine groups and oxygen atoms of the phenolic groups. All of the newly synthesized complexes were evaluated for their antimicrobial activities. The results showed the Ag(I) complex exhibited better activities than the commercial antimicrobial reference drugs. The metal complexes were also evaluated for their in-vitro anti-colon human cancer (HCT-116) and mammalian cells of the African green monkey kidney (VERO). The Ag(I) and Co(II) complexes with selectivity index value 17.00 and 15.63, respectively, exhibited better activity than methotrexate as a reference drug with selectivity index value 13.30, while complexes Ni(II) and Mn(II) with selectivity index values 9.30 and 8.59, respectively, were found to be nearly as active as methotrexate. Molecular docking studies further helped in understanding the mode of action of the compounds through their various interactions with the active sites of the dihydrofolate reductase enzyme. The observed activity of the Ag(I), Mn(II) and Ni(II) complexes gave rise to the conclusion that they might exert their action through inhibition of the dihydrofolate reductase enzyme.

Shuddhodan Narhari Kadam, Ajay Niwruttirao Ambhore, Milind Vithalrao Gaikwad, Rahul Datta Kamble, Shrikant Vasantappa Hese, Madhav Janardan Hebade, Bhaskar Sadashiv Dawane
DOI 10.5155/eurjchem.7.4.431-435.1485

The present report describes a microwave assisted convenient and efficient protocol for the synthesis of new 6-(4-substituted-phenyl)-3-methylimidazo[2,1-b]thiazole-2-carbohydra- zide derivatives. The current method holds a tag of green synthesis by virtue of catalyst and solvent free media. Moreover, the procedure offers excellent yield and purity of the products under mild condition compared with conventional method.

Hayat Hamza Abbas
DOI 10.5155/eurjchem.7.4.436-441.1445

Complexes of Cu(II), Co(II) and Mn(II) with two Schiff base ligands {[(2-carboxyphenyl)imino]methyl} phenol (HLA) and {[(2-hydroxyphenyl)imino]methyl} phenol (HLB) were synthesized and characterized by FT-IR, UV-Visible, 1H NMR spectroscopy and elemental analysis. All the synthesized complexes have been evaluated for their thermal degradation studies using TG-DTA analytical methods in static air. Thermodynamic and kinetic parameters were evaluated from the TG-DTA curves using Arrhenius equation.

Sitti Rahmawati, Cynthia Linaya Radiman, Muhamad Abdulkadir Martoprawiro
DOI 10.5155/eurjchem.7.4.442-447.1506

The repeating unit of sulfonated “nata de coco” is D-glucose sulfonate. This research aims to determine the most stable structures of sulfonated nata de coco polymer membrane, the energy and hydrogen bonds, in order to understand the characteristics, local hydration, and proton transfer on the membrane on the ab initio electronic structure calculation. The minimum energy structure for its monomer (two, three, four and five) are calculated by B3LYP/6-311G (d) method. The calculations show that there is no significant energy change on the structure interaction of two, three, four and five monomer of sulfonated nata de coco with one water molecule, which is about -18.82 kcal/mole. Those calculations that two monomers form of sulfonated nata de coco might be used to further calculation and research, because it can be considered as the representative for their polymer. The optimization and B3LYP/6-311G (d) calculation shows the amount of water molecule used for proton transfer is closely related to the formation of hydrogen bonding with sulfonic group. By the addition of one or two water molecule, the dissociated proton is stabilized by formation of hydronium ion. For further addition of water molecule (three to ten water molecules), the proton dissociation is also stabilized by the formation of Zundel ion and Eigen ion. The calculation of interaction energy with n water molecule (n = 1-10) shows that both energy change (∆E), and enthalpy change (∆H) are more negative. This implies that the interaction with water molecule is stronger. The bonding energy is about 14.0-16.5 kcal/mole per water molecule. On the addition of four and eight water molecules, proton dissociation forms two Zundel ion and two Eigen ions and causes lower bonding energy about 2 kcal/mole. Those optimization and energy calculations conclude that the formation of hydrogen bonding among water molecule and sulfonic group affects proton transfer on sulfonated nata de coco membrane.

Efdal Cimen, Ilkay Gumus, Omer Celik, Ebru Keskin, Hakan Arslan
DOI 10.5155/eurjchem.7.4.448-453.1509

The centrosymmetric binuclear complex, [Zn2(C8H7O2)4(C7H7NO)2], has been synthesized and characterized by FT-IR and NMR methods. The obtained Zn(II) metal complex has been also characterized by a single crystal X-ray diffraction study. Crystal data for C46H42N2O10Zn2: Monoclinic, Space group P21/c (no. 14), a = 10.4827(3) Å, b = 8.6141(2) Å, c = 24.7582(6) Å, β = 101.066(1) °, V = 2194.07(10) Å3, Z = 4, Dcalc = 1.383 g/cm3, 22545 reflections measured (3.96° ≤ 2Θ ≤ 52.74°), 4465 unique (Rint = 0.0388, Rsigma = 0.0333) which were used in all calculations. The final R1 was 0.0489 (I ≥ 2s(I)) and wR2 was 0.1533 (all data). The four nearest oxygen atoms around each zinc ion form a distorted square-planar arrangement, and the distorted square-pyramidal coordination is completed by the nitrogen atom of the 1-(pyridin-4-yl)ethanone compound.

Mohamed Ahadu Shareef, Mohamed Musthafa, Devadasan Velmurugan, Subramani Karthikeyan, Singaravelu Ganesan, Syed Ali Padusha, Saiyad Musthafa, Jamal Mohamed
DOI 10.5155/eurjchem.7.4.454-462.1505

2-((4-Methylpiperazin-1-yl)(thiophen-2-yl)methyl)hydrazinecarboxamide (L1) and (2-(piperazin-1-yl(thiophen-2-yl)methyl)hydrazinecarboxamide (L2) from the family of thiophene-2-carboxaldehyde derivatives have been synthesized. These new compounds have good antibacterial as well as antifungal activity and also less toxic in nature. Exemplary binding characteristics of these novel compounds and pharmacokinetic mechanism were confirmed by optical spectroscopic, anticancer and docking studies. The binding of thiophene-2-carboxaldehyde derivatives to carrier protein, Human Serum Albumin (HSA) has been investigated by studying its quenching mechanism, binding kinetics and the molecular distance (r) between donor (HSA) and acceptor (thiophene-2-carboxaldehyde derivatives) according to Forster’s theory of non-radiative energy transfer (FRET). The micro environment of HSA has also been studied by using synchronous fluorescence spectroscopy technique and the molecular docking technique has been used to explore the hydrogen bonding, hydrophobic interaction between the human serum albumin with L1 and L2 compound.

Omar Melad
DOI 10.5155/eurjchem.7.4.463-467.1449

Poly o-phenylenediamine (PoPD) doped with different acids such as hydrochloric, sulfuric, formic, phosphoric and glacial acetic acids was synthesized by a chemical oxidative polymerization technique using potassium dichromate as oxidizing agent. The polymer products were characterized by FT-IR and UV-visible spectroscopy. The FT-IR spectra showed shift to lower wave number in case of PoPD-H2SO4 and PoPD-H3PO4, indicating that the doping degree of PoPD in H2SO4 and H3PO4 are the greatest. A successful doping of PoPD in H3PO4 was observed in UV-vis spectroscopy. The three steps decomposition observed from the thermogravimetric analysis (TGA). The second step loss related to the loss of the dopant is found to be higher in H3PO4 doped polymer. The electrical conductivity values of PoPD-H2SO4 and PoPD-H3PO4 are found to be the highest among the other acids.

Kamal Usef Sadek, Maghraby Ali Selim, Abdul-Aziz Alnajjar, Mohamed Atallah, Mohamed Hilmy Elnagdi
DOI 10.5155/eurjchem.7.4.468-472.1508

A novel multi-component reaction between arylhydrazonals, malononitrile and aromatic aldehydes under high pressure utilizing Q-tube was carried out. The reaction of arylhydrazonal (1j) with malononitrile and aromatic aldehydes afforded the corresponding biphenyl derivatives (4). However, compound 1h reacted with malononitrile and aromatic aldehydes (7) to afford pyridazino[5,4,3-de]1,6-naphthyridine-7-carbonitrile derivatives (8). In contrast, the arylhydrazonal (1k) at the same reaction conditions afforded the corresponding pyridazinoquinazoline derivative (22). A rationalization for the difference in behavior for reaction of compounds 1h-k with malononitrile and aromatic aldehydes was postulated. Based on these findings a mechanism to account for the formation of the reaction products is suggested excluding possible initial dimerization of malononitrile as has been previously reported.