J. Serb. Chem. Soc. 75 (1) 1–9 (2010)
UDC 547.416:547.235.2’211+546.571:66.095.252.091.7; JSCS–3935; doi: 10.2298/JSC1001001G; Original scientific paper

Stereoselective cyclo-addition reactions of azomethine ylides catalysed by in situ generated Ag(I)/bisphosphine complexes
RONALD GRIGG*, SUREN HUSINEC** and VLADIMIR SAVIĆ*^,***
*Molecular Innovation, Diversity and Automated Synthesis (MIDAS) Centre, Department of Chemistry, Leeds University, Woodhouse Lane, Leeds LS2 9JT, UK,

**Institute of Chemistry, Technology and Metallurgy, Centre for Chemistry, P.O. Box 815, Njegoševa 12, 11000 Belgrade, Serbia

***Department of Organic Chemistry, Faculty of Pharmacy,University of Belgrade, Vojvode Stepe 450, 11000 Belgrade, Serbia

(Received 15 October 2008, revised 10 November 2009)

Stereoselective cyclo-addition reactions of azomethine ylides promoted by in situ generated Ag(I)/bisphosphine complexes were studied. Under the optimised conditions, the pyrrolidine products were isolated in up to 84 % yield and with up to 71 % e.e. The effects of various reaction variables on the stereoselectivity were also investigated.

Keywords: azomethine ylides; stereoselectivity; chiral phosphine; Ag(I).

J. Serb. Chem. Soc. 75 (1) 11–17 (2010)
UDC 547.821+547.853:547.7/.8; JSCS–3936; doi: 10.2298/JSC1001011A; Original scientific paper

Substituted pyridopyrimidinones. Part IV. 2-Chloro-4H-pyrido[1,2-a]pyrimidin-4-one as a synthone of some new heterotricycles
MOHAMED ABASS, MOSTAFA M. ISMAIL, WAFAA R. ABDEL-MONEM and AISHA S. MAYAS
Department of Chemistry, Faculty of Education, Ain ShAMs University, Roxy, Cairo 11757, Egypt

(Received 27 November 2008, revised 9 June 2009)

2-Chloro-4H-pyrido[1,2-a]pyrimidin-4-one (1) was utilized as a synthone precursor to prepare novel heterotricyclic systems. 2-Azido and 2-hydrazino derivatives (2 and 3) were obtained by nucleophilic replacement evolving compound 1. The hydrazine derivative 3 was transformed into the azido derivative 2 by nitrosation. Treatment of compound 3 with [bis(methylthio)methylene]malononitrile afforded 2-pyrazolylpyridopyrimidine 4. When compound 1 was reacted with 5-AMino-3-(methylthio)-1H-pyrazole-4-carbonitrile, the sAMe compound 4 was obtained with no evidence for the production of (pyrazolyl-AMino)pyridopyrimidine 5 or pyrazolodipyridopyrimidine 6. Poly-functionalized dipyridopyrimidine 8 was obtained by reaction of compound 1 with 2-[(methylthio)-(phenylAMino)methylene]propanedinitrile. Cyanoguanidine was reacted with compound 1 to afford N-pyridopyrimidinylguanidine 9, which was subjected to cyclization reaction, in presence of piperidinium acetate, to give pyridopyrimidopyrimidine 10.

Keywords: pyridopyrimidine; dipyridopyrimidine; pyridopyrimidopyrimidine.

J. Serb. Chem. Soc. 75 (1) 19–26 (2010)
UDC 615.371+66.022.362:615.37:57.083.32; JSCS–3937; doi: 10.2298/JSC01001019M;  Original scientific paper

Stability evaluation of house dust mite vaccines for sublingual immunotherapy
LIDIJA BURAZER, KATARINA MILOVANOVIĆ, TANJA ĆIRKOVIĆ-VELIČKOVIĆ* and MARIJA GAVROVIĆ-JANKULOVIĆ*

Institute of Virology, Vaccines and Sera – Torlak, Vojvode Stepe 458, Belgrade, Serbia

*Faculty of Chemistry, Department of Biochemistry, Studentski trg 16, Belgrade, Serbia

(Received 30 April, revised 7 July 2009)

Allergen-specific immunotherapy with house dust mite (HDM) allergen extracts can effectively alleviate the symptoms of allergic rhinitis and asthma. The efficacy of the immunotherapeutic treatment is highly dependent on the quality of house dust mite vaccines. This study was performed to assess the stability of house dust mite allergen vaccines prepared for sublingual immunotherapy. Lyophilized Dermatophagoides pteronyssinus (Dpt) mite bodies were the starting material for the production of sublingual vaccines in four therapeutic concentrations. The stability of the extract for vaccine production, which was stored below 4 °C for one month, showed consistence in the protein profile in SDS PAGE. ELISA-inhibition showed that the potencies of Dpt vaccines during a 12 month period were to 65–80 % preserved at all analyzed therapeutic concentrations. This study showed that glycerinated Dpt vaccines stored at 4 °C preserved their IgE-binding potential during a 12 month period, implying their suitability for sublingual immunotherapeutic treatment of HDM allergy.

Keywords: Dermatophagoides pteronyssinus; allergen extract; vaccines; ELISA inhibition; stability.

J. Serb. Chem. Soc. 75 (1) 27–34 (2010)
UDC 635.71:665.52/.54:615.28–188; JSCS–3938; doi: 10.2298/JSC1001027P; Original scientific paper

Essential oils of Thymus pulegioides and Thymus glabrescens from Romania: chemical composition and antimicrobial activity
MARIANA PAVEL, MIHAILO RISTIĆ* and TATJANA STEVIĆ*
University of Medicine and Pharmacy, Faculty of Pharmacy, Bucharest, Romania

*Institute for Medicinal Plant Research “Dr. Josif Pančić”, Belgrade, Serbia

(Received 14 April, revised 2. June 2009)

The aim of this work was to analyse the chemical composition and antimicrobial properties of essential oils isolated from two wild-growing species of thyme (Thymus pulegioides L. and T. glabrescens Willd.) originating from different locations in Romania. The yield of essential oil was determined according to European Pharmacopoeia standards. Qualitative and quantitative analysis of the oils was performed using GC and GC/MS. The antimicrobial activity was tested by the microdilution technique against GrAM-negative and GrAM-positive bacteria (Escherichia coli, Salmonella typhimurium, S. enteritisdis, Enterobacter cloacae, Pseudomonas aeruginosa, Proteus mirabilis, Staphylococcus aureus, S. epidermidis, Streptococcus faecalis, Bacillus subtilis, Micrococcus luteus, M. flavus and Listeria monocytogenes) and human pathogen yeast Candida albicans. The essential oil of Thymus pulegioides was obtained in a yield of 0.7–1 % (v/d.w. herbal drug) and the main components were carvacrol (50.5–62.6 %), g-terpinene (9.8–9.9 %) and p-cymene (5.8–7.1 %). The essential oil of T. glabrescens was obtained in a yield of 0.7 (v/d.w. herbal drug) and the main components were geraniol (55.5 %), neryl acetate (11.1 %) and β-bisabolene (6.7 %). The essential oils inhibited microbial growth at concentrations of 10.8–27 μl/ml.

Keywords: Thymus pulegioides; Thymus glabrescens; essential oil; antimicrobial; composition.

J. Serb. Chem. Soc. 75 (1) 35–43 (2010)

J. Serb. Chem. Soc. 75 (1) 45–59 (2010)

J. Serb. Chem. Soc. 75 (1) 61–74 (2010)

UDC 742+547.52+547.7–36+547.884.2:548.58; JSCS–3941; doi: 10.2298/JSC1001061B; Original scientific paper

J. Serb. Chem. Soc. 75 (1) 75–81 (2010)

UDC 546.302+547.587.11:54.081; JSCS–3942; doi: 10.2298/JSC1001075S; Original scientific paper

A study of the formation constants of ternary and quaternary complexes of some bivalent transition metals

SANGITA SHARMA, DIPIKA DALWADI and MADHURJYA NEOG

Department of Chemistry, Hemchandracharya North Gujarat University, Patan-384 265, Gujarat, India

(Received 27 January, revised 14 September 2009)

The formation of hetero-ligand 1:1:1, M(II)-Opda-Sal/Gly ternary and 1:1:1:1, M(II)-Opda-Sal-Gly quaternary complexes, where M(II) = Ni, Cu, Zn and Cd; Opda = o‑phenylenediAMine, Sal = salicylic acid, Gly = glycine, was studied pH-metrically in aqueous medium. The formation constants for the resulting ternary and quaternary complexes were evaluated at a constant ionic strength, μ = 0.20 mol dm^-3 and temperature, 30±0.1 °C. The order of the formation constants in terms of the metal ion for both type of complexes was found to be Cu(II) > Ni(II) > Zn(II) > Cd(II). This order was explained based on the increasing number of fused rings, the coordination number of the metal ions, the Irving – WilliAM order and the stability of various species. The expected species formed in solution were pruned with the Fortran IV progrAM SPEPLOT and the stability of the ternary and quaternary complexes is explained.

Keywords: formation constants; transition metals; salicylic acid; quaternary complexes.

J. Serb. Chem. Soc. 75 (1) 83–90 (2010)

UDC 547.678.004.14+547.534:530.18:66.022.362; JSCS–3943, doi: 10.2298/JSC1001083F; Original scientific paper

Effect of a ring on the cyclic conjugation in another ring: applications to acenaphthylene-type polycyclic conjugated molecules

BORIS FURTULA, IVAN GUTMAN, SVETLANA JEREMIĆ and SLAVKO RADENKOVIĆ

Faculty of Science, University of Kragujevac, P. O. Box 60, 34000 Kragujevac, Serbia

(Received 2 June 2009)

In a recent work, a method was developed for assessing the influence ief(G, Z₀|Z₁) of a ring Z₁ on the energy effect of another ring Z₀ in a polycyclic conjugated molecule G. Herein, a report is given of detailed numerical investigations of ief(G, Z₀|Z₁) aimed at the elucidation of the influence of various six-membered rings on the intensity of cyclic conjugation in the five-membered ring of acenaphthylene-type molecules. The earlier discovered regularities for cyclic conjugation in acenaphthylene-type molecules (in particular, the PCP rule and the linear rule) could thus not only be rationalized, but also a number of hitherto concealed regularities could be envisaged.

Keywords: cyclic conjugation; energy effect of cyclic conjugation; acenaphthylene-type hydrocarbons; PCP-rule.

J. Serb. Chem. Soc. 75 (1) 91–99 (2010)

UDC 547.534.2+519.11:544.01:541; JSCS–3944; doi: 10.2298/JSC1001091M; Original scientific paper

The Fujita combinatorial enumeration for the non-rigid group of 2,4-dimethylbenzene

ALI MOGHANI, SOROOR NAGHDI SEDEH and MOHAMMAD REZA SOROUHESH*

Department of Color Physics, Institute for Colorants, Paints and Coatings (ICPC), Tehran, Iran

*Department of Mathematics, IslAMic Azad University, South Branch Tehran, Tehran, Iran

(Received 1 June, revised 21 July 2009)

Using non-rigid group theory, it was previously shown that the full non-rigid group of 2,4-dimethylbenzene is an ummatured and isomorphic to the group C₂´(C₃wrC₂) of order 36, where C_n is the cyclic group of order n, the symbols ´ and wr stand for the direct and wreath products, respectively. Herein, it is first shown that this group has 12 dominant classes. Then, the Markaracter Table, the Table of all integer-valued characters and the unit subduced cycle index (USCI) Table of the full non-rigid group of 2,4-dimethylbenzene are successfully derived for the first time.

Keywords: Full non-rigid group; character; unit subduced cycle index; 2,4-dimethylbenzene.

J. Serb. Chem. Soc. 75 (1) 101–112 (2010)

UDC 547.426.1:543.544.3:543.51:531.3+541.124; JSCS–3945; doi: 10.2298/JSC1001091M; Original scientific paper

Investigation of the kinetics and mechanism of the glycerol chlorination reaction using gas chromatography–mass spectrometry

XIUQUAN LING*, DINGQIANG LU*^,**, JUN WANG*, MINGXIN LIANG*, SHUMIN ZHANG*, WEI REN*, JIANHUI CHEN* and PINGKAI OUYANG*

*State Key Laboratory of Materials-Oriented Chemical Engineering, College of Life Science and Pharmaceutical Engineering, Nanjing University of Technology, Nanjing 210009, China

**Jiangsu Provincial Institute of Materia Medica, Nanjing 210009, China

(Received 21 November 2008, revised 11 June 2009)

As a primary by-product in biodiesel production, glycerol can be used to prepare an important fine chemical, epichlorohydrin, by the glycerol chlorination reaction. Although this process has been applied in industrial production, unfortunately, less attention has been paid to the analysis and separation of the compounds in the glycerol chlorination products. In this study, a convenient and accurate method to determine the products in glycerol chlorination reaction was established and based on the results the kinetic mechanism of the reaction was investigated. The structure of main products, including 1,3--dichloropropan-2-ol, 2,3-dichloropropan-1-ol, 3-chloro-1,2-propanediol, 2-chloro-1,3-propanediol and glycerol was ascertained by gas chromatography–mass spectrometry and the isomers of the products were distinguished. Apidic acid was considered as the best catalyst because of its excellent catalytic effect and high boiling point. The mechanism of the glycerol chlorination reaction was proposed and a new kinetic model was developed. Kinetic equations of the process in the experimental range were obtained by data fitting and the activation energies of each tandem reaction were 30.7, 41.8, 29.4 and 49.5 kJ mol^-1, respectively. This study revealed the process and mechanism of the kinetics and provides the theoretical basis for engineering problems.

Keywords: glycerol; monochloropropanediol; dichloropropanol; chlorination reaction; gas chromatography–mass spectrometry; kinetic model.

J. Serb. Chem. Soc. 75 (1) 113–128 (2010)

UDC 543.421+543.57:546.48’815’19+552.5(Sava); JSCS–3946; doi: 10.2298/JSC1001113M; Original scientific paper

Determination of Cd, Pb and As in sediments of the Sava River by electrothermal atomic absorption spectrometry

SIMONA MURKO, RADMILA MILAČIČ, MARJAN VEBER* and JANEZ ŠČANČAR

Department of Environmental Sciences, Jožef Stefan Institute, JAMova 39, 1000 Ljubljana, Slovenia

*Faculty of Chemistry and Chemical Technology, University of Ljubljana, Aškerčeva 5, 1000 Ljubljana, Slovenia

(Received 12 January, revised 11 June 2009)

The applicability of nitric acid, palladium nitrate and a mixture of palladium and magnesium nitrate as matrix modifiers were estimated for the accurate and reproducible determination of cadmium (Cd), lead (Pb) and arsenic (As) in sediments of the Sava River by electrothermal atomic absorption spectrometry, ETAAS. Decomposition of the sAMples was done in a closed vessel microwave-assisted digestion system using nitric, hydrochloric and hydrofluoric acids, followed by the addition of boric acid to convert the fluorides into soluble complexes. The parAMeters for the determination of Cd, Pb and As in sediments were optimised for each individual element and for each matrix modifier. In addition, two sediment reference materials were also analysed. In determination of Cd and Pb, nitric acid was found to be the most appropriate matrix modifier. The accurate and reliable determination of Cd and Pb in sediments was possible also in the presence of boric acid. The use of a mixture of palladium and magnesium nitrate efficiently compensated for matrix effects and enabled the accurate and reliable determination of As in the sediments. Quantification of Cd and As was performed by calibration using acid matched standard solutions, while the standard addition method was applied for the quantification of Pb. The repeatability of the analytical procedure for the determination of Cd, Pb and As in sediments was ±5 % for Cd, ±4 % for Pb and ±2 % for As. The LOD values of the analytical procedure were found to be 0.05 mg/kg for Cd and 0.25 mg/kg for Pb and As, while the LOQ values were 0.16 mg/kg for Cd and 0.83 mg/kg for Pb and As. Finally, Cd, Pb and As were successfully determined in sediments of the Sava River in Slovenia.

Keywords: cadmium; lead; arsenic; sediments; closed vessel microwave assisted digestion; ETAAS.

J. Serb. Chem. Soc. 75 (1) 129–142 (2010)

UDC 628.165:66–913.2:579.68; JSCS–3947; doi: 10.2298/JSC1001129K; Original scientific paper

The effect of the application of halotolerant microorganisms on the efficiency of a pilot-scale constructed wetland for saline wastewater treatment

MILANA KARAJIĆ, ALEŠ LAPANJE*, JAKA RAZINGER*, ALEXIS ZRIMEC* and DANIJEL VRHOVŠEK

LIMNOS Company for Applied Ecology, Podlimbarskega 31, 1000 Ljubljana, Slovenia

*Institute of Physical Biology, Toplarniška 19, 1000 Ljubljana, Slovenia

(Received 8 June, revised 8 November 2009)

In order to find the optimal design characteristics of constructed wetlands for saline wastewater treatment, halotolerant microorganisms, isolated from the water of the Sečovlje salterns, were inoculated into the media of a pilot-scale constructed wetland (CW). The purpose of this study was to exAMine the influence of different salinities on the efficiency of halotolerant microorganisms for the removal of pollutants in order to evaluate the possibility of their employment for saline wastewater treatment. The efficiency of AMmonium removal (34.1 %) was the highest with 0 % NaCl in wastewater and slightly lower (31.8) when 2 g/dm³ saccharose was added to aerated 1.5 % NaCl wastewater. The highest removal efficiency of chemical oxygen demand (COD) in the pilot-scale subsurface flow (SSF) CW was 83.6 % when saccharose (2 g/dm³) was added to aerated 1.5 % NaCl wastewater. It was found that removal efficiency of the pilot-scale constructed wetland with inoculated halo-tolerant microorganisms showed a higher sensitivity to aeration and the presence of saccharose than to variation of the salinity of the wastewater. It can be concluded that halotolerant microorganisms, isolated from the Sečovlje salterns, are not sensitive to the changes in salinity and are, therefore, an alternative in the treatment of saline wastewater with a constructed wetland. However, with aeration their efficiency could be further improved.

Keywords: constructed wetlands; saline wastewater; halotolerant microorganisms.

J. Serb. Chem. Soc. 75 (1) 143–156 (2010)

2009 List of referees

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