JSCS - Vol 72, No 4

JSCS Vol 72, No. 5

Whole issue - PDF (1.453 KB WinZip file)

J. Serb. Chem. Soc. 72 (5) 421–427 (2007)

UDC 66.094.2:547.26'11:547.21–32, JSCS–3572, doi: 10.2298/JSC0705421O; Original scientific paper

Asymmetric Meerwein–Ponndorf–Verley reduction of long chain keto alkanoic acid methyl esters

HÜLYA ÇELIK ONAR, BELMA HASDEMIR and AYE YUSUFO[1]LU

Department of Chemistry, Faculty of Engineering, Istanbul University, 34320 Avcìlar, Istanbul, Turkey

(Received 6 April, revised 10 August 2006)

3-, 7- and 13-Monoketo tetradecanoic acid methyl esters carrying a ketogroup at the ends and at the middle of the chain with 14 carbon atoms were reduced by a Meerwein–Ponndorf–Verley reaction in the presence of R-(+)-1,1'-binaphthalene-2,2'-diol, 1,2:5,6-D-di-O-isopropylidene-D-mannitol and L-(–)-menthol. The highest enantiomeric purity of 65% ee was found for 13-hydroxy ester isomer. The enantiomeric excess was determined by ¹H-NMR shift with Eu(tfc)₃ and by optical rotation.

Keywords: asymmetric Meerwein–Ponndorf–Verley reduction, monoketo tetradecanoic acid, R-(+)-1,1'-binaphthalene-2,2'-diol (BINOL), 1,2:5,6-D-di-O-isopropylidene-D-mannitol, L-(–)-menthol.

Full Article - PDF 102 KB

J. Serb. Chem. Soc. 72 (5) 429–435

UDC 542.913+547.822:615.214, JSCS–3573 doi: 10.2298/JSC0705429A; Original scientific paper

Synthesis and pharmacological evaluation of several N-(2-nitrophenyl)piperazine derivatives

DEANA ANDRIC, GORDANA TOVILOVIC*, GORAN ROGLIC, DJURDJICA VASKOVIC*, VUKIC SOSKIC**^,***, MIRKO TOMIC* and SLADJANA KOSTIC-RAJACIC**

Faculty of Chemistry, University of Belgrade, Studentski trg 16, 11000 Belgrade, Serbia

*Department of Biochemistry, Institute for Biological Research, Bulevar Despota Stefana 142, 11060 Belgrade, Serbia

**Centre for Chemistry, Institute for Chemistry, Technology and Metallurgy, Njegoseva 12, 11000 Belgrade, Serbia

***Proteosys AG, Carl-Zeiss-Str. 51, 55129 Mainz, Germany

(Received 7 April, revised 15 December 2006)

Six newly synthesized heterocyclic (2-nitrophenyl)piperazines, with a specific structure of the heteroaryl group, whichmimics the catechol moiety of dopAMine (benzimidazoles and substituted benzimidazoles), were evaluated for their binding affinity to rat dopAMine (DA), serotonin (5-HT) and α₁ receptors. All compounds with a benzimidazole group had a 5-HT_2A/D₂ receptors binding ratio characteristic for atypical neuroleptics (>1, pK_i values). Compound 7c, 4-bromo-6-{2-[4-(2-nitrophenyl)piperazin-1-yl]ethyl}-1H-benzimidazole, expressed higher affinities for all receptor classes than clozapine. Also, it exhibited the best characteristic for atypical neuroleptics and presents a compound with the best profile for further in vivo investigations.

Keywords: arylpiperazines, benzimidazoles, dopAMine receptors, serotonin receptors, atypical antipsychotic.

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J. Serb. Chem. Soc. 72 (5) 437–442 (2007)

UDC 547.466.1+542.913:615.281/.282, JSCS–3574, 10.2298/JSC0705437B; Original scientific paper

The synthesis and antimicrobial study of some azetidinone derivatives with the para-anisidine moiety

ISHWAR K. BHAT, SUNIL K. CHAITHANYA, P. D. SATYANARAYANA and BALAKRISHNA KALLURAYA*

Department of Pharmaceutical Chemistry, N. G. S. M. Institute of Pharmaceutical Sciences, Mangalore-575 005, India

*Department of Studies in Chemistry, Mangalore University, Mangalagangothri 574199, India

(Received 29 June 2005, revised 17 April 2006)

Azetidinones were synthesized from p-anisidine in two steps. First the Schiff's bases were prepared by reacting the hydrazide of an anisidine derivative with different aromatic aldehydes. Cyclocondensation of the Schiff's bases with chloroacetyl chloride in the presence of triethylAMine resulted in the formation of the corresponding azetidinone analogues. The structures of the newly synthesized compounds were confirmed by IR, ¹H NMR and mass spectroscopic analysis. The antibacterial and antifungal potential of the synthesized compounds were evaluated by the agar disc method.

Keywords: azetidinones, Schiff's bases, antibacterial, antifungal.

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J. Serb. Chem. Soc. 72 (5) 443–449 (2007)

UDC 547.78+542.913:615.281, JSCS–3575, 10.2298/JSC0705443S; Short communication

Synthesis and antibacterial studies of some novel isoxazoline derivatives

TEJASKUMAR SHAH and VIKAS DESAI

Department of Chemistry, B. K. M. Science College, Valsad-396001 (Affiliated to Veer Narmad South Gujarat University, Surat-395007) State-Gujarat, India

(Received 31 March, revised 11 September 2006)

A series of 3-[3-(2,4-dichloro-5-fluorophenyl)-5-(2-furyl)-4,5-dihydro-1H-pyrazol-1-yl]-5-(substituted phenyl/2-thienyl)isoxazolines (4a-j) were prepared. The structures of the isoxazoline derivatives were confirmed on the bases of elemental analysis and spectral data. The compounds were screened for their in vitro antibacterial activity using grAM-positive bacteria and grAM-negative bacteria.

Keywords: isoxazoline, chalcone, antibacterial activity, heterocyclic synthesis.

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J. Serb. Chem. Soc. 72 (5) 451–457 (2007)

UDC 582.282.23:664.642:66.094.941+577.15, JSCS–3576, doi: 10.2298/JSC0705451V; Original scientific paper

Utilization of baker's yeast (Saccharomyces cerevisiae) for the production of yeast extract: effects of different enzymatic treatments on solid, protein and carbohydrate recovery

TATJANA VUKASINOVIC MILIC, MARICA RAKIN and SLAVICA SILER-MARINKOVIC

Faculty of Technology and Metallurgy, Karnegijeva 4, Belgrade, Serbia

(Received 5 May, revised 4 December 2006)

Yeast extract (YE) was produced from commercial pressed baker's yeast (active and inactivated) using two enzymes: papain and lyticase. The effects of enzyme concentration and hydrolysis time on the recovery of solid, protein and carbohydrate were investigated. Autolysis, as a basic method for cell lysis was also used and the results compared. The optimal extraction conditions were investigated. The optimal concentrations of papain and lyticase were found to be 2.5 % and 0.025 %, respectively.

Keywords: baker's yeast, yeast extract, enzymatic hydrolysis, papain, lyticase.

Full Article - PDF 95 KB

J. Serb. Chem. Soc. 72 (5) 459–466 (2007)

UDC 547.784+546.472:615.281, JSCS–3577, doi: 10.2298/JSC0705459P; Original scientific paper

Antibacterial evaluation of some benzimidazole derivatives and their zinc(II) complexes

S. O. PODUNAVAC-KUZMANOVIC and D. M. CVETKOVIC

Faculty of Technology, Bul. Cara Lazara 1, 21000 Novi Sad, Serbia

(Received 10 May, revised 28 August 2006)

Zinc(II) chloride was reacted with some 1-benzylbenzimidazole derivatives (L) to give complexes of the formula ZnL₂Cl₂. All the ligands and their zinc(II) complexes were evaluated for their in vitro antibacterial activity against Pseudomonas aeruginosa, Bacillus cereus, Staphylococcus aureus and Sarcina lutea. Themajority of the investigated compounds displayed in vitro antimicrobial activity against very persistent microorganisms. It was found that all the tested compounds were more active against grAM-positive than grAM-negative bacteria. The minimum inhibitory concentration (MIC) was determined for all ligands and their complexes. The effect of the structure of the ligands and complexes on the antimicrobial activity is discussed. The complexes were found to be more toxic than the ligands.

Keywords: benzimidazole derivatives, complexes, zinc(II), antibacterial activity, in vitro studies.

Full Article - PDF 95 KB

J. Serb. Chem. Soc. 72 (5) 467–474 (2007)

UDC 547.562.1+541.183:679.91, JSCS–3578, doi: 10.2298/JSC0705467Y; Original scientific paper

Adsorption of phenol and chlorophenols on pure and modified sepiolite

A. YILDIZ and A. GÜR

Department of Chemistry, Science-Art Faculty, Yüzüncü Yil University Van-Turkey

(Received 20 December 2005, revised 10 May 2006)

In this work, pure sepiolite and sepiolite modified by nitric acid (HNO₃), ethylenediAMinetetraacetic acid (EDTA) and hexadecyltrimethyl-AMmonium (HDTMA) were used ad adsorbents. The changes on the surface were studied by IR spectroscopy. The adsorption of solutions of phenol and phenol derivatives in pure ethanol on these adsorbents were exAMined by means of gas chromatography. It was found that the adsorption capacities of the clay–organic complexes (sepiolite–EDTA and sepiolite–HDTMA) were higher than those of pure sepiolite and sepiolite–HNO₃.

Keywords: adsorption, clay, sepiolite, phenol, chlorophenol.

Full Article - PDF 168 KB

J. Serb. Chem. Soc. 72 (5) 475–484 (2007)

UDC 544.112.001.57+547.55/.56:669.3, JSCS– 3579, doi: 10.2298/JSC0705475L; Original scientific paper

Molecular simulation study of 1,5-diphenylcarbazide self-assembled monolayers on a copper surface

GUANGZENG LIU*, SHENHAO CHEN*^,**, HONGFANG MA* and XIUYU LIU*

*Department of Chemistry, Shandong University, Jinan 250100, P. R. China

**State Key Laboratory for Corrosion and Protection, Shenyang 110015, P. R. China

(Received 10 February, revised 20 October 2006)

In this study, the adsorption process of 1,5- diphenylcarbazide (DPC) self-assembled monolayers on a copper surface was investigated by using molecular mechanics. The results indicated that the interaction of the α-electrons in the –NH–NH– group and the π-electrons in the phenyl ring could lead to strong adsorption of the highly symmetric DPC molecules on a copper surface. The synergy effect of the phenyl ring and the –NH–NH– group made the whole DPC molecule lay in parallel orientation on a copper surface when the coverage was low. However, at high coverage, the phenyl ring was slightly tilted because of the repulsion of the DPC molecules, while the –NH–NH–groups remained parallel to the copper surface.

Keywords: self-assembled monolayers (SAMs) 1,5-diphenylcarbazide, copper, molecular mechanics.

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J. Serb. Chem. Soc. 72 (5) 485–494 (2007)

UDC 547.295.94+666.122.3+541.183:66–971, JSCS– 3580, doi: 10.2298/JSC0705485S; Original scientific paper

Equilibrium and thermodynAMic studies of stearic acid adsorption on Celtek clay

AHMET SARI and MUSTAFA SOYLAK*

Department of Chemistry, Gaziosmanpaşa University, 60240, Tokat, Turkey

*Department of Chemistry, Erciyes University, 38039, Kayseri, Turkey

(Received 14 April, revised 9 August 2006)

This paper presents the equilibrium and thermodynAMic parAMeters of the adsorption of stearic acid on Celtek clay as a function of temperature. It was found that the adsorption of stearic acid on Celtek clay decreased with increasing temperature from 293 to 313 K. The equilibrium modelled data fitted well with the linear forms of both the Langmuir and the Freundlich models (R² = 0.99 in both cases). The R_L and 1/n values determined from the isotherm models proved that Celtek clay is a suitable adsorbent for stearic acid. The Dubinin–Radushkevich (D–R) isotherm was applied to describe the nature of the adsorption of stearic acid on Celtek clay and it was found that the adsorption occurred physically. ThermodynAMic parAMeters of adsorption, such as Gibbs free energy change (ΔG⁰), enthalpy change (ΔH⁰) and enthropy change (ΔS⁰) were also calculated. These parAMeters showed that the adsorption of stearic acid on Celtek clay was feasible, spontaneous, and exothermic in nature. On the basis of the results, it can be concluded that Celtek clay has considerable potential for the removal of stearic acid from the main sources, such as raw and edible soybean, sunflower and olive oils.

Keywords: stearic acid, Celtek clay, adsorption, isotherm, thermodynAMic parAMeter.

Full Article - PDF 165 KB

J. Serb. Chem. Soc. 72 (5) 495–512 (2007)

UDC 547.466+547.426.1:536.5:541.25, JSCS–3581, doi: 10.2298/JSC0705495A; Original scientific paper

Volumetric, viscometric and refractive index behaviour of AMino acids in aqueous glycerol at different temperatures

A. ALI, S. KHAN and F. NABI

Department of Chemistry, JAMia Millia IslAMia (Central University), New Delhi-110025, India

(Received 3 May, revised 12 October 2006)

Densities, ρ, viscosities, η, and refractive indices, n_D, of solutions of some AMino acids (glycine, DL–alanine, DL–α–AMino–n–butyric acid, L‑valine and L‑leucine) in the concentration range 0.02 to 0.10 m in 5 % (v/v) aqueous glycerol were determined at 298.15, 303.15, 308.15 and 313.15 K. These experimental data were used to calculate the apparent molar volumes, Φν, the infinite dilution apparent molar volumes, Φν⁰, the partial molar volumes of transfer, Φν⁰ _(tr), of the AMino acids from aqueous to aqueous glycerol solution, as well as the viscosity A and B coefficients of the Jones–Dole equation of the AMino acids. The free energies of activation of viscous flow, Δμ₁^0# and Δμ₂^0# per mole of solvent and solute, respectively, were obtained by application of the transition–state theory to the B coefficient data and the corresponding activation enthalpy, ΔH*, and entropy, ΔS*, were also determined. The Φν⁰, B coefficients and Δμ₂^0# were found to vary linearly with increasing number of carbon atoms in the alkyl chain of the AMino acids, and they were split into contributions from the zwitterionic end groups (NH₃⁺, COO^-) and methylene (CH₂) groups of the AMino acids. The experimental values of the refractive indices, n_D, were used to calculate the molar refractive indices, R_D, of the AMino acids + aqueous glycerol ternary mixtures. The results were interpreted in the light of the solute–solvent and solute–solute interactions in the mixed solvents.

Keywords: apparent molar volumes, transfer volumes, viscosity B-coefficient, activation parAMeters, side-chain contributions.

Full Article - PDF 138 KB

J. Serb. Chem. Soc. 72 (5) 513–521 (2007)

UDC 546.26–037:677.017.4:547–31166.017, JSCS–3582, doi: 10.2298/JSC0705513D; Original scientific paper

Non-linear elastic behaviour of carbon fibres of different structural and mechanical characteristic

ISIDOR M. DJORDJEVIC, DANIELA R. SEKULIC and MOMCILO M. STEVANOVIC

Institute of Nuclear Sciences Vinca, POB 522, 11000 Belgrade, Serbia

(Received 24 January, revised 15 June2006)

Five types of polyacrylonitrile, PAN, based carbon fibres, differing in modulus, breaking strain and in crystallite orientation, have been studied. Non-Hookean behaviour was investigated by computing the tangent tensile and compression moduli as a function of strain, from the axial stress–strain response obtained in standard tensile, compression, as well as in modified flexural tests of unidirectional carbon/ epoxy composites. The dependences of the tensile modulus on tensile strain of the carbon fibres were extracted from data obtained in single-filAMent tensile tests. Analytical expressions for the tensile modulus–tensile strain and compression modulus–compression strain dependences in the performed test were deduced. The structural characterization of the carbon fibres was performed by X-ray diffraction on bundle of parallel fibres. The interlayer spacing d₀₀₂ and the apparent lateral dimension of the crystallites L_c were deduced by processing the 002 diffraction profiles. The established modulus–strain dependences were correlated with the fibre characteristics (breaking strain and mean modulus values), as well as with the characteristic of the 002 diffraction profile and the d₀₀₂ and L_c values.

Keywords: carbon fibres, carbon/epoxy composites, non-linear elasticity, crystallite preferential orientation.

Full Article - PDF 111 KB

J. Serb. Chem. Soc. 72 (5) 523–531 (2007)

UDC 66.021.3+546.21+66–936:54–72+66.023, JSCS–3583, doi: 10.2298/JSC0705523V; Original scientific paper

Oxygen mass transfer in a 16.6 cm i. d. multiphase reciprocating plate column

LJUBISA S. VASIC, IVANA B. BANKOVIC-ILIC, MIODRAG L. LAZIC, VLADA B. VELJKOVIC and DEJAN U. SKALA*

Faculty of Technology, University of Nis, Bulevar oslobodjenja 124, 16000 Leskovac, Serbia

*Faculty of Technology and Metallurgy, Karnegijeva 4, University of Belgarde, Belgrade, Serbia

The effects of vibration intensity, superficial gas velocity and content of solid particles on the volumetric oxygen mass transfer coefficient (k₁a) in a 16.6 cm i.d. multiphase reciprocating plate column were strudied. The k₁a increased with increasing vibration intensity and superficial gas velocity, and decreased with increasing content of solid particles. The k₁a was correlated with the specific time-averaged power consumtion, the superficial gas velocity, the column diAMeter and the content of solid particles.

Keywords: reciprocating plate column, volumetric oxygenmass transfer coefficient, power consumption, superfiical gas velocity, sulphite method.

Full Article - PDF 131 KB

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