Vol 76, No 12 - Abstracts

JSCS Vol 76, No. 12

Whole issue - PDF 3,176 KB

J. Serb. Chem. Soc. 76 (12) 1597–1606 (2011)

UDC 547.783:547.6:544.022:615.28–188; JSCS–4232; doi: 10.2298/JSC110314143T; Original scientific paper

Structure–activity relationships of 3-substituted-5,5-diphenylhydantoins as potential antiproliferative and antimicrobial agents

NEMANJA TRIŠOVIĆ, BOJAN BOŽIĆ, ANA OBRADOVIĆ*, OLGICA STEFANOVIĆ*, SNEŽANA MARKOVIĆ*, LJILJANA ČOMIĆ*, BILJANA BOŽIĆ** and GORDANA UŠĆUMLIĆ

Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4,11000 Belgrade, Serbia

*Faculty of Science, University of Kragujevac, Radoja Domanovića 12, 34000 Kragujevac and **Faculty of Biology, University of Belgrade, Studentski trg 3, 11000 Belgrade, Serbia

(Received 14 March, revised 2 May 2011)

A series of twelve 3-substituted-5,5-diphenylhydantoins was synthesized, including some whose anticonvulsant activities have already been reported in the literature. Their antiproliferative activities against HCT-116 human colon carcinoma cells were evaluated to determine structure–activity relationships. Almost all of the compounds exhibited statistically significant antiproliferative effects at a concentration of 100 μM, while the derivative bearing a benzyl group was active even at lower concentrations. Moreover, their in vitro antibacterial activities against Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 25923 and clinical isolates of Escherichia coli, Proteus mirabilis, Pseudomonas aeruginosa, Enterococcus faecalis and Staphylococcus aureus were evaluated. Only the 3-isopropyl and 3-benzyl derivatives showed weak antibacterial activities against the GrAM-positive bacterium E. faecalis and the GrAM-negative bacteria E. coli ATCC 25922 and E. coli.

Keywords: phenytoin derivatives; antiproliferative activity; antimicrobial activity; structure–activity relationship.

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J. Serb. Chem. Soc. 76 (12) 1607–1615 (2011)

UDC 547.532–326+66.095.13:66–911.4+544.478; JSCS–4233; doi: 10.2298/JSC110102144Z; Original scientific paper

Novel Brønsted-acidic ionic liquids based on benzothiazolium cations as catalysts for esterification reactions

XIAN SI ZHOU, JIA BING LIU, WEN FENG LUO, YI WEN ZHANG and HANG SONG

School of Chemical Engineering, Sichuan University, Chengdu 610065, P. R. China

(Received 2 January, revised 18 March 2011)

Three novel Brønsted-acidic ionic liquids based on benzothiazolium cations were prepared, which served as catalysts for the synthesis of benzoic esters. All three gave good yields of the target esters in esterification reactions. Moreover, they combine the advantages of both homogeneous and heterogeneous solid catalysts in esterification reactions, which enabled them to serve as homogeneous catalysts to catalyze the reactions and be conveniently recovered by simple filtration after the reactions. They could be reused several times without noticeable decrease in efficiency.

Keywords: benzoic esters; benzothiazolium salts; catalyst; esterification; ionic liquid.

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J. Serb. Chem. Soc. 76 (12) 1617–1626 (2011)

UDC 547.72+547.831:615.281–188:615.276–188; JSCS–4234; doi: 10.2298/JSC110131142A; Original scientific paper

Synthesis of quinoline-attached furan-2(3H)-ones having anti-inflAMmatory and antibacterial properties with reduced gastro-intestinal toxicity and lipid peroxidation

MOHAMMAD M. ALAM, DEBA PRIYA SARKAR, ASIF HUSAIN, AKRANTH MARELLA, MOHAMMAD SHAQUIQUZZAMAN, MYMOONA AKHTER, MOHAMMAD SHAHARYAR, OZAIR ALAM and FAIZUL AZAM*

Department of Pharmaceutical Chemistry, Faculty of Pharmacy, JAMia HAMdard (HAMdard University), New Delhi-110 062, India

*Department of Medicinal Chemistry, Faculty of Pharmacy, Seventh of October University, P. O. Box 2247, Misurata, Libya

(Received 31 January, revised 4 May 2011)

A series of 5-aryl-3-[(2-chloroquinolin-3-yl)methylene] furan-2(3H)-ones (3a–p) were synthesized. The required 3-(substituted benzoyl)propionic acids 2a–d were prepared under Friedеl–Crafts acylation reaction conditions. The substituted 2-chloroquinoline-3-carboxaldehydes 1a–d were synthesized by reaction of substituted phenylethanone oxime with phosphorus oxychloride in presence of dimethylformAMide using the Vilsmeier–Haack reaction method. These compounds were screened for their anti-inflAMmatory and antibacterial activities along with their ulcerogenic and lipid peroxidation potentials. The compounds that showed significant anti-inflAMmatory activity were further screened for their analgesic activity. The compounds were less toxic in terms of ulcerogenicity as compared to a standard, which was also supported by lipid peroxidation studies. The antibacterial activities were performed against Staphylococcus aureus and Escherichia coli. Compounds 3f, 3n and 3o showed significant activity against both S. aureus and E. coli having an minimum inhibitory concentration (MIC) value of 6.25 μg mL^-1.

Keywords: furanone; quinoline; anti-inflAMmatory; analgesic; antibacterial activity.

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J. Serb. Chem. Soc. 76 (12) 1627–1637 (2011)

UDC 634.4:665.52/.54:54.062+54.02; JSCS–4235; doi: 10.2298/JSC101218141A; Original scientific paper

Chemical composition of the essential oils of Citrus sinensis cv. Valencia and a quantitative structure–retention relationship study for the prediction of retention indices by multiple linear regression

PARVIZ ABEROOMAND AZAR, MEHDI NEKOEI, KAMBIZ LARIJANI and SAKINEH BAHRAMINASAB*

Department of Chemistry, Science and Research Branch, IslAMic Azad University, Tehran, Iran

*Department of Chemistry, Shahrood branch, IslAMic Azad University, Shahrood, Iran

(Received 18 December 2010, revised 27 February 2011)

The chemical composition of the volatile fraction obtained by head-space solid phase microextraction (HS–SPME), single drop microextraction (SDME) and the essential oil obtained by cold-press from the peels of C. sinensis cv. Valencia were analyzed employing gas chromatography–flAMe ionization detector (GC–FID) and gas chromatography–mass spectrometry (GC–MS). The main components were limonene (61.34, 68.27 and 90.50 %), myrcene (17.55, 12.35 and 2.50 %), sabinene (6.50, 7.62 and 0.5 %) and a-pinene (0, 6.65 and 1.4 %) respectively obtained by HS–SPME, SDME and cold-press. Then a quantitative structure–retention relationship (QSRR) study for the prediction of retention indices (RI) of the compounds was developed by application of structural descriptors and the multiple linear regression (MLR) method. Principal components analysis was used to select the training set. A simple model with low standard errors and high correlation coefficients was obtained. The results illustrated that linear techniques such as MLR combined with a successful variable selection procedure are capable of generating an efficient QSRR model for prediction of the retention indices of different compounds. This model, with high statistical significance (R²train = 0.983, R²test = 0.970, Q²LOO = 0.962, Q²LGO = 0.936, REP(%) = 3.00), could be used adequately for the prediction and description of the retention indices of the volatile compounds.

Keywords: Citrus sinensis cv. Valencia; volatile constituents; HS–SPME; SDME; QSRR..

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J. Serb. Chem. Soc. 76 (12) 1639–1648 (2011)

UDC 546.562+542.9+547.571+547.551:537.621; JSCS–4236; doi: 10.2298/JSC101112140C; Original scientific pape

Spectral, thermal and magnetic properties of Cu(II) and Ni(II) complexes with Schiff base ligands

BEATA CRISTÓVÃO

Department of General and Coordination Chemistry, Maria Curie-Sklodowska University, Maria Curie-Sklodowska sq. 2, PL. 20-031 Lublin, Poland

(Received 12 November 2010, revised 7 March 2011)

Mononuclear copper(II) and nickel(II) complexes of the formulae [Cu(L¹)] (1), [Ni(L¹)] (2), [Cu(L²)] (3) and [Cu(L³)H2O] (4) (where L¹ = N,N’-ethylenebis(4,6-dimethoxysalicylideanAMinato), L² = N,N’-ethylenebis(5-bromosalicylidenAMinato) and L³ = N,N’-ethylenebis(5-bromo-3-methoxysalicylidenAMinato)) were synthesized as microcrystalline powders and characterized by IR spectroscopy, thermal analysis and magnetic measurements. The magnetic susceptibility of the Cu(II) complexes changed with temperature according to the Curie–Weiss law. The complexes 1, 3 and 4 exhibit magnetic moments of 2.29, 2.20 and 1.88 µ_B, respectively, at 303 K. These values practically do not change with lowering the temperature to 77 K. The nickel(II) complex 2 is diAMagnetic.

Keywords: copper(II) complexes; Schiff base; magnetic properties.

Full Article - PDF 333 KB Available OnLine: 31. 10. 2011. Cited by

J. Serb. Chem. Soc. 76 (12) 1649–1660 (2011)

UDC 547.854+548.121:541.12.011/.017; JSCS–4237; doi: 2298/JSC110713147E; Original scientific paper

The role of Duschinsky rotation in intersystem crossing: a case study of uracil

MIHAJLO ETINSKI

Faculty of Physical Chemistry, University of Belgrade, Studentski trg 12–16, P. O. Box 47, 11158 Belgrade, Serbia

(Received 13 July 2011)

The intersystem crossing rate for the transition between the lowest excited singlet and triplet electronic states of uracil was studied by means of ab initio methods. The rate was evaluated using the time-dependent approach based on the correlation function and its two approximations: the second-order cumulant expansion and the short-time approximation. The normal modes of the singlet and triplet states are related by the Duschinsky transformation, i.e., by rotation and translation. It was found that for singlet–triplet adiabatic energy gaps below 6000 cm^-1, the inclusion of the Duschinsky rotation is necessary for quantitative results. Above energy gaps of 6000 cm^-1, the rates obtained with and without the Duschinsky rotation are similar. The cumulant expansion approximates well the correlation function. The short-time approximation, although crude, can be used as the first estimate of the rate.

Keywords: uracil; excited states; intersystem crossing.

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J. Serb. Chem. Soc. 76 (12) 1661–1671 (2011)

UDC 546.46’72–31+665.652.7:54–32.004.12+54–36.004.12; JSCS–4238; doi: 10.2298/JSC110429149H; Original scientific paper

Mg–Fe-mixed oxides derived from layered double hydroxides: a study of the surface properties

MILICA S. HADNAĐEV-KOSTIĆ, TATJANA J. VULIĆ, RADMILA P. MARINKOVIĆ-NEDUČIN, ALEKSANDAR D. NIKOLIĆ* and BRANISLAV JOVIĆ*

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

*Faculty of Science, University of Novi Sad, Serbia

(Received 29 April, revised 1 June 2011)

The influence of surface properties on the selectivity of the synthesized catalysts was studied, considering that their selectivity towards particular hydrocarbons is crucial for their overall activity in the chosen Fischer–Tropsch reaction. Magnesium- and iron-containing layered double hydroxides (LDH), with the general formula: [Mg_1-xFeV_x(OH)₂](CO₃)_x/2×mH₂O, x = n(Fe)/(n(Mg)+n(Fe)), synthesized with different Mg/Fe ratio and their thermally derived mixed oxides were investigated. Magnesium was chosen because of its basic properties, whereas iron was selected due to its well-known high Fischer-Tropsch activity, redox properties and the ability to form specific active sites in the layered LDH structure required for catalytic application. The thermally less stable multiphase system (synthesized outside the optimal single LDH phase range with additional Fe-phase), having a lower content of surface acid and base active sites, a lower surface area and smaller fraction of smaller mesopores, showed higher selectivity in the Fischer-Tropsch reaction. The results of this study imply that the metastability of derived multiphase oxides structure has a greater influence on the formation of specific catalyst surface sites than other investigated surface properties.

Keywords: Mg–Fe-LDHs; hydrotalcite; acid–base properties; Fischer–Tropsch reaction; selectivity.

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J. Serb. Chem. Soc. 76 (12) 1673–1685 (2011)

UDC 542.913–732:546.92’97’811–44:547.262+66.094.3; JSCS–4239; doi: 10.2298/JSC110405166S; Original scientific paper

Microwave synthesis and characterization of Pt and Pt–Rh–Sn electrocatalysts for ethanol oxidation

Sanja STEVANOVIĆ, DuŠan TRIPKOVIĆ*, Dejan POLETI**, Jelena ROGAN**, Amalija TRIPKOVIĆ and Vladislava M. JOVANOVIĆ

Department of Electrochemistry, ICTM, University of Belgrade, Njegoševa 12, Belgrade, Serbia, *Materials Science Division, Argonne National Laboratory, Argonne, IL 60439, USA

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

(Received 5, revised 29 April 2011)

Carbon-supported Pt and Pt–Rh–Sn catalysts were synthesized by the microwave-polyol method in ethylene glycol solution and were investigated in the ethanol electro-oxidation reaction. The catalysts were characterized in terms of structure, morphology and composition employing the X-ray diffraction (XRD), scanning tunneling microscopy and energy-dispersive X-ray spectroscopy techniques. The STM analysis indicated rather uniform particles and particle sizes below 2 nm for both catalysts. The XRD analysis of the Pt/C catalyst revealed two phases, one with the main characteristic peaks of the face-centered cubic crystal structure (fcc) of platinum and the other related to the graphite-like structure of the carbon support, Vulcan XC-72R. However, in the XRD pattern of the Pt–Rh–Sn/C catalyst, diffraction peaks for Pt, Rh or Sn could not be resolved, indicating extremely low crystallinity. The small particle sizes and homogeneous size distributions of both catalysts could be attributed to the advantages of the microwave-assisted modified polyol process in ethylene glycol solution. The Pt–Rh–Sn/C catalyst was highly active for ethanol oxidation with the onset potential shifted by more than 150 mV to more negative values and with currents nearly 5 times higher in comparison to the Pt/C catalyst. The stability tests of the catalysts, as studied by chronoAMperometric experiments, revealed that the Pt–Rh–Sn/C catalyst was evidently less poisoned than the Pt/C catalyst. The increased activity of Pt–Rh–Sn/C in comparison to Pt/C catalyst was most probably promoted by the bi-functional mechanism and the electronic effect of the alloyed metals.

Keywords: Pt–Rh–Sn catalyst; ethanol oxidation; polyol synthesis; microwave irradiation; STM.

Full Article - PDF 339 KB Available OnLine: 17. 11. 2011. Cited by

J. Serb. Chem. Soc. 76 (12) 1687–1701 (2011)

UDC 546.982’922+543.51:530.145.6; JSCS–4240; doi: 10.2298/JSC110201145D; Original scientific paper

Comparison of MALDI-TOF mass spectra of [PdCl(dien)]Cl and [Ru(en)₂Cl₂]Cl acquired with different matrices

BOJANA DAMNJANOVIĆ, BILJANA PETROVIĆ*, JASMINA DIMITRIĆ-MARKOVIĆ** and MARIJANA PETKOVIĆ

Laboratory of Physical Chemistry, Institute of Nuclear Sciences “Vinča”, University of Belgrade, Belgrade, Serbia

*Department of Chemistry, Faculty of Science, University of Kragujevac, Kragujevac, Serbia

**Faculty of Physical Chemistry, University of Belgrade, Belgrade, Serbia

(Received 1 February, revised 15 April 2011)

In this work, the matrix-assisted laser desorption and ionization time-of-flight (MALDI-TOF) mass spectra of two cationic complexes, i.e., [PdCl(dien)]Cl and [Ru(en)₂Cl₂]Cl, acquired under different conditions were analyzed. The spectra were recorded with three matrices with or without trifluoroacetic acid (TFA), i.e., two traditional matrices, i.e., 2,5-dihydroxybenzoic acid and a-cyano-hydroxycinnAMic acid, and one flavonoid, quercetin. The spectra acquired with quercetin appeared to be the simplest, whereas in the spectra obtained with other matrices, peaks arising either from the addition of matrix molecules or from the fragmentation products were detectable. Addition of TFA did not complicate the spectra of the Pd(II) and Ru(III) complexes when the traditional matrices were used. On the other hand, the spectra of Pd complex were simpler, whereas the addition of TFA in the case of the Ru complex resulted in a higher number of peaks, some of which could not be identified. Taken together, the results of this study once more emphasize the differences arising in the MALDI-TOF mass spectra of transition metal complexes in dependence on the applied matrix.

Keywords: MALDI-TOF MS; metallo-drugs; matrix; peak assignment.

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J. Serb. Chem. Soc. 76 (12) 1703–1723 (2011)

UDC 678.652+678.84:66.095.26:541.124:543.42:536.5.004.12; JSCS–4241; doi: 10.2298/JSC110307146P; Short communication

Influence of the content of hard segments on the properties of novel urethane–siloxane copolymers based on a poly(ε-caprolactone)-b-poly(dimethylsiloxane)-b-poly(ε-caprolactone) triblock copolymer

MARIJA V. PERGAL, VESNA V. ANTIĆ*, SANJA OSTOJIĆ**, MILENA MARINOVIĆ-CINCOVIĆ*** and JASNA DJONLAGIĆ****

Center of Chemistry, Institute of Chemistry, Technology and Metallurgy, University of Belgrade, Studentski trg 12–16, Belgrade, Serbia

*Faculty of Agriculture, University of Belgrade, Nemanjina 6, Belgrade, Serbia

**Institute of General and Physical Chemistry, Studentski trg 12–16, Belgrade, Serbia

***Vinča Institute of Nuclear Sciences, P. O. Box 522, Belgrade, Serbia

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

(Received 7 March, revised 8 April 2011)

A series of novel thermoplastic urethane–siloxane copolymers (TPUSs) based on a α,ω-dihydroxy-[poly(ε-caprolactone)-b-poly(dimethylsiloxane)-b-poly(ε-caprolactone)] (α,ω-dihydroxy-PCL-PDMS-PCL) triblock copolymer, 4,4’-methylenediphenyl diisocyanate (MDI) and 1,4-butanediol (BD) was synthesized. The effects of the content (9–63 mass %) of hard urethane segments and their degree of polymerization on the properties of the segmented TPUSs were investigated. The structure, composition and hard segment degree of polymerization of the hard segments were exAMined using ¹H- and quantitative ¹³C-NMR spectroscopy. The degree of crystallinity of the synthesized copolymers was determined using wide-angle X-ray scattering (WAXS). The surface properties were evaluated by measuring the water contact angle and water absorption. In the series of the TPUSs, the average degree of polymerization of the hard segments was varied from 1.2 to 14.4 MDI-BD units. It was found that average values from 3.8 to 14.4 MDI-BD units were effective segment lengths for crystallization of hard segments, which resulted in an increase in the degree of microphase separation of the copolymers. Spherulite-like superstructures were observed in copolymer films by scanning electron microscopy (SEM), which are believed to arise from the crystallization of the hard segments and/or PCL segments, depending on the content of the hard segments. The surface of the copolymers becAMe more hydrophobic with increasing weight fraction of PDMS. The synthesized copolymers based on a PCL-PDMS-PCL segment showed good thermal stability, which increased with increasing content of soft PDMS segments, as was confirmed by the value of the starting temperature of thermal degradation.

Keywords: urethane–siloxane copolymers; polyaddition; hard segment content; quantitative ¹³C-NMR spectroscopy; thermal properties; X-ray scattering.

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J. Serb. Chem. Soc. 76 (12) 1725–1737 (2011)

UDC 639.42+546.47/.49+546.56+546.815:504.42(262)(497.16); JSCS–4242; doi: 10.2298/JSC110420095S; Original scientific paper

Trace elements concentrations (Zn, Cu, Pb, Cd, As and Hg) in the Mediterranean mussel (Mytilus galloprovincialis) and evaluation of mussel quality and possible human health risk from cultivated and wild sites of the southeastern Adriatic Sea, Montenegro

SLAVKA STANKOVIĆ, MIHAJLO JOVIć*, RAšA MILANOV** and DANIJELA JOKSIMOVIĆ***

Faculty of Technology and Metallurgy, Karnegijeva 4, University of Belgrade, 11000 Belgrade, Serbia

*Institute of Nuclear Science Vinča, University of Belgrade, 11000 Belgrade, Serbia

**Ministry of Health, Sector for Sanitary Control, Omladinskih brigada 1, 11070 Belgrade, Serbia

***Institute of Marine Biology, University of Montenegro, 85330 Kotor, Dobrota bb, Montenegro

(Received 20 April, revised 18 June 2011)

The Mediterranean mussel Mytilus galloprovincialis (L.) was collected from the fall 2005 to the winter 2009 from the six sites on the Montenegrin coastline. Two wild sAMples were collected from the open sea coastline, and two cultivated and two wild were from the Boka Kotorska Bay. The mussels soft tissue was analyzed for zinc, copper, lead, cadmium, arsenic and total mercury. Concentrations of these metals, in mg kg^-1 dry weight, ranged from 135–210 for Zn, 6.2–14.5 for Cu, 4.0–11.5 for Pb, 1.7–2.1 for Cd, 5.8–12.4 for As and 0.1–0.5 for Hg. The metals were found to be present in the sAMples at different levels, but not in concentrations higher than maximum residual levels prescribed by the European Union (EU) and US Food and Drug Administration (USFDA) regulations for seafood. This indicates that the consumption of wild or cultivated mussels from the studied area is safe in moderate quantities.

Keywords: M. galloprovincialis; trace elements; mussel quality; health risks; Montenegro; Adriatic.

Full Article - PDF 279 KB Available OnLine: 28. 06. 2011. Cited by